Document and Entity Information	6 Months Ended
Document and Entity Information	Jun. 30, 2012	Jul. 24, 2012
Document and Entity Information
Entity Registrant Name	Transocean Ltd.
Entity Central Index Key	0001451505
Document Type	10-Q
Document Period End Date	Jun. 30, 2012
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		359,389,049
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Operating revenues
Contract drilling revenues	$ 2,390	$ 2,220	$ 2,096	$ 4,610	$ 4,056	$ 8,374	$ 8,986
Other revenues	185	117	238	302	422	762	480
Total operating revenues	2,575	2,337	2,334	4,912	4,478	9,136	9,466
Costs and expenses
Operating and maintenance	2,357	1,463	1,528	3,820	2,905	7,001	5,089
Depreciation and amortization	345	355	359	700	713	1,445	1,536
General and administrative	79	69	66	148	133	288	246
Total costs and expenses	2,781	1,887	1,953	4,668	3,751	8,734	6,871
Loss on impairment	(12)	(227)	(25)	(239)	(25)	(5,229)	(1,010)
Gain (loss) on disposal of assets, net	55	(4)	(1)	51	7	4	257
Operating income (loss)	(163)	219	355	56	709	(4,823)	1,842
Other income (expense), net
Interest income	13	15	5	28	20	44	23
Interest expense, net of amounts capitalized	(183)	(180)	(147)	(363)	(292)	(621)	(567)
Other, net	(6)	(18)	(5)	(24)	(2)	(81)	(23)
Total other income (expense), net	(176)	(183)	(147)	(359)	(274)	(658)	(567)
Income (loss) from continuing operations before income tax expense	(339)	36	208	(303)	435	(5,481)	1,275
Income tax (benefit) expense	(29)	17	77	(12)	143	379	340
Income (loss) from continuing operations	(310)	19	131	(291)	292	(5,860)	935
Income from discontinued operations, net of tax	7	(1)	2	6	174	183	34
Net income (loss)	(303)	18	133	(285)	466	(5,677)	969
Net income attributable to noncontrolling interest	1	8	9	9	23	77	43
Net income (loss) attributable to controlling interest	$ (304)	$ 10	$ 124	$ (294)	$ 443	$ (5,754)	$ 926
Earnings (loss) per share-basic
Earnings (loss) from continuing operations (in dollars per share)	$ (0.88)	$ 0.03	$ 0.38	$ (0.85)	$ 0.84	$ (18.45)	$ 2.77
Earnings from discontinued operations (in dollars per share)	$ 0.02		$ 0.01	$ 0.02	$ 0.54	$ 0.57	$ 0.11
Earnings (loss) per share (in dollars per share)	$ (0.86)	$ 0.03	$ 0.39	$ (0.83)	$ 1.38	$ (17.88)	$ 2.88
Earnings (loss) per share-diluted
Earnings (loss) from continuing operations (in dollars per share)	$ (0.88)	$ 0.03	$ 0.38	$ (0.85)	$ 0.84	$ (18.45)	$ 2.77
Earnings from discontinued operations (in dollars per share)	$ 0.02		$ 0.01	$ 0.02	$ 0.54	$ 0.57	$ 0.11
Earnings (loss) per share (in dollars per share)	$ (0.86)	$ 0.03	$ 0.39	$ (0.83)	$ 1.38	$ (17.88)	$ 2.88
Weighted-average shares outstanding
Basic (in shares)	353		320	352	319
Diluted (in shares)	353		320	352	320

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net income (loss)	$ (303)	$ 133	$ (285)	$ 466
Other comprehensive income (loss) before income taxes
Unrecognized components of net periodic benefit costs	1		(27)	(6)
Unrecognized gain (loss) on derivative instruments	(3)	(8)		(7)
Recognized components of net periodic benefit costs	10	6	23	12
Recognized loss on derivative instruments	6	3	3	5
Other comprehensive income (loss) before income taxes	14	1	(1)	4
Income taxes related to other comprehensive income (loss)	1		(2)	(2)
Other comprehensive income (loss), net of income taxes	15	1	(3)	2
Total comprehensive income (loss)	(288)	134	(288)	468
Total comprehensive income attributable to noncontrolling interest	1	3	9	21
Total comprehensive income (loss) attributable to controlling interest	$ (289)	$ 131	$ (297)	$ 447

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 3,964	$ 4,017
Accounts receivable, net of allowance for doubtful accounts of $28 at June 30, 2012 and December 31, 2011	2,124	2,176
Materials and supplies, net of allowance for obsolescence of $81 and $73 at June 30, 2012 and December 31, 2011, respectively	676	627
Deferred income taxes, net	142	142
Assets held for sale	9	26
Other current assets	452	537
Total current assets	7,367	7,525
Property and equipment	30,559	29,037
Property and equipment of consolidated variable interest entities	813	2,252
Less accumulated depreciation	9,165	8,756
Property and equipment, net	22,207	22,533
Goodwill	3,099	3,217
Other assets	1,769	1,757
Total assets	34,442	35,032
Liabilities and equity
Accounts payable	917	880
Accrued income taxes	121	89
Debt due within one year	2,772	1,942
Debt of consolidated variable interest entities due within one year	28	245
Other current liabilities	2,888	2,372
Total current liabilities	6,726	5,528
Long-term debt	9,862	10,756
Long-term debt of consolidated variable interest entities	177	593
Deferred income taxes, net	487	519
Other long-term liabilities	1,581	1,893
Total long-term liabilities	12,107	13,761
Commitments and contingencies
Redeemable noncontrolling interest		116
Shares, CHF 15.00 par value, 402,282,355 authorized, 167,617,649 conditionally authorized, and 373,830,649 and 365,135,298 issued at June 30, 2012 and December 31, 2011, respectively; 359,284,907 and 349,805,793 outstanding at June 30, 2012 and December 31, 2011, respectively	5,127	4,982
Additional paid-in capital	7,472	7,211
Treasury shares, at cost, 2,863,267 held at June 30, 2012 and December 31, 2011	(240)	(240)
Retained earnings	3,780	4,180
Accumulated other comprehensive loss	(516)	(496)
Total controlling interest shareholders' equity	15,623	15,637
Noncontrolling interest	(14)	(10)
Total equity	15,609	15,627
Total liabilities and equity	$ 34,442	$ 35,032

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) In Millions, except Share data, unless otherwise specified	Jun. 30, 2012 USD ($)	Jun. 30, 2012 CHF	Dec. 31, 2011 USD ($)	Dec. 31, 2011 CHF
CONDENSED CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 28		$ 28
Materials and supplies, allowance for obsolescence (in dollars)	$ 81		$ 73
Shares, CHF par value (in Swiss francs per share)		15.00		15.00
Shares, authorized	402,282,355	402,282,355	402,282,355	402,282,355
Shares, conditionally authorized	167,617,649	167,617,649	167,617,649	167,617,649
Shares, issued	373,830,649	373,830,649	365,135,298	365,135,298
Shares, outstanding	359,284,907	359,284,907	349,805,793	349,805,793
Treasury shares	2,863,267	2,863,267	2,863,267	2,863,267

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References+ Details

- Definition

The amount of the valuation account as of the balance sheet date which reduces the carrying amount of inventory to net realizable value; takes into consideration such factors as market value, excessive quantities based on expected sales, technological obsolescence, and shrinkage. May also provide for estimated product returns or price concessions pertaining to product cost.

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

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+ Details

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (USD $) In Millions, except Share data, unless otherwise specified	Total	Total controlling interest shareholders' equity	Shares	Additional paid-in capital	Treasury shares, at cost	Retained earnings	Accumulated other comprehensive loss	Noncontrolling interest
Balance at Dec. 31, 2010	$ 21,340	$ 21,348	$ 4,482	$ 7,504	$ (240)	$ 9,934	$ (332)	$ (8)
Balance (in shares) at Dec. 31, 2010			319,000,000
Increase (Decrease) in Shareholders' Equity
Issuance of shares under share-based compensation plans	(7)	(7)	8	(15)
Issuance of shares under share-based compensation plans (in shares)			1,000,000
Share-based compensation	54	54		54
Obligation for distribution of qualifying additional paid-in capital	(1,016)	(1,016)		(1,016)
Other, net	2	2		2
Net income (loss) attributable to controlling interest	443					443
Other comprehensive income (loss) attributable to controlling interest							4
Total comprehensive income (loss) attributable to controlling interest	447	447
Total comprehensive income (loss) attributable to noncontrolling interest	21							(4)
Total comprehensive income (loss)	468
Balance at Jun. 30, 2011	20,816	20,828	4,490	6,529	(240)	10,377	(328)	(12)
Balance (in shares) at Jun. 30, 2011			320,000,000
Balance at Mar. 31, 2011
Increase (Decrease) in Shareholders' Equity
Net income (loss) attributable to controlling interest	124
Other comprehensive income (loss) attributable to controlling interest							7
Total comprehensive income (loss) attributable to controlling interest	131
Total comprehensive income (loss) attributable to noncontrolling interest	3
Total comprehensive income (loss)	134
Balance at Jun. 30, 2011	20,816				(240)		(328)
Balance at Dec. 31, 2011	15,627	15,637	4,982	7,211	(240)	4,180	(496)	(10)
Balance (in shares) at Dec. 31, 2011			350,000,000
Increase (Decrease) in Shareholders' Equity
Issuance of shares under share-based compensation plans	(6)	(6)	11	(17)
Issuance of shares in exchange for noncontrolling interest	367	367	134	233
Issuance of shares in exchange for noncontrolling interest (in shares)			9,000,000
Share-based compensation	48	48		48
Obligation for distribution of qualifying additional paid-in capital		0		0
Other, net	(3)	(3)		(3)
Net income (loss) attributable to controlling interest	(294)					(294)
Fair value adjustment of redeemable noncontrolling interest	106	(106)				(106)
Reclassification of redeemable noncontrolling interest	17	(17)					(17)
Other comprehensive income (loss) attributable to controlling interest							(3)
Total comprehensive income (loss) attributable to controlling interest	(297)	(297)
Total comprehensive income (loss) attributable to noncontrolling interest	9							(4)
Total comprehensive income (loss)	(288)
Balance at Jun. 30, 2012	15,609	15,623	5,127	7,472	(240)	3,780	(516)	(14)
Balance (in shares) at Jun. 30, 2012			359,000,000
Balance at Mar. 31, 2012
Increase (Decrease) in Shareholders' Equity
Net income (loss) attributable to controlling interest	(304)
Other comprehensive income (loss) attributable to controlling interest							15
Total comprehensive income (loss) attributable to controlling interest	(289)
Total comprehensive income (loss) attributable to noncontrolling interest	1
Total comprehensive income (loss)	(288)
Balance at Jun. 30, 2012	$ 15,609				$ (240)		$ (516)

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities
Net income (loss)	$ (303)	$ 133	$ (285)	$ 466
Adjustments to reconcile to net cash provided by operating activities
Amortization of drilling contract intangibles	(12)	(10)	(23)	(20)
Depreciation and amortization	345	359	700	713
Share-based compensation expense	25	27	48	54
Loss on impairment	12	25	239	25
(Gain) loss on disposal of assets, net	(55)	1	(51)	(7)
(Gain) loss on disposal of discontinued operations, net	(10)		(10)	(169)
Amortization of debt issue costs, discounts and premiums, net	17	36	35	62
Deferred income taxes	(26)	12	(43)	36
Other, net	20	14	41	11
Changes in deferred revenue, net	7	(3)	(5)	43
Changes in deferred expenses, net	28	(48)	(21)	(84)
Changes in operating assets and liabilities	411	(206)	374	(400)
Net cash provided by operating activities	459	340	999	730
Cash flows from investing activities
Capital expenditures	(236)	(293)	(496)	(533)
Proceeds from disposal of assets, net	144	5	185	18
Proceeds from disposal of discontinued operations, net	17		17	259
Other, net	13	(27)	25	(33)
Net cash used in investing activities	(62)	(315)	(269)	(289)
Cash flows from financing activities
Changes in short-term borrowings, net	(260)	5	(260)	56
Proceeds from debt				5
Repayments of debt	(173)	(202)	(320)	(249)
Proceeds from restricted cash investments	84		192
Deposits to restricted cash investments	(74)		(116)
Distribution of qualifying additional paid-in capital		(254)	(278)	(254)
Other, net	8	3	(1)	(4)
Net cash used in financing activities	(415)	(448)	(783)	(446)
Net decrease in cash and cash equivalents	(18)	(423)	(53)	(5)
Cash and cash equivalents at beginning of period	3,982	3,772	4,017	3,354
Cash and cash equivalents at end of period	$ 3,964	$ 3,349	$ 3,964	$ 3,349

Nature of Business

6 Months Ended

Jun. 30, 2012

Nature of Business

Nature of Business

Note 1—Nature of Business

Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” the “Company,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. We specialize in technically demanding sectors of the offshore drilling business with a particular focus on deepwater and harsh environment drilling services. Our mobile offshore drilling fleet is considered one of the most versatile fleets in the world. We contract our drilling rigs, related equipment and work crews predominantly on a dayrate basis to drill oil and gas wells. At June 30, 2012, we owned or had partial ownership interests in and operated 130 mobile offshore drilling units. As of this date, our fleet consisted of 50 High-Specification Floaters (Ultra-Deepwater, Deepwater and Harsh Environment semisubmersibles and drillships), 25 Midwater Floaters, 10 High-Specification Jackups, 44 Standard Jackups and one swamp barge. In addition, we had two Ultra-Deepwater drillships and three High-Specification Jackups under construction. See Note 11—Drilling Fleet.

We also provide oil and gas drilling management services, drilling engineering and drilling project management services through Applied Drilling Technology Inc., our wholly owned subsidiary, and through ADT International, a division of one of our United Kingdom (“U.K”). subsidiaries (together, “ADTI”). ADTI conducts drilling management services primarily on either a dayrate or a completed-project, fixed-price (or “turnkey”) basis.

Significant Accounting Policies

6 Months Ended

Jun. 30, 2012

Significant Accounting Policies

Significant Accounting Policies

Note 2—Significant Accounting Policies

Basis of presentation—We have prepared our accompanying unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the United States (“U.S.”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the U.S. Securities and Exchange Commission (“SEC”). Pursuant to such rules and regulations, these financial statements do not include all disclosures required by accounting principles generally accepted in the U.S. for complete financial statements. The condensed consolidated financial statements reflect all adjustments, which are, in the opinion of management, necessary for a fair presentation of financial position, results of operations and cash flows for the interim periods. Such adjustments are considered to be of a normal recurring nature unless otherwise noted. Operating results for the three and six months ended June 30, 2012 are not necessarily indicative of the results that may be expected for the year ending December 31, 2012 or for any future period. The accompanying condensed consolidated financial statements and notes thereto should be read in conjunction with the audited consolidated financial statements and notes thereto as of December 31, 2011 and 2010 and for each of the three years in the period ended December 31, 2011 included in our annual report on Form 10-K filed on February 27, 2012.

Accounting estimates—To prepare financial statements in accordance with accounting principles generally accepted in the U.S., we are required to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosures of contingent assets and liabilities. On an ongoing basis, we evaluate our estimates and assumptions, including those related to our allowance for doubtful accounts, materials and supplies obsolescence, property and equipment, investments, notes receivable, goodwill and other intangible assets, income taxes, defined benefit pension plans and other postretirement benefits, contingencies and share-based compensation. We base our estimates and assumptions on historical experience and on various other factors we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying amounts of assets and liabilities that are not readily apparent from other sources. Actual results could differ from such estimates.

Fair value measurements—We estimate fair value at a price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants in the principal market for the asset or liability. Our valuation techniques require inputs that we categorize using a three-level hierarchy, from highest to lowest level of observable inputs, as follows: (1) significant observable inputs, including unadjusted quoted prices for identical assets or liabilities in active markets (“Level 1”), (2) significant other observable inputs, including direct or indirect market data for similar assets or liabilities in active markets or identical assets or liabilities in less active markets (“Level 2”), and (3) significant unobservable inputs, including those that require considerable judgment for which there is little or no market data (“Level 3”). When multiple input levels are required for a valuation, we categorize the entire fair value measurement according to the lowest level of input that is significant to the measurement even though we may have also utilized significant inputs that are more readily observable.

Consolidation—We consolidate entities in which we have a majority voting interest and entities that meet the criteria for variable interest entities for which we are deemed to be the primary beneficiary for accounting purposes. We eliminate intercompany transactions and accounts in consolidation. We apply the equity method of accounting for investments in entities if we have the ability to exercise significant influence over an entity that (a) does not meet the variable interest entity criteria or (b) meets the variable interest entity criteria, but for which we are not deemed to be the primary beneficiary. We apply the cost method of accounting for investments in other entities if we do not have the ability to exercise significant influence over the unconsolidated entity. See Note 5—Variable Interest Entities.

Share-based compensation—Share-based compensation expense was $25 million and $48 million for the three and six months ended June 30, 2012, respectively. Share-based compensation expense was $27 million and $54 million for the three and six months ended June 30, 2011, respectively.

Capitalized interest—We capitalize interest costs for qualifying construction and upgrade projects. We capitalized interest costs on construction work in progress of $12 million and $25 million for the three and six months ended June 30, 2012, respectively. We capitalized interest costs for construction work in progress of $10 million and $25 million for the three and six months ended June 30, 2011, respectively.

Reclassifications—We have made certain reclassifications, which did not have an effect on net income, to prior period amounts to conform with the current period’s presentation. These reclassifications did not have a material effect on our condensed consolidated statement of financial position, results of operations or cash flows.

Subsequent events—We evaluate subsequent events through the time of our filing on the date we issue our financial statements. See Note 20—Subsequent Events.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

+ References+ Details

New Accounting Pronouncements

6 Months Ended

Jun. 30, 2012

New Accounting Pronouncements

New Accounting Pronouncements

Note 3—New Accounting Pronouncements

Recently Adopted Accounting Standards

Intangibles-goodwill and other—Effective January 1, 2012, we adopted the accounting standards update that amends the goodwill impairment testing requirements by giving an entity the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount and whether the two-step impairment test is required. The update is effective for goodwill impairment tests performed for annual and interim periods beginning after December 15, 2011. Our adoption did not have an effect on our condensed consolidated financial statements because a goodwill impairment test was not required in the six months ended June 30, 2012.

Fair value measurements—Effective January 1, 2012, we adopted the accounting standards update that requires additional disclosure about fair value measurements that involve significant unobservable inputs, including additional quantitative information about the unobservable inputs, a description of valuation techniques used, and a qualitative evaluation of the sensitivity of these measurements. Our adoption did not have a material effect on the disclosures contained in our notes to condensed consolidated financial statements.

Recently Issued Accounting Standards

Balance sheet—Effective January 1, 2013, we will adopt the accounting standards update that expands the disclosure requirements for the offsetting of assets and liabilities related to certain financial instruments and derivative instruments. The update requires disclosures to present both gross information and net information for financial instruments and derivative instruments that are eligible for net presentation due to a right of offset, an enforceable master netting arrangement or similar agreement. The update is effective for interim and annual periods beginning on or after January 1, 2013. We do not expect that our adoption will have a material effect on our condensed consolidated balance sheet or the disclosures contained in our notes to condensed consolidated financial statements.

- Definition

The entire disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6801783&loc=d3e22583-107794

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Retrospective Application

-URI http://asc.fasb.org/extlink&oid=6523989

Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 01

-Paragraph b

-Subparagraph 6

-Article 10

+ Details

Correction of Errors in Previously Reported Consolidated Financial Statements

6 Months Ended

Jun. 30, 2012

Correction of Errors in Previously Reported Consolidated Financial Statements

Correction of Errors in Previously Reported Consolidated Financial Statements

Note 4—Correction of Errors in Previously Reported Consolidated Financial Statements

We perform assessments of our contingencies and corresponding assets for insurance recoveries on an ongoing basis to evaluate the appropriateness of our balances and disclosures for such contingencies and insurance recoveries. We establish liabilities for estimated loss contingencies when we believe a loss is probable and the amount of the probable loss can be reasonably estimated. We recognize corresponding assets for those loss contingencies that we believe are probable of being recovered through insurance. In performing these assessments in the three months ended June 30, 2012, we identified an error in our previously issued financial statements for the year ended December 31, 2011 and the three months ended March 31, 2012 related to the recognition of assets for insurance recoveries related to legal and other costs totaling $67 million and $37 million, respectively, which we have concluded should not have been recorded because they were not probable of recovery.

We assessed the materiality of this error in accordance with SEC Staff Accounting Bulletin (“SAB”) No. 99, Materiality and SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements (“SAB 108”), using both the rollover method and the iron curtain method, as defined in SAB 108, and concluded the error, inclusive of other adjustments discussed below, was immaterial to prior years but could be material to the current year. Under SAB 108, if the prior year error that, if corrected in the current year, would be material to the current year, the prior year financial statements should be corrected, even though such correction previously was immaterial to the prior year financial statements. Correcting prior year financial statements for immaterial errors does not require our previously filed reports to be amended, but rather these corrections will be made the next time we file the prior period consolidated financial statements.

In addition to the adjustments in 2011 and 2012 related to the assets for insurance recoveries, we recorded other adjustments related to the years ended December 31, 2011 and 2010 and the three months ended March 31, 2012 to correct for immaterial errors for repair and maintenance costs, income taxes, discontinued operations, and the allocation of net income attributable to noncontrolling interest. These other adjustments were not previously recorded in the appropriate periods, as we concluded that they were immaterial to our previously issued consolidated financial statements.

For the three months ended March 31, 2012, the correction of these errors reduced income from continuing operations by $55 million and net income attributable to controlling interest by $32 million. For the three and six month periods ended June 30, 2011, correction of these errors reduced income from continuing operations by $31 million and $34 million, respectively, and net income attributable to controlling interest by $31 million and $22 million, respectively. For the year ended December 31, 2011, correction of these errors increased loss from continuing operations by $31 million and net loss attributable to controlling interest by $29 million. For the year ended December 31, 2010, correction of these errors reduced income from continuing operations by $19 million and net income attributable to controlling interest by $35 million. The summary of adjustments for increases and (decreases) to net income (loss) from continuing operations and net income (loss) attributable to controlling interest for the applicable periods were as follows (in millions):

	Three months ended						Six months ended			Years ended
	March 31, 2012			June 30, 2011			June 30, 2011			December 31, 2011			December 31, 2010

Legal and other costs	$	(37	)	$	(19	)	$	(30	)	$	(67	)	$	—
Repair and maintenance costs	—			(32		)	(48		)	11			(11		)
Income tax (expense) benefit	7			5			20			16			(4		)
Other immaterial adjustments, net	(25		)	15			24			9			(4		)
Net adjustment to income from continuing operations	(55		)	(31		)	(34		)	(31		)	(19		)
Net adjustment to income from discontinued operations, net of tax	14			—			(4		)	(14		)	—
Net adjustment to net income attributable to noncontrolling interest	9			—			16			16			(16		)
Net adjustment to net income attributable to controlling interest	$	(32	)	$	(31	)	$	(22	)	$	(29	)	$	(35	)

The effects of the corrections of the errors on our consolidated statements of operations and balance sheets are presented in the tables below. The corrections of the errors had no effect on our consolidated statements of comprehensive income (loss) other than the effect of the changes to net income (loss) for each period. The corrections of the errors had no effect on the previously reported amounts of operating, investing, and financing cash flows in our consolidated statements of cash flows.

	Three months ended March 31, 2012
	Previously reported			Adjustments			As adjusted
Operating revenues
Contract drilling revenues	$	2,214		$	6		$	2,220
Other revenues	117			—			117
	2,331			6			2,337
Costs and expenses
Operating and maintenance	1,410			53			1,463
Depreciation and amortization	351			4			355
General and administrative	69			—			69
	1,830			57			1,887
Loss on impairment	(227		)	—			(227		)
Gain (loss) on disposal of assets, net	(4		)	—			(4		)
Operating income (loss)	270			(51		)	219

Other income (expense), net
Interest income	15			—			15
Interest expense, net of amounts capitalized	(180		)	—			(180		)
Other, net	(7		)	(11		)	(18		)
	(172		)	(11		)	(183		)
Income (loss) from continuing operations before income tax expense	98			(62		)	36
Income tax (benefit) expense	24			(7		)	17
Income (loss) from continuing operations	74			(55		)	19
Income (loss) from discontinued operations, net of tax	(15		)	14			(1		)

Net income (loss)	59			(41		)	18
Net income (loss) attributable to noncontrolling interest	17			(9		)	8
Net income (loss) attributable to controlling interest	$	42		$	(32	)	$	10

Earnings (loss) per share-basic
Earnings (loss) from continuing operations	$	0.16		$	(0.13	)	$	0.03
Earnings (loss) from discontinued operations	(0.04		)	0.04			—
Earnings (loss) per share	$	0.12		$	(0.09	)	$	0.03

Earnings (loss) per share-diluted
Earnings (loss) from continuing operations	$	0.16		$	(0.13	)	$	0.03
Earnings (loss) from discontinued operations	(0.04		)	0.04			—
Earnings (loss) per share	$	0.12		$	(0.09	)	$	0.03

	Three months ended June 30, 2011									Six months ended June 30, 2011
	Previously reported			Adjustments			As adjusted			Previously reported			Adjustments			As adjusted
Operating revenues
Contract drilling revenues	$	2,096		$	—		$	2,096		$	4,056		$	—		$	4,056
Other revenues	238			—			238			422			—			422
	2,334			—			2,334			4,478			—			4,478
Costs and expenses
Operating and maintenance	1,492			36			1,528			2,851			54			2,905
Depreciation and amortization	359			—			359			713			—			713
General and administrative	66			—			66			133			—			133
	1,917			36			1,953			3,697			54			3,751
Loss on impairment	(25		)	—			(25		)	(25		)	—			(25		)
Gain (loss) on disposal of assets, net	(1		)	—			(1		)	7			—			7
Operating income (loss)	391			(36		)	355			763			(54		)	709

Other income (expense), net
Interest income	5			—			5			20			—			20
Interest expense, net of amounts capitalized	(147		)	—			(147		)	(292		)	—			(292		)
Other, net	(5		)	—			(5		)	(2		)	—			(2		)
	(147		)	—			(147		)	(274		)	—			(274		)
Income (loss) from continuing operations before income tax expense	244			(36		)	208			489			(54		)	435
Income tax (benefit) expense	82			(5		)	77			163			(20		)	143
Income (loss) from continuing operations	162			(31		)	131			326			(34		)	292
Income (loss) from discontinued operations, net of tax	2			—			2			178			(4		)	174

Net income (loss)	164			(31		)	133			504			(38		)	466
Net income (loss) attributable to noncontrolling interest	9			—			9			39			(16		)	23
Net income (loss) attributable to controlling interest	$	155		$	(31	)	$	124		$	465		$	(22	)	$	443

Earnings (loss) per share-basic
Earnings (loss) from continuing operations	$	0.47		$	(0.09	)	$	0.38		$	0.89		$	(0.05	)	$	0.84
Earnings (loss) from discontinued operations	0.01			—			0.01			0.55			(0.01		)	0.54
Earnings (loss) per share	$	0.48		$	(0.09	)	$	0.39		$	1.44		$	(0.06	)	$	1.38

Earnings (loss) per share-diluted
Earnings (loss) from continuing operations	$	0.47		$	(0.09	)	$	0.38		$	0.89		$	(0.05	)	$	0.84
Earnings (loss) from discontinued operations	0.01			—			0.01			0.55			(0.01		)	0.54
Earnings (loss) per share	$	0.48		$	(0.09	)	$	0.39		$	1.44		$	(0.06	)	$	1.38

	Year ended December 31, 2011									Year ended December 31, 2010
	Previously reported			Adjustments			As adjusted			Previously reported			Adjustments			As adjusted
Operating revenues
Contract drilling revenues	$	8,380		$	(6	)	$	8,374		$	8,986		$	—		$	8,986
Other revenues	762			—			762			480			—			480
	9,142			(6		)	9,136			9,466			—			9,466
Costs and expenses
Operating and maintenance	6,956			45			7,001			5,074			15			5,089
Depreciation and amortization	1,449			(4		)	1,445			1,536			—			1,536
General and administrative	288			—			288			246			—			246
	8,693			41			8,734			6,856			15			6,871
Loss on impairment	(5,229		)	—			(5,229		)	(1,010		)	—			(1,010		)
Gain (loss) on disposal of assets, net	4			—			4			257			—			257
Operating income (loss)	(4,776		)	(47		)	(4,823		)	1,857			(15		)	1,842

Other income (expense), net
Interest income	44			—			44			23			—			23
Interest expense, net of amounts capitalized	(621		)	—			(621		)	(567		)	—			(567		)
Other, net	(81		)	—			(81		)	(23		)	—			(23		)
	(658		)	—			(658		)	(567		)	—			(567		)
Income (loss) from continuing operations before income tax expense	(5,434		)	(47		)	(5,481		)	1,290			(15		)	1,275
Income tax (benefit) expense	395			(16		)	379			336			4			340
Income (loss) from continuing operations	(5,829		)	(31		)	(5,860		)	954			(19		)	935
Income (loss) from discontinued operations, net of tax	197			(14		)	183			34			—			34

Net income (loss)	(5,632		)	(45		)	(5,677		)	988			(19		)	969
Net income (loss) attributable to noncontrolling interest	93			(16		)	77			27			16			43
Net income (loss) attributable to controlling interest	$	(5,725	)	$	(29	)	$	(5,754	)	$	961		$	(35	)	$	926

Earnings (loss) per share-basic
Earnings (loss) from continuing operations	$	(18.40	)	$	(0.05	)	$	(18.45	)	$	2.88		$	(0.11	)	$	2.77
Earnings (loss) from discontinued operations	0.61			(0.04		)	0.57			0.11			—			0.11
Earnings (loss) per share	$	(17.79	)	$	(0.09	)	$	(17.88	)	$	2.99		$	(0.11	)	$	2.88

Earnings (loss) per share-diluted
Earnings (loss) from continuing operations	$	(18.40	)	$	(0.05	)	$	(18.45	)	$	2.88		$	(0.11	)	$	2.77
Earnings (loss) from discontinued operations	0.61			(0.04		)	0.57			0.11			—			0.11
Earnings (loss) per share	$	(17.79	)	$	(0.09	)	$	(17.88	)	$	2.99		$	(0.11	)	$	2.88

	December 31, 2011									December 31, 2010
	Previously reported			Adjustments			As adjusted			Previously reported			Adjustments			As adjusted
Assets
Cash and cash equivalents	$	4,017		$	—		$	4,017		$	3,394		$	(40	)	$	3,354
Accounts receivable, net
Trade	2,049			—			2,049			1,653			—			1,653
Other	127			—			127			190			—			190
Materials and supplies, net	627			—			627			514			—			514
Deferred income taxes, net	142			—			142			115			—			115
Assets held for sale	26			—			26			—			—			—
Other current assets	621			(84		)	537			329			43			372
Total current assets	7,609			(84		)	7,525			6,195			3			6,198

Property and equipment	29,037			—			29,037			26,721			—			26,721
Property and equipment of consolidated variable interest entities	2,252			—			2,252			2,214			—			2,214
Less accumulated depreciation	8,760			(4		)	8,756			7,616			—			7,616
Property and equipment, net	22,529			4			22,533			21,319			—			21,319
Goodwill	3,205			12			3,217			8,132			—			8,132
Other assets	1,745			12			1,757			1,165			—			1,165
Total assets	$	35,088		$	(56	)	$	35,032		$	36,811		$	3		$	36,814

Liabilities and equity
Accounts payable	$	880		$	—		$	880		$	832		$	—		$	832
Accrued income taxes	89			—			89			109			—			109
Debt due within one year	1,942			—			1,942			1,917			—			1,917
Debt of consolidated variable interest entities due within one year	97			148			245			95			148			243
Other current liabilities	2,350			22			2,372			883			12			895
Total current liabilities	5,358			170			5,528			3,836			160			3,996

Long-term debt	10,756			—			10,756			8,354			—			8,354
Long-term debt of consolidated variable interest entities	741			(148		)	593			855			(148		)	707
Deferred income taxes, net	523			(4		)	519			575			10			585
Other long-term liabilities	1,903			(10		)	1,893			1,791			—			1,791
Total long-term liabilities	13,923			(162		)	13,761			11,575			(138		)	11,437

Commitments and contingencies
Redeemable noncontrolling interest	116			—			116			25			16			41

Shares	4,982			—			4,982			4,482			—			4,482
Additional paid-in capital	7,211			—			7,211			7,504			—			7,504
Treasury shares, at cost	(240		)	—			(240		)	(240		)	—			(240		)
Retained earnings	4,244			(64		)	4,180			9,969			(35		)	9,934
Accumulated other comprehensive loss	(496		)	—			(496		)	(332		)	—			(332		)
Total controlling interest shareholders’ equity	15,701			(64		)	15,637			21,383			(35		)	21,348
Noncontrolling interest	(10		)	—			(10		)	(8		)	—			(8		)
Total equity	15,691			(64		)	15,627			21,375			(35		)	21,340
Total liabilities and equity	$	35,088		$	(56	)	$	35,032		$	36,811		$	3		$	36,814

- Definition

The entire disclosure for reporting accounting changes and error corrections. It includes the conveyance of information necessary for a user of the Company's financial information to understand all aspects and required disclosure information concerning all changes and error corrections reported in the Company's financial statements for the period.

+ References+ Details

Variable Interest Entities

6 Months Ended

Jun. 30, 2012

Variable Interest Entities

Variable Interest Entities

Note 5—Variable Interest Entities

Consolidated variable interest entities—The carrying amounts associated with our consolidated variable interest entities, after eliminating the effect of intercompany transactions, were as follows (in millions):

	June 30, 2012						December 31, 2011
	Assets		Liabilities		Net carrying amount		Assets		Liabilities		Net carrying amount
Variable interest entity
TPDI	$	—	$	—	$	—	$	1,562	$	673	$	889
ADDCL	929		315		614		930		334		596
Total	$	929	$	315	$	614	$	2,492	$	1,007	$	1,485

Angola Deepwater Drilling Company Limited (“ADDCL”), a consolidated Cayman Islands company, is a variable interest entity for which we are the primary beneficiary. Accordingly, we consolidate the operating results, assets and liabilities of ADDCL.

Transocean Pacific Drilling Inc. (“TPDI”), a consolidated British Virgin Islands company, met the definition of a variable interest entity for which we were the primary beneficiary. On May 31, 2012, TPDI became a wholly owned subsidiary, and no longer meets the definition of a variable interest entity. See Note 16—Redeemable Noncontrolling Interest.

Unconsolidated variable interest entities—As holder of two notes receivable and a lender under a working capital loan, we have a variable interest in Awilco Drilling plc (“Awilco”), a U.K. company listed on the Oslo Stock Exchange. In the three months ended March 31, 2012, Awilco encountered operational downtime, both planned and unplanned, and disputed billings, at which time we reevaluated whether Awilco met the definition of a variable interest entity. Based on our reevaluation, we determined that Awilco now met the definition of a variable interest entity since its equity at risk is insufficient to permit it to carry on its activities without additional subordinated financial support. We also continue to believe that we are not the primary beneficiary since we do not have the power to direct the activities that most significantly impact the entity’s economic performance.

The notes receivable were originally accepted in exchange for and are secured by two drilling units. The notes receivable have stated interest rates of nine percent and are payable in scheduled quarterly installments of principal and interest through maturity in January 2015. The working capital loan, also secured by the two drilling units, has a stated interest rate of 10 percent and is payable in scheduled quarterly installments of principal and interest through maturity in January 2013. We evaluate the credit quality and financial condition of Awilco quarterly. The aggregate carrying amount of the notes receivable was $107 million and $110 million at June 30, 2012 and December 31, 2011, respectively. The aggregate carrying amount of the working capital loan receivable was $11 million and $29 million at June 30, 2012 and December 31, 2011, respectively. At June 30, 2012, our aggregate exposure to loss on these receivable instruments was $118 million.

Business Combination

6 Months Ended

Jun. 30, 2012

Business Combination

Business Combination

Note 6—Business Combination

As of October 3, 2011, the acquisition date, we held 99 percent of the shares of Aker Drilling ASA (“Aker Drilling”), a Norwegian company formerly listed on the Oslo Stock Exchange, having paid an aggregate amount of NOK 7.9 billion, equivalent to $1.4 billion. On October 4, 2011, we acquired the remaining noncontrolling interest from holders of Aker Drilling that were required to tender their shares pursuant to Norwegian law. We believe the acquisition of Aker Drilling enhances the composition of our High-Specification Floater fleet and strengthens our presence in Norway. In accounting for the business combination, we applied the acquisition method of accounting, recording the assets and liabilities of Aker Drilling at their estimated fair values as of the acquisition date.

As of October 3, 2011, the acquisition price included the following, measured at estimated fair value: current assets of $323 million, drilling rigs and other property and equipment of $1.8 billion, other assets of $756 million, and the assumption of long-term debt of $1.6 billion and other liabilities of $291 million. The acquired assets included $901 million of cash investments restricted for the payment of certain assumed debt instruments. The excess of the purchase price over the estimated fair value of net assets acquired was approximately $286 million, which was recorded as goodwill. Certain fair value measurements have not been completed, and the acquisition price allocation remains preliminary due to the timing of the acquisition and due to the number of acquired assets and assumed liabilities.

We subsequently made adjustments to the estimated fair value of certain assets and liabilities, which are reflected in the amounts noted above, with a corresponding net increase to goodwill in the amount of $12 million. We continue to review the estimated fair values of property and equipment and other assets and to evaluate the assumed tax positions and contingencies.

In the three and six months ended June 30, 2012, our operating revenues included approximately $100 million and $195 million of contract drilling revenues, respectively, associated with the operations of the two Harsh Environment, Ultra-Deepwater semisubmersibles that we acquired in our acquisition of Aker Drilling.

Unaudited pro forma combined operating results, assuming the acquisition was completed as of January 1, 2011, were as follows (in millions, except per share data):

	Three months ended June 30, 2011		Six months ended June 30, 2011
Operating revenues	$	2,438	$	4,682
Operating income	406		808
Income from continuing operations	$	175	$	339

Per share earnings from continuing operations
Basic	$	0.52	$	0.99
Diluted	$	0.52	$	0.99

The pro forma financial information includes various adjustments, primarily related to depreciation expense resulting from the fair value adjustments to the acquired property and equipment. The pro forma information is not necessarily indicative of the results of operations had the acquisition of Aker Drilling been completed on the assumed dates or the results of operations for any future periods.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph F4

-Subparagraph e

-Appendix F

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51, 52

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 805

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Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 88-16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef

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+ Details

Impairments

6 Months Ended

Jun. 30, 2012

Impairments

Impairments

Note 7—Impairments

Assets held for sale—During the three and six months ended June 30, 2012, we recognized aggregate losses of $12 million ($0.03 per diluted share from continuing operations) and $29 million ($0.08 per diluted share from continuing operations), which had no tax effect, respectively, associated with the impairment of GSF Adriatic II and GSF Rig 136, which were classified as assets held for sale at the time of impairment. We measured the impairments of the drilling units and related equipment as the amount by which the carrying amounts exceeded the estimated fair values less costs to sell. We estimated the fair value of the assets using significant other observable inputs, representing Level 2 fair value measurements, including binding sale and purchase agreements for the drilling units and related equipment.

In the three and six months ended June 30, 2011, we recognized an aggregate loss of $25 million ($0.08 per diluted share from continuing operations), which had no tax effect, associated with the impairment of George H. Galloway, GSF Britannia, and GSF Labrador, which were classified as held for sale at the time of impairment. We measured the impairments of the drilling units and related equipment as the amount by which the carrying amounts exceeded the estimated fair values less costs to sell. We estimated the fair values of the assets using significant other observable inputs, representing Level 2 fair value measurements, including binding sale and purchase agreements for the drilling units and related equipment.

Definite-lived intangible assets—During the six months ended June 30, 2012, we determined that the customer relationships intangible asset associated with our drilling management services reporting unit was impaired due to the declining market outlook for these services in the shallow water of U.S. Gulf of Mexico as well as the increased regulatory environment for obtaining drilling permits and the diminishing demand for our drilling management services. We estimated the fair value of the customer relationships intangible asset using the multiperiod excess earnings method, a valuation methodology that applies the income approach. Our valuation required us to project the future performance of the drilling management services reporting unit based on significant unobservable inputs, representing a Level 3 fair value measurement, including assumptions for future commodity prices, projected demand for our services, rig availability and dayrates. As a result of our valuation, we determined that the carrying amount of the customer relationships intangible asset exceeded its fair value, and we recognized a loss on impairment of $53 million ($37 million, or $0.11 per diluted share from continuing operations, net of tax) in the six months ended June 30, 2012.

Goodwill and other indefinite-lived intangible assets—As a result of our annual impairment test, performed as of October 1, 2011, we determined that the goodwill associated with our contract drilling services reporting unit was impaired due to a decline in projected cash flows and market valuations for this reporting unit. In the year ended December 31, 2011, we recognized a loss on impairment, representing our best estimate, in the amount of $5.2 billion ($16.15 per diluted share from continuing operations), which had no tax effect. In the six months ended June 30, 2012, we completed our analysis and recognized an incremental adjustment to our original estimate in the amount of $118 million ($0.34 per diluted share from continuing operations), which had no tax effect. We estimated the implied fair value of the goodwill using a variety of valuation methods, including cost, income, and market approaches. Our valuation required us to project the future performance of our contract drilling services reporting unit based on significant unobservable inputs, representing a Level 3 fair value measurement, including assumptions for future commodity prices, projected demand for our services, rig availability and dayrates.

During the six months ended June 30, 2012, we determined that the trade name intangible asset associated with our drilling management services reporting unit was impaired due to the declining market outlook for these services in the shallow waters of the U.S. Gulf of Mexico as well as the increased regulatory environment for obtaining drilling permits and the diminishing demand for drilling management services. We estimated the fair value of the trade name intangible asset using the relief from royalty method, a valuation methodology that applies the income approach. Our valuation required us to project the future performance of the drilling management services reporting unit based on significant unobservable inputs, representing a Level 3 fair value measurement, including assumptions for future commodity prices, projected demand for drilling management services, rig availability and dayrates. As a result of our valuation, we determined that the carrying amount of the trade name intangible asset exceeded its fair value, and we recognized a loss on impairment of $39 million ($25 million, or $0.07 per diluted share from continuing operations, net of tax) in the six months ended June 30, 2012.

Income Taxes

6 Months Ended

Jun. 30, 2012

Income Taxes

Income Taxes

Note 8—Income Taxes

Tax rate—Transocean Ltd., a holding company and Swiss resident, is exempt from cantonal and communal income tax in Switzerland, but is subject to Swiss federal income tax. At the federal level, qualifying net dividend income and net capital gains on the sale of qualifying investments in subsidiaries are exempt from Swiss federal income tax. Consequently, Transocean Ltd. expects dividends from its subsidiaries and capital gains from sales of investments in its subsidiaries to be exempt from Swiss federal income tax.

Our provision for income taxes is based on the tax laws and rates applicable in the jurisdictions in which we operate and earn income. The relationship between our provision for or benefit from income taxes and our income or loss before income taxes can vary significantly from period to period considering, among other factors, (a) the overall level of income before income taxes, (b) changes in the blend of income that is taxed based on gross revenues rather than income before taxes, (c) rig movements between taxing jurisdictions and (d) our rig operating structures. Generally, our annual marginal tax rate is lower than our annual effective tax rate.

Our estimated annual effective tax rates were 29.6 percent and 24.6 percent for the six months ended June 30, 2012 and 2011, respectively. These rates were based on estimated annual income before income taxes for each period after adjusting for various discrete items, including certain immaterial adjustments to prior period tax expense.

Deferred taxes—The valuation allowance for our non-current deferred tax assets was as follows (in millions):

	June 30, 2012		December 31, 2011
Valuation allowance for non-current deferred tax assets	$	178	$	183

Unrecognized tax benefits—The liabilities related to our unrecognized tax benefits, including related interest and penalties that we recognize as a component of income tax expense, were as follows (in millions):

	June 30, 2012		December 31, 2011
Unrecognized tax benefits, excluding interest and penalties	$	438	$	515
Interest and penalties	193		256
Unrecognized tax benefits, including interest and penalties	$	631	$	771

We engage in ongoing discussions with tax authorities regarding the resolution of tax matters in the various jurisdictions in which we operate. Both the ultimate resolutions of these tax matters and the timing of any resolution or closure of the tax audits are highly uncertain. It is reasonably possible that the total amount of our existing liabilities for unrecognized tax benefits could increase or decrease in the next 12 months primarily due to the progression of open audits or the expiration of statutes of limitations. However, we cannot reasonably estimate a range of potential changes in our existing liabilities for unrecognized tax benefits due to various uncertainties, such as the unresolved nature of various audits.

Tax returns—We file federal and local tax returns in several jurisdictions throughout the world. With few exceptions, we are no longer subject to examinations of our U.S. and non-U.S. tax matters for years prior to 2006. For the three and six months ended June 30, 2012, the amount of current tax benefit recognized from the settlement of disputes with tax authorities and from the expiration of statutes of limitations, including interest and penalties, was $146 million and $194 million, respectively.

Our tax returns in the major jurisdictions in which we operate, other than the U.S., Norway and Brazil which are mentioned below, are generally subject to examination for periods ranging from three to six years. We have agreed to extensions beyond the statute of limitations in two major jurisdictions for up to 17 years. Tax authorities in certain jurisdictions are examining our tax returns and in some cases have issued assessments. We are defending our tax positions in those jurisdictions. While we cannot predict or provide assurance as to the final outcome of these proceedings, we do not expect the ultimate liability to have a material adverse effect on our consolidated statement of financial position or results of operations, although it may have a material adverse effect on our consolidated cash flows.

U.S. tax investigations—With respect to our 2004 U.S. federal income tax return, the U.S. tax authorities withdrew all of their previously proposed tax adjustments, including all claims related to transfer pricing. In January 2012, a judge in the U.S. Tax Court entered a decision of no deficiency for the 2004 tax year and cancelled the trial previously scheduled to take place in February 2012. With respect to our 2005 U.S. federal income tax returns, the U.S. tax authorities have withdrawn all of their previously proposed tax adjustments. In May 2010, we received an assessment from the U.S. tax authorities related to our 2006 and 2007 U.S. federal income tax returns. In July 2010, we filed a protest letter with the U.S. tax authorities responding to this assessment. The significant issues raised in the assessment relate to transfer pricing for certain charters of drilling rigs between our subsidiaries and the creation of intangible assets resulting from the performance of engineering services between our subsidiaries. These two items would result in net adjustments of approximately $278 million of additional taxes, excluding interest and penalties. An unfavorable outcome on these adjustments could result in a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. We believe our U.S. federal income tax returns are materially correct as filed, and we intend to continue to vigorously defend against all such claims.

In addition, the May 2010 assessment included adjustments related to a series of restructuring transactions that occurred between 2001 and 2004. These restructuring transactions impacted our basis in our former subsidiary, TODCO, which we disposed of in 2004 and 2005. The authorities are disputing the amount of capital losses that resulted from the disposition of TODCO. We utilized a portion of the capital losses to offset capital gains on our U.S. federal income tax returns for 2006 through 2009. The majority of the capital losses were unutilized and expired on December 31, 2009. The adjustments would also impact the amount of certain net operating losses and other carryovers in 2006 and later years. The authorities are also contesting the characterization of certain amounts of income received in 2006 and 2007 as capital gain and thus the availability of the capital loss to offset such gains. These claims with respect to our U.S. federal income tax returns for 2006 through 2009 could result in net tax adjustments of approximately $295 million, excluding interest and penalties. An unfavorable outcome on these potential adjustments could result in a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. We believe that our U.S. federal income tax returns are materially correct as filed, and we intend to continue to vigorously defend against any potential claims.

The May 2010 assessment also included certain claims with respect to withholding taxes and certain other items resulting in net tax adjustments of approximately $160 million, excluding interest. In addition, the tax authorities assessed penalties associated with the various tax adjustments for the 2006 and 2007 audits in the aggregate amount of approximately $88 million, excluding interest. An unfavorable outcome on these adjustments could result in a material adverse effect on our consolidated statement of financial position, results of operations and cash flows. We believe that our U.S. federal income tax returns are materially correct as filed, and we intend to continue to vigorously defend against potential claims.

In February 2012, we received an assessment from the U.S. tax authorities related to our 2008 and 2009 U.S. federal income tax returns. The significant issues raised in the assessment relate to transfer pricing for certain charters of drilling rigs between our subsidiaries and the creation of intangible assets resulting from the performance of engineering services between our subsidiaries. These items would result in net adjustments of approximately $473 million of additional taxes, excluding interest and penalties. An unfavorable outcome on these adjustments could result in a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. Furthermore, if the authorities were to continue to pursue these positions with respect to subsequent years and were successful in such assertions, our effective tax rate on worldwide earnings with respect to years following 2009 could increase substantially, and could have a material adverse effect on our consolidated results of operations and cash flows. We believe our U.S. federal income tax returns are materially correct as filed, and we intend to continue to vigorously defend against all such claims.

Norway tax investigations—Norwegian civil tax and criminal authorities are investigating various transactions undertaken by our subsidiaries in 2001 and 2002 as well as the actions of certain employees of our former external tax advisors on these transactions. The authorities issued tax assessments of approximately $115 million, plus interest, related to the migration of a subsidiary that was previously subject to tax in Norway, approximately $70 million, plus interest, related to a 2001 dividend payment, and approximately $7 million, plus interest, related to certain foreign exchange deductions and dividend withholding tax. We have filed or expect to file appeals to these tax assessments. We have provided a parent company guarantee in the amount of approximately $117 million with respect to one of these tax disputes. Furthermore, we may be required to provide some form of additional financial security, in an amount up to $206 million, including interest and penalties, for other assessed amounts as these disputes are appealed and addressed by the Norwegian courts. The authorities have indicated that they plan to seek penalties of 60 percent on most but not all matters. In June 2011, the Norwegian authorities issued criminal indictments against two of our subsidiaries alleging misleading or incomplete disclosures in Norwegian tax returns for the years 1999 through 2002, as well as inaccuracies in Norwegian statutory financial statements for the years ended December 31, 1996 through 2001. The criminal trial has been scheduled for December 2012. Two employees of our former external tax advisors were also issued indictments with respect to the disclosures in our tax returns. In October 2011, the Norwegian authorities issued criminal indictments against a Norwegian tax attorney related to certain of our restructuring transactions and to the 2001 dividend payment. The indicted Norwegian tax attorney worked for us in an advisory capacity on these transactions. We believe the charges brought against us are without merit and do not alter our technical assessment of the underlying claims. In January 2012, the Norwegian authorities supplemented the previously issued criminal indictments by issuing a financial claim of approximately $309 million, jointly and severally, against our two subsidiaries, the two external advisors and the external tax attorney. This compensation claim directly overlaps with an existing civil tax assessment and does not represent an incremental financial exposure to us. In February 2012, the authorities dropped the previously existing tax assessment related to a certain restructuring transaction. In April 2012, the Norwegian tax authorities supplemented the previously issued criminal indictments against our two subsidiaries by extending a criminal indictment against a third subsidiary on the same matter, alleging misleading or incomplete disclosures in Norwegian tax returns for the years 2001 and 2002. We believe our Norwegian tax returns are materially correct as filed, and we intend to continue to vigorously contest any assertions to the contrary by the Norwegian civil and criminal authorities in connection with the various transactions being investigated. An unfavorable outcome on the Norwegian civil or criminal tax matters could result in a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Brazil tax investigations—Certain of our Brazilian income tax returns for the years 2000 through 2004 are currently under examination. The Brazilian tax authorities have issued tax assessments totaling $98 million, plus a 75 percent penalty in the amount of $74 million and interest through December 31, 2011 in the amount of $143 million. We believe our returns are materially correct as filed, and we are vigorously contesting these assessments. On January 25, 2008, we filed a protest letter with the Brazilian tax authorities, and we are currently engaged in the appeals process. An unfavorable outcome on these proposed assessments could result in a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Other tax matters—We conduct operations through our various subsidiaries in a number of countries throughout the world. Each country has its own tax regimes with varying nominal rates, deductions and tax attributes. From time to time, we may identify changes to previously evaluated tax positions that could result in adjustments to our recorded assets and liabilities. Although we are unable to predict the outcome of these changes, we do not expect the effect, if any, resulting from these assessments to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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+ Details

Discontinued Operations

6 Months Ended

Jun. 30, 2012

Discontinued Operations

Discontinued Operations

Note 9—Discontinued Operations

Oil and gas properties—In March 2011, in connection with our efforts to dispose of non-strategic assets, we engaged an unaffiliated advisor to coordinate the sale of the assets of our oil and gas properties reporting unit, a component of our other operations segment, which comprises the exploration, development and production activities performed by Challenger Minerals Inc. and Challenger Minerals (North Sea) Limited, our wholly owned oil and gas subsidiaries. In October 2011, we completed the sale of Challenger Minerals (North Sea) Limited. In April 2012, we completed the sale of the assets of Challenger Minerals Inc. for net cash proceeds of $7 million. In May 2012, we received an additional $10 million of cash proceeds from the buyer of Challenger Minerals (North Sea) Limited, and recognized a gain on the disposal of discontinued operations in the amount of $10 million during the three and six months ended June 30, 2012.

Caspian Sea operations—In February 2011, in connection with our efforts to dispose of non-strategic assets, we sold the subsidiary that owns the High-Specification Jackup Trident 20, located in the Caspian Sea. The disposal of this subsidiary, a component of our contract drilling services segment, reflects our decision to discontinue operations in the Caspian Sea. As a result of the sale, we received net cash proceeds of $259 million and, in the six months ended June 30, 2011, we recognized a gain on the disposal of the discontinued operations of $169 million ($0.52 per diluted share from discontinued operations), which had no tax effect. Through June 2011, we continued to operate Trident 20 under a bareboat charter to perform services for the customer and the buyer reimbursed us for the approximate cost of providing these services. Additionally, we provided certain transition services to the buyer through September 2011.

Summarized results of discontinued operations—The summarized results of operations included in income from discontinued operations were as follows (in millions):

	Three months ended June 30,						Six months ended June 30,
	2012			2011			2012			2011
Operating revenues	$	2		$	22		$	5		$	48
Costs and expenses	(3		)	(18		)	(5		)	(41		)
Loss on impairment (a)	—			—			(6		)	—
Gain on disposal of discontinued operations, net	10			—			10			169
Income from discontinued operations before income tax expense	9			4			4			176
Income tax benefit (expense)	(2		)	(2		)	2			(2		)
Income from discontinued operations, net of tax	$	7		$	2		$	6		$	174

(a) During the six months ended June 30, 2012, we recognized a loss on impairment of our oil and gas properties, which were classified as assets held for sale, in the amount of $6 million ($4 million or $0.01 per diluted share from discontinued operations, net of tax) since the carrying amount of the properties exceeded the estimated fair value less costs to sell the properties. We estimated fair value based on significant other observable inputs, representing a Level 2 fair value measurement, including a binding sale and purchase agreement for the properties.

Assets and liabilities of discontinued operations—As a result of our decision to discontinue the operations of our oil and gas properties reporting unit and the operations of our Caspian Sea subsidiary, we have classified the related assets and liabilities of these components of our business to other current assets and other current liabilities as of December 31, 2011. The carrying amounts of the major classes of assets and liabilities associated with these operations were classified as follows (in millions):

	June 30, 2012		December 31, 2011
Assets
Oil and gas properties, net	$	5	$	24
Other related assets	2		2
Assets held for sale	$	7	$	26

Accounts receivable	$	1	$	6
Other assets	11		11
Other current assets	$	12	$	17

Liabilities
Accounts payable	$	1	$	3
Other liabilities	5		14
Other current liabilities	$	6	$	17

- Definition

The entire disclosure for the facts and circumstances leading to the completed or expected disposal, manner and timing of disposal, the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the segment in which the disposal group was reported, and the classification (whether sold or classified as held for sale) and carrying value of the assets and liabilities comprising the disposal group. Includes all disposal groups, including those classified as components of the entity (discontinued operations).

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+ Details

Earnings Per Share

6 Months Ended

Jun. 30, 2012

Earnings Per Share

Earnings Per Share

Note 10—Earnings Per Share

The numerator and denominator used for the computation of basic and diluted per share earnings from continuing operations were as follows (in millions, except per share data):

	Three months ended June 30,									Six months ended June 30,
	2012					2011				2012					2011
	Basic			Diluted		Basic		Diluted		Basic			Diluted		Basic		Diluted
Numerator for earnings (loss) per share
Income (loss) from continuing operations attributable to controlling interest	$	(311	)	(311	)	122		122		$	(300	)	(300	)	269		269
Undistributed earnings allocable to participating securities	—			—		(1	)	(1	)	—			—		(2	)	(2	)
Income (loss) from continuing operations available to shareholders	$	(311	)	(311	)	121		121		$	(300	)	(300	)	267		267

Denominator for earnings (loss) per share
Weighted-average shares outstanding	353			353		320		320		352			352		319		319
Effect of stock options and other share-based awards	—			—		—		—		—			—		—		1
Weighted-average shares for per share calculation	353			353		320		320		352			352		319		320

Per share earnings (loss) from continuing operations	$	(0.88	)	(0.88	)	0.38		0.38		$	(0.85	)	(0.85	)	0.84		0.84

For the three and six months ended June 30, 2012, respectively, 2.2 million and 2.0 million share-based awards were excluded from the calculation since the effect would have been anti-dilutive. For the three and six months ended June 30, 2011, respectively, 1.5 million and 1.7 million share-based awards were excluded from the calculation since the effect would have been anti-dilutive.

The 1.50% Series B Convertible Senior Notes and 1.50% Series C Convertible Senior Notes did not have an effect on the calculation for the periods presented. See Note 12—Debt.

- Definition

The entire disclosure for earnings per share.

+ References+ Details

Drilling Fleet

6 Months Ended

Jun. 30, 2012

Drilling Fleet

Drilling Fleet

Note 11—Drilling Fleet

Expansion—Capital expenditures and other capital additions, including capitalized interest, for the six months ended June 30, 2012 and 2011 were as follows (in millions):

	Six months ended June 30,
	2012			2011
Construction work in progress, at beginning of period	$	1,395		$	1,484

Newbuild construction program
Transocean Ao Thai (a)	45			10
Transocean Honor (b)	35			76
Transocean Andaman (c)	26			70
Transocean Siam Driller (c)	26			70
Deepwater Asgard (d)	21			—
Deepwater Invictus (d)	13			—
Deepwater Champion (e)	—			76
Other construction projects	330			231
Total capital expenditures	496			533
Changes in accrued capital expenditures	32			(31		)

Property and equipment placed into service
Transocean Honor (b)	(262		)	—
Deepwater Champion (e)	—			(881		)
Other property and equipment	(341		)	(262		)
Construction work in progress, at end of period	$	1,320		$	843

(a) Transocean Ao Thai, a Keppel FELS Super B class design High-Specification Jackup, under construction at Keppel FELS’ yard in Singapore, is expected to commence operations in the fourth quarter of 2013.

(b) Transocean Honor, a PPL Pacific Class 400 design High-Specification Jackup, commenced operations in May 2012.

(c) Transocean Siam Driller and Transocean Andaman, two Keppel FELS Super B class design High-Specification Jackups, under construction at Keppel FELS’ yard in Singapore, are expected to commence operations in the first quarter of 2013.

(d) Deepwater Asgard and Deepwater Invictus, two Ultra-Deepwater drillships under construction at the Daewoo Shipbuilding & Marine Engineering Co. Ltd. shipyard in Korea, are expected to be ready to commence operations in the second quarter of 2014.

(e) Deepwater Champion, an Ultra-Deepwater drillship, commenced operations in May 2011.

Dispositions—During the six months ended June 30, 2012, in connection with our efforts to dispose of non-strategic assets, we completed the sales of the Standard Jackups, GSF Adriatic II, GSF Rig 136, Roger W. Mowell, Transocean Nordic and Transocean Shelf Explorer, and related equipment. In the three and six months ended June 30, 2012, we received aggregate net cash proceeds of $145 million and $179 million, respectively, and recognized a net gain on disposal of these assets in the amount of $64 million ($0.18 per diluted share from continuing operations), which had no tax effect (see Note 7—Impairments). For the three and six months ended June 30, 2012, we recognized losses on disposal of unrelated assets in the amount of $9 million and $13 million, respectively.

During the six months ended June 30, 2011, in connection with our efforts to dispose of non-strategic assets, we sold the High-Specification Jackup Trident 20 and the Standard Jackup Transocean Mercury. The sale of Trident 20 reflected our decision to discontinue operations in the Caspian Sea (see Note 9—Discontinued Operations). In connection with the sale of Transocean Mercury, we received net cash proceeds of $10 million and recognized a net gain on disposal of the drilling unit and related equipment in the amount of $9 million ($0.03 per diluted share from continuing operations), which had no tax effect. For the three and six months ended June 30, 2011, we recognized losses on disposal of unrelated assets in the amount of $1 million and $2 million, respectively.

Assets held for sale—During the six months ended June 30, 2012, we committed to a plan to sell our Standard Jackup Trident 17. At June 30, 2012, the drilling unit and related equipment were classified as assets held for sale with an aggregate net carrying amount of $2 million. See Note 20—Subsequent Events.

- Definition

The entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures.

+ References+ Details

Debt

6 Months Ended

Jun. 30, 2012

Debt

Debt

Note 12—Debt

Debt, net of unamortized discounts, premiums and fair value adjustments, was comprised of the following (in millions):

	June 30, 2012						December 31, 2011
	Transocean Ltd. and subsidiaries		Consolidated variable interest entities		Consolidated total		Transocean Ltd. and subsidiaries		Consolidated variable interest entities		Consolidated total
5% Notes due February 2013	$	252	$	—	$	252	$	253	$	—	$	253
5.25% Senior Notes due March 2013 (a)	505		—		505		507		—		507
TPDI Credit Facilities due March 2015	438		—		438		—		473		473
4.95% Senior Notes due November 2015 (a)	1,121		—		1,121		1,120		—		1,120
Aker Revolving Credit and Term Loan Facility due December 2015	174		—		174		594		—		594
5.05% Senior Notes due December 2016 (a)	999		—		999		999		—		999
Callable Bonds due February 2016	265		—		265		267		—		267
ADDCL Credit Facilities due December 2017	—		205		205		—		217		217
Eksportfinans Loans due January 2018	815		—		815		884		—		884
6.00% Senior Notes due March 2018 (a)	998		—		998		998		—		998
7.375% Senior Notes due April 2018 (a)	247		—		247		247		—		247
TPDI Notes due October 2019	—		—		—		—		148		148
6.50% Senior Notes due November 2020 (a)	899		—		899		899		—		899
6.375% Senior Notes due December 2021 (a)	1,199		—		1,199		1,199		—		1,199
7.45% Notes due April 2027 (a)	97		—		97		97		—		97
8% Debentures due April 2027 (a)	57		—		57		57		—		57
7% Notes due June 2028	311		—		311		311		—		311
Capital lease contract due August 2029	667		—		667		676		—		676
7.5% Notes due April 2031 (a)	598		—		598		598		—		598
1.50% Series B Convertible Senior Notes due December 2037 (a)	—		—		—		30		—		30
1.50% Series C Convertible Senior Notes due December 2037 (a)	1,693		—		1,693		1,663		—		1,663
6.80% Senior Notes due March 2038 (a)	999		—		999		999		—		999
7.35% Senior Notes due December 2041 (a)	300		—		300		300		—		300
Total debt	12,634		205		12,839		12,698		838		13,536
Less debt due within one year
5% Notes due February 2013	252		—		252		—		—		—
5.25% Senior Notes due March 2013 (a)	505		—		505		—		—		—
TPDI Credit Facilities due March 2015	70		—		70		—		70		70
Aker Revolving Credit and Term Loan Facility due December 2015	90		—		90		90		—		90
ADDCL Credit Facilities due November 2017	—		28		28		—		27		27
Eksportfinans Loans due January 2018	142		—		142		142		—		142
TPDI Notes due October 2019	—		—		—		—		148		148
Capital lease contract due August 2029	20		—		20		17		—		17
1.50% Series B Convertible Senior Notes due December 2037 (a)	—		—		—		30		—		30
1.50% Series C Convertible Senior Notes due December 2037 (a)	1,693		—		1,693		1,663		—		1,663
Total debt due within one year	2,772		28		2,800		1,942		245		2,187
Total long-term debt	$	9,862	$	177	$	10,039	$	10,756	$	593	$	11,349

(a) Transocean Inc., a 100 percent owned subsidiary of Transocean Ltd., is the issuer of the notes and debentures, which have been guaranteed by Transocean Ltd. Transocean Ltd. has also guaranteed borrowings under the Five-Year Revolving Credit Facility. Transocean Ltd. and Transocean Inc. are not subject to any significant restrictions on their ability to obtain funds from their consolidated subsidiaries by dividends, loans or return of capital distributions. See Note 19—Condensed Consolidating Financial Information.

Scheduled maturities—In preparing the scheduled maturities of our debt, we assume the noteholders will exercise their options to require us to repurchase the 1.50% Series C Convertible Senior Notes in December 2012. At June 30, 2012, the scheduled maturities of our debt were as follows (in millions):

	Transocean Ltd. and subsidiaries		Consolidated variable interest entities		Consolidated total
Twelve months ending June 30,
2013	$	2,792	$	28	$	2,820
2014	316		29		345
2015	463		31		494
2016	1,519		61		1,580
2017	1,169		36		1,205
Thereafter	6,365		20		6,385
Total debt, excluding unamortized discounts, premiums and fair value adjustments	12,624		205		12,829
Total unamortized discounts, premiums and fair value adjustments, net	10		—		10
Total debt	$	12,634	$	205	$	12,839

Five-Year Revolving Credit Facility—We have a $2.0 billion revolving credit facility established by the Five-Year Revolving Credit Facility Agreement dated November 1, 2011 (the “Five-Year Revolving Credit Facility”). Throughout the term of the Five-Year Revolving Credit Facility, we pay a facility fee on the daily unused amount of the underlying commitment, which ranges from 0.13 percent to 0.33 percent, based on our Debt Rating, and was 0.275 percent at June 30, 2012. At June 30, 2012, we had $24 million in letters of credit issued and outstanding, we had no borrowings outstanding, and we had $2.0 billion available borrowing capacity under the Five-Year Revolving Credit Facility.

TPDI Credit Facilities—TPDI has a bank credit agreement for a $1.265 billion secured credit facility (the “TPDI Credit Facilities”), comprised of a $1.0 billion senior term loan, a $190 million junior term loan and a $75 million revolving credit facility, which was established to finance the construction of and is secured by Dhirubhai Deepwater KG1 and Dhirubhai Deepwater KG2. One of our other subsidiaries participates as a lender in the senior and junior term loans with an aggregate commitment of $595 million. At June 30, 2012, $875 million was outstanding under the TPDI Credit Facilities, of which $437 million was due to the other subsidiary and was eliminated in consolidation. On June 30, 2012, the weighted-average interest rate was 2.1 percent. See Note 13—Derivatives and Hedging and Note 16—Redeemable Noncontrolling Interest.

At June 30, 2012, TPDI had an outstanding letter of credit in the amount of $60 million to satisfy its liquidity requirements under the TPDI Credit Facilities. Additionally, TPDI is required to maintain certain cash balances in accounts restricted for the payment of the scheduled installments on the TPDI Credit Facilities. TPDI had restricted cash investments of $23 million at June 30, 2012 and December 31, 2011.

Aker Revolving Credit and Term Loan Facility—Aker Drilling has a credit facility established by the Revolving Credit and Term Loan Facility Agreement dated February 21, 2011 (the “Aker Revolving Credit and Term Loan Facility”), comprised of a $500 million revolving credit facility (the “Aker Revolving Credit Facility”) and a $400 million term loan (the “Aker Term Loan”), which is secured by Transocean Spitsbergen and Transocean Barents and guaranteed by Transocean Ltd.

During the six months ended June 30, 2012, we prepaid $138 million of borrowings under the Aker Term Loan, and we recognized a loss on retirement of debt in the amount of less than $1 million. At June 30, 2012, we had $173 million of borrowings outstanding under the Aker Term Loan and no borrowings outstanding under the Aker Revolving Credit Facility. On June 30, 2012, the weighted-average interest rate of borrowings under the Aker Term Loan was 3.0 percent.

Callable Bonds—Aker Drilling is the obligor on the FRN Aker Drilling ASA Senior Unsecured Callable Bond Issue 2011/2016 (the “FRN Callable Bonds”) and the 11% Aker Drilling ASA Senior Unsecured Callable Bond Issue 2011/2016 (the “11% Callable Bonds,” and together with the FRN Callable Bonds, the “Callable Bonds”), which are publicly traded on the Oslo Stock Exchange. At June 30, 2012, the total aggregate principal amounts of the FRN Callable Bonds and the 11% Callable Bonds were NOK 940 million and NOK 560 million, equivalent to $158 million and $94 million, respectively, using an exchange rate of NOK 5.95 to US $1.00. At June 30, 2012, the interest rate on the FRN Callable Bonds was 9.3 percent. See Note 13—Derivatives and Hedging.

ADDCL Credit Facilities—ADDCL has a senior secured bank credit agreement for a credit facility (the “ADDCL Primary Loan Facility”) comprised of Tranche A and Tranche C for $215 million and $399 million, respectively, which was established to finance the construction of and is secured by Discoverer Luanda. Unaffiliated financial institutions provide the commitment for and borrowings under Tranche A, and one of our subsidiaries provides the commitment for Tranche C. At June 30, 2012, $177 million was outstanding under Tranche A at a weighted-average interest rate of 1.5 percent. At June 30, 2012, $399 million was outstanding under Tranche C, which was eliminated in consolidation.

Additionally, ADDCL has a secondary bank credit agreement for a $90 million credit facility (the “ADDCL Secondary Loan Facility” and together with the ADDCL Primary Loan Facility, the “ADDCL Credit Facilities”), for which one of our subsidiaries provides 65 percent of the total commitment. At June 30, 2012, $80 million was outstanding under the ADDCL Secondary Loan Facility, of which $52 million was due to one of our subsidiaries and has been eliminated in consolidation. On June 30, 2012, the weighted-average interest rate was 3.6 percent.

ADDCL is required to maintain certain cash balances in accounts restricted for the payment of the scheduled installments on the ADDCL Credit Facilities. ADDCL had restricted cash investments of $17 million and $16 million at June 30, 2012 and December 31, 2011, respectively.

Eksportfinans Loans—The Eksportfinans Loans require cash collateral to remain on deposit at a financial institution (the “Aker Restricted Cash Investments”) through expiration. The aggregate principal amount of the Aker Restricted Cash Investments was $819 million and $889 million at June 30, 2012 and December 31, 2011, respectively.

TPDI Notes—TPDI had previously issued promissory notes (the “TPDI Notes”), which had maturities through October 2019 and were payable to one of our subsidiaries and its former second shareholder, Quantum Pacific Management Limited (“Quantum”). On May 31, 2012, in connection with the exchange of Quantum’s interest in TPDI for our shares, the TPDI Notes payable to Quantum were extinguished and contributed as additional paid-in capital. See Note 16—Redeemable Noncontrolling Interest.

1.50% Series B and 1.50% Series C Convertible Senior Notes—Including amortization of the unamortized discount, the effective interest rates for the Series C Convertible Senior Notes was 5.28 percent. At June 30, 2012, the remaining period over which the discount will be amortized is less than one year. Interest expense, excluding amortization of debt issue costs, was as follows (in millions):

	Three months ended June 30,				Six months ended June 30,
	2012		2011		2012		2011
Interest expense
Series B Convertible Senior Notes due 2037	$	—	$	20	$	—	$	40
Series C Convertible Senior Notes due 2037	22		21		43		41

The carrying amounts of the liability components of the outstanding Convertible Senior Notes were as follows (in millions):

	June 30, 2012							December 31, 2011
	Principal amount		Unamortized discount			Carrying amount		Principal amount		Unamortized discount			Carrying amount
Carrying amount of liability component
Series B Convertible Senior Notes due 2037	$	—	$	—		$	—	$	30	$	—		$	30
Series C Convertible Senior Notes due 2037	1,722		(29		)	1,693		1,722		(59		)	1,663

In March 2012, we redeemed the remaining $30 million of aggregate principal amount of our Series B Convertible Senior Notes for an aggregate cash payment of $30 million.

The carrying amounts of the equity components of the outstanding Convertible Senior Notes were as follows (in millions):

	June 30, 2012		December 31, 2011
Carrying amount of equity component
Series B Convertible Senior Notes due 2037	$	—	$	4
Series C Convertible Senior Notes due 2037	276		276

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References+ Details

Derivatives and Hedging

6 Months Ended

Jun. 30, 2012

Derivatives and Hedging

Derivatives and Hedging

Note 13—Derivatives and Hedging

Derivatives designated as hedging instruments—Two of our wholly owned subsidiaries have interest rate swaps, which are designated and have qualified as fair value hedges, to reduce our exposure to changes in the fair values of the 5% Notes due February 2013 and the 5.25% Senior Notes due March 2013. The interest rate swaps have aggregate notional amounts equal to the corresponding face values of the hedged instruments and have stated maturities that coincide with those of the hedged instruments. We have determined that the hedging relationships qualify for, and we have applied, the shortcut method of accounting, under which the interest rate swaps are considered to have no ineffectiveness and no ongoing assessment of effectiveness is required. Accordingly, changes in the fair value of the interest rate swaps recognized in interest expense offset changes in the fair value of the hedged fixed-rate notes. Through the stated maturities of the interest rate swaps, we receive semi-annual interest at a fixed rate equal to that of the underlying debt instrument and pay variable interest semi-annually at three-month London Interbank Offered Rate plus a margin.

One of our wholly owned subsidiaries had previously entered into interest rate swaps, which were designated and qualified as fair value hedges, to reduce our exposure to changes in the fair values of the 4.95% Senior Notes due November 2015. In the three months ended June 30, 2012, we terminated these interest rate swaps and received an aggregate net cash payment of $23 million.

TPDI has interest rate swaps, which have been designated and qualify as a cash flow hedge, to reduce the variability of cash interest payments associated with the variable rate borrowings under the TPDI Credit Facilities through December 31, 2014. The aggregate notional amount corresponds with the aggregate outstanding amount of the borrowings under the TPDI Credit Facilities.

Aker Drilling has cross-currency interest rate swaps, which have been designated and qualify as a cash flow hedge, to reduce the variability of cash interest payments and the final principal payment, due at maturity in February 2016, associated with the changes in the U.S. dollar to Norwegian kroner exchange rate. The aggregate notional amount corresponds with the aggregate outstanding amount of the 11% Callable Bonds.

At June 30, 2012, the aggregate notional amounts and the weighted average interest rates associated with our derivatives designated as hedging instruments were as follows (in millions, except weighted average interest rates):

	Pay					Receive
	Aggregate notional amount		Fixed or variable rate	Weighted average rate		Aggregate notional amount			Fixed or variable rate	Weighted average rate
Interest rate swaps, fair value hedges	$	750	variable	3.6	%	$	750		fixed	5.2	%
Interest rate swaps, cash flow hedges	$	420	fixed	2.4	%	$	420		variable	0.5	%
Cross-currency swaps, cash flow hedges	$	102	fixed	8.9	%	NOK		560	fixed	11.0	%

The effect on our condensed consolidated statements of operations resulting from derivatives designated as cash flow hedges was as follows (in millions):

		Three months ended June 30,				Six months ended June 30,
	Statement of operations classification	2012		2011		2012		2011
Loss associated with effective portion	Interest expense, net of amounts capitalized	$	2	$	3	$	3	$	5
Loss associated with effective portion	Other, net	4		—		—		—

The balance sheet classification and aggregate carrying amount of our derivatives designated as hedging instruments, measured at fair value, including accrued interest, were as follows (in millions):

	Balance sheet classification	June 30, 2012		December 31, 2011
Interest rate swaps, fair value hedges	Other current assets	$	11	$	5
Interest rate swaps, fair value hedges	Other assets	—		31
Interest rate swaps, cash flow hedges	Other long-term liabilities	15		16
Cross-currency swaps, cash flow hedges	Other current assets	1		—
Cross-currency swaps, cash flow hedges	Other long-term liabilities	7		7

Derivatives not designated as hedging instruments—In connection with our acquisition of Aker Drilling, we assumed certain derivatives not designated as hedging instruments. In the three months ended June 30, 2012, we terminated the interest rate swaps not designated as hedging instruments and made an aggregate cash payment of $14 million. The effect on our condensed consolidated statements of operations resulting from changes in the fair values of derivatives not designated as hedging instruments was as follows (in millions):

		Three months ended June 30,				Six months ended June 30,
	Statement of operations classification	2012		2011		2012		2011
Loss associated with undesignated interest rate swaps	Interest expense, net of amounts capitalized	$	—	$	—	$	1	$	—

The balance sheet classification and aggregate carrying amount of our derivatives not designated as hedging instruments, measured at fair value, were as follows (in millions):

	Balance sheet classification	June 30, 2012		December 31, 2011
Interest rate swaps, undesignated	Other long-term liabilities	$	—	$	15

- Definition

The entire disclosure for the entity's entire derivative instruments and hedging activities. Describes an entity's risk management strategies, derivatives in hedging activities and non-hedging derivative instruments, the assets, obligations, liabilities, revenues and expenses arising therefrom, and the amounts of and methodologies and assumptions used in determining the amounts of such items.

+ References

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+ Details

Postemployment Benefit Plans

6 Months Ended

Jun. 30, 2012

Postemployment Benefit Plans

Postemployment Benefit Plans

Note 14—Postemployment Benefit Plans

We have several defined benefit pension plans, both funded and unfunded, covering substantially all of our U.S. employees, including certain frozen plans, assumed in connection with our mergers, that cover certain current employees and certain former employees and directors of our predecessors (the “U.S. Plans”). We also have various defined benefit plans in the U.K., Norway, Nigeria, Egypt and Indonesia that cover our employees in those areas (the “Non-U.S. Plans”). Additionally, we offer several unfunded contributory and noncontributory other postretirement employee benefit plans covering substantially all of our U.S. employees (the “OPEB Plans”).

The components of net periodic benefit costs, before tax, and funding contributions for these plans were as follows (in millions):

	Three months ended June 30, 2012											Three months ended June 30, 2011
	U.S. Plans			Non-U.S. Plans			OPEB Plans		Total			U.S. Plans			Non-U.S. Plans			OPEB Plans			Total
Net periodic benefit costs
Service cost	$	12		$	9		$	—	$	21		$	11		$	5		$	1		$	17
Interest cost	15			8			—		23			15			6			—			21
Expected return on plan assets	(16		)	(8		)	—		(24		)	(16		)	(7		)	—			(23		)
Settlements and curtailments	—			—			—		—			1			—			—			1
Actuarial losses, net	10			1			—		11			6			—			—			6
Prior service cost, net	(1		)	—			—		(1		)	(1		)	—			(1		)	(2		)
Transition obligation, net	—			—			—		—			—			1			—			1
Net periodic benefit costs	$	20		$	10		$	—	$	30		$	16		$	5		$	—		$	21

Funding contributions	$	100		$	9		$	1	$	110		$	55		$	6		$	2		$	63

	Six months ended June 30, 2012											Six months ended June 30, 2011
	U.S. Plans			Non-U.S. Plans			OPEB Plans		Total			U.S. Plans			Non-U.S. Plans			OPEB Plans			Total
Net periodic benefit costs
Service cost	$	24		$	16		$	—	$	40		$	22		$	10		$	1		$	33
Interest cost	29			13			1		43			29			11			1			41
Expected return on plan assets	(31		)	(13		)	—		(44		)	(32		)	(12		)	—			(44		)
Settlements and curtailments	2			—			—		2			1			—			—			1
Actuarial losses, net	20			2			—		22			12			—			—			12
Prior service cost, net	(1		)	—			—		(1		)	(1		)	—			(1		)	(2		)
Transition obligation, net	—			—			—		—			—			1			—			1
Net periodic benefit costs	$	43		$	18		$	1	$	62		$	31		$	10		$	1		$	42

Funding contributions	$	103		$	17		$	2	$	122		$	68		$	13		$	3		$	84

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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+ Details

Contingencies

6 Months Ended

Jun. 30, 2012

Contingencies

Contingencies

Note 15—Contingencies

Macondo well incident

Overview—On April 22, 2010, the Ultra-Deepwater Floater Deepwater Horizon sank after a blowout of the Macondo well caused a fire and explosion on the rig. Eleven persons were declared dead and others were injured as a result of the incident. At the time of the explosion, Deepwater Horizon was located approximately 41 miles off the coast of Louisiana in Mississippi Canyon Block 252 and was contracted to BP America Production Co. (“BP”).

We are currently unable to estimate the full impact the Macondo well incident will have on us. We have recognized a liability for estimated loss contingencies that we believe are probable and for which a reasonable estimate can be made. As of June 30, 2012, we have recognized a liability for such loss contingencies in the amount of $2.0 billion. This liability takes into account certain events related to the litigation and investigations arising out of the incident. There are loss contingencies related to the Macondo well incident that we believe are reasonably possible and for which we do not believe a reasonable estimate can be made. These contingencies could increase the liabilities we ultimately recognize. As of June 30, 2012, we have also recognized an asset of $235 million associated with the portion of our estimated losses that we believe is recoverable from insurance primarily related to personal injury and fatality claims of our crew and vendors. Although we have available policy limits that could result in additional amounts recoverable from insurance, recovery of such additional amounts is not probable and we are not currently able to estimate such amounts (see “—Insurance coverage”). Our estimates involve a significant amount of judgment. As a result of new information or future developments, we may adjust our estimated loss contingencies arising out of the Macondo well incident or our estimated recoveries from insurance, and the resulting losses could have a material adverse effect on our consolidated statement of financial position, results of operations and cash flows. As of December 31, 2011, the amount of the estimated liability was $1.2 billion, and the estimated recoverable amount was $237 million.

Many of the Macondo well related claims are pending in the U.S. District Court, Eastern District of Louisiana (the “MDL Court”). The first phase of a three-phase trial was scheduled to commence on March 5, 2012. However, on March 2, 2012, BP and the Plaintiff’s Steering Committee (the “PSC”) announced that they had agreed to a partial settlement related primarily to private party environmental and economic loss claims as well as response effort related claims (the “BP/PSC Settlement”). The BP/PSC Settlement agreement was filed with the MDL Court on April 28, 2012 and provides that (a) the BP/PSC Settlement is subject to court approvals, (b) to the extent permitted by law, BP will assign to the settlement class certain of BP’s claims, rights and recoveries against us for damages with protections such that the settlement class is barred from collecting any amounts from us unless it is finally determined that we cannot recover such amounts from BP, and (c) the settlement class releases all claims for compensatory damages against us but purports to retain claims for punitive damages against us. On May 2, 2012, the MDL Court granted preliminary approval of the economic and property damage class settlement between BP and the PSC and has scheduled a fairness hearing for approval of the settlement for November 8, 2012. After giving consideration to the BP/PSC Settlement, the MDL Court ordered that the first phase of the trial, at which liability will be determined, be rescheduled for January 14, 2013. There can be no assurance as to the outcome of the trial, as to the timing of any phase of trial, that we will not enter into a settlement as to some or all of the matters related to the Macondo well incident, including those to be determined at a trial, or the timing or terms of any such settlement.

In April 2011, several defendants in the Macondo well litigation before the Multi-District Litigation Panel (the “MDL”) filed cross-claims or third-party claims against us and certain of our subsidiaries, and other defendants. BP filed a claim seeking contribution under the Oil Pollution Act of 1990 (“OPA”) and maritime law, subrogation and claimed breach of contract, unseaworthiness, negligence and gross negligence. BP also sought a declaration that it is not liable in contribution, indemnification, or otherwise to us. Anadarko Petroleum Corporation (“Anadarko”), which owned a 25 percent non-operating interest in the Macondo well, asserted claims of negligence, gross negligence, and willful misconduct and is seeking indemnity under state and maritime law and contribution under maritime and state law as well as OPA. MOEX Offshore 2007 LLC (“MOEX”), which owns a 10 percent non-operating interest in the Macondo well, filed claims of negligence under state and maritime law, gross negligence under state law, gross negligence and willful misconduct under maritime law and is seeking indemnity under state and maritime law and contribution under maritime law and OPA. Cameron International Corporation (“Cameron”), the manufacturer and designer of the blowout preventer, asserted multiple claims for contractual indemnity and declarations regarding contractual obligations under various contracts and quotes and is also seeking non-contractual indemnity and contribution under maritime law and OPA. As part of the BP/PSC Settlement, one or more of these claims against us and certain of our subsidiaries may be assigned to the PSC settlement class. Halliburton Company (“Halliburton”), which provided cementing and mud-logging services to the operator, filed a claim seeking contribution and indemnity under maritime law, contractual indemnity and alleging negligence and gross negligence. Additionally, certain other third parties filed claims for indemnity and contribution.

On April 20, 2011, we filed cross-claims and counter-claims against BP, Halliburton, Cameron, Anadarko, MOEX, certain of these parties’ affiliates, the U.S. and certain other third parties. We seek indemnity, contribution (including contribution under OPA), and subrogation under OPA, and we have asserted claims for breach of warranty of workmanlike performance, strict liability for manufacturing and design defect, breach of express contract, and damages for the difference between the fair market value of Deepwater Horizon and the amount received from insurance proceeds. We are not pursuing arbitration on the key contractual issues with BP; instead, we are relying on the court to resolve the disputes. With regard to the U.S., we are not currently seeking recovery of monetary damages, but rather a declaration regarding relative fault and contribution via credit, setoff, or recoupment.

Notices of alleged non-compliance—The Department of the Interior’s Bureau of Safety and Environmental Enforcement issued four notices of alleged non-compliance with regulatory requirements to us on October 12, 2011. While we cannot predict or provide assurance as to the full outcome of these citations, they could result in the assessment of civil penalties. Our appeal is stayed by mutual agreement with the Department of Interior until a ruling is issued in the MDL.

Insurance coverage—At the time of the Macondo well incident, our excess liability insurance program offered aggregate insurance coverage of $950 million, excluding a $15 million deductible and a $50 million self-insured layer through our wholly owned captive insurance subsidiary. This excess liability insurance coverage consisted of a first and a second layer of $150 million each, a third and fourth layer of $200 million each and a fifth layer of $250 million. The first four excess layers have similar coverage and contractual terms, while the $250 million fifth layer is on a different policy form, which varies to some extent from the underlying coverage and contractual terms. Generally, we believe that the policy forms for all layers include coverage for personal injury and fatality claims of our crew and vendors, actual and compensatory damages, punitive damages and related legal defense costs and that the policy forms for the first four excess layers provide coverage for fines; however, we do not expect payments deemed to be criminal in nature to be covered by any of the layers.

In May 2010, we received notice from BP maintaining that it believes that it is entitled to additional insured status under our excess liability insurance program. Our insurers have also received notices from Anadarko and MOEX advising of their intent to preserve any rights they may have to our insurance policies as an additional insured under the drilling contract. In response, our wholly owned captive insurance subsidiary and our first four excess layer insurers filed declaratory judgment actions in the Houston Division of the U.S. District Court for the Southern District of Texas in May 2010 seeking a judgment declaring that they have limited additional insured obligations to BP, Anadarko and MOEX. We are parties to the declaratory judgment actions, which have been transferred to the MDL for discovery and other purposes in the MDL Court. On November 15, 2011, the MDL Court ruled that BP’s coverage rights are limited to the scope of our indemnification of BP in the drilling contract. A final judgment was entered against BP, Anadarko and MOEX, and BP has filed an appeal. While we cannot predict when the appellate court will hear arguments or the outcome of the appeal, we do not expect it to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. The appellate proceeding is in the briefing stage. We believe that additional insured coverage for BP, Anadarko or MOEX under the $250 million fifth layer of our insurance program is also limited to the scope of our indemnification of BP under the drilling contract.

Additionally, our first layer of excess insurers filed interpleader actions on June 17, 2011. The insurers contend that they face multiple, and potentially competing, claims to the relevant insurance proceeds. In these actions, the insurers effectively ask the court to manage disbursement of the funds to the alleged claimants, as appropriate, and discharge the insurers of any additional liability. The parties to the interpleader actions have executed a protocol agreement to facilitate the reimbursement and funding of settlements of personal injury and fatality claims of our crew and vendors using insurance funds and claims have been submitted to the court for review. The court has not yet issued any rulings and no payments have yet been received.

See Note 20—Subsequent Events.

Litigation—As of June 30, 2012, 374 actions or claims were pending against us, along with other unaffiliated defendants, in state and federal courts. Additionally, government agencies have initiated investigations into the Macondo well incident. We have categorized below the nature of the legal actions or claims. We are evaluating all claims and intend to vigorously defend any claims and pursue any and all defenses available. In addition, we believe we are entitled to contractual defense and indemnity for all wrongful death and personal injury claims made by non-employees and third-party subcontractors’ employees as well as all liabilities for pollution or contamination, other than for pollution or contamination originating on or above the surface of the water. See “—Contractual indemnity.”

Wrongful death and personal injury—As of June 30, 2012, we have been named, along with other unaffiliated defendants, in nine complaints that were pending in state and federal courts in Louisiana and Texas involving multiple plaintiffs that allege wrongful death and other personal injuries arising out of the Macondo well incident. Per the order of the MDL, these claims have been centralized for discovery purposes in the MDL Court. The complaints generally allege negligence and seek awards of unspecified economic damages and punitive damages. BP, MI-SWACO, Weatherford Ltd. and Cameron and certain of their affiliates, have, based on contractual arrangements, also made indemnity demands upon us with respect to personal injury and wrongful death claims asserted by our employees or representatives of our employees against these entities. See “—Contractual indemnity.”

Economic loss—As of June 30, 2012, we and certain of our subsidiaries were named, along with other unaffiliated defendants, in 155 pending individual complaints as well as 179 putative class-action complaints that were pending in the federal and state courts in Louisiana, Texas, Mississippi, Alabama, Georgia, Kentucky, South Carolina, Tennessee, Florida and possibly other courts. The complaints generally allege, among other things, potential economic losses as a result of environmental pollution arising out of the Macondo well incident and are based primarily on the OPA and state OPA analogues. The plaintiffs are generally seeking awards of unspecified economic, compensatory and punitive damages, as well as injunctive relief. These actions have been transferred to the MDL. See “—Contractual indemnity.”

Federal securities claims—Two federal securities law class actions were pending in the U.S. District Court, Southern District of New York, naming us and certain of our officers and directors as defendants. One of these actions, which was dismissed on March 20, 2012, generally alleged violations of Section 10(b) of the Securities Exchange Act of 1934 (the “Exchange Act”), Rule 10b-5, as promulgated under the Exchange Act, and Section 20(a) of the Exchange Act in connection with the Macondo well incident. The plaintiffs sought awards of unspecified economic damages, including damages resulting from the decline in our stock price after the Macondo well incident. The plaintiffs chose not to file an appeal, and this case is now closed. The other action, which is still pending, was filed by a former GlobalSantaFe Corporation shareholder, alleging that the joint proxy statement related to the GlobalSantaFe Corporation shareholder meeting in connection with our merger with GlobalSantaFe Corporation violated Section 14(a) of the Exchange Act, Rule 14a-9 promulgated thereunder and Section 20(a) of the Exchange Act. The plaintiff claims that GlobalSantaFe Corporation shareholders received inadequate consideration for their shares as a result of the alleged violations and seeks rescissory and compensatory damages. The defendants filed a motion to dismiss that resulted in the dismissal of one of two plaintiffs on March 30, 2012 and the subsequent filing of an amended complaint. A motion to dismiss the remaining named plaintiff is pending.

Other federal statutes—Several of the claimants have made assertions under the statutes, including the Clean Water Act, the Endangered Species Act, the Migratory Bird Treaty Act, the Clean Air Act, the Comprehensive Environmental Response Compensation and Liability Act and the Emergency Planning and Community Right-to-Know Act.

Shareholder derivative claims—In June 2010, two shareholder derivative suits were filed by our shareholders naming us as a nominal defendant and certain of our officers and directors as defendants in the District Courts of the State of Texas. These cases have been consolidated in state court in Harris County, Texas. Plaintiffs filed an amended consolidated complaint on June 25, 2012, alleging breach of fiduciary duty, unjust enrichment, and waste of corporate assets in connection with the Macondo well incident. The plaintiffs are generally seeking, on our behalf, restitution and disgorgement of all profits, benefits and other compensation from the defendants, as well as injunctive relief. Defendants expect to file a motion to dismiss in August 2012.

U.S. Department of Justice claims—On December 15, 2010, the U.S. Department of Justice (“DOJ”) filed a civil lawsuit against us and other unaffiliated defendants. The complaint alleges violations under OPA and the Clean Water Act, including claims for per barrel civil penalties of up to $1,100 per barrel or up to $4,300 per barrel if gross negligence or willful misconduct is established, and the DOJ reserved its rights to amend the complaint to add new claims and defendants. The U.S. government has estimated that up to 4.1 million barrels of oil were discharged and subject to penalties. The complaint asserts that all defendants named are jointly and severally liable for all removal costs and damages resulting from the Macondo well incident. On December 6, 2011, the DOJ filed a motion for partial summary judgment seeking a ruling that we were jointly and severely liable under OPA, and liable for civil penalties under the Clean Water Act, for all of the discharges from the Macondo well on the theory that discharges not only came from the well but also from the blowout preventer and riser, appurtenances of Deepwater Horizon.

On January 9, 2012, we filed our opposition to the motion and filed a cross-motion for partial summary judgment seeking a ruling that we are not liable for the subsurface discharge of hydrocarbons. On February 22, 2012, the MDL Court ruled that we are not liable as a responsible party for damages under OPA with respect to the below surface discharges from the Macondo well. The court also ruled that the below surface discharge was discharged from the well facility, and not from the Deepwater Horizon vessel, within the meaning of the Clean Water Act, and that we therefore are not liable for such discharges as an owner of the vessel under the Clean Water Act. However, the court ruled that the issue of whether we could be held liable for such discharge under the Clean Water Act as an “operator” of the well facility could not be resolved on summary judgment. The court did not determine whether we could be liable for removal costs under OPA, or the extent of such removal costs.

In addition to the civil complaint, the DOJ served us with civil investigative demands on December 8, 2010. These demands were part of an investigation by the DOJ to determine if we made false claims, or false statements in support of claims, in connection with the operator’s acquisition of the leasehold interest in the Mississippi Canyon Block 252, Gulf of Mexico and drilling operations on Deepwater Horizon.

The DOJ is also conducting a criminal investigation into the Macondo well incident. On March 7, 2011, the DOJ announced the formation of a new task force to lead the criminal investigation. The task force served us with informal requests for documents in March 2011, and a grand jury issued a subpoena requesting documents from us on April 13, 2011. We have had a number of communications with the task force since that time, and the task force has made informal requests for additional information from us from time to time. The task force is investigating possible violations by us and certain unaffiliated parties of the Clean Water Act, the Migratory Bird Treaty Act, the Refuse Act, the Endangered Species Act, and the Seaman’s Manslaughter Act, among other federal statutes, and possible criminal liabilities including fines under those statutes and under the Alternative Fines Act. Under the Alternatives Fines Act, a corporate defendant convicted of a criminal offense may be subject to a fine in the amount of twice the gross pecuniary loss suffered by third parties as a result of the offense. If we are charged with or convicted of certain criminal offenses, we may be subject to suspension or debarment as a contractor or subcontractor on certain government contracts, including leases.

State and other government claims—In June 2010, the Louisiana Department of Environmental Quality (the “LDEQ”) issued a consolidated compliance order and notice of potential penalty to us and certain of our subsidiaries asking us to eliminate and remediate discharges of oil and other pollutants into waters and property located in the State of Louisiana, and to submit a plan and report in response to the order. In October 2010, the LDEQ rescinded its enforcement actions against us and our subsidiaries but reserved its rights to seek civil penalties for future violations of the Louisiana Environmental Quality Act.

In September 2010, the State of Louisiana filed a declaratory judgment seeking to designate us as a responsible party under OPA and the Louisiana Oil Spill Prevention and Response Act for the discharges emanating from the Macondo well.

Additionally, suits have been filed by the State of Alabama and the cities of Greenville, Evergreen, Georgiana and McKenzie, Alabama in the U.S. District Court, Middle District of Alabama; the Mexican States of Veracruz, Quintana Roo and Tamaulipas in the U.S. District Court, Western District of Texas; and the City of Panama City Beach, Florida in the U.S. District Court, Northern District of Florida. Suits were also filed by the City of New Orleans, by and on behalf of multiple Parishes, and by or on behalf of the Town of Grand Isle, Grand Isle Independent Levee District, the Town of Jean Lafitte, the Lafitte Area Independent Levee District, the City of Gretna, the City of Westwego, and the City of Harahan in the MDL Court. Additional suits were filed by or on behalf of other Parishes in the respective Parish courts and were removed to federal court. A local government master complaint also was filed in which cities, municipalities, and other local government entities can and have joined. Generally, these governmental entities allege economic losses under OPA and other statutory environmental state claims and also assert various common law state claims. The claims have been centralized in the MDL and will proceed in accordance with the MDL scheduling order. The city of Panama City Beach’s claim was voluntarily dismissed.

On August 26, 2011, the MDL Court ruled on the motion to dismiss certain economic loss claims. The court ruled that state law, both statutory and common law, is preempted by maritime law, notwithstanding OPA’s savings provisions. Accordingly, all claims brought under state law were dismissed. Secondly, general maritime law claims that do not allege physical damage to a proprietary interest were dismissed, unless the claim falls into the commercial fisherman exception. The court ruled that OPA claims for economic loss do not require physical damage to a proprietary interest. Third, the MDL Court ruled that presentment under OPA is a mandatory condition precedent to filing suit against a responsible party. Finally, the MDL Court ruled that claims for punitive damages may be available under general maritime law in claims against responsible parties and non-responsible parties. Certain Louisiana parishes have appealed portions of this ruling, and appellate action is in the briefing stage. We cannot predict when the appellate court will hear arguments or the outcome of the appeal.

The Mexican States’ OPA claims were dismissed for failure to demonstrate that recovery under OPA was authorized by treaty or executive agreement. This ruling may be appealed.

By letter dated May 5, 2010, the Attorneys General of the five Gulf Coast states of Alabama, Florida, Louisiana, Mississippi and Texas informed us that they intend to seek recovery of pollution clean-up costs and related damages arising from the Macondo well incident. In addition, by letter dated June 21, 2010, the Attorneys General of the 11 Atlantic Coast states of Connecticut, Delaware, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New York, North Carolina, Rhode Island and South Carolina informed us that their states have not sustained any damage from the Macondo well incident but they would like assurances that we will be responsible financially if damages are sustained. We responded to each letter from the Attorneys General and indicated that we intend to fulfill our obligations as a responsible party for any discharge of oil from Deepwater Horizon on or above the surface of the water, and we assume that the operator will similarly fulfill its obligations under OPA for discharges from the undersea well.

Wreck removal—By letter dated December 6, 2010, the U.S. Coast Guard requested us to formulate and submit a comprehensive oil removal plan to remove any diesel fuel contained in the sponsons and fuel tanks that can be recovered from Deepwater Horizon. We have conducted a survey of the rig wreckage and have confirmed that no diesel fuel remains on the rig. We have insurance coverage for wreck removal for up to 25 percent of Deepwater Horizon’s insured value, or $140 million, with any excess wreck removal liability generally covered to the extent of our remaining excess liability limits. The U.S. Coast Guard has not requested that we remove the rig wreckage from the sea floor.

Contractual indemnity—Under our drilling contract for Deepwater Horizon, the operator has agreed, among other things, to assume full responsibility for and defend, release and indemnify us from any loss, expense, claim, fine, penalty or liability for pollution or contamination, including control and removal thereof, arising out of or connected with operations under the contract other than for pollution or contamination originating on or above the surface of the water from hydrocarbons or other specified substances within the control and possession of the contractor, as to which we agreed to assume responsibility and protect, release and indemnify the operator. Although we do not believe it is applicable to the Macondo well incident, we also agreed to indemnify and defend the operator up to a limit of $15 million for claims for loss or damage to third parties arising from pollution caused by the rig while it is off the drilling location, while the rig is underway or during drive off or drift off of the rig from the drilling location. The operator has also agreed, among other things, (1) to defend, release and indemnify us against loss or damage to the reservoir, and loss of property rights to oil, gas and minerals below the surface of the earth and (2) to defend, release and indemnify us and bear the cost of bringing the well under control in the event of a blowout or other loss of control. We agreed to defend, release and indemnify the operator for personal injury and death of our employees, invitees and the employees of our subcontractors while the operator agreed to defend, release and indemnify us for personal injury and death of its employees, invitees and the employees of its other subcontractors, other than us. We have also agreed to defend, release and indemnify the operator for damages to the rig and equipment, including salvage or removal costs.

Although we believe we are entitled to contractual defense and indemnity, given the potential amounts involved in connection with the Macondo well incident, the operator has sought to avoid its indemnification obligations. In particular, the operator, in response to our request for indemnification, has generally reserved all of its rights and stated that it could not at this time conclude that it is obligated to indemnify us. In doing so, the operator has asserted that the facts are not sufficiently developed to determine who is responsible and has cited a variety of possible legal theories based upon the contract and facts still to be developed. We believe this reservation of rights is without justification and that the operator is required to honor its indemnification obligations contained in our contract and described above.

In April 2011, BP filed a claim seeking a declaration that it is not liable to us in contribution, indemnification, or otherwise. On November 1, 2011, we filed a motion for partial summary judgment, seeking enforcement of the indemnity obligations for pollution and civil fines and penalties contained in the drilling contract with BP. On January 26, 2012, the court ruled that the drilling contract requires BP to indemnify us for compensatory damages asserted by third parties against us related to pollution that did not originate on or above the surface of the water, even if the claim is the result of our strict liability, negligence, or gross negligence. The court also held that BP does not owe us indemnity to the extent that we are held liable for civil penalties under the Clean Water Act or for punitive damages. The court deferred ruling on BP’s argument that we breached the drilling contract or materially increased BP’s risk or prejudiced its rights so as to vitiate BP’s indemnity obligations. Our motion for partial summary judgment and the court’s ruling did not address the issue of contractual indemnity for criminal fines and penalties. The law generally considers contractual indemnity for criminal fines and penalties to be against public policy.

Other legal proceedings

Brazil Frade field incident—On or about November 7, 2011, oil was released from fissures in the ocean floor in the vicinity of a development well being drilled by Chevron off the coast of Rio de Janeiro in the Frade field with Sedco 706. The release was ultimately controlled, the well was plugged, and the released oil is being contained by Chevron.

On March 15, 2012, Chevron publicly announced that it had identified a new sheen in Frade field whose source was determined to be seepage from an 800-meter fissure 3 kilometers away from the location of the November incident. Chevron and the Brazilian National Agency of Petroleum have publicly stated that, while further studies are being conducted, the new seepage, which was estimated by Chevron, at the time, to be five liters, is now believed to be unrelated to the November incident.

On or about December 13, 2011, a federal prosecutor in the town of Campos in Rio de Janeiro State filed a civil public action against Chevron and us seeking BRL 20.0 billion, equivalent to approximately $10.0 billion, and seeking a preliminary and permanent injunction preventing Chevron and us from operating in Brazil. The prosecutor amended the requested injunction on December 15, 2011, to seek to prevent Chevron and us from conducting extraction or transportation activities in Brazil and to seek to require Chevron to stop the release and remediate its effects. On January 11, 2012, a judge of the federal court in Campos issued an order finding that the case should be transferred to the federal court in Rio de Janeiro. The prosecutor has appealed this jurisdictional decision, and that appeal remains pending. On February 24, 2012, the court in Rio de Janeiro issued an order denying the federal prosecutor’s request for a preliminary injunction. The prosecutor further appealed this decision, and a three-judge panel heard the appeal on May 8, 2012. See Note 20—Subsequent Events.

On March 28, 2012, the original trial court complaint was served on us. On May 24, 2012, we filed our responsive papers, in the form of a defense. The lawsuit will continue in the trial court, and there remains a risk that Brazilian authorities could temporarily or permanently enjoin us from further operations in Brazil.

On December 21, 2011, a federal police marshal investigating the release filed a report with the federal court in Rio de Janeiro State recommending the indictment of Chevron, us, and 17 individuals, five of whom are our employees. The report recommended indictment on four counts, three alleging environmental offenses and one alleging false statements by Chevron in connection with its cleanup efforts. The federal court in Rio de Janeiro State forwarded the report to the federal court in Campos for a decision on the proper jurisdiction for the matter. On March 16, 2012, the Campos federal prosecutor sought and obtained from a special duty judge in Rio de Janeiro injunctions against the 17 individuals preventing them from leaving the country without court permission and requiring the Campos court to obtain their passports. On March 21, 2012, the Campos prosecutor issued the recommended indictments against the two companies and the 17 individuals. The prosecutor requested that the defendants be enjoined from disposing of property and that bail be set at BRL 10 million for the companies and BRL 1 million for the individuals. The Campos court ruled that it does not have jurisdiction over the matter, and the file was transferred to the court in Rio de Janerio. On or about June 15, 2012, the Rio de Janeiro court amended the travel order to state that the individuals could receive their passports back and travel with prior notice to the court. The indictments must be approved by a court of competent jurisdiction to become effective. As of June 30, 2012, the court has not yet approved the indictments.

On March 27, 2012, the union of oil industry workers in Brazil, Federacao Unica dos Petroleiros (“FUP”), filed a civil lawsuit in federal court in Rio de Janeiro against Chevron and us alleging a number of claims, including negligence on our part, and seeking a permanent injunction enjoining our operations in Brazil. The lawsuit sought unspecified damages. On or about April 16, 2012, the court issued an order transferring this case to the same court in Rio de Janeiro in which the initial civil public action is pending. On or about May 1, 2012, the Rio de Janeiro court dismissed this lawsuit, without prejudice, as duplicative of the other civil lawsuits.

On or about April 3, 2012, the same federal prosecutor who filed the original civil public action and the criminal indictments filed a new civil lawsuit against Chevron and us in federal court in Campos. The lawsuit alleges the new seepage discovered in March 2012 is related to the November 2011 incident and release. The lawsuit seeks an additional BRL 20.0 billion in damages. On April 16, 2012, this case was transferred to Rio de Janeiro. On June 15, 2012, the Rio de Janeiro court held that the case was not related to the first civil lawsuit and will be assigned to a new court. We have not been served in this matter to date.

The drilling services and charter contracts between Chevron and us provide, among other things, for Chevron to indemnify and defend us for claims based on pollution or contamination originating from below the surface of the water, including claims for control or removal or property loss or damage, including but not limited to third-party claims and liabilities, with an excludable amount of $250,000 per occurrence if the claim arises from our negligence. We have submitted a claim for indemnity and defense to Chevron under these contracts. Chevron responded that our request was premature, and requested that we confirm our intent to indemnify and defend Chevron regarding alleged violations of safety regulations aboard Sedco 706 that have resulted in the issuance of notices of infractions and any other claims or liabilities that may fall within our legal obligations. Discussions between Chevron and us are ongoing.

We intend to defend ourselves vigorously against any claims that are brought based on the incident. While we cannot predict or provide assurance as to the final outcome of these proceedings, we do not expect it to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Asbestos Litigation—In 2004, several of our subsidiaries were named, along with numerous other unaffiliated defendants, in 21 complaints filed on behalf of 769 plaintiffs in the Circuit Courts of the State of Mississippi and which claimed injuries arising out of exposure to asbestos allegedly contained in drilling mud during these plaintiffs’ employment in drilling activities between 1965 and 1986. Each individual plaintiff was subsequently required to file a separate lawsuit, and the original 21 multi-plaintiff complaints were then dismissed by the Circuit Courts. The amended complaints resulted in two of our subsidiaries being named as direct defendants in seven cases each. We have or may have an indirect interest in an additional 12 cases, for a total of 26 cases of interest. The complaints generally allege that the defendants used or manufactured asbestos-containing drilling mud additives for use in connection with drilling operations and have included allegations of negligence, products liability, strict liability and claims allowed under the Jones Act and general maritime law. The plaintiffs generally seek awards of unspecified compensatory and punitive damages. In each of these cases, the complaints have named other unaffiliated defendant companies, including companies that allegedly manufactured the drilling-related products that contained asbestos. All of these cases are being governed for discovery and trial setting by a single Case Management Order entered by a Special Master appointed by the court to reside over all the cases, and none of the 14 cases in which we are a named defendant have been scheduled for trial or pre-trial discovery. The preliminary information available on these claims is not sufficient to determine if there is an identifiable period for alleged exposure to asbestos, whether any asbestos exposure in fact occurred, the vessels potentially involved in the claims, or the basis on which the plaintiffs would support claims that their injuries were related to exposure to asbestos. However, the initial evidence available would suggest that we would have significant defenses to liability and damages. None of our companies have manufactured or distributed drilling mud or additives for same, and the handling of such additives by one of our employees would be a relatively infrequent occurrence that likely would have involved a non-asbestos product. In 2011, the Special Master issued a ruling that a Jones Act employer defendant, such as us, cannot be sued for punitive damages, and this ruling has now been obtained in three of our 14 cases. To date, seven of the 769 cases have gone to trial against defendants who allegedly manufactured or distributed drilling mud additives. None of these cases have involved an individual Jones Act employer, and we have not been a defendant in any of these cases. Two of the cases resulted in defense verdicts, and one case ended with a hung jury. Four cases resulted in verdicts for the plaintiff. Because the jury awarded punitive damages, two of these cases resulted in a substantial verdict in favor of the plaintiff; however, both of these verdicts have since been vacated by the trial court. The first plaintiff verdict was vacated on the basis that the plaintiff failed to meet its burden of proof. While the court’s decision is consistent with our general evaluation of the strength of these cases, it is currently being reviewed on appeal. The second plaintiff verdict was vacated because the presiding judge was removed from hearing any asbestos cases due to a conflict of interest, but when this case ultimately went to trial earlier this year, it resulted in a defense verdict. The two remaining plaintiff verdicts are under appeal by the defendants. We intend to defend these lawsuits vigorously, although there can be no assurance as to the ultimate outcome. We historically have maintained broad liability insurance, although we are not certain whether insurance will cover the liabilities, if any, arising out of these claims. Based on our evaluation of the exposure to date, we do not expect the liability, if any, resulting from these claims to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

One of our subsidiaries was involved in lawsuits arising out of the subsidiary’s involvement in the design, construction and refurbishment of major industrial complexes. The operating assets of the subsidiary were sold and its operations discontinued in 1989, and the subsidiary has no remaining assets other than the insurance policies involved in its litigation, with its insurers and, either directly or indirectly as the beneficiary of a qualified settlement fund, funding from settlements with insurers, assigned rights from insurers and coverage-in-place settlement agreements with insurers, and funds received from the commutation of certain insurance policies. The subsidiary has been named as a defendant, along with numerous other companies, in lawsuits alleging bodily injury or personal injury as a result of exposure to asbestos. As of June 30, 2012, the subsidiary was a defendant in approximately 899 lawsuits, some of which include multiple plaintiffs, and we estimate that there are approximately 2,087 plaintiffs in these lawsuits. For many of these lawsuits, we have not been provided with sufficient information from the plaintiffs to determine whether all or some of the plaintiffs have claims against the subsidiary, the basis of any such claims, or the nature of their alleged injuries. The first of the asbestos-related lawsuits was filed against the subsidiary in 1990. Through June 30, 2012, the costs incurred to resolve claims, including both defense fees and expenses and settlement costs, have not been material, all known deductibles have been satisfied or are inapplicable, and the subsidiary’s defense fees and expenses and settlement costs have been met by insurance made available to the subsidiary. The subsidiary continues to be named as a defendant in additional lawsuits, and we cannot predict the number of additional cases in which it may be named a defendant nor can we predict the potential costs to resolve such additional cases or to resolve the pending cases. However, the subsidiary has in excess of $1.0 billion in insurance limits potentially available to the subsidiary. Although not all of the policies may be fully available due to the insolvency of certain insurers, we believe that the subsidiary will have sufficient funding from settlements and claims payments from insurers, assigned rights from insurers and coverage-in-place settlement agreements with insurers to respond to these claims. While we cannot predict or provide assurance as to the final outcome of these matters, we do not believe that the current value of the claims where we have been identified will have a material impact on our consolidated statement of financial position, results of operations or cash flows.

Rio de Janeiro tax assessment—In the third quarter of 2006, we received tax assessments of approximately $182 million from the state tax authorities of Rio de Janeiro in Brazil against one of our Brazilian subsidiaries for taxes on equipment imported into the state in connection with our operations. The assessments resulted from a preliminary finding by these authorities that our subsidiary’s record keeping practices were deficient. We currently believe that the substantial majority of these assessments are without merit. We filed an initial response with the Rio de Janeiro tax authorities on September 9, 2006 refuting these additional tax assessments. In September 2007, we received confirmation from the state tax authorities that they believe the additional tax assessments are valid, and as a result, we filed an appeal on September 27, 2007 to the state Taxpayer’s Council contesting these assessments. While we cannot predict or provide assurance as to the final outcome of these proceedings, we do not expect it to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Brazilian import license assessment—In the fourth quarter of 2010, one of our Brazilian subsidiaries received an assessment from the Brazilian federal tax authorities in Rio de Janeiro of approximately $234 million, including interest and penalties, based upon the alleged failure to timely apply for import licenses for certain equipment and for allegedly providing improper information on import license applications. We responded to the assessment on December 22, 2010, and we currently believe that a substantial majority of the assessment is without merit. While we cannot predict or provide assurance as to the final outcome of these proceedings, we do not expect it to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Other matters—We are involved in various tax matters and various regulatory matters. We are also involved in lawsuits relating to damage claims arising out of hurricanes Katrina and Rita, all of which are insured and which are not material to us. As of June 30, 2012, we were involved in a number of other lawsuits, including a dispute for municipal tax payments in Brazil and a dispute involving customs procedures in India, neither of which is material to us, and all of which have arisen in the ordinary course of our business. We do not expect the liability, if any, resulting from these other matters to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows. We cannot predict with certainty the outcome or effect of any of the litigation matters specifically described above or of any such other pending or threatened litigation. There can be no assurance that our beliefs or expectations as to the outcome or effect of any lawsuit or other litigation matter will prove correct and the eventual outcome of these matters could materially differ from management’s current estimates.

Other environmental matters

Hazardous waste disposal sites—We have certain potential liabilities under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”) and similar state acts regulating cleanup of various hazardous waste disposal sites, including those described below. CERCLA is intended to expedite the remediation of hazardous substances without regard to fault. Potentially responsible parties (“PRPs”) for each site include present and former owners and operators of, transporters to and generators of the substances at the site. Liability is strict and can be joint and several.

We have been named as a PRP in connection with a site located in Santa Fe Springs, California, known as the Waste Disposal, Inc. site. We and other PRPs have agreed with the U.S. Environmental Protection Agency (“EPA”) and the DOJ to settle our potential liabilities for this site by agreeing to perform the remaining remediation required by the EPA. The form of the agreement is a consent decree, which has been entered by the court. The parties to the settlement have entered into a participation agreement, which makes us liable for approximately eight percent of the remediation and related costs. The remediation is complete, and we believe our share of the future operation and maintenance costs of the site is not material. There are additional potential liabilities related to the site, but these cannot be quantified, and we have no reason at this time to believe that they will be material.

One of our subsidiaries has been ordered by the California Regional Water Quality Control Board (“CRWQCB”) to develop a testing plan for a site known as Campus 1000 Fremont in Alhambra, California. This site was formerly owned and operated by certain of our subsidiaries. It is presently owned by an unrelated party, which has received an order to test the property. We have also been advised that one or more of our subsidiaries is likely to be named by the EPA as a PRP for the San Gabriel Valley, Area 3, Superfund site, which includes this property. Testing has been completed at the property but no contaminants of concern were detected. In discussions with CRWQCB staff, we were advised of their intent to issue us a “no further action” letter but it has not yet been received. Based on the test results, we would contest any potential liability. We have no knowledge at this time of the potential cost of any remediation, who else will be named as PRPs, and whether in fact any of our subsidiaries is a responsible party. The subsidiaries in question do not own any operating assets and have limited ability to respond to any liabilities.

Resolutions of other claims by the EPA, the involved state agency or PRPs are at various stages of investigation. These investigations involve determinations of:

· the actual responsibility attributed to us and the other PRPs at the site;

· appropriate investigatory or remedial actions; and

· allocation of the costs of such activities among the PRPs and other site users.

Our ultimate financial responsibility in connection with those sites may depend on many factors, including:

· the volume and nature of material, if any, contributed to the site for which we are responsible;

· the number of other PRPs and their financial viability; and

· the remediation methods and technology to be used.

It is difficult to quantify with certainty the potential cost of these environmental matters, particularly in respect of remediation obligations. Nevertheless, based upon the information currently available, we believe that our ultimate liability arising from all environmental matters, including the liability for all other related pending legal proceedings, asserted legal claims and known potential legal claims which are likely to be asserted, is adequately accrued and should not have a material effect on our statement of financial position or results of operations. Estimated costs of future expenditures for environmental remediation obligations are not discounted to their present value.

Contamination litigation

On July 11, 2005, one of our subsidiaries was served with a lawsuit filed on behalf of three landowners in Louisiana in the 12th Judicial District Court for the Parish of Avoyelles, State of Louisiana. The lawsuit named 19 other defendants, all of which were alleged to have contaminated the plaintiffs’ property with naturally occurring radioactive material, produced water, drilling fluids, chlorides, hydrocarbons, heavy metals and other contaminants as a result of oil and gas exploration activities. Experts retained by the plaintiffs issued a report suggesting significant contamination in the area operated by the subsidiary and another codefendant (the “Co-Defendant”), and claimed that over $300 million would be required to properly remediate the contamination. The experts retained by the defendants conducted their own investigation and concluded that the remediation costs would amount to no more than $2.5 million. The Co-Defendant settled the actions with the three landowners (the “Settlement”). The Co-Defendant subsequently filed suit in 2008 against the subsidiary and certain of its insurers in the Court of Avoyelles Parish to determine their liability for the Settlement.

On March 11, 2010, the Co-Defendant filed a motion for leave to amend the pending litigation in Avoyelles Parish to add GlobalSantaFe Corporation, Transocean Worldwide Inc., its successor, and two other subsidiaries under the single business enterprise doctrine contained in Louisiana law, as well as various additional insurers. The single business enterprise doctrine is similar to corporate veil piercing doctrines. A subsequent amendment added a claim for abuse of process under Louisiana law for an earlier bankruptcy filed by the subsidiary in Delaware, which was ultimately dismissed by a bankruptcy court and various other actions undertaken by our subsidiary, GlobalSantaFe Corporation and Transocean Worldwide Inc. Judgment was granted on a motion in favor of the Co-Defendant on the single business enterprise claims on July 16, 2012.

A scheduling order has been entered in the Avoyelles Parish lawsuit and a jury trial is set on these matters for September 17, 2012. Discovery is ongoing. In addition to the motion on the single business enterprise claims, which was granted in favor of the Co-Defendant on July 16, 2012, various other motions for partial summary judgment have been filed by the subsidiary seeking to have certain claims of the Co-Defendant dismissed as prescribed under Louisiana law and to address insurance coverage for the claims. These other motions are scheduled to be heard on August 17, 2012.

We believe that the legal theories advanced by the Co-Defendant should not be applied against the subsidiary, GlobalSantaFe Corporation or Transocean Worldwide Inc. and the two other subsidiaries. We intend to continue to vigorously defend against any action taken in an attempt to impose liability under the theories discussed above or otherwise and believe there are good and valid defenses thereto. While we cannot predict or provide assurance as to the final outcome of these proceedings, we do not expect them to have a material adverse effect on our consolidated statement of financial position, results of operations or cash flows.

Retained risk

Our hull and machinery and excess liability insurance program consists of commercial market and captive insurance policies. We periodically evaluate our insurance limits and self-insured retentions. As of June 30, 2012, the insured value of our drilling rig fleet was approximately $31.7 billion, excluding our rigs under construction.

Hull and machinery coverage—Under the hull and machinery program, we generally maintain a $125 million per occurrence deductible, limited to a maximum of $200 million per policy period. Subject to the same shared deductible, we also have coverage for costs incurred to mitigate damage to a rig up to an amount equal to 25 percent of a rig’s insured value. Also subject to the same shared deductible, we have additional coverage for wreck removal for up to 25 percent of a rig’s insured value, with any excess generally covered to the extent of our remaining excess liability coverage described below. However, we generally retain the risk for all hull and machinery exposures for our Standard Jackups and swamp barge, which are self-insured through our wholly owned captive insurance company.

Excess liability coverage—We carry $775 million of commercial market excess liability coverage, exclusive of the deductibles and self-insured retention, noted below, which generally covers offshore risks such as personal injury, third-party property claims, and third-party non-crew claims, including wreck removal and pollution. Our excess liability coverage has (1) separate $10 million per occurrence deductibles on collision liability claims and (2) separate $5 million per occurrence deductibles on crew personal injury claims and on other third-party non-crew claims. Through our wholly owned captive insurance company, we have retained the risk of the primary $50 million excess liability coverage. In addition, we generally retain the risk for any liability losses in excess of $825 million.

Other insurance coverage—We also carry $100 million of additional insurance that generally covers expenses that would otherwise be assumed by the well owner, such as costs to control the well, redrill expenses and pollution from the well. This additional insurance provides coverage for such expenses in circumstances in which we have legal or contractual liability arising from our gross negligence or willful misconduct.

We have elected to self-insure operators extra expense coverage for ADTI. This coverage provides protection against expenses related to well control, pollution and redrill liability associated with blowouts. ADTI’s customers assume, and indemnify ADTI for, liability associated with blowouts in excess of a contractually agreed amount, generally $50 million.

We do not generally carry commercial market insurance coverage for loss of revenue unless it is contractually required. We do not generally carry commercial market insurance coverage for physical damage losses, including liability for wreck removal expenses, to our fleet caused by named windstorms in the U.S. Gulf of Mexico and war perils worldwide.

Letters of credit and surety bonds

We had outstanding letters of credit totaling $578 million and $650 million at June 30, 2012 and December 31, 2011, respectively, issued under various committed and uncommitted credit lines provided by several banks to guarantee various contract bidding, performance activities and customs obligations.

As is customary in the contract drilling business, we also have various surety bonds in place that secure customs obligations relating to the importation of our rigs and certain performance and other obligations. We had outstanding surety bonds totaling $12 million at June 30, 2012 and December 31, 2011.

- Definition

The entire disclosure for commitments and contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 14

-Paragraph 3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.25)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 825

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6449706&loc=d3e16207-108621

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-SubTopic 10

-Section 50

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14435-108349

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25287-109308

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9, 10, 11, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Redeemable Noncontrolling Interest

6 Months Ended

Jun. 30, 2012

Redeemable Noncontrolling Interest

Redeemable Noncontrolling Interest

Note 16—Redeemable Noncontrolling Interest

On February 29, 2012, Quantum exercised its rights under the put option agreement to exchange its interest in TPDI for our shares or cash, at its election. Based on the redemption value of Quantum’s interest as of that date, we adjusted the carrying amount of the noncontrolling interest and reclassified Quantum’s interest to other current liabilities with a corresponding adjustment in the amount of $106 million to retained earnings within shareholders’ equity. We measured the estimated fair value of Quantum’s interest using significant other observable inputs, representing a Level 2 fair value measurement.

On March 29, 2012, Quantum elected to exchange its interest in TPDI for our shares, net of Quantum’s share of TPDI’s indebtedness, as defined in the put option agreement. Quantum had the right, prior to closing of this exchange, to change its election to cash, net of Quantum’s share of TPDI’s indebtedness.

The carrying amount of Quantum’s interest was measured at its estimated fair value through settlement of the exchange transaction on May 31, 2012, resulting in an adjustment of $25 million to increase the liability with corresponding adjustments to other expense on our condensed consolidated statement of operations. On May 31, 2012, we issued 8,695,351 shares to Quantum in a non-cash exchange for its interest in TPDI to satisfy our obligation, resulting in an adjustment of $134 million and $233 million to shares and additional paid-in capital, respectively. The adjustment included the extinguishment of $148 million of TPDI Notes payable to Quantum and accrued and unpaid interest of $16 million. As a result of this transaction, TPDI became our wholly owned subsidiary.

In accordance with the terms of the put option agreement, the final cash settlement based on 50 percent of TPDI’s working capital at May 29, 2012 is due within 65 days of closing the transaction. At June 30, 2012, the carrying amount of our liability for the final cash settlement was $72 million, recorded in other current liabilities.

Until February 29, 2012, Quantum had the unilateral right, pursuant to a put option agreement, to exchange its 50 percent interest in TPDI for our shares or cash, at its election, at an amount based on an appraisal of the fair value of the drillships that are owned by TPDI, subject to certain adjustments. Accordingly, we presented Quantum’s interest as redeemable noncontrolling interest on our condensed consolidated balance sheets until Quantum exercised its rights under the put option agreement. Changes in redeemable noncontrolling interest were as follows (in millions):

	Six months ended June 30,
	2012			2011
Redeemable noncontrolling interest
Balance, beginning of period	$	116		$	41
Net income attributable to noncontrolling interest	13			27
Other comprehensive loss attributable to noncontrolling interest	—			(2		)
Fair value adjustment to redeemable noncontrolling interest	106			—
Reclassification to accumulated other comprehensive loss	17			—
Reclassification to other current liabilities	(252		)	—
Balance, end of period	$	—		$	66

Shareholders' Equity

6 Months Ended

Jun. 30, 2012

Shareholders' Equity

Shareholders' Equity

Note 17—Shareholders’ Equity

Distribution of qualifying additional paid-in capital—In May 2011, at our annual general meeting, our shareholders approved the distribution of additional paid-in capital in the form of a U.S. dollar denominated dividend of $3.16 per outstanding share, payable in four equal installments of $0.79 per outstanding share, subject to certain limitations. On June 15, 2011, we paid the first installment in the aggregate amount of $254 million to shareholders of record as of May 20, 2011. On March 21, 2012, we paid the final installment in the aggregate amount of $278 million to shareholders of record as of February 24, 2012.

Shares held by subsidiary—In December 2008, we issued 16 million of our shares to one of our subsidiaries for future use to satisfy our obligations to deliver shares in connection with awards granted under our incentive plans or other rights to acquire our shares. Our subsidiary held approximately 12 million shares at June 30, 2012 and December 31, 2011.

Accumulated other comprehensive loss—The changes in accumulated other comprehensive loss for the six months ended June 30, 2012 and 2011 were as follows (in millions):

	Three months ended June 30, 2012												Three months ended June 30, 2011
	Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments			Unrecognized gains (losses) on marketable securities			Total			Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments		Unrecognized gains (losses) on marketable securities			Total
Balance, beginning of period	$	(517	)	$	(12	)	$	(2	)	$	(531	)	$	(337	)	$	4	$	(2	)	$	(335	)
Other comprehensive income attributable to controlling interest	11			4			—			15			6			1		—			7
Balance, end of period	$	(506	)	$	(8	)	$	(2	)	$	(516	)	(331		)	$	5	$	(2	)	$	(328	)

	Six months ended June 30, 2012												Six months ended June 30, 2011
	Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments			Unrecognized gains (losses) on marketable securities			Total			Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments		Unrecognized gains (losses) on marketable securities			Total
Balance, beginning of period	$	(501	)	$	7		$	(2	)	$	(496	)	$	(335	)	$	5	$	(2	)	$	(332	)
Reclassification from redeemable noncontrolling interest	—			(17		)	—			(17		)	—			—		—			—
Other comprehensive income (loss) attributable to controlling interest	(5		)	2			—			(3		)	4			—		—			4
Balance, end of period	$	(506	)	$	(8	)	$	(2	)	$	(516	)	(331		)	$	5	$	(2	)	$	(328	)

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

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-Paragraph 1

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+ Details

Financial Instruments

6 Months Ended

Jun. 30, 2012

Financial Instruments

Financial Instruments

Note 18—Financial Instruments

The carrying amounts and fair values of our financial instruments were as follows (in millions):

	June 30, 2012				December 31, 2011
	Carrying amount		Fair value		Carrying amount		Fair value
Cash and cash equivalents	$	3,964	$	3,964	$	4,017	$	4,017
Accounts receivable	2,124		2,124		2,176		2,176
Notes receivable and working capital loan receivable	118		118		139		139
Restricted cash investments	857		902		929		970
Long-term debt, including current maturities	12,634		13,985		12,698		13,074
Long-term debt of consolidated variable interest entities, including current maturities	205		205		838		838
Derivative instruments, assets	12		12		36		36
Derivative instruments, liabilities	22		22		38		38

We estimated the fair value of each class of financial instruments, for which estimating fair value is practicable, by applying the following methods and assumptions:

Cash and cash equivalents—The carrying amount of cash and cash equivalents, which are stated at cost plus accrued interest, approximates fair value because of the short maturities of those instruments.

Accounts receivable—The carrying amount, net of valuation allowance, approximates fair value because of the short maturities of those instruments.

Notes receivable and working capital loan receivable—The aggregate carrying amount represents the amortized cost of our investments, which approximates the estimated fair value. We measured the estimated fair value using significant unobservable inputs, representing a Level 3 fair value measurement, including the credit ratings of the borrowers. At June 30, 2012, the aggregate carrying amount of our notes receivable and working capital loan receivable was $118 million, including $17 million and $101 million recorded in other current assets and other assets, respectively. At December 31, 2011, the aggregate carrying amount of our notes receivable and working capital loan receivable was $139 million, including $37 million and $102 million recorded in other current assets and other assets, respectively.

Restricted cash investments—The carrying amount of the Aker Restricted Cash Investments represents the amortized cost of our investment, which was at $817 million and $889 million at June 30, 2012 and December 31, 2011, respectively. We measured the estimated fair value of the Aker Restricted Investments using significant other observable inputs, representing a Level 2 fair value measurement. The estimated fair value of the Aker Restricted Cash Investments was $862 million and $930 million at June 30, 2012 and December 31, 2011, respectively.

The aggregate carrying amount of the restricted cash investments for the TPDI Credit Facilities and the ADDCL Credit Facilities approximates fair value due to the short term nature of the instruments in which the restricted cash investments are held. The aggregate carrying amount of the restricted cash investments for the TPDI Credit Facilities and the ADDCL Credit Facilities was $40 million at June 30, 2012 and December 31, 2011.

Debt—The aggregate carrying amount of our fixed-rate debt was $11.9 billion at June 30, 2012 and December 31, 2011. We measured the estimated fair value of our fixed-rate debt using significant other observable inputs, representing a Level 2 fair value measurement, including the terms and credit spreads for the instruments. The aggregate estimated fair value of our fixed-rate debt was $13.1 billion and $12.2 billion at June 30, 2012 and December 31, 2011, respectively.

The aggregate carrying amount of our variable-rate debt approximates fair value because the terms of those debt instruments include short-term interest rates and exclude penalties for prepayment. We measured the estimated fair value of our variable-rate debt using significant other observable inputs, representing a Level 2 fair value measurement, including the terms and credit spreads for the instruments. The aggregate carrying amount of our variable-rate debt was $777 million and $761 million at June 30, 2012 and December 31, 2011, respectively.

Debt of consolidated variable interest entities—The aggregate carrying amount of the variable-rate debt of our consolidated variable interest entities approximates fair value because the terms of those debt instruments include short-term interest rates and exclude penalties for prepayments. We measured the estimated fair value of the debt of our consolidated variable interest entities using significant other observable inputs, representing a Level 2 fair value measurement, including the terms and credit spreads of the instruments. The aggregate carrying amount of the variable-rate debt of our consolidated variable interest entities was $205 million and $838 million at June 30, 2012 and December 31, 2011, respectively.

Derivative instruments—The aggregate carrying amount of our derivative instruments represents the estimated fair value, measured using significant other observable inputs, representing a Level 2 fair value measurement, including the interest rates and terms of the instruments.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 3, 10, 14, 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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+ Details

Condensed Consolidating Financial Information

6 Months Ended

Jun. 30, 2012

Condensed Consolidating Financial Information

Condensed Consolidating Financial Information

Note 19—Condensed Consolidating Financial Information

Transocean Inc., a wholly owned subsidiary of Transocean Ltd., is the issuer of certain notes and debentures, which have been guaranteed by Transocean Ltd. Transocean Ltd. has also guaranteed borrowings under the Five-Year Revolving Credit Facility. Transocean Ltd.’s guarantee of debt securities of Transocean Inc. is full and unconditional. Transocean Ltd. is not subject to any significant restrictions on its ability to obtain funds by dividends, loans or capital distributions from its consolidated subsidiaries.

The following tables present condensed consolidating financial information for (a) Transocean Ltd. (the “Parent Guarantor”), (b) Transocean Inc. (the “Subsidiary Issuer”), and (c) the other direct and indirect wholly owned and partially owned subsidiaries of the Parent Guarantor (the “Other Subsidiaries”), none of which guarantee any indebtedness of the Subsidiary Issuer. The tables also include the consolidating adjustments necessary to present the condensed financial statements on a consolidated basis. The following condensed consolidating financial information may not necessarily be indicative of the results of operations, financial position or cash flows had the subsidiaries operated as independent entities (in millions):

	Three months ended June 30, 2012
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	2,581		$	(6	)	$	2,575
Cost and expenses	21			1			2,765			(6		)	2,781
Loss on impairment	—			—			(12		)	—			(12		)
Loss on disposal of assets, net	—			—			55			—			55
Operating loss	(21		)	(1		)	(141		)	—			(163		)

Other income (expense), net
Interest expense, net	(4		)	(139		)	(27		)	—			(170		)
Equity in earnings	(279		)	(186		)	—			465			—
Other, net	—			18			(24		)	—			(6		)
	(283		)	(307		)	(51		)	465			(176		)
Loss from continuing operations before income tax expense	(304		)	(308		)	(192		)	465			(339		)
Income tax benefit	—			—			(29		)	—			(29		)
Loss from continuing operations	(304		)	(308		)	(163		)	465			(310		)
Income from discontinued operations, net of tax	—			—			7			—			7

Net Loss	(304		)	(308		)	(156		)	465			(303		)
Net income attributable to noncontrolling interest	—			—			1			—			1
Net loss attributable to controlling interest	(304		)	(308		)	(157		)	465			(304		)

Other comprehensive income before income taxes	1			7			6			—			14
Income taxes related to other comprehensive income	—			—			1			—			1
Other comprehensive income, net of income taxes	1			7			7			—			15

Total comprehensive loss	(303		)	(301		)	(149		)	465			(288		)
Total comprehensive income attributable to noncontrolling interest	—			—			1			—			1
Total comprehensive loss attributable to controlling interest	$	(303	)	$	(301	)	$	(150	)	$	465		$	(289	)

	Six months ended June 30, 2012
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	4,923		$	(11	)	$	4,912
Cost and expenses	32			2			4,645			(11		)	4,668
Loss on impairment	—			—			(239		)	—			(239		)
Gain on disposal of assets, net	—			—			51			—			51
Operating income (loss)	(32		)	(2		)	90			—			56

Other income (expense), net
Interest expense, net	(7		)	(273		)	(55		)	—			(335		)
Equity in earnings	(255		)	(16		)	—			271			—
Other, net	—			9			(33		)	—			(24		)
	(262		)	(280		)	(88		)	271			(359		)
Income (loss) from continuing operations before income tax expense	(294		)	(282		)	2			271			(303		)
Income tax benefit	—			—			(12		)	—			(12		)
Income from continuing operations	(294		)	(282		)	14			271			(291		)
Loss from discontinued operations, net of tax	—			—			6			—			6

Net Income (loss)	(294		)	(282		)	20			271			(285		)
Net income attributable to noncontrolling interest	—			—			9			—			9
Net income (loss) attributable to controlling interest	(294		)	(282		)	11			271			(294		)

Other comprehensive income (loss) before income taxes	(4		)	—			3			—			(1		)
Income taxes related to other comprehensive income (loss)	—			—			(2		)	—			(2		)
Other comprehensive income (loss), net of income taxes	(4		)	—			1			—			(3		)

Total comprehensive income (loss)	(298		)	(282		)	21			271			(288		)
Total comprehensive income attributable to noncontrolling interest	—			—			9			—			9
Total comprehensive income (loss) attributable to controlling interest	$	(298	)	$	(282	)	$	12		$	271		$	(297	)

	Three months ended June 30, 2011
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	2,339		$	(5	)	$	2,334
Cost and expenses	14			1			1,943			(5		)	1,953
Loss on impairment	—			—			(25		)	—			(25		)
Loss on disposal of assets, net	—			—			(1		)	—			(1		)
Operating income (loss)	(14		)	(1		)	370			—			355

Other income (expense), net
Interest expense, net	—			(130		)	(12		)	—			(142		)
Equity in earnings	139			283			2			(422		)	2
Other, net	(1		)	(9		)	3			—			(7		)
	138			144			(7		)	(422		)	(147		)
Income from continuing operations before income tax expense	124			143			363			(422		)	208
Income tax expense	—			—			77			—			77
Income from continuing operations	124			143			286			(422		)	131
Income from discontinued operations, net of tax	—			—			2			—			2

Net income	124			143			288			(422		)	133
Net income attributable to noncontrolling interest	—			—			9			—			9
Net income attributable to controlling interest	124			143			279			(422		)	124

Other comprehensive income (loss) before income taxes	2			3			(4		)	—			1
Income taxes related to other comprehensive income (loss)	—			—			—			—			—
Other comprehensive income (loss), net of income taxes	2			3			(4		)	—			1

Total comprehensive income	126			146			284			(422		)	134
Total comprehensive income attributable to noncontrolling interest	—			—			3			—			3
Total comprehensive income attributable to controlling interest	$	126		$	146		$	281		$	(422	)	$	131

	Six months ended June 30, 2011
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	4,487		$	(9	)	$	4,478
Cost and expenses	24			2			3,734			(9		)	3,751
Loss on impairment	—			—			(25		)	—			(25		)
Gain on disposal of assets, net	—			—			7			—			7
Operating income (loss)	(24		)	(2		)	735			—			709

Other income (expense), net
Interest expense, net	—			(261		)	(11		)	—			(272		)
Equity in earnings	468			771			4			(1,239		)	4
Other, net	(1		)	(32		)	27			—			(6		)
	467			478			20			(1,239		)	(274		)
Income from continuing operations before income tax expense	443			476			755			(1,239		)	435
Income tax expense	—			—			143			—			143
Income from continuing operations	443			476			612			(1,239		)	292
Income from discontinued operations, net of tax	—			—			174			—			174

Net income	443			476			786			(1,239		)	466
Net income attributable to noncontrolling interest	—			—			23			—			23
Net income attributable to controlling interest	443			476			763			(1,239		)	443

Other comprehensive income (loss) before income taxes	(1		)	(2		)	7			—			4
Income taxes related to other comprehensive income (loss)	—			—			(2		)	—			(2		)
Other comprehensive income (loss), net of income taxes	(1		)	(2		)	5			—			2

Total comprehensive income	442			474			791			(1,239		)	468
Total comprehensive income attributable to noncontrolling interest	—			—			21			—			21
Total comprehensive income attributable to controlling interest	$	442		$	474		$	770		$	(1,239	)	$	447

	June 30, 2012
	Parent Guarantor		Subsidiary Issuer		Other Subsidiaries		Consolidating adjustments			Consolidated

Assets
Cash and cash equivalents	$	19	$	2,206	$	1,739	$	—		$	3,964
Other current assets	10		2,536		2,684		(1,827		)	3,403
Total current assets	29		4,742		4,423		(1,827		)	7,367

Property and equipment, net	1		—		22,206		—			22,207
Goodwill	—		—		3,099		—			3,099
Investment in affiliates	16,101		27,989		—		(44,090		)	—
Other assets	3		1,620		19,296		(19,150		)	1,769
Total assets	16,134		34,351		49,024		(65,067		)	34,442

Liabilities and equity
Debt due within one year	—		2,198		602		—			2,800
Other current liabilities	110		312		5,331		(1,827		)	3,926
Total current liabilities	110		2,510		5,933		(1,827		)	6,726

Long-term debt	370		16,191		12,628		(19,150		)	10,039
Other long-term liabilities	31		381		1,656		—			2,068
Total long-term liabilities	401		16,572		14,284		(19,150		)	12,107

Commitments and contingencies

Total equity	15,623		15,269		28,807		(44,090		)	15,609
Total liabilities and equity	$	16,134	$	34,351	$	49,024	$	(65,067	)	$	34,442

	December 31, 2011
	Parent Guarantor		Subsidiary Issuer		Other Subsidiaries		Consolidating adjustments			Consolidated

Assets
Cash and cash equivalents	$	3	$	2,793	$	1,221	$	—		$	4,017
Other current assets	8		784		4,465		(1,749		)	3,508
Total current assets	11		3,577		5,686		(1,749		)	7,525

Property and equipment, net	1		—		22,532		—			22,533
Goodwill	—		—		3,217		—			3,217
Investment in affiliates	16,439		27,646		—		(44,085		)	—
Other assets	—		1,368		19,065		(18,676		)	1,757
Total assets	16,451		32,591		50,500		(64,510		)	35,032

Liabilities and equity
Debt due within one year	—		1,693		494		—			2,187
Other current liabilities	294		367		4,429		(1,749		)	3,341
Total current liabilities	294		2,060		4,923		(1,749		)	5,528

Long-term debt	495		14,308		15,222		(18,676		)	11,349
Other long-term liabilities	25		439		1,948		—			2,412
Total long-term liabilities	520		14,747		17,170		(18,676		)	13,761

Commitments and contingencies
Redeemable noncontrolling interest	—		—		116		—			116

Total equity	15,637		15,784		28,291		(44,085		)	15,627
Total liabilities and equity	$	16,451	$	32,591	$	50,500	$	(64,510	)	$	35,032

	Six months ended June 30, 2012
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Cash flows from operating activities	$	(31	)	$	(570	)	$	1,600		$	—		$	999

Cash flows from investing activities
Capital expenditures	—			—			(496		)	—			(496		)
Proceeds from disposal of assets, net	—			—			185			—			185
Proceeds from disposal of discontinued operations, net	—			—			17			—			17
Investing activities with affiliates, net	—			(1,816		)	(2,269		)	4,085			—
Other, net	—			19			6			—			25
Net cash used in investing activities	—			(1,797		)	(2,557		)	4,085			(269		)

Cash flows from financing activities
Changes in short-term borrowings, net	—			—			(260		)	—			(260		)
Repayments of debt	—			(30		)	(290		)	—			(320		)
Proceeds from restricted cash investments	—			—			192			—			192
Deposits to restricted cash investments	—			—			(116		)	—			(116		)
Distribution of qualifying additional paid-in capital	(278		)	—			—			—			(278		)
Financing activities with affiliates, net	325			1,819			1,941			(4,085		)	—
Other, net	—			(9		)	8			—			(1		)
Net cash provided by (used in) financing activities	47			1,780			1,475			(4,085		)	(783		)

Net increase (decrease) in cash and cash equivalents	16			(587		)	518			—			(53		)
Cash and cash equivalents at beginning of period	3			2,793			1,221			—			4,017
Cash and cash equivalents at end of period	$	19		$	2,206		$	1,739		$	—		$	3,964

	Six months ended June 30, 2011
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Cash flows from operating activities	$	(24	)	$	(485	)	$	1,239		$	—		$	730

Cash flows from investing activities
Capital expenditures	—			—			(533		)	—			(533		)
Proceeds from disposal of assets, net	—			—			18			—			18
Proceeds from disposal of discontinued operations, net	—			—			259			—			259
Investing activities with affiliates, net	—			(268		)	(748		)	1,016			—
Other, net	—			(29		)	(4		)	—			(33		)
Net cash used in investing activities	—			(297		)	(1,008		)	1,016			(289		)

Cash flows from financing activities
Changes in short-term borrowings, net	—			56			—			—			56
Proceeds from debt	—						5			—			5
Repayments of debt	—			(177		)	(72		)	—			(249		)
Distribution of qualifying paid-in capital	(254		)	—			—			—			(254		)
Financing activities with affiliates, net	256			748			12			(1,016		)	—
Other, net	—			(4		)	—			—			(4		)
Net cash provided by (used in) financing activities	2			623			(55		)	(1,016		)	(446		)

Net increase (decrease) in cash and cash equivalents	(22		)	(159		)	176			—			(5		)
Cash and cash equivalents at beginning of period	38			2,041			1,275			—			3,354
Cash and cash equivalents at end of period	$	16		$	1,882		$	1,451		$	—		$	3,349

Subsequent Events

6 Months Ended

Jun. 30, 2012

Subsequent Events

Subsequent Events

Note 20—Subsequent Events

Drilling Fleet—Subsequent to June 30, 2012, we completed the sale of the Standard Jackup Trident 17. Also subsequent to June 30, 2012, we entered into agreements to sell the Deepwater Floater Discoverer 534 and the Standard Jackup GSF Rig 103, and we reclassified the drilling units and related equipment, having an aggregate carrying amount of $87 million, to assets held for sale.

Macondo well incident—insurance coverage—Our second layer of excess insurers filed an interpleader action on July 31, 2012. Like the interpleader actions filed by the first layer of excess insurers, the second layer of excess insurers contend that they face multiple, and potentially competing, claims to the relevant insurance proceeds. In this action, the insurers effectively ask the court to manage disbursement of the funds to the alleged claimants, as appropriate, and discharge the insurers of any additional liability. The court has not yet issued any rulings on this action.

Brazil Frade field incident—On July 31, 2012, trial resumed in the federal court in Rio de Janeiro on the order denying the federal prosecutor’s request for a preliminary injunction preventing Chevron and us from operating in Brazil. The reporting judge was not present; however, the remaining two members of the panel granted the preliminary injunction. The terms of the preliminary injunction have not been disclosed to us. The preliminary injunction cannot become effective until finalized by the reporting judge, which we expect will take until at least September 2012. We intend to defend ourselves vigorously against any claims that are brought based on the incident. While we cannot predict or provide assurance as to the final outcome of these proceedings, if the ruling is upheld, it could have a material adverse effect on our future consolidated statement of financial position, results of operations or cash flows.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2012

Significant Accounting Policies

Basis of presentation

Accounting estimates

Fair value measurements

Consolidation

Share-based compensation

Capitalized interest

Reclassifications

Subsequent events

Subsequent events—We evaluate subsequent events through the time of our filing on the date we issue our financial statements. See Note 20—Subsequent Events.

- Definition

Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 46

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02, 03

-Article 3A

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details

- Definition

Disclosure of accounting policy for stock option and stock incentive plans. This disclosure may include (1) the types of stock option or incentive plans sponsored by the entity (2) the groups that participate in (or are covered by) each plan (3) significant plan provisions and (4) how stock compensation is measured, and the methodologies and significant assumptions used to determine that measurement.

+ References+ Details

- Definition

Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.

+ References+ Details

Correction of Errors in Previously Reported Consolidated Financial Statements (Tables)

6 Months Ended

Jun. 30, 2012

Correction of Errors in Previously Reported Consolidated Financial Statements

Summary of correction of previously reported financial statements

	Three months ended						Six months ended			Years ended
	March 31, 2012			June 30, 2011			June 30, 2011			December 31, 2011			December 31, 2010

Legal and other costs	$	(37	)	$	(19	)	$	(30	)	$	(67	)	$	—
Repair and maintenance costs	—			(32		)	(48		)	11			(11		)
Income tax (expense) benefit	7			5			20			16			(4		)
Other immaterial adjustments, net	(25		)	15			24			9			(4		)
Net adjustment to income from continuing operations	(55		)	(31		)	(34		)	(31		)	(19		)
Net adjustment to income from discontinued operations, net of tax	14			—			(4		)	(14		)	—
Net adjustment to net income attributable to noncontrolling interest	9			—			16			16			(16		)
Net adjustment to net income attributable to controlling interest	$	(32	)	$	(31	)	$	(22	)	$	(29	)	$	(35	)

	Three months ended March 31, 2012
	Previously reported			Adjustments			As adjusted
Operating revenues
Contract drilling revenues	$	2,214		$	6		$	2,220
Other revenues	117			—			117
	2,331			6			2,337
Costs and expenses
Operating and maintenance	1,410			53			1,463
Depreciation and amortization	351			4			355
General and administrative	69			—			69
	1,830			57			1,887
Loss on impairment	(227		)	—			(227		)
Gain (loss) on disposal of assets, net	(4		)	—			(4		)
Operating income (loss)	270			(51		)	219

Other income (expense), net
Interest income	15			—			15
Interest expense, net of amounts capitalized	(180		)	—			(180		)
Other, net	(7		)	(11		)	(18		)
	(172		)	(11		)	(183		)
Income (loss) from continuing operations before income tax expense	98			(62		)	36
Income tax (benefit) expense	24			(7		)	17
Income (loss) from continuing operations	74			(55		)	19
Income (loss) from discontinued operations, net of tax	(15		)	14			(1		)

Net income (loss)	59			(41		)	18
Net income (loss) attributable to noncontrolling interest	17			(9		)	8
Net income (loss) attributable to controlling interest	$	42		$	(32	)	$	10

Earnings (loss) per share-basic
Earnings (loss) from continuing operations	$	0.16		$	(0.13	)	$	0.03
Earnings (loss) from discontinued operations	(0.04		)	0.04			—
Earnings (loss) per share	$	0.12		$	(0.09	)	$	0.03

Earnings (loss) per share-diluted
Earnings (loss) from continuing operations	$	0.16		$	(0.13	)	$	0.03
Earnings (loss) from discontinued operations	(0.04		)	0.04			—
Earnings (loss) per share	$	0.12		$	(0.09	)	$	0.03

	Three months ended June 30, 2011									Six months ended June 30, 2011
	Previously reported			Adjustments			As adjusted			Previously reported			Adjustments			As adjusted
Operating revenues
Contract drilling revenues	$	2,096		$	—		$	2,096		$	4,056		$	—		$	4,056
Other revenues	238			—			238			422			—			422
	2,334			—			2,334			4,478			—			4,478
Costs and expenses
Operating and maintenance	1,492			36			1,528			2,851			54			2,905
Depreciation and amortization	359			—			359			713			—			713
General and administrative	66			—			66			133			—			133
	1,917			36			1,953			3,697			54			3,751
Loss on impairment	(25		)	—			(25		)	(25		)	—			(25		)
Gain (loss) on disposal of assets, net	(1		)	—			(1		)	7			—			7
Operating income (loss)	391			(36		)	355			763			(54		)	709

Other income (expense), net
Interest income	5			—			5			20			—			20
Interest expense, net of amounts capitalized	(147		)	—			(147		)	(292		)	—			(292		)
Other, net	(5		)	—			(5		)	(2		)	—			(2		)
	(147		)	—			(147		)	(274		)	—			(274		)
Income (loss) from continuing operations before income tax expense	244			(36		)	208			489			(54		)	435
Income tax (benefit) expense	82			(5		)	77			163			(20		)	143
Income (loss) from continuing operations	162			(31		)	131			326			(34		)	292
Income (loss) from discontinued operations, net of tax	2			—			2			178			(4		)	174

Net income (loss)	164			(31		)	133			504			(38		)	466
Net income (loss) attributable to noncontrolling interest	9			—			9			39			(16		)	23
Net income (loss) attributable to controlling interest	$	155		$	(31	)	$	124		$	465		$	(22	)	$	443

Earnings (loss) per share-basic
Earnings (loss) from continuing operations	$	0.47		$	(0.09	)	$	0.38		$	0.89		$	(0.05	)	$	0.84
Earnings (loss) from discontinued operations	0.01			—			0.01			0.55			(0.01		)	0.54
Earnings (loss) per share	$	0.48		$	(0.09	)	$	0.39		$	1.44		$	(0.06	)	$	1.38

Earnings (loss) per share-diluted
Earnings (loss) from continuing operations	$	0.47		$	(0.09	)	$	0.38		$	0.89		$	(0.05	)	$	0.84
Earnings (loss) from discontinued operations	0.01			—			0.01			0.55			(0.01		)	0.54
Earnings (loss) per share	$	0.48		$	(0.09	)	$	0.39		$	1.44		$	(0.06	)	$	1.38

	Year ended December 31, 2011									Year ended December 31, 2010
	Previously reported			Adjustments			As adjusted			Previously reported			Adjustments			As adjusted
Operating revenues
Contract drilling revenues	$	8,380		$	(6	)	$	8,374		$	8,986		$	—		$	8,986
Other revenues	762			—			762			480			—			480
	9,142			(6		)	9,136			9,466			—			9,466
Costs and expenses
Operating and maintenance	6,956			45			7,001			5,074			15			5,089
Depreciation and amortization	1,449			(4		)	1,445			1,536			—			1,536
General and administrative	288			—			288			246			—			246
	8,693			41			8,734			6,856			15			6,871
Loss on impairment	(5,229		)	—			(5,229		)	(1,010		)	—			(1,010		)
Gain (loss) on disposal of assets, net	4			—			4			257			—			257
Operating income (loss)	(4,776		)	(47		)	(4,823		)	1,857			(15		)	1,842

Other income (expense), net
Interest income	44			—			44			23			—			23
Interest expense, net of amounts capitalized	(621		)	—			(621		)	(567		)	—			(567		)
Other, net	(81		)	—			(81		)	(23		)	—			(23		)
	(658		)	—			(658		)	(567		)	—			(567		)
Income (loss) from continuing operations before income tax expense	(5,434		)	(47		)	(5,481		)	1,290			(15		)	1,275
Income tax (benefit) expense	395			(16		)	379			336			4			340
Income (loss) from continuing operations	(5,829		)	(31		)	(5,860		)	954			(19		)	935
Income (loss) from discontinued operations, net of tax	197			(14		)	183			34			—			34

Net income (loss)	(5,632		)	(45		)	(5,677		)	988			(19		)	969
Net income (loss) attributable to noncontrolling interest	93			(16		)	77			27			16			43
Net income (loss) attributable to controlling interest	$	(5,725	)	$	(29	)	$	(5,754	)	$	961		$	(35	)	$	926

Earnings (loss) per share-basic
Earnings (loss) from continuing operations	$	(18.40	)	$	(0.05	)	$	(18.45	)	$	2.88		$	(0.11	)	$	2.77
Earnings (loss) from discontinued operations	0.61			(0.04		)	0.57			0.11			—			0.11
Earnings (loss) per share	$	(17.79	)	$	(0.09	)	$	(17.88	)	$	2.99		$	(0.11	)	$	2.88

Earnings (loss) per share-diluted
Earnings (loss) from continuing operations	$	(18.40	)	$	(0.05	)	$	(18.45	)	$	2.88		$	(0.11	)	$	2.77
Earnings (loss) from discontinued operations	0.61			(0.04		)	0.57			0.11			—			0.11
Earnings (loss) per share	$	(17.79	)	$	(0.09	)	$	(17.88	)	$	2.99		$	(0.11	)	$	2.88

	December 31, 2011									December 31, 2010
	Previously reported			Adjustments			As adjusted			Previously reported			Adjustments			As adjusted
Assets
Cash and cash equivalents	$	4,017		$	—		$	4,017		$	3,394		$	(40	)	$	3,354
Accounts receivable, net
Trade	2,049			—			2,049			1,653			—			1,653
Other	127			—			127			190			—			190
Materials and supplies, net	627			—			627			514			—			514
Deferred income taxes, net	142			—			142			115			—			115
Assets held for sale	26			—			26			—			—			—
Other current assets	621			(84		)	537			329			43			372
Total current assets	7,609			(84		)	7,525			6,195			3			6,198

Property and equipment	29,037			—			29,037			26,721			—			26,721
Property and equipment of consolidated variable interest entities	2,252			—			2,252			2,214			—			2,214
Less accumulated depreciation	8,760			(4		)	8,756			7,616			—			7,616
Property and equipment, net	22,529			4			22,533			21,319			—			21,319
Goodwill	3,205			12			3,217			8,132			—			8,132
Other assets	1,745			12			1,757			1,165			—			1,165
Total assets	$	35,088		$	(56	)	$	35,032		$	36,811		$	3		$	36,814

Liabilities and equity
Accounts payable	$	880		$	—		$	880		$	832		$	—		$	832
Accrued income taxes	89			—			89			109			—			109
Debt due within one year	1,942			—			1,942			1,917			—			1,917
Debt of consolidated variable interest entities due within one year	97			148			245			95			148			243
Other current liabilities	2,350			22			2,372			883			12			895
Total current liabilities	5,358			170			5,528			3,836			160			3,996

Long-term debt	10,756			—			10,756			8,354			—			8,354
Long-term debt of consolidated variable interest entities	741			(148		)	593			855			(148		)	707
Deferred income taxes, net	523			(4		)	519			575			10			585
Other long-term liabilities	1,903			(10		)	1,893			1,791			—			1,791
Total long-term liabilities	13,923			(162		)	13,761			11,575			(138		)	11,437

Commitments and contingencies
Redeemable noncontrolling interest	116			—			116			25			16			41

Shares	4,982			—			4,982			4,482			—			4,482
Additional paid-in capital	7,211			—			7,211			7,504			—			7,504
Treasury shares, at cost	(240		)	—			(240		)	(240		)	—			(240		)
Retained earnings	4,244			(64		)	4,180			9,969			(35		)	9,934
Accumulated other comprehensive loss	(496		)	—			(496		)	(332		)	—			(332		)
Total controlling interest shareholders’ equity	15,701			(64		)	15,637			21,383			(35		)	21,348
Noncontrolling interest	(10		)	—			(10		)	(8		)	—			(8		)
Total equity	15,691			(64		)	15,627			21,375			(35		)	21,340
Total liabilities and equity	$	35,088		$	(56	)	$	35,032		$	36,811		$	3		$	36,814

- Definition

Tabular disclosure of prior period adjustments to previously issued financial statements including (1) the effect of the correction on each financial statement line item and any per-share amounts affected for each prior period presented (2) the cumulative effect of the change on retained earnings or other appropriate components of equity or net assets in the statement of financial position, as of the beginning of the earliest period presented, and (3) the effect of the prior period adjustments (both gross and net of applicable income tax) on the net income of each prior period presented in the entity's annual report for the year in which the adjustments are made.

+ References+ Details

Variable Interest Entities (Tables)

6 Months Ended

Jun. 30, 2012

Variable Interest Entities

Carrying Amounts of Variable Interest Entities

	June 30, 2012						December 31, 2011
	Assets		Liabilities		Net carrying amount		Assets		Liabilities		Net carrying amount
Variable interest entity
TPDI	$	—	$	—	$	—	$	1,562	$	673	$	889
ADDCL	929		315		614		930		334		596
Total	$	929	$	315	$	614	$	2,492	$	1,007	$	1,485

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 167

-Paragraph 22E

-Appendix D

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 46R

-Paragraph 4

-Subparagraph g

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 167

-Paragraph 22B

-Appendix D

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 167

-Paragraph 23A

-Appendix D

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5710-111685

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 5A

-URI http://asc.fasb.org/extlink&oid=7880789&loc=SL6759159-111685

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5747-111685

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5728-111685

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=7880789&loc=SL6228884-111685

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Variable Interest Entity

-URI http://asc.fasb.org/extlink&oid=6528138

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 35

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 46R

-Paragraph 2, 14, 15, 16, 23, 24, 25, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 13: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 167

-Paragraph 24

-Appendix D

Reference 14: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS140-4/FIN46(R)-8

-Paragraph C4

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Business Combination (Tables)

6 Months Ended

Jun. 30, 2012

Business Combination

Schedule of pro forma combined operating results

	Three months ended June 30, 2011		Six months ended June 30, 2011
Operating revenues	$	2,438	$	4,682
Operating income	406		808
Income from continuing operations	$	175	$	339

Per share earnings from continuing operations
Basic	$	0.52	$	0.99
Diluted	$	0.52	$	0.99

- Definition

Tabular disclosure of pro forma results of operations for a material business acquisition or series of individually immaterial business acquisitions that are material in the aggregate.

+ References+ Details

Income Taxes (Tables)

6 Months Ended

Jun. 30, 2012

Income Taxes

Valuation allowance for non-current deferred tax assets

	June 30, 2012		December 31, 2011
Valuation allowance for non-current deferred tax assets	$	178	$	183

Schedule of unrecognized tax benefits, including related interest and penalties

	June 30, 2012		December 31, 2011
Unrecognized tax benefits, excluding interest and penalties	$	438	$	515
Interest and penalties	193		256
Unrecognized tax benefits, including interest and penalties	$	631	$	771

- Definition

Tabular disclosure of tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities (i.e., uncertain tax positions) and other types of income tax contingencies, including: (1) the policy on classification of interest and penalties; (2) a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of the period; the total amount(s) of: (3) unrecognized tax benefits that, if recognized, would affect the effective tax rate, and (4) interest and penalties recognized in each of the income statement and balance sheet; (5) for positions for which it is reasonably possible that the total amounts unrecognized will significantly change within 12 months of the reporting date the: (i) nature of the uncertainty, (ii) nature of the event that could occur that would cause the change, and (iii) an estimate of the range of the reasonably possible change or a statement that an estimate of the range cannot be made; and (6) a description of tax years that remain subject to examination by major tax jurisdictions.

+ References+ Details

- Definition

Tabular disclosure of valuation allowances to reduce deferred tax assets to net realizable value, including identification of the deferred tax asset more likely than not will not be fully realized and the corresponding amount of the valuation allowance.

+ References+ Details

Discontinued Operations (Tables)

6 Months Ended

Jun. 30, 2012

Discontinued Operations

Summarized results income statement, assets and liabilities of discontinued operations

	Three months ended June 30,						Six months ended June 30,
	2012			2011			2012			2011
Operating revenues	$	2		$	22		$	5		$	48
Costs and expenses	(3		)	(18		)	(5		)	(41		)
Loss on impairment (a)	—			—			(6		)	—
Gain on disposal of discontinued operations, net	10			—			10			169
Income from discontinued operations before income tax expense	9			4			4			176
Income tax benefit (expense)	(2		)	(2		)	2			(2		)
Income from discontinued operations, net of tax	$	7		$	2		$	6		$	174

	June 30, 2012		December 31, 2011
Assets
Oil and gas properties, net	$	5	$	24
Other related assets	2		2
Assets held for sale	$	7	$	26

Accounts receivable	$	1	$	6
Other assets	11		11
Other current assets	$	12	$	17

Liabilities
Accounts payable	$	1	$	3
Other liabilities	5		14
Other current liabilities	$	6	$	17

- Definition

Tabular disclosure of disposal groups, which may include the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the classification and carrying value of the assets and liabilities comprising the disposal group, and the segment in which the disposal group was reported. Also may include the amount of adjustments to amounts previously reported in discontinued operations such as resolution of contingencies arising from the disposal transaction or the operations of the component prior to disposal.

+ References+ Details

Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2012

Earnings Per Share

Earnings Per Share

	Three months ended June 30,									Six months ended June 30,
	2012					2011				2012					2011
	Basic			Diluted		Basic		Diluted		Basic			Diluted		Basic		Diluted
Numerator for earnings (loss) per share
Income (loss) from continuing operations attributable to controlling interest	$	(311	)	(311	)	122		122		$	(300	)	(300	)	269		269
Undistributed earnings allocable to participating securities	—			—		(1	)	(1	)	—			—		(2	)	(2	)
Income (loss) from continuing operations available to shareholders	$	(311	)	(311	)	121		121		$	(300	)	(300	)	267		267

Denominator for earnings (loss) per share
Weighted-average shares outstanding	353			353		320		320		352			352		319		319
Effect of stock options and other share-based awards	—			—		—		—		—			—		—		1
Weighted-average shares for per share calculation	353			353		320		320		352			352		319		320

Per share earnings (loss) from continuing operations	$	(0.88	)	(0.88	)	0.38		0.38		$	(0.85	)	(0.85	)	0.84		0.84

Drilling Fleet (Tables)

6 Months Ended

Jun. 30, 2012

Drilling Fleet

Actual capital expenditures and other capital additions, including capitalized interest

	Six months ended June 30,
	2012			2011
Construction work in progress, at beginning of period	$	1,395		$	1,484

Newbuild construction program
Transocean Ao Thai (a)	45			10
Transocean Honor (b)	35			76
Transocean Andaman (c)	26			70
Transocean Siam Driller (c)	26			70
Deepwater Asgard (d)	21			—
Deepwater Invictus (d)	13			—
Deepwater Champion (e)	—			76
Other construction projects	330			231
Total capital expenditures	496			533
Changes in accrued capital expenditures	32			(31		)

Property and equipment placed into service
Transocean Honor (b)	(262		)	—
Deepwater Champion (e)	—			(881		)
Other property and equipment	(341		)	(262		)
Construction work in progress, at end of period	$	1,320		$	843

(b) Transocean Honor, a PPL Pacific Class 400 design High-Specification Jackup, commenced operations in May 2012.

(e) Deepwater Champion, an Ultra-Deepwater drillship, commenced operations in May 2011.

Debt (Tables)

6 Months Ended

Jun. 30, 2012

Debt

Debt, net of unamortized discounts, premiums and fair value adjustments

	June 30, 2012						December 31, 2011
	Transocean Ltd. and subsidiaries		Consolidated variable interest entities		Consolidated total		Transocean Ltd. and subsidiaries		Consolidated variable interest entities		Consolidated total
5% Notes due February 2013	$	252	$	—	$	252	$	253	$	—	$	253
5.25% Senior Notes due March 2013 (a)	505		—		505		507		—		507
TPDI Credit Facilities due March 2015	438		—		438		—		473		473
4.95% Senior Notes due November 2015 (a)	1,121		—		1,121		1,120		—		1,120
Aker Revolving Credit and Term Loan Facility due December 2015	174		—		174		594		—		594
5.05% Senior Notes due December 2016 (a)	999		—		999		999		—		999
Callable Bonds due February 2016	265		—		265		267		—		267
ADDCL Credit Facilities due December 2017	—		205		205		—		217		217
Eksportfinans Loans due January 2018	815		—		815		884		—		884
6.00% Senior Notes due March 2018 (a)	998		—		998		998		—		998
7.375% Senior Notes due April 2018 (a)	247		—		247		247		—		247
TPDI Notes due October 2019	—		—		—		—		148		148
6.50% Senior Notes due November 2020 (a)	899		—		899		899		—		899
6.375% Senior Notes due December 2021 (a)	1,199		—		1,199		1,199		—		1,199
7.45% Notes due April 2027 (a)	97		—		97		97		—		97
8% Debentures due April 2027 (a)	57		—		57		57		—		57
7% Notes due June 2028	311		—		311		311		—		311
Capital lease contract due August 2029	667		—		667		676		—		676
7.5% Notes due April 2031 (a)	598		—		598		598		—		598
1.50% Series B Convertible Senior Notes due December 2037 (a)	—		—		—		30		—		30
1.50% Series C Convertible Senior Notes due December 2037 (a)	1,693		—		1,693		1,663		—		1,663
6.80% Senior Notes due March 2038 (a)	999		—		999		999		—		999
7.35% Senior Notes due December 2041 (a)	300		—		300		300		—		300
Total debt	12,634		205		12,839		12,698		838		13,536
Less debt due within one year
5% Notes due February 2013	252		—		252		—		—		—
5.25% Senior Notes due March 2013 (a)	505		—		505		—		—		—
TPDI Credit Facilities due March 2015	70		—		70		—		70		70
Aker Revolving Credit and Term Loan Facility due December 2015	90		—		90		90		—		90
ADDCL Credit Facilities due November 2017	—		28		28		—		27		27
Eksportfinans Loans due January 2018	142		—		142		142		—		142
TPDI Notes due October 2019	—		—		—		—		148		148
Capital lease contract due August 2029	20		—		20		17		—		17
1.50% Series B Convertible Senior Notes due December 2037 (a)	—		—		—		30		—		30
1.50% Series C Convertible Senior Notes due December 2037 (a)	1,693		—		1,693		1,663		—		1,663
Total debt due within one year	2,772		28		2,800		1,942		245		2,187
Total long-term debt	$	9,862	$	177	$	10,039	$	10,756	$	593	$	11,349

Scheduled maturities of debt

	Transocean Ltd. and subsidiaries		Consolidated variable interest entities		Consolidated total
Twelve months ending June 30,
2013	$	2,792	$	28	$	2,820
2014	316		29		345
2015	463		31		494
2016	1,519		61		1,580
2017	1,169		36		1,205
Thereafter	6,365		20		6,385
Total debt, excluding unamortized discounts, premiums and fair value adjustments	12,624		205		12,829
Total unamortized discounts, premiums and fair value adjustments, net	10		—		10
Total debt	$	12,634	$	205	$	12,839

Interest expense, excluding amortization of debt issue costs

	Three months ended June 30,				Six months ended June 30,
	2012		2011		2012		2011
Interest expense
Series B Convertible Senior Notes due 2037	$	—	$	20	$	—	$	40
Series C Convertible Senior Notes due 2037	22		21		43		41

Carrying amounts of liability components of outstanding convertible senior notes

	June 30, 2012							December 31, 2011
	Principal amount		Unamortized discount			Carrying amount		Principal amount		Unamortized discount			Carrying amount
Carrying amount of liability component
Series B Convertible Senior Notes due 2037	$	—	$	—		$	—	$	30	$	—		$	30
Series C Convertible Senior Notes due 2037	1,722		(29		)	1,693		1,722		(59		)	1,663

Carrying amounts of equity components of outstanding convertible senior notes

	June 30, 2012		December 31, 2011
Carrying amount of equity component
Series B Convertible Senior Notes due 2037	$	—	$	4
Series C Convertible Senior Notes due 2037	276		276

Derivatives and Hedging (Tables)

6 Months Ended

Jun. 30, 2012

Derivatives designated as hedging instruments

Derivatives designated as hedging and not designated as hedging instruments

Schedule of aggregate notional amounts and the weighted average interest rates associated with derivatives

	Pay					Receive
	Aggregate notional amount		Fixed or variable rate	Weighted average rate		Aggregate notional amount			Fixed or variable rate	Weighted average rate
Interest rate swaps, fair value hedges	$	750	variable	3.6	%	$	750		fixed	5.2	%
Interest rate swaps, cash flow hedges	$	420	fixed	2.4	%	$	420		variable	0.5	%
Cross-currency swaps, cash flow hedges	$	102	fixed	8.9	%	NOK		560	fixed	11.0	%

Schedule of effect on the entity's condensed consolidated statement of operations resulting from derivatives designated as cash flow hedges

		Three months ended June 30,				Six months ended June 30,
	Statement of operations classification	2012		2011		2012		2011
Loss associated with effective portion	Interest expense, net of amounts capitalized	$	2	$	3	$	3	$	5
Loss associated with effective portion	Other, net	4		—		—		—

Schedule of balance sheet classification and aggregate carrying amount of the entity's derivatives measured at fair value, including accrued interest

	Balance sheet classification	June 30, 2012		December 31, 2011
Interest rate swaps, fair value hedges	Other current assets	$	11	$	5
Interest rate swaps, fair value hedges	Other assets	—		31
Interest rate swaps, cash flow hedges	Other long-term liabilities	15		16
Cross-currency swaps, cash flow hedges	Other current assets	1		—
Cross-currency swaps, cash flow hedges	Other long-term liabilities	7		7

Derivative not designated as hedging instruments | Interest rate swaps

Derivatives designated as hedging and not designated as hedging instruments

Schedule of effect on the entity's condensed consolidated statement of operations resulting from derivatives designated as cash flow hedges

		Three months ended June 30,				Six months ended June 30,
	Statement of operations classification	2012		2011		2012		2011
Loss associated with undesignated interest rate swaps	Interest expense, net of amounts capitalized	$	—	$	—	$	1	$	—

Schedule of balance sheet classification and aggregate carrying amount of the entity's derivatives measured at fair value, including accrued interest

	Balance sheet classification	June 30, 2012		December 31, 2011
Interest rate swaps, undesignated	Other long-term liabilities	$	—	$	15

- Definition

Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges.

+ References+ Details

- Definition

Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.

+ References+ Details

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=7476318&loc=d3e41678-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=7476318&loc=d3e41620-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579240-113959

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=7476318&loc=d3e41641-113959

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=7476318&loc=d3e41638-113959

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(n)(2))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

+ Details

Postemployment Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2012

Postemployment Benefit Plans

Net Periodic Benefit Costs Before Tax

	Three months ended June 30, 2012											Three months ended June 30, 2011
	U.S. Plans			Non-U.S. Plans			OPEB Plans		Total			U.S. Plans			Non-U.S. Plans			OPEB Plans			Total
Net periodic benefit costs
Service cost	$	12		$	9		$	—	$	21		$	11		$	5		$	1		$	17
Interest cost	15			8			—		23			15			6			—			21
Expected return on plan assets	(16		)	(8		)	—		(24		)	(16		)	(7		)	—			(23		)
Settlements and curtailments	—			—			—		—			1			—			—			1
Actuarial losses, net	10			1			—		11			6			—			—			6
Prior service cost, net	(1		)	—			—		(1		)	(1		)	—			(1		)	(2		)
Transition obligation, net	—			—			—		—			—			1			—			1
Net periodic benefit costs	$	20		$	10		$	—	$	30		$	16		$	5		$	—		$	21

Funding contributions	$	100		$	9		$	1	$	110		$	55		$	6		$	2		$	63

	Six months ended June 30, 2012											Six months ended June 30, 2011
	U.S. Plans			Non-U.S. Plans			OPEB Plans		Total			U.S. Plans			Non-U.S. Plans			OPEB Plans			Total
Net periodic benefit costs
Service cost	$	24		$	16		$	—	$	40		$	22		$	10		$	1		$	33
Interest cost	29			13			1		43			29			11			1			41
Expected return on plan assets	(31		)	(13		)	—		(44		)	(32		)	(12		)	—			(44		)
Settlements and curtailments	2			—			—		2			1			—			—			1
Actuarial losses, net	20			2			—		22			12			—			—			12
Prior service cost, net	(1		)	—			—		(1		)	(1		)	—			(1		)	(2		)
Transition obligation, net	—			—			—		—			—			1			—			1
Net periodic benefit costs	$	43		$	18		$	1	$	62		$	31		$	10		$	1		$	42

Funding contributions	$	103		$	17		$	2	$	122		$	68		$	13		$	3		$	84

Redeemable Noncontrolling Interest (Tables)

6 Months Ended

Jun. 30, 2012

Redeemable Noncontrolling Interest

Changes in redeemable noncontrolling interest

	Six months ended June 30,
	2012			2011
Redeemable noncontrolling interest
Balance, beginning of period	$	116		$	41
Net income attributable to noncontrolling interest	13			27
Other comprehensive loss attributable to noncontrolling interest	—			(2		)
Fair value adjustment to redeemable noncontrolling interest	106			—
Reclassification to accumulated other comprehensive loss	17			—
Reclassification to other current liabilities	(252		)	—
Balance, end of period	$	—		$	66

- Definition

Tabular disclosure of redeemable noncontrolling interest (as defined) included in the statement of financial position as either a liability or temporary equity. As of the date of the statement of financial position, such redeemable noncontrolling interest is currently redeemable, as defined, for cash or other assets of the entity at (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number D-98

-Paragraph 44

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number D-98

-Paragraph 43

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number D-98

-Paragraph 40

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number D-98

-Paragraph 41

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number D-98

-Paragraph 42

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 25

-Appendix A

+ Details

Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2012

Shareholders' Equity

Changes in accumulated other comprehensive income

	Three months ended June 30, 2012												Three months ended June 30, 2011
	Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments			Unrecognized gains (losses) on marketable securities			Total			Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments		Unrecognized gains (losses) on marketable securities			Total
Balance, beginning of period	$	(517	)	$	(12	)	$	(2	)	$	(531	)	$	(337	)	$	4	$	(2	)	$	(335	)
Other comprehensive income attributable to controlling interest	11			4			—			15			6			1		—			7
Balance, end of period	$	(506	)	$	(8	)	$	(2	)	$	(516	)	(331		)	$	5	$	(2	)	$	(328	)

	Six months ended June 30, 2012												Six months ended June 30, 2011
	Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments			Unrecognized gains (losses) on marketable securities			Total			Unrecognized components of net periodic benefit costs			Unrecognized gains (losses) on derivative instruments		Unrecognized gains (losses) on marketable securities			Total
Balance, beginning of period	$	(501	)	$	7		$	(2	)	$	(496	)	$	(335	)	$	5	$	(2	)	$	(332	)
Reclassification from redeemable noncontrolling interest	—			(17		)	—			(17		)	—			—		—			—
Other comprehensive income (loss) attributable to controlling interest	(5		)	2			—			(3		)	4			—		—			4
Balance, end of period	$	(506	)	$	(8	)	$	(2	)	$	(516	)	(331		)	$	5	$	(2	)	$	(328	)

Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2012

Financial Instruments

Carrying amounts and fair values of the financial instruments

	June 30, 2012				December 31, 2011
	Carrying amount		Fair value		Carrying amount		Fair value
Cash and cash equivalents	$	3,964	$	3,964	$	4,017	$	4,017
Accounts receivable	2,124		2,124		2,176		2,176
Notes receivable and working capital loan receivable	118		118		139		139
Restricted cash investments	857		902		929		970
Long-term debt, including current maturities	12,634		13,985		12,698		13,074
Long-term debt of consolidated variable interest entities, including current maturities	205		205		838		838
Derivative instruments, assets	12		12		36		36
Derivative instruments, liabilities	22		22		38		38

- Definition

Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such certain disclosures about the financial instruments, assets, and liabilities include: (1) the fair value of the required items together with their carrying amounts (as appropriate) and (2) the methodology and assumptions used in developing such estimates of fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph c(2), d, e, f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph a, c(1), c(2), c(3), d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13467-108611

Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 30

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 14

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6447952&loc=d3e13220-108610

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 19

-Subparagraph a, b, c(1), d(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 15

-Subparagraph b-d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Condensed Consolidating Financial Information (Tables)

6 Months Ended

Jun. 30, 2012

Condensed Consolidating Financial Information

Schedule of condensed consolidating statement of operations

	Three months ended June 30, 2012
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	2,581		$	(6	)	$	2,575
Cost and expenses	21			1			2,765			(6		)	2,781
Loss on impairment	—			—			(12		)	—			(12		)
Loss on disposal of assets, net	—			—			55			—			55
Operating loss	(21		)	(1		)	(141		)	—			(163		)

Other income (expense), net
Interest expense, net	(4		)	(139		)	(27		)	—			(170		)
Equity in earnings	(279		)	(186		)	—			465			—
Other, net	—			18			(24		)	—			(6		)
	(283		)	(307		)	(51		)	465			(176		)
Loss from continuing operations before income tax expense	(304		)	(308		)	(192		)	465			(339		)
Income tax benefit	—			—			(29		)	—			(29		)
Loss from continuing operations	(304		)	(308		)	(163		)	465			(310		)
Income from discontinued operations, net of tax	—			—			7			—			7

Net Loss	(304		)	(308		)	(156		)	465			(303		)
Net income attributable to noncontrolling interest	—			—			1			—			1
Net loss attributable to controlling interest	(304		)	(308		)	(157		)	465			(304		)

Other comprehensive income before income taxes	1			7			6			—			14
Income taxes related to other comprehensive income	—			—			1			—			1
Other comprehensive income, net of income taxes	1			7			7			—			15

Total comprehensive loss	(303		)	(301		)	(149		)	465			(288		)
Total comprehensive income attributable to noncontrolling interest	—			—			1			—			1
Total comprehensive loss attributable to controlling interest	$	(303	)	$	(301	)	$	(150	)	$	465		$	(289	)

	Six months ended June 30, 2012
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	4,923		$	(11	)	$	4,912
Cost and expenses	32			2			4,645			(11		)	4,668
Loss on impairment	—			—			(239		)	—			(239		)
Gain on disposal of assets, net	—			—			51			—			51
Operating income (loss)	(32		)	(2		)	90			—			56

Other income (expense), net
Interest expense, net	(7		)	(273		)	(55		)	—			(335		)
Equity in earnings	(255		)	(16		)	—			271			—
Other, net	—			9			(33		)	—			(24		)
	(262		)	(280		)	(88		)	271			(359		)
Income (loss) from continuing operations before income tax expense	(294		)	(282		)	2			271			(303		)
Income tax benefit	—			—			(12		)	—			(12		)
Income from continuing operations	(294		)	(282		)	14			271			(291		)
Loss from discontinued operations, net of tax	—			—			6			—			6

Net Income (loss)	(294		)	(282		)	20			271			(285		)
Net income attributable to noncontrolling interest	—			—			9			—			9
Net income (loss) attributable to controlling interest	(294		)	(282		)	11			271			(294		)

Other comprehensive income (loss) before income taxes	(4		)	—			3			—			(1		)
Income taxes related to other comprehensive income (loss)	—			—			(2		)	—			(2		)
Other comprehensive income (loss), net of income taxes	(4		)	—			1			—			(3		)

Total comprehensive income (loss)	(298		)	(282		)	21			271			(288		)
Total comprehensive income attributable to noncontrolling interest	—			—			9			—			9
Total comprehensive income (loss) attributable to controlling interest	$	(298	)	$	(282	)	$	12		$	271		$	(297	)

	Three months ended June 30, 2011
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	2,339		$	(5	)	$	2,334
Cost and expenses	14			1			1,943			(5		)	1,953
Loss on impairment	—			—			(25		)	—			(25		)
Loss on disposal of assets, net	—			—			(1		)	—			(1		)
Operating income (loss)	(14		)	(1		)	370			—			355

Other income (expense), net
Interest expense, net	—			(130		)	(12		)	—			(142		)
Equity in earnings	139			283			2			(422		)	2
Other, net	(1		)	(9		)	3			—			(7		)
	138			144			(7		)	(422		)	(147		)
Income from continuing operations before income tax expense	124			143			363			(422		)	208
Income tax expense	—			—			77			—			77
Income from continuing operations	124			143			286			(422		)	131
Income from discontinued operations, net of tax	—			—			2			—			2

Net income	124			143			288			(422		)	133
Net income attributable to noncontrolling interest	—			—			9			—			9
Net income attributable to controlling interest	124			143			279			(422		)	124

Other comprehensive income (loss) before income taxes	2			3			(4		)	—			1
Income taxes related to other comprehensive income (loss)	—			—			—			—			—
Other comprehensive income (loss), net of income taxes	2			3			(4		)	—			1

Total comprehensive income	126			146			284			(422		)	134
Total comprehensive income attributable to noncontrolling interest	—			—			3			—			3
Total comprehensive income attributable to controlling interest	$	126		$	146		$	281		$	(422	)	$	131

	Six months ended June 30, 2011
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Operating revenues	$	—		$	—		$	4,487		$	(9	)	$	4,478
Cost and expenses	24			2			3,734			(9		)	3,751
Loss on impairment	—			—			(25		)	—			(25		)
Gain on disposal of assets, net	—			—			7			—			7
Operating income (loss)	(24		)	(2		)	735			—			709

Other income (expense), net
Interest expense, net	—			(261		)	(11		)	—			(272		)
Equity in earnings	468			771			4			(1,239		)	4
Other, net	(1		)	(32		)	27			—			(6		)
	467			478			20			(1,239		)	(274		)
Income from continuing operations before income tax expense	443			476			755			(1,239		)	435
Income tax expense	—			—			143			—			143
Income from continuing operations	443			476			612			(1,239		)	292
Income from discontinued operations, net of tax	—			—			174			—			174

Net income	443			476			786			(1,239		)	466
Net income attributable to noncontrolling interest	—			—			23			—			23
Net income attributable to controlling interest	443			476			763			(1,239		)	443

Other comprehensive income (loss) before income taxes	(1		)	(2		)	7			—			4
Income taxes related to other comprehensive income (loss)	—			—			(2		)	—			(2		)
Other comprehensive income (loss), net of income taxes	(1		)	(2		)	5			—			2

Total comprehensive income	442			474			791			(1,239		)	468
Total comprehensive income attributable to noncontrolling interest	—			—			21			—			21
Total comprehensive income attributable to controlling interest	$	442		$	474		$	770		$	(1,239	)	$	447

Schedule of condensed consolidating balance sheet

	June 30, 2012
	Parent Guarantor		Subsidiary Issuer		Other Subsidiaries		Consolidating adjustments			Consolidated

Assets
Cash and cash equivalents	$	19	$	2,206	$	1,739	$	—		$	3,964
Other current assets	10		2,536		2,684		(1,827		)	3,403
Total current assets	29		4,742		4,423		(1,827		)	7,367

Property and equipment, net	1		—		22,206		—			22,207
Goodwill	—		—		3,099		—			3,099
Investment in affiliates	16,101		27,989		—		(44,090		)	—
Other assets	3		1,620		19,296		(19,150		)	1,769
Total assets	16,134		34,351		49,024		(65,067		)	34,442

Liabilities and equity
Debt due within one year	—		2,198		602		—			2,800
Other current liabilities	110		312		5,331		(1,827		)	3,926
Total current liabilities	110		2,510		5,933		(1,827		)	6,726

Long-term debt	370		16,191		12,628		(19,150		)	10,039
Other long-term liabilities	31		381		1,656		—			2,068
Total long-term liabilities	401		16,572		14,284		(19,150		)	12,107

Commitments and contingencies

Total equity	15,623		15,269		28,807		(44,090		)	15,609
Total liabilities and equity	$	16,134	$	34,351	$	49,024	$	(65,067	)	$	34,442

	December 31, 2011
	Parent Guarantor		Subsidiary Issuer		Other Subsidiaries		Consolidating adjustments			Consolidated

Assets
Cash and cash equivalents	$	3	$	2,793	$	1,221	$	—		$	4,017
Other current assets	8		784		4,465		(1,749		)	3,508
Total current assets	11		3,577		5,686		(1,749		)	7,525

Property and equipment, net	1		—		22,532		—			22,533
Goodwill	—		—		3,217		—			3,217
Investment in affiliates	16,439		27,646		—		(44,085		)	—
Other assets	—		1,368		19,065		(18,676		)	1,757
Total assets	16,451		32,591		50,500		(64,510		)	35,032

Liabilities and equity
Debt due within one year	—		1,693		494		—			2,187
Other current liabilities	294		367		4,429		(1,749		)	3,341
Total current liabilities	294		2,060		4,923		(1,749		)	5,528

Long-term debt	495		14,308		15,222		(18,676		)	11,349
Other long-term liabilities	25		439		1,948		—			2,412
Total long-term liabilities	520		14,747		17,170		(18,676		)	13,761

Commitments and contingencies
Redeemable noncontrolling interest	—		—		116		—			116

Total equity	15,637		15,784		28,291		(44,085		)	15,627
Total liabilities and equity	$	16,451	$	32,591	$	50,500	$	(64,510	)	$	35,032

Schedule of condensed consolidating statement of cash flows

	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Cash flows from operating activities	$	(31	)	$	(570	)	$	1,600		$	—		$	999

Cash flows from investing activities
Capital expenditures	—			—			(496		)	—			(496		)
Proceeds from disposal of assets, net	—			—			185			—			185
Proceeds from disposal of discontinued operations, net	—			—			17			—			17
Investing activities with affiliates, net	—			(1,816		)	(2,269		)	4,085			—
Other, net	—			19			6			—			25
Net cash used in investing activities	—			(1,797		)	(2,557		)	4,085			(269		)

Cash flows from financing activities
Changes in short-term borrowings, net	—			—			(260		)	—			(260		)
Repayments of debt	—			(30		)	(290		)	—			(320		)
Proceeds from restricted cash investments	—			—			192			—			192
Deposits to restricted cash investments	—			—			(116		)	—			(116		)
Distribution of qualifying additional paid-in capital	(278		)	—			—			—			(278		)
Financing activities with affiliates, net	325			1,819			1,941			(4,085		)	—
Other, net	—			(9		)	8			—			(1		)
Net cash provided by (used in) financing activities	47			1,780			1,475			(4,085		)	(783		)

Net increase (decrease) in cash and cash equivalents	16			(587		)	518			—			(53		)
Cash and cash equivalents at beginning of period	3			2,793			1,221			—			4,017
Cash and cash equivalents at end of period	$	19		$	2,206		$	1,739		$	—		$	3,964

	Six months ended June 30, 2011
	Parent Guarantor			Subsidiary Issuer			Other Subsidiaries			Consolidating adjustments			Consolidated

Cash flows from operating activities	$	(24	)	$	(485	)	$	1,239		$	—		$	730

Cash flows from investing activities
Capital expenditures	—			—			(533		)	—			(533		)
Proceeds from disposal of assets, net	—			—			18			—			18
Proceeds from disposal of discontinued operations, net	—			—			259			—			259
Investing activities with affiliates, net	—			(268		)	(748		)	1,016			—
Other, net	—			(29		)	(4		)	—			(33		)
Net cash used in investing activities	—			(297		)	(1,008		)	1,016			(289		)

Cash flows from financing activities
Changes in short-term borrowings, net	—			56			—			—			56
Proceeds from debt	—						5			—			5
Repayments of debt	—			(177		)	(72		)	—			(249		)
Distribution of qualifying paid-in capital	(254		)	—			—			—			(254		)
Financing activities with affiliates, net	256			748			12			(1,016		)	—
Other, net	—			(4		)	—			—			(4		)
Net cash provided by (used in) financing activities	2			623			(55		)	(1,016		)	(446		)

Net increase (decrease) in cash and cash equivalents	(22		)	(159		)	176			—			(5		)
Cash and cash equivalents at beginning of period	38			2,041			1,275			—			3,354
Cash and cash equivalents at end of period	$	16		$	1,882		$	1,451		$	—		$	3,349

Nature of Business (Details)	Jun. 30, 2012 drillingunit
Nature of Business
Number of mobile offshore drilling units	130
Number of High-Specification Floaters (in drilling units)	50
Number of Midwater Floaters (in drilling units)	25
Number of High-Specification Jackups (in drilling units)	10
Number of Standard Jackups (in drilling units)	44
Number of swamp barge (in drilling units)	1
Number of Ultra-Deepwater drillships under construction (in drilling units)	2
Number of High-Specification Jackups under construction (in drilling units)	3

Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Share-based compensation expense
Share-based compensation expense	$ 25	$ 27	$ 48	$ 54
Capitalized interest
Capitalized interest costs on construction work in progress	$ 12	$ 10	$ 25	$ 25

Correction of Errors in Previously Reported Consolidated Financial Statements (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Operating revenues
Contract drilling revenues	$ 2,390	$ 2,220	$ 2,096	$ 4,610	$ 4,056	$ 8,374	$ 8,986
Other revenues	185	117	238	302	422	762	480
Total operating revenues	2,575	2,337	2,334	4,912	4,478	9,136	9,466
Costs and expenses
Operating and maintenance	2,357	1,463	1,528	3,820	2,905	7,001	5,089
Depreciation and amortization	345	355	359	700	713	1,445	1,536
General and administrative	79	69	66	148	133	288	246
Total costs and expenses	2,781	1,887	1,953	4,668	3,751	8,734	6,871
Loss on impairment	(12)	(227)	(25)	(239)	(25)	(5,229)	(1,010)
Gain (loss) on disposal of assets, net	55	(4)	(1)	51	7	4	257
Operating income (loss)	(163)	219	355	56	709	(4,823)	1,842
Other income (expense), net
Interest income	13	15	5	28	20	44	23
Interest expense, net of amounts capitalized	(183)	(180)	(147)	(363)	(292)	(621)	(567)
Other, net	(6)	(18)	(5)	(24)	(2)	(81)	(23)
Total other income (expense), net	(176)	(183)	(147)	(359)	(274)	(658)	(567)
Income (loss) from continuing operations before income tax expense	(339)	36	208	(303)	435	(5,481)	1,275
Income tax (benefit) expense	(29)	17	77	(12)	143	379	340
Income (loss) from continuing operations	(310)	19	131	(291)	292	(5,860)	935
Income from discontinued operations, net of tax	7	(1)	2	6	174	183	34
Net income (loss)	(303)	18	133	(285)	466	(5,677)	969
Net income attributable to noncontrolling interest	1	8	9	9	23	77	43
Net income (loss) attributable to controlling interest	(304)	10	124	(294)	443	(5,754)	926
Earnings (loss) per share-basic
Earnings (loss) from continuing operations (in dollars per share)	$ (0.88)	$ 0.03	$ 0.38	$ (0.85)	$ 0.84	$ (18.45)	$ 2.77
Earnings from discontinued operations (in dollars per share)	$ 0.02		$ 0.01	$ 0.02	$ 0.54	$ 0.57	$ 0.11
Earnings (loss) per share (in dollars per share)	$ (0.86)	$ 0.03	$ 0.39	$ (0.83)	$ 1.38	$ (17.88)	$ 2.88
Earnings (loss) per share-diluted
Earnings (loss) from continuing operations (in dollars per share)	$ (0.88)	$ 0.03	$ 0.38	$ (0.85)	$ 0.84	$ (18.45)	$ 2.77
Earnings from discontinued operations (in dollars per share)	$ 0.02		$ 0.01	$ 0.02	$ 0.54	$ 0.57	$ 0.11
Earnings (loss) per share (in dollars per share)	$ (0.86)	$ 0.03	$ 0.39	$ (0.83)	$ 1.38	$ (17.88)	$ 2.88
Previously reported
Operating revenues
Contract drilling revenues		2,214	2,096		4,056	8,380	8,986
Other revenues		117	238		422	762	480
Total operating revenues		2,331	2,334		4,478	9,142	9,466
Costs and expenses
Operating and maintenance		1,410	1,492		2,851	6,956	5,074
Depreciation and amortization		351	359		713	1,449	1,536
General and administrative		69	66		133	288	246
Total costs and expenses		1,830	1,917		3,697	8,693	6,856
Loss on impairment		(227)	(25)		(25)	(5,229)	(1,010)
Gain (loss) on disposal of assets, net		(4)	(1)		7	4	257
Operating income (loss)		270	391		763	(4,776)	1,857
Other income (expense), net
Interest income		15	5		20	44	23
Interest expense, net of amounts capitalized		(180)	(147)		(292)	(621)	(567)
Other, net		(7)	(5)		(2)	(81)	(23)
Total other income (expense), net		(172)	(147)		(274)	(658)	(567)
Income (loss) from continuing operations before income tax expense		98	244		489	(5,434)	1,290
Income tax (benefit) expense		24	82		163	395	336
Income (loss) from continuing operations		74	162		326	(5,829)	954
Income from discontinued operations, net of tax		(15)	2		178	197	34
Net income (loss)		59	164		504	(5,632)	988
Net income attributable to noncontrolling interest		17	9		39	93	27
Net income (loss) attributable to controlling interest		42	155		465	(5,725)	961
Earnings (loss) per share-basic
Earnings (loss) from continuing operations (in dollars per share)		$ 0.16	$ 0.47		$ 0.89	$ (18.40)	$ 2.88
Earnings from discontinued operations (in dollars per share)		$ (0.04)	$ 0.01		$ 0.55	$ 0.61	$ 0.11
Earnings (loss) per share (in dollars per share)		$ 0.12	$ 0.48		$ 1.44	$ (17.79)	$ 2.99
Earnings (loss) per share-diluted
Earnings (loss) from continuing operations (in dollars per share)		$ 0.16	$ 0.47		$ 0.89	$ (18.40)	$ 2.88
Earnings from discontinued operations (in dollars per share)		$ (0.04)	$ 0.01		$ 0.55	$ 0.61	$ 0.11
Earnings (loss) per share (in dollars per share)		$ 0.12	$ 0.48		$ 1.44	$ (17.79)	$ 2.99
Adjustments
Summary of adjustments for increases and (decreases) to net income (loss) from continuing operations and net income (loss) attributable to controlling interest
Adjustments related to Legal and other costs account		(37)	(19)		(30)	(67)
Adjustments related to Repair and maintenance costs account			(32)		(48)	11	(11)
Adjustments related to Other immaterial adjustments, net account		(25)	15		24	9	(4)
Operating revenues
Contract drilling revenues		6				(6)
Total operating revenues		6				(6)
Costs and expenses
Operating and maintenance		53	36		54	45	15
Depreciation and amortization		4				(4)
Total costs and expenses		57	36		54	41	15
Operating income (loss)		(51)	(36)		(54)	(47)	(15)
Other income (expense), net
Other, net		(11)
Total other income (expense), net		(11)
Income (loss) from continuing operations before income tax expense		(62)	(36)		(54)	(47)	(15)
Income tax (benefit) expense		7	5		20	16	(4)
Income (loss) from continuing operations		(55)	(31)		(34)	(31)	(19)
Income from discontinued operations, net of tax		14			(4)	(14)
Net income (loss)		(41)	(31)		(38)	(45)	(19)
Net income attributable to noncontrolling interest		9			16	16	(16)
Net income (loss) attributable to controlling interest		$ (32)	$ (31)		$ (22)	$ (29)	$ (35)
Earnings (loss) per share-basic
Earnings (loss) from continuing operations (in dollars per share)		$ (0.13)	$ (0.09)		$ (0.05)	$ (0.05)	$ (0.11)
Earnings from discontinued operations (in dollars per share)		$ 0.04			$ (0.01)	$ (0.04)
Earnings (loss) per share (in dollars per share)		$ (0.09)	$ (0.09)		$ (0.06)	$ (0.09)	$ (0.11)
Earnings (loss) per share-diluted
Earnings (loss) from continuing operations (in dollars per share)		$ (0.13)	$ (0.09)		$ (0.05)	$ (0.05)	$ (0.11)
Earnings from discontinued operations (in dollars per share)		$ 0.04			$ (0.01)	$ (0.04)
Earnings (loss) per share (in dollars per share)		$ (0.09)	$ (0.09)		$ (0.06)	$ (0.09)	$ (0.11)

Correction of Error in Previously Reported Consolidated Financial Statements (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 3,964	$ 3,982	$ 4,017	$ 3,349	$ 3,772	$ 3,354
Trade			2,049			1,653
Other			127			190
Materials and supplies, net	676		627			514
Deferred income taxes, net	142		142			115
Assets held for sale	9		26
Other current assets	452		537			372
Total current assets	7,367		7,525			6,198
Property and equipment	30,559		29,037			26,721
Property and equipment of consolidated variable interest entities	813		2,252			2,214
Less accumulated depreciation	9,165		8,756			7,616
Property and equipment, net	22,207		22,533			21,319
Goodwill	3,099		3,217			8,132
Other assets	1,769		1,757			1,165
Total assets	34,442		35,032			36,814
Liabilities and equity
Accounts payable	917		880			832
Accrued income taxes	121		89			109
Debt due within one year	2,772		1,942			1,917
Debt of consolidated variable interest entities due within one year	28		245			243
Other current liabilities	2,888		2,372			895
Total current liabilities	6,726		5,528			3,996
Long-term debt	9,862		10,756			8,354
Long-term debt of consolidated variable interest entities	177		593			707
Deferred income taxes, net	487		519			585
Other long-term liabilities	1,581		1,893			1,791
Total long-term liabilities	12,107		13,761			11,437
Commitments and contingencies
Redeemable noncontrolling interest			116	66		41
Shares	5,127		4,982			4,482
Additional paid-in capital	7,472		7,211			7,504
Treasury shares, at cost, 2,863,267 held at June 30, 2012 and December 31, 2011	(240)		(240)			(240)
Retained earnings	3,780		4,180			9,934
Accumulated other comprehensive loss	(516)		(496)			(332)
Total controlling interest shareholders' equity	15,623		15,637			21,348
Noncontrolling interest	(14)		(10)			(8)
Total equity	15,609		15,627	20,816		21,340
Total liabilities and equity	34,442		35,032			36,814
Previously reported
Assets
Cash and cash equivalents			4,017			3,394
Trade			2,049			1,653
Other			127			190
Materials and supplies, net			627			514
Deferred income taxes, net			142			115
Assets held for sale			26
Other current assets			621			329
Total current assets			7,609			6,195
Property and equipment			29,037			26,721
Property and equipment of consolidated variable interest entities			2,252			2,214
Less accumulated depreciation			8,760			7,616
Property and equipment, net			22,529			21,319
Goodwill			3,205			8,132
Other assets			1,745			1,165
Total assets			35,088			36,811
Liabilities and equity
Accounts payable			880			832
Accrued income taxes			89			109
Debt due within one year			1,942			1,917
Debt of consolidated variable interest entities due within one year			97			95
Other current liabilities			2,350			883
Total current liabilities			5,358			3,836
Long-term debt			10,756			8,354
Long-term debt of consolidated variable interest entities			741			855
Deferred income taxes, net			523			575
Other long-term liabilities			1,903			1,791
Total long-term liabilities			13,923			11,575
Redeemable noncontrolling interest			116			25
Shares			4,982			4,482
Additional paid-in capital			7,211			7,504
Treasury shares, at cost, 2,863,267 held at June 30, 2012 and December 31, 2011			(240)			(240)
Retained earnings			4,244			9,969
Accumulated other comprehensive loss			(496)			(332)
Total controlling interest shareholders' equity			15,701			21,383
Noncontrolling interest			(10)			(8)
Total equity			15,691			21,375
Total liabilities and equity			35,088			36,811
Adjustments
Assets
Cash and cash equivalents						(40)
Other current assets			(84)			43
Total current assets			(84)			3
Less accumulated depreciation			(4)
Property and equipment, net			4
Goodwill			12
Other assets			12
Total assets			(56)			3
Liabilities and equity
Debt of consolidated variable interest entities due within one year			148			148
Other current liabilities			22			12
Total current liabilities			170			160
Long-term debt of consolidated variable interest entities			(148)			(148)
Deferred income taxes, net			(4)			10
Other long-term liabilities			(10)
Total long-term liabilities			(162)			(138)
Redeemable noncontrolling interest						16
Retained earnings			(64)			(35)
Total controlling interest shareholders' equity			(64)			(35)
Total equity			(64)			(35)
Total liabilities and equity			$ (56)			$ 3

Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012 note drillingunit	Dec. 31, 2011
Carrying amounts associated with consolidated variable interest entities
Assets	$ 929	$ 2,492
Liabilities	315	1,007
Net carrying amount	614	1,485
Unconsolidated Variable interest entities
Number of notes receivable from sale of Midwater Floaters	2
Number of Midwater Floaters sold (in drilling units)	2
Stated interest rate on notes receivable received from sale of Midwater Floaters (as a percent)	9.00%
Stated interest rate on working capital loan (as a percent)	10.00%
Aggregate carrying amounts of notes receivable in connection with sale of Midwater Floaters	107	110
Aggregate carrying amounts of working capital loan receivable in connection with sale of Midwater Floaters	11	29
Aggregate exposure to loss on receivable instruments in connection with sale of Midwater Floaters	118
TPDI
Carrying amounts associated with consolidated variable interest entities
Assets		1,562
Liabilities		673
Net carrying amount		889
ADDCL
Carrying amounts associated with consolidated variable interest entities
Assets	929	930
Liabilities	315	334
Net carrying amount	$ 614	$ 596

Business Combination (Details) (Aker Drilling)	1 Months Ended	3 Months Ended		6 Months Ended
Business Combination (Details) (Aker Drilling)	Oct. 31, 2011 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2011 USD ($)	Oct. 03, 2011 USD ($)	Oct. 03, 2011 NOK
Business Combination
Percentage of equity held by entity immediately before the acquisition date						99.00%	99.00%
Aggregate amount paid						$ 1,400,000,000	7,900,000,000
Purchase price allocated to assets and liabilities at estimated fair value
Current assets						323,000,000
Drilling rigs and other property and equipment						1,800,000,000
Other assets						756,000,000
Other liabilities						291,000,000
Long-term debt						1,600,000,000
Restricted cash investment	901,000,000
Goodwill						286,000,000
Net adjustment to goodwill		12,000,000		12,000,000
Contract drilling revenues associated with the operations of Aker Drilling included in operating revenues		100,000,000		195,000,000
Pro forma combined operating results
Operating revenues			2,438,000,000		4,682,000,000
Operating income			406,000,000		808,000,000
Income from continuing operations			$ 175,000,000		$ 339,000,000
Per share earnings from continuing operations
Basic (in dollars per share)			$ 0.52		$ 0.99
Diluted (in dollars per share)			$ 0.52		$ 0.99

Impairments (Details) (USD $)	3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended
Impairments (Details) (USD $)	Dec. 31, 2011	Jun. 30, 2012	Jun. 30, 2012 Assets Held for Sale	Jun. 30, 2011 Assets Held for Sale	Jun. 30, 2012 Assets Held for Sale	Jun. 30, 2011 Assets Held for Sale	Jun. 30, 2012 Customer relationships	Jun. 30, 2012 Trade name intangible asset
Assets held for sale
Aggregate losses on impairment of assets held for sale			$ 12,000,000	$ 25,000,000	$ 29,000,000	$ 25,000,000
Aggregate losses on impairment of assets per diluted share			$ 0.03	$ 0.08	$ 0.08	$ 0.08	$ 0.11	$ 0.07
Impairment of definite-lived intangible assets
Impairment loss on finite-lived intangible asset							53,000,000
Impairment loss on finite-lived intangible asset, continuing operations							37,000,000
Impairment of goodwill and other indefinite Lived intangible assets
Estimated loss on impairment of goodwill	5,200,000,000
Estimate of loss on impairment of goodwill per diluted share	$ 16.15
Adjustment to original estimate of goodwill		118,000,000
Adjustment to original estimate of goodwill, per diluted share		$ 0.34
Impairment loss on indefinite-lived intangible asset								39,000,000
Impairment loss on indefinite-lived intangible asset, continuing operations, net of tax								$ 25,000,000

Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2012 issue	Jun. 30, 2012 jurisdiction issue	Jun. 30, 2011	Dec. 31, 2011
Components of provision (benefit) for income taxes
Annual effective tax rate (as a percent)		29.60%	24.60%
Deferred taxes
Valuation allowance for non-current deferred tax assets	$ 178	$ 178		$ 183
Unrecognized tax benefits
Unrecognized tax benefits, excluding interest and penalties	438	438		515
Interest and penalties	193	193		256
Unrecognized tax benefits, including interest and penalties	631	631		771
Current tax benefit recognized from the settlement of dispute with tax authorities and lapse of applicable statutes of limitations, including interest and penalties	146	194
Income Tax Examination
Number of jurisdictions with extensions beyond statute of limitations		2
Maximum number of years agreed to extensions beyond the statute of limitations		17 years
Number of tax issues relating to assessment	2	2
2006 and 2007 income tax adjustments, excluding interest and penalties	278	278
2006 through 2009 restructuring transactions tax adjustments excluding interest and penalties	295	295
2006 through 2009 withholding and other tax adjustments, excluding interest	160	160
Assessed penalties associated with the various adjustments for 2006 and 2007 audits, excluding interest		88
Net adjustments of additional taxes, excluding interest and penalties, related to assessments on 2008 and 2009 U.S. federal income tax returns	473	473
Brazil tax assessment penalty	74	74
Brazil tax assessment interest	143	143
Brazil tax assessment for income tax returns 2000 to 2004	98	98
Percentage of penalties to be assessed by Brazil tax authorities	75.00%	75.00%
Minimum
Income Tax Examination
Range of tax returns are subject to examination		3 years
Maximum
Income Tax Examination
Range of tax returns are subject to examination		6 years
Norway Tax Assessments Prior to 2012
Income Tax Examination
Norway tax assessment due to migration of subsidiary, including interest	115	115
Norway tax assessment due to 2001 dividend payment, including interest	70	70
Norway tax assessment due to foreign exchange deductions and dividend withholding taxes, including interest	7	7
Guarantee amount for tax assessment related to the migration of subsidiary	117	117
Norway tax additional financial security, including interest and penalties	206	206
Percentage of penalties to be assessed by Norway tax authorities	60.00%	60.00%
Number of subsidiaries against which notification of criminal charges are issued		2
Number of employees of former external advisors indicted		2
Norway Tax Assessments 2012
Income Tax Examination
Number of subsidiaries against which notification of criminal charges are issued		2
Number of subsidiaries against which notification of criminal charges are extending		2
Number of employees of former external advisors indicted		2
Financial claim issued by the Norweigian authorities supplementing the criminal indictments		$ 309

Discontinued Operations (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended		1 Months Ended		3 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010	May 31, 2012 Challenger Minerals	Apr. 30, 2012 Challenger Minerals	Jun. 30, 2012 Challenger Minerals	Jun. 30, 2012 Challenger Minerals	Feb. 28, 2011 Caspian Sea Operations	Jun. 30, 2011 Caspian Sea Operations
Discontinued Operations
Proceeds from disposal of discontinued operations, net	$ 17			$ 17	$ 259			$ 10	$ 7			$ 259
Earnings (loss) from discontinued operations (in dollars per share)													$ 0.52
Summarized results of discontinued operations
Operating revenues	2		22	5	48
Costs and expenses	(3)		(18)	(5)	(41)
Loss on impairment				(6)
Gain on disposal of discontinued operations, net	10			10	169					10	10		169
Income from discontinued operations before income tax expense	9		4	4	176
Income tax benefit (expense)	(2)		(2)	2	(2)
Income (loss) from discontinued operations, net of tax	7	(1)	2	6	174	183	34
Loss on impairment, net of tax				(4)
Impairment loss per diluted share from discontinued operations, net of tax				$ 0.01
Assets
Oil and gas properties, net	5			5		24
Other related assets	2			2		2
Assets held for sale	7			7		26
Accounts receivable	1			1		6
Other assets	11			11		11
Other current assets	12			12		17
Liabilities
Accounts payable	1			1		3
Other liabilities	5			5		14
Other current liabilities	$ 6			$ 6		$ 17

Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Numerator for earnings (loss) per share, basic
Income (loss) from continuing operations attributable to controlling interest	$ (311)		$ 122	$ (300)	$ 269
Undistributed earnings allocable to participating securities			(1)		(2)
Income (loss) from continuing operations available to shareholders	(311)		121	(300)	267
Denominator for earnings (loss) per share, basic
Weighted-average shares outstanding	353		320	352	319
Weighted-average shares for per share calculation, basic	353		320	352	319
Per share earnings (loss) from continuing operations, basic	$ (0.88)	$ 0.03	$ 0.38	$ (0.85)	$ 0.84	$ (18.45)	$ 2.77
Numerator for earnings (loss) per share, diluted
Income (loss) from continuing operations attributable to controlling interest	(311)		122	(300)	269
Undistributed earnings allocable to participating securities			(1)		(2)
Income (loss) from continuing operations available to shareholders	$ (311)		$ 121	$ (300)	$ 267
Denominator for earnings (loss) per share, diluted
Weighted-average shares outstanding	353		320	352	319
Effect of stock options and other share based awards					1
Weighted-average shares for per share calculation, diluted	353		320	352	320
Per share earnings (loss) from continuing operations, diluted	$ (0.88)	$ 0.03	$ 0.38	$ (0.85)	$ 0.84	$ (18.45)	$ 2.77
1.50% Series B Convertible Senior Notes due December 2037
Anti-dilutive securities
Interest rate on convertible debt not having effect on earning per share calculation (as a percent)	1.50%			1.50%
1.50% Series C Convertible Senior Notes due December 2037
Anti-dilutive securities
Interest rate on convertible debt not having effect on earning per share calculation (as a percent)	1.50%			1.50%
Share-based awards
Anti-dilutive securities
Share-based awards excluded from earnings per share calculation	2.2		1.5	2.0	1.7

Drilling Fleet (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012 drillingunit	Jun. 30, 2011	Jun. 30, 2012 drillingunit	Jun. 30, 2011
Capital expenditures and other capital additions, including capitalized interest costs
Construction work in progress, at beginning of period			$ 1,395	$ 1,484
Total capital expenditures	236	293	496	533
Changes in accrued capital expenditures			32	(31)
Construction work in progress, at end of period	1,320	843	1,320	843
Number of High-Specification Jackups under construction which are expected to commence operations in the first quarter of 2013	3		3
Transocean Honor
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			35	76
Property and equipment placed into service			(262)
Transocean Andaman
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			26	70
Transocean Siam Driller
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			26	70
Deepwater Asgard
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			21
Deepwater Invictus
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			13
Deepwater Asgard and Deepwater Invictus
Capital expenditures and other capital additions, including capitalized interest costs
Number of Ultra-Deepwater Floaters under construction which are expected to commence operations in the second quarter of 2014	2		2
Transocean Ao Thai
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			45	10
Deepwater Champion
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures				76
Property and equipment placed into service				(881)
Other construction projects
Capital expenditures and other capital additions, including capitalized interest costs
Total capital expenditures			330	231
Other property and equipment
Capital expenditures and other capital additions, including capitalized interest costs
Property and equipment placed into service			$ (341)	$ (262)
Transocean Siam Driller and Transocean Andaman
Capital expenditures and other capital additions, including capitalized interest costs
Number of High-Specification Jackups under construction which are expected to commence operations in the first quarter of 2013	2		2

- Definition

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

+ References+ Details

Drilling Fleet (Details 2) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Dispositions
Net cash proceeds from sale of assets	$ 144		$ 5	$ 185	$ 18
Gain (loss) on the sale of assets	55	(4)	(1)	51	7	4	257
Assets held for sale
Carrying amount	9			9		26
Standard Jackups, GSF Adriatic II, GSF Rig 136, Roger W. Mowell, Transocean Nordic and Transocean Shelf Explorer
Dispositions
Net cash proceeds from sale of assets	145			179
Gain (loss) on the sale of assets	64			64
Aggregate losses on impairment of assets per diluted share	$ 0.18			$ 0.18
Sale of Other Assets
Dispositions
Gain (loss) on the sale of assets	9		1	13	2
Sale of Standard Jackup Transocean Mercury
Dispositions
Net cash proceeds from sale of assets					10
Gain (loss) on the sale of assets					9
Gain (loss) on the sale of assets per diluted share					$ 0.03
Sell of Standard Jackup Trident 17
Assets held for sale
Carrying amount	$ 2			$ 2

- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ References+ Details

Debt (Details)	6 Months Ended														6 Months Ended						6 Months Ended																											1 Months Ended									6 Months Ended																																													6 Months Ended
Debt (Details)	Jun. 30, 2012 USD ($)	Jun. 30, 2012 NOK	Dec. 31, 2011 USD ($)	Jun. 30, 2012 5% Notes due February 2013 USD ($)	Dec. 31, 2011 5% Notes due February 2013 USD ($)	Jun. 30, 2012 5.25% Senior Notes due March 2013 USD ($)	Dec. 31, 2011 5.25% Senior Notes due March 2013 USD ($)	Jun. 30, 2012 TPDI Credit Facilities due March 2015 USD ($)	Dec. 31, 2011 TPDI Credit Facilities due March 2015 USD ($)	Jun. 30, 2012 4.95% Senior Notes due November 2015 USD ($)	Dec. 31, 2011 4.95% Senior Notes due November 2015 USD ($)	Jun. 30, 2012 Aker Revolving Credit and Term Loan Facility due December 2015 USD ($)	Dec. 31, 2011 Aker Revolving Credit and Term Loan Facility due December 2015 USD ($)	Feb. 21, 2011 Aker Revolving Credit and Term Loan Facility due December 2015 USD ($)	Jun. 30, 2012 Aker Term Loan Facility due December 2015 USD ($)	Feb. 21, 2011 Aker Term Loan Facility due December 2015 USD ($)	Jun. 30, 2012 5.05% Senior Notes due December 2016 USD ($)	Dec. 31, 2011 5.05% Senior Notes due December 2016 USD ($)	Jun. 30, 2012 Callable Bonds due February 2016 USD ($)	Dec. 31, 2011 Callable Bonds due February 2016 USD ($)	Jun. 30, 2012 FRN Callable Bonds USD ($)	Jun. 30, 2012 FRN Callable Bonds NOK	Jun. 30, 2012 11% Callable Bonds USD ($)	Jun. 30, 2012 11% Callable Bonds NOK	Jun. 30, 2012 ADDCL Credit Facilities due December 2017 USD ($)	Dec. 31, 2011 ADDCL Credit Facilities due December 2017 USD ($)	Jun. 30, 2012 Eksportfinans Loans due January 2018 USD ($)	Dec. 31, 2011 Eksportfinans Loans due January 2018 USD ($)	Jun. 30, 2012 6.00% Senior Notes due March 2018 USD ($)	Dec. 31, 2011 6.00% Senior Notes due March 2018 USD ($)	Jun. 30, 2012 7.375% Senior Notes due April 2018 USD ($)	Dec. 31, 2011 7.375% Senior Notes due April 2018 USD ($)	Dec. 31, 2011 TPDI Notes due October 2019 USD ($)	Jun. 30, 2012 6.50% Senior Notes due November 2020 USD ($)	Dec. 31, 2011 6.50% Senior Notes due November 2020 USD ($)	Jun. 30, 2012 6.375% Senior Notes due December 2021 USD ($)	Dec. 31, 2011 6.375% Senior Notes due December 2021 USD ($)	Jun. 30, 2012 7.45% Notes due April 2027 USD ($)	Dec. 31, 2011 7.45% Notes due April 2027 USD ($)	Jun. 30, 2012 8% Debentures due April 2027 USD ($)	Dec. 31, 2011 8% Debentures due April 2027 USD ($)	Jun. 30, 2012 7% Notes due June 2028 USD ($)	Dec. 31, 2011 7% Notes due June 2028 USD ($)	Jun. 30, 2012 Capital lease contract due August 2029 USD ($)	Dec. 31, 2011 Capital lease contract due August 2029 USD ($)	Jun. 30, 2012 7.5% Notes due April 2031 USD ($)	Dec. 31, 2011 7.5% Notes due April 2031 USD ($)	Mar. 31, 2012 1.50% Series B Convertible Senior Notes due December 2037 USD ($)	Jun. 30, 2012 1.50% Series B Convertible Senior Notes due December 2037	Dec. 31, 2011 1.50% Series B Convertible Senior Notes due December 2037 USD ($)	Jun. 30, 2012 1.50% Series C Convertible Senior Notes due December 2037 USD ($)	Dec. 31, 2011 1.50% Series C Convertible Senior Notes due December 2037 USD ($)	Jun. 30, 2012 6.80% Senior Notes due March 2038 USD ($)	Dec. 31, 2011 6.80% Senior Notes due March 2038 USD ($)	Jun. 30, 2012 7.35% Senior Notes due December 2041 USD ($)	Dec. 31, 2011 7.35% Senior Notes due December 2041 USD ($)	Jun. 30, 2012 Five Year Revolving Credit Facility USD ($)	Jun. 30, 2012 Five Year Revolving Credit Facility Minimum Facility Fee	Jun. 30, 2012 Five Year Revolving Credit Facility Maximum Facility Fee	Jun. 30, 2012 Transocean Ltd. and Subsidiaries USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 5% Notes due February 2013 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 5% Notes due February 2013 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 5.25% Senior Notes due March 2013 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 5.25% Senior Notes due March 2013 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries TPDI Credit Facilities due March 2015 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 4.95% Senior Notes due November 2015 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 4.95% Senior Notes due November 2015 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries Aker Revolving Credit and Term Loan Facility due December 2015 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries Aker Revolving Credit and Term Loan Facility due December 2015 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 5.05% Senior Notes due December 2016 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 5.05% Senior Notes due December 2016 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries Callable Bonds due February 2016 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries Callable Bonds due February 2016 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries Eksportfinans Loans due January 2018 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries Eksportfinans Loans due January 2018 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 6.00% Senior Notes due March 2018 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 6.00% Senior Notes due March 2018 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 7.375% Senior Notes due April 2018 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 7.375% Senior Notes due April 2018 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 6.50% Senior Notes due November 2020 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 6.50% Senior Notes due November 2020 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 6.375% Senior Notes due December 2021 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 6.375% Senior Notes due December 2021 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 7.45% Notes due April 2027 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 7.45% Notes due April 2027 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 8% Debentures due April 2027 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 8% Debentures due April 2027 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 7% Notes due June 2028 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 7% Notes due June 2028 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries Capital lease contract due August 2029 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries Capital lease contract due August 2029 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 7.5% Notes due April 2031 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 7.5% Notes due April 2031 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 1.50% Series B Convertible Senior Notes due December 2037 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 1.50% Series C Convertible Senior Notes due December 2037 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 1.50% Series C Convertible Senior Notes due December 2037 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 6.80% Senior Notes due March 2038 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 6.80% Senior Notes due March 2038 USD ($)	Jun. 30, 2012 Transocean Ltd. and Subsidiaries 7.35% Senior Notes due December 2041 USD ($)	Dec. 31, 2011 Transocean Ltd. and Subsidiaries 7.35% Senior Notes due December 2041 USD ($)	Jun. 30, 2012 Transocean Inc.	Jun. 30, 2012 Consolidated variable interest entities USD ($)	Dec. 31, 2011 Consolidated variable interest entities USD ($)	Dec. 31, 2011 Consolidated variable interest entities TPDI Credit Facilities due March 2015 USD ($)	Jun. 30, 2012 Consolidated variable interest entities ADDCL Credit Facilities due December 2017 USD ($)	Dec. 31, 2011 Consolidated variable interest entities ADDCL Credit Facilities due December 2017 USD ($)	Dec. 31, 2011 Consolidated variable interest entities TPDI Notes due October 2019 USD ($)	Jun. 30, 2012 TPDI TPDI Credit Facilities due March 2015 USD ($)	Dec. 31, 2011 TPDI TPDI Credit Facilities due March 2015 USD ($)	Jun. 30, 2012 TPDI TPDI Credit Facilities Senior Term Loan Due March 2015 USD ($)	Jun. 30, 2012 TPDI TPDI Credit Facilities Junior Term Loan Due March 2015 USD ($)	Jun. 30, 2012 TPDI TPDI Credit Facilities Revolving Credit Facility Due March 2015 USD ($)	Jun. 30, 2012 TPDI Uncommitted Credit Facility Established by Subsidiary USD ($)	Jun. 30, 2012 ADDCL ADDCL Credit Facilities Tranche A Due November 2017 USD ($)	Jun. 30, 2012 ADDCL ADDCL Credit Facilities Tranche C Due November 2017 USD ($)	Jun. 30, 2012 ADDCL ADDCL Secondary Loan Facility Due December 2015 USD ($)	Dec. 31, 2011 ADDCL ADDCL Secondary Loan Facility Due December 2015 USD ($)
Long-term debt by current and noncurrent
Total debt	$ 12,839,000,000		$ 13,536,000,000	$ 252,000,000	$ 253,000,000	$ 505,000,000	$ 507,000,000	$ 438,000,000	$ 473,000,000	$ 1,121,000,000	$ 1,120,000,000	$ 174,000,000	$ 594,000,000				$ 999,000,000	$ 999,000,000	$ 265,000,000	$ 267,000,000					$ 205,000,000	$ 217,000,000	$ 815,000,000	$ 884,000,000	$ 998,000,000	$ 998,000,000	$ 247,000,000	$ 247,000,000	$ 148,000,000	$ 899,000,000	$ 899,000,000	$ 1,199,000,000	$ 1,199,000,000	$ 97,000,000	$ 97,000,000	$ 57,000,000	$ 57,000,000	$ 311,000,000	$ 311,000,000	$ 667,000,000	$ 676,000,000	$ 598,000,000	$ 598,000,000			$ 30,000,000	$ 1,693,000,000	$ 1,663,000,000	$ 999,000,000	$ 999,000,000	$ 300,000,000	$ 300,000,000				$ 12,634,000,000	$ 12,698,000,000	$ 252,000,000	$ 253,000,000	$ 505,000,000	$ 507,000,000	$ 438,000,000	$ 1,121,000,000	$ 1,120,000,000	$ 174,000,000	$ 594,000,000	$ 999,000,000	$ 999,000,000	$ 265,000,000	$ 267,000,000	$ 815,000,000	$ 884,000,000	$ 998,000,000	$ 998,000,000	$ 247,000,000	$ 247,000,000	$ 899,000,000	$ 899,000,000	$ 1,199,000,000	$ 1,199,000,000	$ 97,000,000	$ 97,000,000	$ 57,000,000	$ 57,000,000	$ 311,000,000	$ 311,000,000	$ 667,000,000	$ 676,000,000	$ 598,000,000	$ 598,000,000	$ 30,000,000	$ 1,693,000,000	$ 1,663,000,000	$ 999,000,000	$ 999,000,000	$ 300,000,000	$ 300,000,000		$ 205,000,000	$ 838,000,000	$ 473,000,000	$ 205,000,000	$ 217,000,000	$ 148,000,000
Debt due within one year	2,800,000,000		2,187,000,000	252,000,000		505,000,000		70,000,000	70,000,000			90,000,000	90,000,000												28,000,000	27,000,000	142,000,000	142,000,000					148,000,000											20,000,000	17,000,000					30,000,000	1,693,000,000	1,663,000,000								2,772,000,000	1,942,000,000	252,000,000		505,000,000		70,000,000			90,000,000	90,000,000					142,000,000	142,000,000															20,000,000	17,000,000			30,000,000	1,693,000,000	1,663,000,000						28,000,000	245,000,000	70,000,000	28,000,000	27,000,000	148,000,000
Long-term debt	10,039,000,000		11,349,000,000																																																									9,862,000,000	10,756,000,000																																										177,000,000	593,000,000
Debt instrument interest rate stated percentage				5.00%		5.25%				4.95%							5.05%						11.00%	11.00%					6.00%		7.375%			6.50%		6.375%		7.45%		8.00%		7.00%				7.50%			1.50%		1.50%		6.80%		7.35%
Percentage ownership interest in Transocean Inc. by Transocean Ltd.																																																																																																						100.00%
Credit facility term																																																									5 years
Borrowing capacity, maximum														500,000,000																																											2,000,000,000																																																				1,265,000,000				75,000,000		215,000,000	399,000,000	90,000,000
Weighted-average interest rate (as a percent)																																																																																																													2.10%						1.50%		3.60%
Debt instrument face amount																400,000,000																																																																																															1,000,000,000	190,000,000
Commitment fee percentage at period end																																																									0.275%	0.13%	0.33%
Credit facility available borrowing capacity																																																									2,000,000,000
Letters of credit issued and outstanding																																																									24,000,000																																																									60,000,000
Principal amount	12,829,000,000																				158,000,000	940,000,000	94,000,000	560,000,000																										30,000,000	1,722,000,000	1,722,000,000								12,624,000,000																																											205,000,000												177,000,000
Aggregate commitment of subsidiary in secured term loan																																																																																																													595,000,000
Credit facility amount outstanding															173,000,000																																																																																														875,000,000								80,000,000
Debt due to a subsidiary, eliminated in consolidation																																																																																																													437,000,000							399,000,000	52,000,000
Prepayment of debt	148,000,000														138,000,000																																	30,000,000
Loss on retirement of debt															1,000,000
Restricted investments used as security for debt instruments																											819,000,000	889,000,000																																																																																	23,000,000	23,000,000							17,000,000	16,000,000
NOK exchange rate		5.95
Weighted-average interest rate (as a percent)															3.00%						9.30%	9.30%
Percentage of total commitment under ADDCL secondary bank credit agreement provided by subsidiary																																																																																																																					65.00%

Debt (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Scheduled maturities of debt
2013	$ 2,820
2014	345
2015	494
2016	1,580
2017	1,205
Thereafter	6,385
Total debt, excluding unamortized discounts, premiums and fair value adjustments	12,829
Total unamortized discounts, premiums and fair value adjustments	10
Total debt	12,839	13,536
Transocean Ltd. and Subsidiaries
Scheduled maturities of debt
2013	2,792
2014	316
2015	463
2016	1,519
2017	1,169
Thereafter	6,365
Total debt, excluding unamortized discounts, premiums and fair value adjustments	12,624
Total unamortized discounts, premiums and fair value adjustments	10
Total debt	12,634	12,698
Consolidated variable interest entities
Scheduled maturities of debt
2013	28
2014	29
2015	31
2016	61
2017	36
Thereafter	20
Total debt, excluding unamortized discounts, premiums and fair value adjustments	205
Total debt	$ 205	$ 838

Debt (Details 3) (USD $) In Millions, unless otherwise specified	6 Months Ended		1 Months Ended	3 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Mar. 31, 2012 1.50% Series B Convertible Senior Notes due December 2037	Jun. 30, 2011 1.50% Series B Convertible Senior Notes due December 2037	Jun. 30, 2011 1.50% Series B Convertible Senior Notes due December 2037	Dec. 31, 2011 1.50% Series B Convertible Senior Notes due December 2037	Jun. 30, 2012 1.50% Series C Convertible Senior Notes due December 2037	Jun. 30, 2011 1.50% Series C Convertible Senior Notes due December 2037	Jun. 30, 2012 1.50% Series C Convertible Senior Notes due December 2037	Jun. 30, 2011 1.50% Series C Convertible Senior Notes due December 2037	Dec. 31, 2011 1.50% Series C Convertible Senior Notes due December 2037
Carrying amounts of Convertible Senior Notes
Convertible debt instrument effective interest rate (as a percent)											5.28%
Remaining period over which discount will be amortized									1 year
Interest expense				$ 20	$ 40		$ 22	$ 21	$ 43	$ 41
Principal amount	12,829					30	1,722		1,722		1,722
Unamortized discount							(29)		(29)		(59)
Total debt	12,839	13,536				30	1,693		1,693		1,663
Carrying amount of equity component						4	276		276		276
Aggregate principal amount of debt repurchased	148		30
Aggregate cash payment made for debt repurchased			$ 30

Derivatives and Hedging (Details) In Millions, unless otherwise specified					6 Months Ended							3 Months Ended
	Jun. 30, 2012 4.95% Senior Notes due November 2015	Jun. 30, 2012 5.25% Senior Notes due March 2013	Jun. 30, 2012 5% Notes due February 2013	Jun. 30, 2012 11% Callable Bonds	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swaps subsidiary	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swaps Fair value hedges Pay USD ($)	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swaps Fair value hedges Receive USD ($)	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swaps Cash flow hedges Pay USD ($)	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swaps Cash flow hedges Receive USD ($)	Jun. 30, 2012 Derivatives designated as hedging instruments Cross-currency swaps Cash flow hedges Pay USD ($)	Jun. 30, 2012 Derivatives designated as hedging instruments Cross-currency swaps Cash flow hedges Receive NOK	Jun. 30, 2012 Derivative not designated as hedging instruments Interest rate swaps USD ($)	Jun. 30, 2012 Derivatives de-designated as hedging instruments Interest rate swaps Fair value hedges USD ($)
Derivatives and Hedging
Number of wholly owned subsidiaries in interest rate swap agreements					2
Interest rate on notes hedged to reduce exposure to changes in fair value (as a percent)	4.95%	5.25%	5.00%	11.00%
Cash proceeds from termination of derivatives												$ 14	$ 23
Interest rate description to determine the variable interest on debt hedged					three-month London Interbank Offered Rate
Aggregate notional amount						$ 750	$ 750	$ 420	$ 420	$ 102	560
Weighted average fixed rate (as a percent)							5.20%	2.40%		8.90%	11.00%
Weighted average variable rate (as a percent)						3.60%			0.50%

Derivatives and Hedging (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Derivatives designated as hedging instruments \| Interest rate swaps \| Fair value hedges \| Other current assets
Derivatives designated as hedging and not designated as hedging instruments
Interest rate swaps, fair value hedges	$ 11	$ 5
Derivatives designated as hedging instruments \| Interest rate swaps \| Fair value hedges \| Other assets
Derivatives designated as hedging and not designated as hedging instruments
Interest rate swaps, fair value hedges		31
Derivatives designated as hedging instruments \| Interest rate swaps \| Cash flow hedges \| Other long-term liabilities
Derivatives designated as hedging and not designated as hedging instruments
Interest rate swaps, cash flow hedges	15	16
Derivatives designated as hedging instruments \| Cross-currency swaps \| Cash flow hedges \| Other current assets
Derivatives designated as hedging and not designated as hedging instruments
Interest rate swaps, fair value hedges	1
Derivatives designated as hedging instruments \| Cross-currency swaps \| Cash flow hedges \| Other long-term liabilities
Derivatives designated as hedging and not designated as hedging instruments
Interest rate swaps, cash flow hedges	7	7
Nondesignated \| Interest rate swaps \| Other long-term liabilities
Derivatives designated as hedging and not designated as hedging instruments
Interest rate swaps, cash flow hedges		$ 15

Derivatives and Hedging (Details 3) (Interest rate swaps, USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivatives designated as hedging instruments \| Interest expense, net of amounts capitalized
Effect on statement of operations resulting from changes in the fair values of derivatives designated as cash flow hedges
Loss associated with effective portion	$ 2	$ 3	$ 3	$ 5
Derivatives designated as hedging instruments \| Other, net
Effect on statement of operations resulting from changes in the fair values of derivatives designated as cash flow hedges
Loss associated with effective portion	4
Nondesignated \| Interest expense, net of amounts capitalized
Effect on statement of operations resulting from changes in the fair values of derivatives designated as cash flow hedges
Interest rate swaps not designated as hedging instruments			$ 1

Postemployment Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net periodic benefit costs, before tax
Service cost	$ 21	$ 17	$ 40	$ 33
Interest cost	23	21	43	41
Expected Return on Plan Assets	(24)	(23)	(44)	(44)
Settlements and curtailments		1	2	1
Actuarial losses, net	11	6	22	12
Prior service cost, net	(1)	(2)	(1)	(2)
Transition obligation, net		1		1
Net periodic benefit costs	30	21	62	42
Funding contributions	110	63	122	84
U.S. Plans
Net periodic benefit costs, before tax
Service cost	12	11	24	22
Interest cost	15	15	29	29
Expected Return on Plan Assets	(16)	(16)	(31)	(32)
Settlements and curtailments		1	2	1
Actuarial losses, net	10	6	20	12
Prior service cost, net	(1)	(1)	(1)	(1)
Net periodic benefit costs	20	16	43	31
Funding contributions	100	55	103	68
Non-U.S. Plans
Net periodic benefit costs, before tax
Service cost	9	5	16	10
Interest cost	8	6	13	11
Expected Return on Plan Assets	(8)	(7)	(13)	(12)
Actuarial losses, net	1		2
Transition obligation, net		1		1
Net periodic benefit costs	10	5	18	10
Funding contributions	9	6	17	13
OPEB Plans
Net periodic benefit costs, before tax
Service cost		1		1
Interest cost			1	1
Prior service cost, net		(1)		(1)
Net periodic benefit costs			1	1
Funding contributions	$ 1	$ 2	$ 2	$ 3

Contingencies (Details)														6 Months Ended	1 Months Ended								6 Months Ended				1 Months Ended
Contingencies (Details)	Jun. 30, 2012 Macondo well incident USD ($)	Dec. 31, 2011 Macondo well incident USD ($)	Apr. 22, 2010 Macondo well incident person mile	Jun. 30, 2012 Macondo well incident Insurance coverage claim	Apr. 22, 2010 Macondo well incident Insurance coverage USD ($)	Jun. 30, 2012 Macondo well incident Wrongful death and personal injury lawsuit	Jun. 30, 2012 Macondo well incident Economic loss lawsuit	Jun. 30, 2012 Macondo well incident Federal securities claims lawsuit	Jun. 30, 2010 Macondo well incident Shareholder derivative claims lawsuit	Dec. 15, 2010 Macondo well incident U.S. Department of Justice claims USD ($) bbl	Jun. 30, 2012 Macondo well incident Wreck removal USD ($)	Jun. 30, 2012 Macondo well incident Contractual indemnity USD ($)	Jun. 30, 2012 Macondo well incident Federal securities claims dismissed lawsuit	Jun. 30, 2012 Macondo well incident Notices of alleged non-compliance note	May 31, 2012 Brazil Frade field incident judge	Apr. 30, 2012 Brazil Frade field incident BRL	Mar. 31, 2012 Brazil Frade field incident BRL	Dec. 31, 2011 Brazil Frade field incident USD ($)	Dec. 31, 2011 Brazil Frade field incident BRL	Mar. 21, 2012 Brazil Frade field incident entity	Mar. 15, 2012 Brazil Frade field incident liters kilometers meter	Dec. 21, 2011 Brazil Frade field incident employee individual count	Jun. 30, 2012 Asbestos Litigation USD ($) lawsuit plaintiff subsidiary	Sep. 30, 2006 Rio de Janeiro tax assessment USD ($) subsidiary	Dec. 31, 2010 Brazilian import license assessment USD ($) subsidiary	Jun. 30, 2012 Hazardous waste disposal sites subsidiary	Jul. 31, 2005 Contamination litigation defendant	Jun. 30, 2012 Contamination litigation USD ($) subsidiary	Jul. 11, 2005 Contamination litigation landowner subsidiary	Jun. 30, 2012 Retained risk USD ($)	Jun. 30, 2012 Letters of credit and surety bonds USD ($)	Dec. 31, 2011 Letters of credit and surety bonds USD ($)
Contingencies
Number of persons declared dead			11
Number of miles Deepwater Horizon was off coast of Louisiana			41
Estimated liability recorded based on probable losses related to the rig explosion and fire incident	$ 2,000,000,000	$ 1,200,000,000
Portion of liability related to the rig explosion and fire incident recoverable from insurance	235,000,000	237,000,000
Percentage of non-operating interest of Anadarko in the Macondo well	25.00%
Percentage of non-operating interest of MOEX in the Macondo well	10.00%
Insured status under excess liability insurance program					950,000,000
Deductible amount under excess liability insurance program					15,000,000
Amount covered by fifth layer of excess liability insurance program					250,000,000
Amount covered by third layer of excess liability insurance program					200,000,000
Amount covered by fourth layer of excess liability insurance program					200,000,000
Amount covered by second layer of excess liability insurance program					150,000,000
Amount covered by first layer of excess liability insurance program					150,000,000
Amount covered by self insured layer of excess liability insurance program					50,000,000
Number of actions or claims that were pending				374		9	155	2	2				1										21
Number of putative class action complaints filed alleging, among other things, economic losses as a result of environmental pollution arising out of the Macondo well incident (in lawsuits)							179
Civil penalties per barrel, Maximum (in dollars per barrel)										1,100
Civil penalties per barrel for gross negligence or willful misconduct, Maximum (in dollars per barrel)										4,300
U.S. government's maximum estimate of barrels of oil discharged and subject to penalties										4,100,000
Percentage of asset value covered											25.00%
Amount agreed to indemnify and defend operator of rig												15,000,000
Area of fissure of which seepage is noted																					800
Distance from the November incident																					3
Volume of seepage																					5
Amount sought under civil public action by a federal prosecutor in Brazilian town of Campos in Rio de Janeiro State																20,000,000,000		10,000,000,000	20,000,000,000
Number of judges															3
Number of individuals for whom indictment recommended under investigation report filed																						17
Number of the entity's employees for whom indictment recommended under investigation report filed																						5
Number of counts on which indictment recommended under investigation report filed																						4
Number of counts alleging environmental offenses on which indictment recommended under investigation report filed																						3
Number of counts alleging false statements by Chevron, on which indictment recommended under investigation report filed																						1
Number of companies for whom indictment recommended under investigation report filed																				2
Bail amount requested by federal prosecutor in Brazilian town of Campos In Rio De Janerio State from companies																	10,000,000
Bail amount requested by federal prosecutor in Brazilian town of Campos In Rio De Janerio State from individuals																	1,000,000
Amount excludable per occurrence, claim arising from negligence																		250,000
Number of plaintiffs covered by complaints filed in 2004 in Mississippi regarding asbestos litigation																							769
Number of subsidiaries named as a direct defendant in amended																							2
Number of cases filed under amended complaint in Mississippi (in lawsuits)																							7
Number of additional cases in which there may be an indirect interest (in lawsuits)																							12
Number of total cases in which there may be an indirect interest regarding asbestos litigation (in lawsuits)																							26
Number of cases being governed for discovery and trial setting and in which the Company is named defendant																							14
Number of cases in which ruling has now been obtained and the Company cannot be sued for punitive damages																							3
Number of cases gone to trial against defendants who allegedly manufactured or distributed drilling mud additives																							7
Number of cases gone to trial against defendants, resulting in defense verdict																							2
Number of cases gone to trial against defendants, ended with hung jury																							1
Number of cases gone to trial against defendants, resulting in verdict for the plaintiff																							4
Number of cases resulting in substantial verdict in favor of the plaintiff																							2
Number of cases resulting in substantial verdict in favor of the plaintiff vacated on basis failure to meet burden of proof																							1
Number of cases resulting in substantial verdict in favor of the plaintiff vacated as a result of presiding judge being removed from hearing due to conflict of interest																							1
Number of remaining plaintiff verdicts are under appeal by the defendants																							2
Number of subsidiaries involved in lawsuits arising from design, construction and refurbishment of major industrial complexes																							1
Number of lawsuits alleging personal injury from asbestos exposure for subsidiary involved in design, construction and refurbishment of major industrial complexes																							899
Estimated number of plaintiffs in lawsuits alleging personal injury from asbestos exposure for subsidiary involved in design, construction and refurbishment of major industrial complexes																							2,087
Insurance limits potentially available for damages in lawsuits regarding personal injury from asbestos exposure for subsidiary involved in design, construction and refurbishment of major industrial																							1,000,000,000
Tax assessment from state tax authorities																								182,000,000	234,000,000
Number of subsidiaries involved in tax assessment relating to import license																								1
Number of subsidiaries involved in federal tax assessment relating to import license																									1
Percentage of liability for remediation and related costs																										8.00%
Number of subsidiaries ordered by California Regional Water Quality Control Board to develop testing plan for Alhambra, California site																										1
Minimum number of subsidiaries likely to be named potentially responsible party by US Environmental Protection Agency for superfund site (in counts)																										1
Number of subsidiaries served with a lawsuit																													1
Number of landowners who filed a lawsuit																													3
Number of other defendants involved in lawsuit																											19
Amount claimed by plaintiffs' experts as required remediation costs																												300,000,000
Amount claimed by defendants' experts as required remediation costs																												2,500,000
Number of additional subsidiaries plaintiff attempted to add as defendant																												2
Asset value covered by wreck removal insurance											140,000,000
Aggregate value of drilling rig fleet																														31,700,000,000
Per occurrence insurance deductible on hull and machinery																														125,000,000
Maximum aggregate insurance deductible on hull and machinery per year																														200,000,000
Maximum percentage of asset insured value covered by damage mitigation insurance																														25.00%
Maximum percentage of rig's insured value covered by wreck removal insurance																														25.00%
Commercial market excess liability coverage																														775,000,000
Per occurrence deductible on crew personal injury liability and collision liability claims																														10,000,000
Per occurrence deductible on other third-party non-crew claims																														5,000,000
Aggregate per occurrence deductible on other third party non-crew claims																														50,000,000
Liability loss limit for commercial market excess liability coverage																														825,000,000
Additional insurance that covers expenses that would otherwise be assumed by the well owner																														100,000,000
Maximum liability amount for well control and re-drilling liability related to blowouts																														50,000,000
Outstanding letters of credit																															578,000,000	650,000,000
Surety bonds outstanding																															$ 12,000,000	$ 12,000,000
Notices of alleged non-compliance
Number of notices issued by the Department of the Interior's Bureau of Safety and Environmental Enforcement														4

Redeemable Noncontrolling Interest (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	6 Months Ended
	May 31, 2012	Jun. 30, 2012 D	Jun. 30, 2011
Redeemable Noncontrolling Interest
Adjustment to retained earnings within shareholders' equity		$ 106
Adjustment to increase the liability	25
Issuance of shares in exchange for noncontrolling interest (in shares)	8,695,351
Adjustment to share capital		134
Adjustment to additional paid in capital		233
Extinguishment of TPDI Notes payable		148
Accrued and unpaid interest		16
Percentage of TPDI's working capital		50.00%
Number of days within closing of transaction		65
Carrying amount of liability for the final cash settlement		72
Percentage interest in joint venture (TPDI) that is held by an unaffiliated party (Quantum)		50.00%
Redeemable noncontrolling interest
Balance, beginning of period		116	41
Net income attributable to noncontrolling interest		13	27
Other comprehensive loss attributable to noncontrolling interest			(2)
Fair value adjustment of redeemable noncontrolling interest		106
Reclassification to accumulated other comprehensive loss		17
Reclassification to other current liabilities		(252)
Balance, end of period			$ 66

Shareholders' Equity (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2011	May 31, 2011 installment	Dec. 31, 2008 subsidiary	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Distribution of qualifying additional paid-in capital
Cash distribution approved in the form of additional paid-in capital (in dollars per share)		$ 3.16
Number of quarterly installments (in installments)		4
Amount of installment (in dollars per share)		$ 0.79
Installment of dividend paid	$ 278	$ 254		$ 278	$ 254	$ 278	$ 254
Shares held by subsidiary
Number of issued shares to a subsidiary to satisfy obligations in connection with awards granted under incentive plans or other rights to acquire shares of stocks			16
Number of subsidiaries to whom shares were issued			1
Number of shares held by subsidiary						12		12

- Definition

Cash outflow to owners or shareholders, excluding ordinary dividends. Includes special dividends.

+ References+ Details

Shareholders' Equity (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended								3 Months Ended		6 Months Ended
	Jun. 30, 2012	Dec. 31, 2010	Jun. 30, 2012 Unrecognized components of net periodic benefit costs	Jun. 30, 2011 Unrecognized components of net periodic benefit costs	Jun. 30, 2012 Unrecognized components of net periodic benefit costs	Jun. 30, 2011 Unrecognized components of net periodic benefit costs	Jun. 30, 2012 Unrecognized gains (losses) on derivative investments	Jun. 30, 2011 Unrecognized gains (losses) on derivative investments	Jun. 30, 2012 Unrecognized gains (losses) on derivative investments	Dec. 31, 2010 Unrecognized gains (losses) on derivative investments	Jun. 30, 2012 Unrecognized gains (losses) on marketable securities	Mar. 31, 2012 Unrecognized gains (losses) on marketable securities	Dec. 31, 2011 Unrecognized gains (losses) on marketable securities	Jun. 30, 2011 Unrecognized gains (losses) on marketable securities	Mar. 31, 2011 Unrecognized gains (losses) on marketable securities	Dec. 31, 2010 Unrecognized gains (losses) on marketable securities	Jun. 30, 2012 Accumulated other comprehensive income (loss), Total	Jun. 30, 2011 Accumulated other comprehensive income (loss), Total	Jun. 30, 2012 Accumulated other comprehensive income (loss), Total	Jun. 30, 2011 Accumulated other comprehensive income (loss), Total
Changes in accumulated other comprehensive income
Accumulated other comprehensive loss, balance beginning of period	$ (496)	$ (332)	$ (517)	$ (337)	$ (501)	$ (335)	$ (12)	$ 4	$ 7	$ 5	$ (2)	$ (2)	$ (2)	$ (2)	$ (2)	$ (2)	$ (531)	$ (335)	$ (496)	$ (332)
Reclassification of redeemable noncontrolling interest	17								(17)										(17)
Other comprehensive income (loss) attributable to controlling interest			11	6	(5)	4	4	1	2								15	7	(3)	4
Accumulated other comprehensive loss, balance end of period	$ (516)	$ (332)	$ (506)	$ (331)	$ (506)	$ (331)	$ (8)	$ 5	$ (8)	$ 5	$ (2)	$ (2)	$ (2)	$ (2)	$ (2)	$ (2)	$ (516)	$ (328)	$ (516)	$ (328)

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e681-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669686-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 14, 17, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 30

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569643-111683

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 19

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569616-111683

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

+ Details

Financial Instruments (Details) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Carrying amount
Financial instruments
Cash and cash equivalents	$ 3,964,000,000	$ 4,017,000,000
Accounts receivable	2,124,000,000	2,176,000,000
Notes receivable and working capital loan receivable	118,000,000	139,000,000
Restricted cash investments	857,000,000	929,000,000
Long-term debt, including current maturities	12,634,000,000	12,698,000,000
Derivative instruments, assets	12,000,000	36,000,000
Derivative instruments, liabilities	22,000,000	38,000,000
Debt
Fixed rate debt	11,900,000,000	11,900,000,000
Variable-rate debt	777,000,000	761,000,000
Carrying amount \| Other current assets
Financial instruments
Notes receivable and working capital loan receivable	17,000,000	37,000,000
Carrying amount \| Other assets
Financial instruments
Notes receivable and working capital loan receivable	101,000,000	102,000,000
Carrying amount \| TPDI and ADDCL Credit Facilities
Financial instruments
Restricted cash investments	40,000,000	40,000,000
Carrying amount \| Aker Drilling
Financial instruments
Restricted cash investments	817,000,000	889,000,000
Carrying amount \| Consolidated Variable Ineterest Entities
Financial instruments
Long-term debt of consolidated variable interest entities, including current maturities	205,000,000	838,000,000
Fair value
Financial instruments
Cash and cash equivalents	3,964,000,000	4,017,000,000
Accounts receivable	2,124,000,000	2,176,000,000
Notes receivable and working capital loan receivable	118,000,000	139,000,000
Restricted cash investments	902,000,000	970,000,000
Fair value \| Level 2
Financial instruments
Long-term debt, including current maturities	13,985,000,000	13,074,000,000
Derivative instruments, assets	12,000,000	36,000,000
Derivative instruments, liabilities	22,000,000	38,000,000
Debt
Fixed rate debt	13,100,000,000	12,200,000,000
Variable-rate debt	205,000,000	838,000,000
Fair value \| Level 2 \| Aker Drilling
Financial instruments
Restricted cash investments	862,000,000	930,000,000
Fair value \| Level 2 \| Consolidated Variable Ineterest Entities
Financial instruments
Long-term debt of consolidated variable interest entities, including current maturities	$ 205,000,000	$ 838,000,000

Condensed Consolidating Financial Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Condensed Consolidating Financial Information
Operating revenues	$ 2,575	$ 2,337	$ 2,334	$ 4,912	$ 4,478	$ 9,136	$ 9,466
Cost and expenses	2,781	1,887	1,953	4,668	3,751	8,734	6,871
Loss on impairment	(12)	(227)	(25)	(239)	(25)	(5,229)	(1,010)
Gain (loss) on disposal of assets, net	55	(4)	(1)	51	7	4	257
Operating income (loss)	(163)	219	355	56	709	(4,823)	1,842
Other income (expense), net
Interest expense, net	(170)		(142)	(335)	(272)
Equity in earnings			2		4
Other, net	(6)		(7)	(24)	(6)
Total other income (expense), net	(176)	(183)	(147)	(359)	(274)	(658)	(567)
Loss from continuing operations before income tax expense	(339)	36	208	(303)	435	(5,481)	1,275
Income tax benefit	(29)	17	77	(12)	143	379	340
Income from continuing operations	(310)	19	131	(291)	292	(5,860)	935
Income (loss) from discontinued operations, net of tax	7	(1)	2	6	174	183	34
Net income (loss)	(303)	18	133	(285)	466	(5,677)	969
Net income attributable to noncontrolling interest	1	8	9	9	23	77	43
Net income (loss) attributable to controlling interest	(304)	10	124	(294)	443	(5,754)	926
Other comprehensive income before income taxes	14		1	(1)	4
Income taxes related to other comprehensive income (loss)	1			(2)	(2)
Other comprehensive income (loss), net of income taxes	15		1	(3)	2
Total comprehensive income (loss)	(288)		134	(288)	468
Total comprehensive income attributable to noncontrolling interest	1		3	9	21
Total comprehensive income (loss) attributable to controlling interest	(289)		131	(297)	447
Five Year Revolving Credit Facility
Condensed Consolidating Financial Information
Term of revolving credit facility				5 years
Parent Guarantor
Condensed Consolidating Financial Information
Cost and expenses	21		14	32	24
Operating income (loss)	(21)		(14)	(32)	(24)
Other income (expense), net
Interest expense, net	(4)			(7)
Equity in earnings	(279)		139	(255)	468
Other, net			(1)		(1)
Total other income (expense), net	(283)		138	(262)	467
Loss from continuing operations before income tax expense	(304)		124	(294)	443
Income from continuing operations	(304)		124	(294)	443
Net income (loss)	(304)		124	(294)	443
Net income (loss) attributable to controlling interest	(304)		124	(294)	443
Other comprehensive income before income taxes	1		2	(4)	(1)
Other comprehensive income (loss), net of income taxes	1		2	(4)	(1)
Total comprehensive income (loss)	(303)		126	(298)	442
Total comprehensive income (loss) attributable to controlling interest	(303)		126	(298)	442
Subsidiary Issuer
Condensed Consolidating Financial Information
Cost and expenses	1		1	2	2
Operating income (loss)	(1)		(1)	(2)	(2)
Other income (expense), net
Interest expense, net	(139)		(130)	(273)	(261)
Equity in earnings	(186)		283	(16)	771
Other, net	18		(9)	9	(32)
Total other income (expense), net	(307)		144	(280)	478
Loss from continuing operations before income tax expense	(308)		143	(282)	476
Income from continuing operations	(308)		143	(282)	476
Net income (loss)	(308)		143	(282)	476
Net income (loss) attributable to controlling interest	(308)		143	(282)	476
Other comprehensive income before income taxes	7		3		(2)
Other comprehensive income (loss), net of income taxes	7		3		(2)
Total comprehensive income (loss)	(301)		146	(282)	474
Total comprehensive income (loss) attributable to controlling interest	(301)		146	(282)	474
Other Subsidiaries
Condensed Consolidating Financial Information
Operating revenues	2,581		2,339	4,923	4,487
Cost and expenses	2,765		1,943	4,645	3,734
Loss on impairment	(12)		(25)	(239)	(25)
Gain (loss) on disposal of assets, net	55		(1)	51	7
Operating income (loss)	(141)		370	90	735
Other income (expense), net
Interest expense, net	(27)		(12)	(55)	(11)
Equity in earnings			2		4
Other, net	(24)		3	(33)	27
Total other income (expense), net	(51)		(7)	(88)	20
Loss from continuing operations before income tax expense	(192)		363	2	755
Income tax benefit	(29)		77	(12)	143
Income from continuing operations	(163)		286	14	612
Income (loss) from discontinued operations, net of tax	7		2	6	174
Net income (loss)	(156)		288	20	786
Net income attributable to noncontrolling interest	1		9	9	23
Net income (loss) attributable to controlling interest	(157)		279	11	763
Other comprehensive income before income taxes	6		(4)	3	7
Income taxes related to other comprehensive income (loss)	1			(2)	(2)
Other comprehensive income (loss), net of income taxes	7		(4)	1	5
Total comprehensive income (loss)	(149)		284	21	791
Total comprehensive income attributable to noncontrolling interest	1		3	9	21
Total comprehensive income (loss) attributable to controlling interest	(150)		281	12	770
Consolidating adjustments
Condensed Consolidating Financial Information
Operating revenues	(6)		(5)	(11)	(9)
Cost and expenses	(6)		(5)	(11)	(9)
Other income (expense), net
Equity in earnings	465		(422)	271	(1,239)
Total other income (expense), net	465		(422)	271	(1,239)
Loss from continuing operations before income tax expense	465		(422)	271	(1,239)
Income from continuing operations	465		(422)	271	(1,239)
Net income (loss)	465		(422)	271	(1,239)
Net income (loss) attributable to controlling interest	465		(422)	271	(1,239)
Total comprehensive income (loss)	465		(422)	271	(1,239)
Total comprehensive income (loss) attributable to controlling interest	$ 465		$ (422)	$ 271	$ (1,239)

Condensed Consolidating Financial Information (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 3,964	$ 3,982	$ 4,017	$ 3,349	$ 3,772	$ 3,354
Other current assets	3,403		3,508
Total current assets	7,367		7,525			6,198
Property and equipment, net	22,207		22,533			21,319
Goodwill	3,099		3,217			8,132
Other assets	1,769		1,757			1,165
Total assets	34,442		35,032			36,814
Liabilities and equity
Debt due within one year	2,800		2,187
Other current liabilities	3,926		3,341
Total current liabilities	6,726		5,528			3,996
Long-term debt	10,039		11,349
Other long-term liabilities	2,068		2,412
Total long-term liabilities	12,107		13,761			11,437
Commitments and contingencies
Redeemable noncontrolling interest			116	66		41
Total equity	15,609		15,627	20,816		21,340
Total liabilities and equity	34,442		35,032			36,814
Parent Guarantor
Assets
Cash and cash equivalents	19		3	16		38
Other current assets	10		8
Total current assets	29		11
Property and equipment, net	1		1
Investment in affiliates	16,101		16,439
Other assets	3
Total assets	16,134		16,451
Liabilities and equity
Other current liabilities	110		294
Total current liabilities	110		294
Long-term debt	370		495
Other long-term liabilities	31		25
Total long-term liabilities	401		520
Commitments and contingencies
Total equity	15,623		15,637
Total liabilities and equity	16,134		16,451
Subsidiary Issuer
Assets
Cash and cash equivalents	2,206		2,793	1,882		2,041
Other current assets	2,536		784
Total current assets	4,742		3,577
Investment in affiliates	27,989		27,646
Other assets	1,620		1,368
Total assets	34,351		32,591
Liabilities and equity
Debt due within one year	2,198		1,693
Other current liabilities	312		367
Total current liabilities	2,510		2,060
Long-term debt	16,191		14,308
Other long-term liabilities	381		439
Total long-term liabilities	16,572		14,747
Commitments and contingencies
Total equity	15,269		15,784
Total liabilities and equity	34,351		32,591
Other Subsidiaries
Assets
Cash and cash equivalents	1,739		1,221	1,451		1,275
Other current assets	2,684		4,465
Total current assets	4,423		5,686
Property and equipment, net	22,206		22,532
Goodwill	3,099		3,217
Other assets	19,296		19,065
Total assets	49,024		50,500
Liabilities and equity
Debt due within one year	602		494
Other current liabilities	5,331		4,429
Total current liabilities	5,933		4,923
Long-term debt	12,628		15,222
Other long-term liabilities	1,656		1,948
Total long-term liabilities	14,284		17,170
Commitments and contingencies
Redeemable noncontrolling interest			116
Total equity	28,807		28,291
Total liabilities and equity	49,024		50,500
Consolidating adjustments
Assets
Other current assets	(1,827)		(1,749)
Total current assets	(1,827)		(1,749)
Investment in affiliates	(44,090)		(44,085)
Other assets	(19,150)		(18,676)
Total assets	(65,067)		(64,510)
Liabilities and equity
Other current liabilities	(1,827)		(1,749)
Total current liabilities	(1,827)		(1,749)
Long-term debt	(19,150)		(18,676)
Total long-term liabilities	(19,150)		(18,676)
Commitments and contingencies
Total equity	(44,090)		(44,085)
Total liabilities and equity	$ (65,067)		$ (64,510)

Condensed Consolidating Financial Information (Details 3) (USD $) In Millions, unless otherwise specified	1 Months Ended		3 Months Ended			6 Months Ended
	Jun. 30, 2011	May 31, 2011	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Condensed Consolidating Financial Information
Cash flows from operating activities			$ 459		$ 340	$ 999	$ 730
Cash flows from investing activities
Capital expenditures			(236)		(293)	(496)	(533)
Proceeds from disposal of assets, net			144		5	185	18
Proceeds from disposal of discontinued operations, net			17			17	259
Other, net						25	(33)
Net cash used in investing activities			(62)		(315)	(269)	(289)
Cash flows from financing activities
Changes in short-term borrowings, net			(260)		5	(260)	56
Repayments of debt			(173)		(202)	(320)	(249)
Proceeds from debt							5
Proceeds from restricted cash investments			84			192
Deposits to restricted cash investments			(74)			(116)
Distribution of qualifying additional paid-in capital	(278)	(254)		(278)	(254)	(278)	(254)
Other, net						(1)	(4)
Net cash used in financing activities			(415)		(448)	(783)	(446)
Net decrease in cash and cash equivalents			(18)		(423)	(53)	(5)
Cash and cash equivalents at beginning of period			3,982	4,017	3,772	4,017	3,354
Cash and cash equivalents at end of period	3,349		3,964	3,982	3,349	3,964	3,349
Parent Guarantor
Condensed Consolidating Financial Information
Cash flows from operating activities						(31)	(24)
Cash flows from financing activities
Distribution of qualifying additional paid-in capital						(278)	(254)
Financing activities with affiliates, net						325	256
Net cash used in financing activities						47	2
Net decrease in cash and cash equivalents						16	(22)
Cash and cash equivalents at beginning of period				3		3	38
Cash and cash equivalents at end of period	16		19		16	19	16
Subsidiary Issuer
Condensed Consolidating Financial Information
Cash flows from operating activities						(570)	(485)
Cash flows from investing activities
Investing activities with affiliates, net						(1,816)	(268)
Other, net						19	(29)
Net cash used in investing activities						(1,797)	(297)
Cash flows from financing activities
Changes in short-term borrowings, net							56
Repayments of debt						(30)	(177)
Financing activities with affiliates, net						1,819	748
Other, net						(9)	(4)
Net cash used in financing activities						1,780	623
Net decrease in cash and cash equivalents						(587)	(159)
Cash and cash equivalents at beginning of period				2,793		2,793	2,041
Cash and cash equivalents at end of period	1,882		2,206		1,882	2,206	1,882
Other Subsidiaries
Condensed Consolidating Financial Information
Cash flows from operating activities						1,600	1,239
Cash flows from investing activities
Capital expenditures						(496)	(533)
Proceeds from disposal of assets, net						185	18
Proceeds from disposal of discontinued operations, net						17	259
Investing activities with affiliates, net						(2,269)	(748)
Other, net						6	(4)
Net cash used in investing activities						(2,557)	(1,008)
Cash flows from financing activities
Changes in short-term borrowings, net						(260)
Repayments of debt						(290)	(72)
Proceeds from debt							5
Proceeds from restricted cash investments						192
Deposits to restricted cash investments						(116)
Financing activities with affiliates, net						1,941	12
Other, net						8
Net cash used in financing activities						1,475	(55)
Net decrease in cash and cash equivalents						518	176
Cash and cash equivalents at beginning of period				1,221		1,221	1,275
Cash and cash equivalents at end of period	1,451		1,739		1,451	1,739	1,451
Consolidating adjustments
Cash flows from investing activities
Investing activities with affiliates, net						4,085	1,016
Net cash used in investing activities						4,085	1,016
Cash flows from financing activities
Financing activities with affiliates, net						(4,085)	(1,016)
Net cash used in financing activities						$ (4,085)	$ (1,016)

Subsequent Events (Details) (Drilling fleet / Deepwater Floater, Discoverer 534 and Standard Jackup, GSF Rig 103, USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Drilling fleet / Deepwater Floater, Discoverer 534 and Standard Jackup, GSF Rig 103
Subsequent Events
Carrying value of drilling fleet assets reclassified to assets held for sale	$ 87