0001451505-26-000061 | 10-Q | XBRL Viewer

Significant Accounting Policies	6 Months Ended
Jun. 30, 2026
Significant Accounting Policies
Significant Accounting Policies	Note 2—Significant Accounting Policies Presentation—We 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 promulgated by the U.S. Securities and Exchange Commission. 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 the 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, 2026, are not necessarily indicative of the results that may be expected for the year ending December 31, 2026, 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, 2025 and 2024, and for each of the three years in the period ended December 31, 2025, included in our annual report on Form 10K filed on February 23, 2026. Accounting estimates—To prepare financial statements in accordance with accounting principles generally accepted in the U.S., we must make judgments by applying 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 income taxes, property and equipment, equity investments, contingencies, allowance for excess materials and supplies, assets held for sale, postemployment benefit plans and share-based compensation. We base our estimates and assumptions on historical experience and other factors that we believe are reasonable. Actual results could differ from such estimates. Fair value measurements—We estimate fair value at an exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. 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 a valuation requires multiple input levels, 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.

Significant Accounting Policies

6 Months Ended

Jun. 30, 2026

Note 2—Significant Accounting Policies

Presentation—We 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 promulgated by the U.S. Securities and Exchange Commission. 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 the 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, 2026, are not necessarily indicative of the results that may be expected for the year ending December 31, 2026, 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, 2025 and 2024, and for each of the three years in the period ended December 31, 2025, included in our annual report on Form 10K filed on February 23, 2026.

Accounting estimates—To prepare financial statements in accordance with accounting principles generally accepted in the U.S., we must make judgments by applying 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 income taxes, property and equipment, equity investments, contingencies, allowance for excess materials and supplies, assets held for sale, postemployment benefit plans and share-based compensation. We base our estimates and assumptions on historical experience and other factors that we believe are reasonable. Actual results could differ from such estimates.

Fair value measurements—We estimate fair value at an exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. 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 a valuation requires multiple input levels, 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.

Business	6 Months Ended
Jun. 30, 2026
Business
Business	Note 1—Business Overview Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. As of June 30, 2026, we owned or had partial ownership interests in and operated a fleet of 27 mobile offshore drilling units, consisting of 20 ultra-deepwater drillships and seven harsh environment semisubmersibles. Agreement to acquire Valaris Limited On February 9, 2026, we and Valaris Limited, an exempted company limited by shares incorporated under the laws of Bermuda, ("Valaris") entered into a Business Combination Agreement (the "Agreement"), providing for the combination of Transocean and Valaris (the "Business Combination"). Pursuant to the Agreement, and on the terms and subject to the conditions thereof, we will acquire all of the issued and outstanding common shares, par value $0.01 each, of Valaris (the “Valaris Shares”) in exchange for Transocean Ltd. shares, par value $0.10 each, at an exchange ratio of 15.235 Transocean Ltd. shares for each Valaris Share. Pursuant to the Agreement, and on the terms and subject to the conditions thereof, at the time on which the order of the Supreme Court of Bermuda providing for its sanction of the Scheme of Arrangement is filed with the Registrar of Companies of Bermuda, the Business Combination will become effective and Valaris will become our wholly owned subsidiary. The board of directors of Transocean and Valaris each unanimously approved and declared advisable the Agreement and the transactions contemplated thereby, including the Business Combination. In the three and six months ended June 30, 2026, we incurred acquisition costs of $11 million and $17 million, respectively, recorded in general and administrative costs and expenses.

Business

6 Months Ended

Jun. 30, 2026

Business

Business

Note 1—Business

Overview

Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. As of June 30, 2026, we owned or had partial ownership interests in and operated a fleet of 27 mobile offshore drilling units, consisting of 20 ultra-deepwater drillships and seven harsh environment semisubmersibles.

Agreement to acquire Valaris Limited

On February 9, 2026, we and Valaris Limited, an exempted company limited by shares incorporated under the laws of Bermuda, ("Valaris") entered into a Business Combination Agreement (the "Agreement"), providing for the combination of Transocean and Valaris (the "Business Combination"). Pursuant to the Agreement, and on the terms and subject to the conditions thereof, we will acquire all of the issued and outstanding common shares, par value $0.01 each, of Valaris (the “Valaris Shares”) in exchange for Transocean Ltd. shares, par value $0.10 each, at an exchange ratio of 15.235 Transocean Ltd. shares for each Valaris Share. Pursuant to the Agreement, and on the terms and subject to the conditions thereof, at the time on which the order of the Supreme Court of Bermuda providing for its sanction of the Scheme of Arrangement is filed with the Registrar of Companies of Bermuda, the Business Combination will become effective and Valaris will become our wholly owned subsidiary. The board of directors of Transocean and Valaris each unanimously approved and declared advisable the Agreement and the transactions contemplated thereby, including the Business Combination. In the three and six months ended June 30, 2026, we incurred acquisition costs of $11 million and $17 million, respectively, recorded in general and administrative costs and expenses.

Income Taxes	6 Months Ended
Jun. 30, 2026
Income Taxes
Income Taxes	Note 7—Income Taxes Tax provision and rate—In the six months ended June 30, 2026 and 2025, our effective tax rate was (19.8) percent and 10.3 percent, respectively, based on income or loss before income taxes. In the six months ended June 30, 2026 and 2025, the effect of various discrete period tax items was a net tax benefit of $137 million and $189 million, respectively. In the six months ended June 30, 2026, such discrete items included changes to operating structures and valuation allowances. In the six months ended June 30, 2025, such discrete items included changes to various uncertain tax positions, valuation allowances and rig basis changes related to impairment. In the six months ended June 30, 2026 and 2025, our effective tax rate, excluding discrete items, was 42.8 percent and 268.9 percent, respectively, based on income or loss before income taxes. In the six months ended June 30, 2025, we recognized a net tax benefit of $169 million, primarily resulting from a release of uncertain tax positions. Tax positions and returns—We conduct operations through our various subsidiaries in countries throughout the world. Each country has its own tax regimes with varying nominal rates, deductions and tax attributes that are subject to changes resulting from new legislation, interpretation or guidance. From time to time, as a result of these changes, we may revise previously evaluated tax positions, which could cause us to adjust our recorded tax assets and liabilities. Tax authorities in certain jurisdictions are examining our tax returns and, in some cases, have issued assessments. We intend to defend our tax positions vigorously. Although we can provide no assurance as to the outcome of the aforementioned changes, examinations or assessments, we do not expect the ultimate liability to have a material adverse effect on our condensed consolidated statement of financial position or results of operations; however, it could have a material adverse effect on our condensed consolidated statement of cash flows. Brazil tax investigations—In December 2005, the Brazilian tax authorities began issuing tax assessments with respect to our tax returns for the years 2000 through 2004. In May 2014, the Brazilian tax authorities issued an additional tax assessment for the years 2009 and 2010. We filed protests with the Brazilian tax authorities for the assessments and are engaged in the appeals process, and a portion of two cases were favorably closed. As of June 30, 2026, the remaining aggregate tax assessment, including interest and penalties, was for corporate income tax of BRL 533 million, equivalent to $103 million, and indirect tax of BRL 98 million, equivalent to $19 million. We believe our returns are materially correct as filed, and we are vigorously contesting these assessments. An unfavorable outcome on these proposed assessments could have a material adverse effect on our condensed consolidated statement of financial position, results of operations or cash flows.

Income Taxes

6 Months Ended

Jun. 30, 2026

Income Taxes

Income Taxes

Note 7—Income Taxes

Tax provision and rate—In the six months ended June 30, 2026 and 2025, our effective tax rate was (19.8) percent and 10.3 percent, respectively, based on income or loss before income taxes. In the six months ended June 30, 2026 and 2025, the effect of various discrete period tax items was a net tax benefit of $137 million and $189 million, respectively. In the six months ended June 30, 2026,

such discrete items included changes to operating structures and valuation allowances. In the six months ended June 30, 2025, such discrete items included changes to various uncertain tax positions, valuation allowances and rig basis changes related to impairment. In the six months ended June 30, 2026 and 2025, our effective tax rate, excluding discrete items, was 42.8 percent and 268.9 percent, respectively, based on income or loss before income taxes.

In the six months ended June 30, 2025, we recognized a net tax benefit of $169 million, primarily resulting from a release of uncertain tax positions.

Tax positions and returns—We conduct operations through our various subsidiaries in countries throughout the world. Each country has its own tax regimes with varying nominal rates, deductions and tax attributes that are subject to changes resulting from new legislation, interpretation or guidance. From time to time, as a result of these changes, we may revise previously evaluated tax positions, which could cause us to adjust our recorded tax assets and liabilities. Tax authorities in certain jurisdictions are examining our tax returns and, in some cases, have issued assessments. We intend to defend our tax positions vigorously. Although we can provide no assurance as to the outcome of the aforementioned changes, examinations or assessments, we do not expect the ultimate liability to have a material adverse effect on our condensed consolidated statement of financial position or results of operations; however, it could have a material adverse effect on our condensed consolidated statement of cash flows.

Brazil tax investigations—In December 2005, the Brazilian tax authorities began issuing tax assessments with respect to our tax returns for the years 2000 through 2004. In May 2014, the Brazilian tax authorities issued an additional tax assessment for the years 2009 and 2010. We filed protests with the Brazilian tax authorities for the assessments and are engaged in the appeals process, and a portion of two cases were favorably closed. As of June 30, 2026, the remaining aggregate tax assessment, including interest and penalties, was for corporate income tax of BRL 533 million, equivalent to $103 million, and indirect tax of BRL 98 million, equivalent to $19 million. We believe our returns are materially correct as filed, and we are vigorously contesting these assessments. An unfavorable outcome on these proposed assessments could have a material adverse effect on our condensed consolidated statement of financial position, results of operations or cash flows.

Business (Details)		3 Months Ended	6 Months Ended
Business (Details)	Feb. 09, 2026 $ / shares	Jun. 30, 2026 USD ($) item $ / shares	Jun. 30, 2026 USD ($) item $ / shares	Dec. 31, 2025 $ / shares
Business
Number of mobile offshore drilling units \| $		27	27
Shares, Par value		$ 0.1	$ 0.1	$ 0.1
Valaris Limited
Business
Shares, Par value	$ 0.1
Share exchange ratio	15.235
Acquisition costs \| $		$ 11,000,000	$ 17,000,000
Valaris Limited \| Valaris Limited
Business
Shares, Par value	$ 0.01
Ultra-deepwater floaters
Business
Number of mobile offshore drilling units \| item		20	20
Harsh environment floaters
Business
Number of mobile offshore drilling units \| item		7	7

Long-Lived Assets (Impairments) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2025
Long-Lived Assets.
Aggregate loss on impairment of assets held for sale	$ 1,136	$ 1,136
Aggregate loss on impairment of assets held for sale, net of tax	$ 1,130	$ 1,130
Loss associated with impairment, net of tax (per share)	$ 1.27	$ 1.27

Equity (Warrants) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended		12 Months Ended
	Apr. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Mar. 13, 2026
Equity
Number of warrants issued to subscribe			22.2
Exercise price				$ 3.71
Estimated fair value			$ 16.0
No of warrants exercised		22.2
Shares issued	$ 9.7

Debt (Credit Agreement) (Details) - Five-Year Revolving Credit Facility $ in Millions	6 Months Ended
	Jun. 30, 2026 USD ($)
Debt
Early maturity trigger, principal due within 91 days	$ 325
Early maturity trigger available cash	250
Permitted commitment increase	250
Credit facility amount outstanding	0
Letters of credit issued and outstanding	54
Credit facility available borrowing capacity	$ 456
Spread on variable rate basis (as a percent)	2.75%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:SecuredOvernightFinancingRateSofrMember
Variable rate spread adjustment (as a percent)	0.10%
Commitment fee (as a percent)	0.50%
Minimum
Debt
Commitment fee (as a percent)	0.375%
Maximum
Debt
Commitment fee (as a percent)	1.00%
June 2028
Debt
Borrowing capacity, maximum	$ 510

Income Taxes (Provision) (Details) R$ in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2026 USD ($)	Jun. 30, 2026 BRL (R$)	Jun. 30, 2025 USD ($)
Income taxes
Effective tax rate (as a percent)	(19.80%)	(19.80%)	10.30%
Various discrete tax items expense (benefit)	$ (137)		$ (189)
Annual effective tax rate excluding discrete items (as a percent)	42.80%	42.80%	268.90%
Unrecognized Tax Benefits, Period Increase (Decrease)			$ 169
BRAZIL \| Corporate income tax
Income taxes
Net adjustments of additional taxes, including interest and penalties	$ 103	R$ 533
BRAZIL \| Indirect tax
Income taxes
Net adjustments of additional taxes, including interest and penalties	$ 19	R$ 98

Debt (Interest Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Debt (Interest Expense) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Interest Expense
Amortization			$ 20	$ 25
(Gain) loss on adjustment to bifurcated compound exchange feature			19	(65)
Total	$ (20)	$ 112	256	228
Convertible debt instruments
Interest Expense
Contractual interest	3	6	6	11
Amortization	5	5	10	11
(Gain) loss on adjustment to bifurcated compound exchange feature	(134)	(29)	19	(65)
Total	$ (126)	$ (18)	$ 35	$ (43)

Debt (Exchangeable bonds) (Details) - 4.625% Senior Guaranteed Exchangeable Bonds due September 2029 $ / shares in Units, $ in Millions		6 Months Ended
	Mar. 30, 2026	Jun. 30, 2026 USD ($) $ / shares	Mar. 30, 2028	Dec. 31, 2025 USD ($)
Debt
Debt instrument interest rate stated percentage	4.625%	4.625%
Bifurcated compound exchange feature, at estimated fair value		$ 145.0		$ 126.0
Effective interest rate (as a percent)		18.30%
Fair value of debt		$ 389.0
Debt conversion ratio		290.6618
Debt conversion (in dollars per share) \| $ / shares		$ 3.44
Shares issuable (in shares)		75.3
Plan
Debt
Debt instrument interest rate stated percentage			4.625%
Amount to repurchase upon the occurrence of certain events (as a percent)	115
Trading days for calculation of average stock price	20 days

Long-Lived Assets (Disposals) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2026	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Disposals
Gain (loss) on the sale of assets		$ (2)	$ 7	$ 2	$ 9
Proceeds from disposal of assets, net of costs to sell				26	10
Assets sold, not discontinued operations \| Rig sales
Disposals
Gain (loss) on the sale of assets				4
Proceeds from disposal of assets, net of costs to sell				27		$ 3
Assets sold, not discontinued operations \| Rig sales \| Subsequent Event
Disposals
Proceeds from disposal of assets, net of costs to sell	$ 3
Assets sold, not discontinued operations \| Other property and equipment
Disposals
Gain (loss) on the sale of assets				(2)	9
Proceeds from disposal of assets, net of costs to sell				$ 2	$ 10

Equity (Share Issuance) (Details) - 4.00% Senior Guaranteed Exchangeable Bonds due December 2025 shares in Millions, $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2025 USD ($) shares	Jun. 30, 2025 USD ($) shares	Jun. 30, 2025 USD ($) shares
Equity
Shares issued upon conversion (in shares) \| shares	18.6	18.6	18.6
Debt issued in exchange transactions \| $	$ 49	$ 50	$ 50
Debt instrument interest rate stated percentage	4.00%	4.00%	4.00%

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2026	Jul. 28, 2026
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2026
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Securities Act File Number	001-38373
Entity Registrant Name	Transocean Ltd.
Entity Incorporation, State or Country Code	V8
Entity Tax Identification Number	98-0599916
Entity Address, Address Line One	Turmstrasse 30
Entity Address, City or Town	Steinhausen
Entity Address, Country	CH
Entity Address, Postal Zip Code	6312
Country Region	41
City Area Code	41
Local Phone Number	749-0500
Title of 12(b) Security	Shares, $0.10 par value
Trading Symbol	RIG
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,116,880,085
Entity Central Index Key	0001451505
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q2
Amendment Flag	false

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Jun. 30, 2026 shares
Mr. Brady K. Long
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On May 22, 2026, Mr. Brady K. Long, our Executive Vice President and Chief Legal Officer, adopted a Rule 10b5-1 trading arrangement, as such term is defined under Item 408(a) of Regulation S-K of the Securities Act of 1933, that is intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of up to 198,622 shares of Transocean Ltd. (the “CLO Plan”). Sales may not commence under the CLO Plan until September 20, 2026 at the earliest and only at specified market prices. Unless earlier terminated in accordance with its terms and conditions, the CLO Plan expires on August 15, 2027.
Name	Mr. Brady K. Long
Title	Executive Vice President and Chief Legal Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	May 22, 2026
Expiration Date	August 15, 2027
Aggregate Available	198,622
Mr. Jason Pack
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On July 2, 2026, Mr. Jason Pack, our Senior Vice President and Chief Accounting Officer, adopted a Rule 10b5-1 trading arrangement, as such term is defined under Item 408(a) of Regulation S-K of the Securities Act of 1933, that is intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of up to 262,103 shares of Transocean Ltd. (the “CAO Plan”). Sales may not commence under the CAO Plan until October 1, 2026 at the earliest and only at specified market prices. Unless earlier terminated in accordance with its terms and conditions, the CAO Plan expires on September 15, 2027.
Name	Mr. Jason Pack
Title	Senior Vice President and Chief Accounting Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	July 2, 2026
Expiration Date	September 15, 2027
Aggregate Available	262,103

Contingencies (Legal Proceedings) (Details) - Asbestos litigation	6 Months Ended
	Jun. 30, 2026 plaintiff lawsuit
Contingencies
Number of claims \| lawsuit	562
LOUISIANA
Contingencies
Number of plaintiffs	6
Illinois, Missouri and California
Contingencies
Number of plaintiffs	36

Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Financial instruments
Total debt	$ 5,119	$ 5,657
Carrying amount
Financial instruments
Cash and cash equivalents	509	620
Restricted cash and cash equivalents	286	377
Total debt	5,119	5,657
Fair value
Financial instruments
Cash and cash equivalents	509	620
Restricted cash and cash equivalents	286	377
Total debt	$ 5,329	$ 5,755

Significant Accounting Policies (Policies)	6 Months Ended
Significant Accounting Policies (Policies)	Jun. 30, 2026
Significant Accounting Policies
Presentation	Presentation—We 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 promulgated by the U.S. Securities and Exchange Commission. 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 the 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, 2026, are not necessarily indicative of the results that may be expected for the year ending December 31, 2026, 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, 2025 and 2024, and for each of the three years in the period ended December 31, 2025, included in our annual report on Form 10K filed on February 23, 2026.
Accounting estimates	Accounting estimates—To prepare financial statements in accordance with accounting principles generally accepted in the U.S., we must make judgments by applying 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 income taxes, property and equipment, equity investments, contingencies, allowance for excess materials and supplies, assets held for sale, postemployment benefit plans and share-based compensation. We base our estimates and assumptions on historical experience and other factors that we believe are reasonable. Actual results could differ from such estimates.
Fair value measurements	Fair value measurements—We estimate fair value at an exchange price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. 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 a valuation requires multiple input levels, 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.
Accounting standards updates	Recently issued accounting standards updates not yet adopted Disaggregated income statement expenses—Effective for the year ending December 31, 2027, we will adopt the accounting standards update that requires, in the notes to consolidated financial statements, disaggregated disclosures of certain categories of expenses that are included in expense line items on the face of the consolidated statements of operations. The disclosures will be required on an annual and interim basis. We will provide the new disclosures, as required, for annual periods beginning with our annual report on Form 10-K for the year ending December 31, 2027, and subsequently, for interim periods beginning with our quarterly report on Form 10-Q for the quarterly period ending March 31, 2028. We continue to evaluate the requirements. Although our adoption will require us to augment certain disclosures in the notes to consolidated financial statements, we do not expect such adoption to have a material effect on our consolidated statements of financial position, operations or cash flows.

Long-Lived Assets (Assets held for sale) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Assets held for sale
Assets held for sale	$ 1	$ 24
Assets held for sale
Assets held for sale
Assets held for sale	$ 1	$ 24

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Assets
Cash and cash equivalents	$ 509	$ 620
Accounts receivable, net of allowance of $2 at June 30, 2026 and December 31, 2025	604	540
Materials and supplies, net of allowance of $146 and $140 at June 30, 2026 and December 31, 2025, respectively	379	378
Assets held for sale	1	24
Restricted cash and cash equivalents	286	377
Other current assets	133	142
Total current assets	1,912	2,081
Property and equipment	17,490	17,451
Less accumulated depreciation	(5,147)	(4,874)
Property and equipment, net	12,343	12,577
Deferred tax assets, net	70	61
Other assets	842	923
Total assets	15,167	15,642
Liabilities and equity
Accounts payable	283	242
Accrued income taxes	9	22
Debt due within one year	397	445
Other current liabilities	514	627
Total current liabilities	1,203	1,336
Long-term debt	4,722	5,212
Deferred tax liabilities, net	340	404
Other long-term liabilities	532	582
Total long-term liabilities	5,594	6,198
Commitments and contingencies
Shares, $0.10 par value, 1,445 authorized, 141 conditionally authorized, 1,304 issued and 1,117 outstanding at June 30, 2026 and 1,204 authorized, 141 conditionally authorized, 1,204 issued and 1,102 outstanding at December 31, 2025	112	110
Additional paid-in capital	15,617	15,604
Accumulated deficit	(7,219)	(7,460)
Accumulated other comprehensive loss	(140)	(146)
Total equity	8,370	8,108
Total liabilities and equity	$ 15,167	$ 15,642

Debt (Maturities) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Scheduled maturities of debt
Total principal amount of debt	$ 5,107	$ 5,686
Total installments
Scheduled maturities of debt
2027	405
2028	332
2029	1,148
2030	729
2031	1,296
Thereafter	1,197
Total principal amount of debt	5,107
Total unamortized debt-related balances, net	(133)
Bifurcated compound exchange feature, at estimated fair value	145
Total carrying amount of debt	$ 5,119

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total controlling interest shareholders' equity	Shares	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Noncontrolling interest	Total
Balance, beginning at Dec. 31, 2024	$ 10,284	$ 87	$ 14,880	$ (4,545)	$ (138)	$ 1	$ 10,285
Increase (Decrease) in Shareholders' Equity
Total comprehensive income (loss)	(1,020)						(1,020)
Share-based compensation	16		16				16
Issuance of shares	73	3	70				73
Net income (loss)				(1,017)			(1,017)
Total comprehensive income (loss)					(3)		(1,020)
Balance, end at Jun. 30, 2025	9,353	90	14,966	(5,562)	(141)	1	9,354
Balance, beginning at Mar. 31, 2025	10,210	88	14,887	(4,624)	(141)		10,211
Increase (Decrease) in Shareholders' Equity
Total comprehensive income (loss)	(938)						(938)
Share-based compensation	8		8				8
Issuance of shares	73	2	71				73
Net income (loss)				(938)			(938)
Total comprehensive income (loss)							(938)
Balance, end at Jun. 30, 2025	9,353	90	14,966	(5,562)	(141)	$ 1	9,354
Balance, beginning at Dec. 31, 2025	8,108	110	15,604	(7,460)	(146)		8,108
Increase (Decrease) in Shareholders' Equity
Total comprehensive income (loss)	247						247
Share-based compensation	15		15				15
Issuance of shares		2	(2)
Net income (loss)				241			241
Total comprehensive income (loss)					6		247
Balance, end at Jun. 30, 2026	8,370	112	15,617	(7,219)	(140)		8,370
Balance, beginning at Mar. 31, 2026	8,192	111	15,611	(7,389)	(141)		8,192
Increase (Decrease) in Shareholders' Equity
Total comprehensive income (loss)	171						171
Share-based compensation	7		7				7
Issuance of shares		1	(1)
Net income (loss)				170			170
Total comprehensive income (loss)					1		171
Balance, end at Jun. 30, 2026	$ 8,370	$ 112	$ 15,617	$ (7,219)	$ (140)		$ 8,370

Revenues (Changes in Contract Liabilities) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025
Changes to contract liabilities
Total contract liabilities, beginning of period	$ 273	$ 443
Decrease due to recognition of revenues for goods and services	(110)	(130)
Increase due to goods and services transferred over time	27	46
Total contract liabilities, end of period	$ 190	$ 359

Revenues (Disaggregation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Revenues (Disaggregation) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Revenue
Contract drilling revenues	$ 966	$ 988	$ 2,047	$ 1,894
U.S.
Revenue
Contract drilling revenues	344	408	777	802
Brazil
Revenue
Contract drilling revenues	167	221	399	413
Norway
Revenue
Contract drilling revenues	177	140	356	299
Australia
Revenue
Contract drilling revenues	107	92	209	175
Other Countries
Revenue
Contract drilling revenues	171	127	306	205
Ultra-deepwater floaters
Revenue
Contract drilling revenues	623	699	1,371	1,357
Ultra-deepwater floaters \| U.S.
Revenue
Contract drilling revenues	344	408	777	802
Ultra-deepwater floaters \| Brazil
Revenue
Contract drilling revenues	167	221	399	413
Ultra-deepwater floaters \| Other Countries
Revenue
Contract drilling revenues	112	70	195	142
Harsh environment floaters
Revenue
Contract drilling revenues	343	289	676	537
Harsh environment floaters \| Norway
Revenue
Contract drilling revenues	177	140	356	299
Harsh environment floaters \| Australia
Revenue
Contract drilling revenues	107	92	209	175
Harsh environment floaters \| Other Countries
Revenue
Contract drilling revenues	$ 59	$ 57	$ 111	$ 63

Revenues (Contract Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025	Jun. 30, 2025	Dec. 31, 2024
Contract balances
Contract liabilities, recorded in other current liabilities	$ 120	$ 181
Contract liabilities, recorded in other long-term liabilities	70	92
Total contract liabilities	$ 190	$ 273	$ 359	$ 443

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Millions, $ in Millions	Jun. 30, 2026	Dec. 31, 2025
CONDENSED CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts	$ 2	$ 2
Materials and supplies, allowance for obsolescence	$ 146	$ 140
Shares, Par value	$ 0.1	$ 0.1
Shares, authorized	1,445	1,204
Shares, conditionally authorized	141	141
Shares, issued	1,304	1,204
Shares, outstanding	1,117	1,102

Debt (Details) - USD ($) $ in Millions	Jun. 30, 2026	Mar. 31, 2026	Mar. 30, 2026	Dec. 31, 2025
Principal amount
Total principal amount of debt	$ 5,107			$ 5,686
Debt due within one year	405			458
Long-term debt	4,702			5,228
Carrying amount
Total debt	5,119			5,657
Debt due within one year	397			445
Long-term debt	4,722			5,212
7.45% Notes due April 2027
Principal amount
Total principal amount of debt	52			52
Debt due within one year	52
Carrying amount
Total debt	52			52
Debt due within one year	$ 52
Debt instrument interest rate stated percentage	7.45%
8.00% Debentures due April 2027
Principal amount
Total principal amount of debt	$ 22			22
Debt due within one year	22
Carrying amount
Total debt	22			22
Debt due within one year	$ 22
Debt instrument interest rate stated percentage	8.00%
4.50% Shipyard Loans due September 2027
Principal amount
Total principal amount of debt	$ 149			209
Debt due within one year	144			136
Carrying amount
Total debt	145			202
Debt due within one year	$ 140			129
Debt instrument interest rate stated percentage	4.50%
8.375% Senior Secured Notes due February 2028
Principal amount
Total principal amount of debt				425
Debt due within one year				135
Carrying amount
Total debt				421
Debt due within one year				133
Debt instrument interest rate stated percentage	8.375%	8.375%
7.00% Notes due June 2028
Principal amount
Total principal amount of debt	$ 209			209
Carrying amount
Total debt	$ 210			210
Debt instrument interest rate stated percentage	7.00%
8.00% Senior Secured Notes due September 2028
Principal amount
Total principal amount of debt	$ 200			235
Debt due within one year	70			70
Carrying amount
Total debt	198			233
Debt due within one year	$ 69			69
Debt instrument interest rate stated percentage	8.00%
8.25% Senior Notes due May 2029
Principal amount
Total principal amount of debt	$ 900			900
Carrying amount
Total debt	$ 891			889
Debt instrument interest rate stated percentage	8.25%
4.625% Senior Guaranteed Exchangeable Bonds due September 2029
Principal amount
Total principal amount of debt	$ 259			259
Carrying amount
Total debt	$ 320			292
Debt instrument interest rate stated percentage	4.625%		4.625%
8.75% Senior Secured Notes due February 2030
Principal amount
Total principal amount of debt	$ 822			881
Debt due within one year	117			117
Carrying amount
Total debt	811			868
Debt due within one year	$ 114			114
Debt instrument interest rate stated percentage	8.75%
7.50% Notes due April 2031
Principal amount
Total principal amount of debt	$ 396			396
Carrying amount
Total debt	$ 395			395
Debt instrument interest rate stated percentage	7.50%
8.50% Senior Notes due May 2031
Principal amount
Total principal amount of debt	$ 900			900
Carrying amount
Total debt	$ 889			888
Debt instrument interest rate stated percentage	8.50%
7.875% Senior Guaranteed Notes due October 2032
Principal amount
Total principal amount of debt	$ 500			500
Carrying amount
Total debt	$ 493			493
Debt instrument interest rate stated percentage	7.875%
6.80% Senior Notes due March 2038
Principal amount
Total principal amount of debt	$ 610			610
Carrying amount
Total debt	$ 606			605
Debt instrument interest rate stated percentage	6.80%
7.35% Senior Notes due December 2041
Principal amount
Total principal amount of debt	$ 88			88
Carrying amount
Total debt	$ 87			$ 87
Debt instrument interest rate stated percentage	7.35%