Document and Entity Information Document Information [Table] Document Information [Line Items] Document and Entity Information Document Type Document Quarterly Report Document Period End Date Document Transition Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, Country Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag CONSOLIDATED STATEMENTS OF OPERATIONS Statement [Table] Statement [Line Items] Statement Operating Income (Loss) [Abstract] Operating revenues Revenue from Contract with Customer, Excluding Assessed Tax Contract drilling revenues Revenues Revenue from Contract with Customer, Product and Service [Extensible List] Costs and Expenses [Abstract] Costs and expenses Cost of Goods and Services Sold Operating and maintenance Cost, Product and Service [Extensible List] Depreciation, Depletion and Amortization Depreciation and amortization General and Administrative Expense. General and administrative Costs and Expenses Total costs and expenses Other Asset Impairment Charges Loss on impairment Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Loss on disposal of assets, net Gain (loss) on disposal of assets, net Gain (loss) on the sale of assets Operating Income (Loss) Operating loss Nonoperating Income (Expense) [Abstract] Other income (expense), net Investment Income, Interest Interest income Interest Expense Interest expense, net of amounts capitalized Gains (Losses) on Extinguishment of Debt Loss on retirement of debt Aggregate net gain (loss) Gain (loss) on retirement of debt Other Nonoperating Income (Expense) Other, net Nonoperating Income (Expense) Total other income (expense), net Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Loss before income tax expense Income Tax Expense (Benefit) Income tax expense Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Income (loss) from continuing operations Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss Net loss Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to noncontrolling interest Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Parent Net loss attributable to controlling interest Net loss attributable to controlling interest Earnings Per Share, Basic and Diluted [Abstract] Loss per share Earnings Per Share, Basic Basic (in dollars per share) Loss per share, basic (in dollars per share) Earnings Per Share, Diluted Diluted (in dollars per share) Loss per share, diluted (in dollars per share) Weighted Average Number of Shares Outstanding, Diluted [Abstract] Denominator for loss per share, diluted Weighted-average shares outstanding Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Weighted-average shares for per share calculation, basic Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) Weighted-average shares for per share calculation, diluted CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments and Tax Components of net periodic benefit costs before reclassifications Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax Components of net periodic benefit costs reclassified to net loss Other Comprehensive Income (Loss), before Tax Other comprehensive income (loss) before income taxes Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other comprehensive income (loss) attributable to controlling interest Other comprehensive income (loss) attributable to controlling interest Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive loss Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest Total comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Parent Total comprehensive loss attributable to controlling interest Total comprehensive loss attributable to controlling interest CONSOLIDATED BALANCE SHEETS Assets [Abstract] Assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Receivables, Net, Current Accounts receivable, net of allowance of $2 at June 30, 2020 Prepaid Supplies Materials and supplies, net of allowance of $122 and $127 at June 30, 2020 and December 31, 2019, respectively Restricted Cash and Investments, Current Restricted cash accounts and investments Other Assets, Current Other current assets Assets, Current Total current assets Property, Plant and Equipment, Gross Property and equipment Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less accumulated depreciation Property, Plant and Equipment, Net Property and equipment, net Finite-Lived Intangible Assets, Net Contract intangible assets Deferred Income Tax Assets, Net Deferred income taxes, net Other Assets, Noncurrent Other assets Assets Total assets Liabilities and Equity [Abstract] Liabilities and equity Accounts Payable, Current Accounts payable Accrued Income Taxes, Current Accrued income taxes Debt Current Debt due within one year Other Liabilities, Current Other current liabilities Liabilities, Current Total current liabilities Long-term Debt and Capital Lease Obligations Long-term debt Deferred Income Tax Liabilities, Net Deferred income taxes, net Other Liabilities, Noncurrent Other long-term liabilities Liabilities, Noncurrent Total long-term liabilities Commitments and Contingencies. Commitments and contingencies Common Stock, Value, Issued Shares, CHF 0.10 par value, 824,648,925 authorized, 142,365,398 conditionally authorized, 639,674,414 issued and 614,612,545 outstanding at June 30, 2020, and 639,674,422 authorized, 142,365,398 conditionally authorized, 617,970,525 issued and 611,871,374 outstanding at December 31, 2019 Additional Paid in Capital Additional paid-in capital Retained Earnings (Accumulated Deficit). Accumulated deficit Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Stockholders' Equity Attributable to Parent Total controlling interest shareholders' equity Stockholders' Equity Attributable to Noncontrolling Interest Noncontrolling interest Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance Balance Total equity Liabilities and Equity Total liabilities and equity Allowance for Doubtful Accounts Receivable, Current Allowance for doubtful accounts Inventory Valuation Reserves Materials and supplies, allowance for obsolescence Common Stock, Par or Stated Value Per Share Shares, CHF par value (in Swiss francs per share) Common Stock, Shares Authorized Shares, authorized Conditional capital represents the amount of additional registered shares that the board is authorized to issue without obtaining additional shareholder approval. Shares Conditionally Authorized Shares, conditionally authorized Common Stock, Shares, Issued Shares, issued Common Stock, Shares, Outstanding Shares, outstanding CONSOLIDATED STATEMENTS OF EQUITY Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Parent [Member] Total controlling interest shareholders' equity Common Stock [Member] Shares Additional Paid In Capital [Member] Additional paid-in capital Retained Earnings [Member] Retained earnings (accumulated deficit) Accumulated Other Comprehensive Income [Member] Accumulated other comprehensive loss Noncontrolling Interest [Member] Noncontrolling interest Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Shareholders' Equity Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Issuance of shares under share-based compensation plans Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Share-based compensation Cumulative Effect of New Accounting Principle in Period of Adoption Effect of adopting accounting standards update Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest Total comprehensive income (loss) attributable to noncontrolling interest The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent and is not considered redeemable or temporary. Such redeemable or temporary interest is classified outside of permanent equity. Comprehensive Income Net of Tax Including Portion Attributable to Noncontrolling Interest 1 Total comprehensive loss Stockholders' Equity, Other Other, net CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile to net cash provided by operating activities: Amortization of Intangible Assets Contract intangible asset amortization Share-based Compensation. Share-based compensation expense Equity Method Investment, Other than Temporary Impairment Loss on impairment of investment in unconsolidated affiliate Deferred Income Tax Expense (Benefit) Deferred income tax expense Other Noncash Income (Expense) Other, net Increase (Decrease) in Deferred Revenue Changes in deferred revenues, net Increase (Decrease) in Deferred Charges Changes in deferred costs, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Changes in other operating assets and liabilities, net Net Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities Payments to Acquire Property, Plant, and Equipment Capital expenditures Total capital expenditures Proceeds from Sale of Property, Plant, and Equipment Net cash proceeds from sale of assets Proceeds from disposal of assets, net Payments to Acquire Interest in Subsidiaries and Affiliates Investments in unconsolidated affiliates Proceeds from Maturities, Prepayments and Calls of Short-term Investments Proceeds from maturities of unrestricted and restricted investments Payments for (Proceeds from) Other Investing Activities Other, net Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Proceeds from Issuance of Long-term Debt Proceeds from issuance of debt, net of discounts and issue costs Proceeds from issuance of debt Repayments of Long-term Debt Repayments of debt Proceeds from (Payments for) Other Financing Activities Other, net Net Cash Provided by (Used in) Financing Activities Net cash provided by (used in) financing activities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Net increase (decrease) in unrestricted and restricted cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Unrestricted and restricted cash and cash equivalents, end of period Unrestricted and restricted cash and cash equivalents, beginning of period Business Nature of Operations [Text Block] Business Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Significant Accounting Policies Accounting Standards Updates New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Accounting Standards Updates Unconsolidated Affiliates Equity Method Investments and Joint Ventures Disclosure [Text Block] Unconsolidated Affiliates Revenues Revenue from Contract with Customer [Text Block] Revenues Drilling Fleet Property, Plant and Equipment Disclosure [Text Block] Drilling Fleet Debt Debt Disclosure [Text Block] Debt Income Taxes Income Tax Disclosure [Text Block] Income Taxes Loss Per Share Earnings Per Share [Text Block] Loss Per Share Contingencies Commitments and Contingencies Disclosure [Text Block] Commitments Financial Instruments Fair Value Disclosures [Text Block] Financial Instruments Basis of Accounting, Policy [Policy Text Block] Presentation Use of Estimates, Policy [Policy Text Block] Accounting estimates Fair Value of Financial Instruments, Policy [Policy Text Block] Fair value measurements Disaggregation of Revenue [Table Text Block] Schedule of revenue disaggregation Contract with Customer, Asset and Liability [Table Text Block] Schedule of contract balances and changes Disclosure of actual capital expenditures and other capital additions, including capitalized interest, for remaining major construction projects. Actual Capital Expenditures and Other Capital Additions Including Capitalized Interest [Table Text Block] Changes in our construction work in progress, including capital expenditures and capitalized interest Schedule of Debt [Table Text Block] Debt, net of unamortized discounts, premiums and fair value adjustments Schedule of Maturities of Long-term Debt [Table Text Block] Scheduled maturities of debt Schedule of Extinguishment of Debt [Table Text Block] Schedule of debt retirements Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Loss Per Share Fair Value, by Balance Sheet Grouping [Table Text Block] Carrying amounts and fair values of the financial instruments Number of mobile offshore drilling units. Number of Mobile Offshore Drilling Units Number of mobile offshore drilling units Number of mobile offshore drilling units under construction we own, had partial ownership interests in or operated at the measurement date. Number of Mobile Offshore Drilling Units Under Construction Number of mobile offshore drilling units under construction Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Line Items] Investments Equity Method Investment, Ownership Percentage Ownership percentage Payments to Acquire Equity Method Investments Equity method investment payment Equity Securities, FV-NI, Measurement Input Investment fair value measurement Equity Method Investment, Aggregate Cost Aggregate carrying amount of equity investment Related Party Transaction, Amounts of Transaction Related party transaction Disaggregation of Revenue [Table] Disaggregation of Revenue [Line Items] Revenue Capitalized Contract Cost, Amortization Recognized pre-operating costs Capitalized Contract Cost, Net Unrecognized pre-operating costs Receivable with Imputed Interest, Face Amount Face amount of receivable Contract with Customer, Performance Obligation Satisfied in Previous Period Performance obligations satisfied in previous periods Receivable with Imputed Interest, Net Amount Receivable net of discount Contract with Customer, Asset and Liability [Abstract] Contract balances Contract with Customer, Liability, Current Deferred contract revenues, recorded in other current liabilities Contract with Customer, Liability, Noncurrent Deferred contract revenues, recorded in other long-term liabilities Contract with Customer, Liability Total contract liabilities, at end of period Total contract liabilities, at beginning of period Total contract liabilities Change in Contract with Customer, Asset and Liability [Abstract] Significant changes to contract liabilities Contract with Customer, Liability, Revenue Recognized Decrease due to recognition of revenues for goods and services Amount of increase in contract with customer obligation for the transfer goods or services to customers. Contract with Customer, Liability, Increase (Decrease) for Transfer to Customer Increase due to goods and services transferred over time Description of capital expenditures and other capital additions, including capitalized interest, by way of major ongoing construction projects. Actual Capital Expenditures and Other Capital Additions, Including Capitalized Interest [Table] Actual Capital Expenditures and Other Capital Additions, Including Capitalized Interest [Line Items] Changes in construction work in progress, including capital expenditures and other capital additions, such as capitalized interest, for our major construction projects Movement in Property, Plant and Equipment [Roll Forward] Changes in construction work in progress, including capital expenditures and other capital additions, such as capitalized interest Construction in Progress, Gross Construction work in progress, at end of period Construction work in progress, at beginning of period The change in accrued but unpaid capital expenditures. Change in Accrual of Construction in Progress Expenditures Changes in accrued capital additions Property, Plant and Equipment, Transfers and Changes Property and equipment placed into service Schedule of Impaired Long-Lived Assets Held and Used [Table] Impaired Long-Lived Assets Held and Used [Line Items] Impairment of assets held and used Impairment of Long-Lived Assets Held-for-use Impairment of in use assets Impairment Effect on Earnings Per Share, after Tax Loss associated with impairment, net of tax (per share) Represents the tax effect of impairments recognized during the period for long-lived assets classified as held and used in continuing operations. Long Lived Assets Held And Used, Impairment Charge Continuing Operations, Tax Effect Loss associated with in use asset impairment, tax effect Schedule of Long Lived Assets Held-for-sale [Table] Long Lived Assets Held-for-sale [Line Items] Assets held for sale Impairment of Long-Lived Assets to be Disposed of Aggregate loss on impairment of assets held for sale Represents the loss recognized for an asset classified as held for sale in continuing operations, net of tax. Long Lived Assets Held For Sale Impairment Charge Continuing Operations, Net Of Tax Aggregate loss on impairment of assets held for sale, net of tax Represents the tax effect of impairments recognized during the period for long-lived assets held in continuing operations for abandonment, exchange or sale. Impairment of Long Lived Assets to be Disposed of Continuing Operations, Tax Effect Aggregate loss on impairment of assets held for sale, tax effect Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Dispositions Assets of Disposal Group, Including Discontinued Operation, Current Assets held for sale, included in other current assets Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument Name [Domain] Debt Instrument, Name [Domain] A debt instrument, representing a financial security with a fixed interest rate and a stated maturity. Senior Notes Due6.50 Percent November2020 [Member] 6.50% Senior Notes due November 2020 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due6.375 Percent December2021 [Member] 6.375% Senior Notes due December 2021 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due5.52 Percent May2022 [Member] 5.52% Senior Notes due May 2022 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due3.8 Percent October2022 [Member] 3.80% Senior Notes due October 2022 Represents the information pertaining to 5.375% Senior Secured Notes due May 2023 Senior Secured Notes Due5.375 Percent May2023 [Member] 5.375% Senior Secured Notes due May 2023 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due9 Percent July2023 [Member] 9.00% Senior Notes due July 2023 Represents the 5.875% senior secured notes due January 2024. Senior Notes Due5.875 Percent January2024 [Member] 5.875% Senior Secured Notes due January 2024 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due7.75 Percent October2024 [Member] 7.75% Senior Secured Notes due October 2024 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due6.25 Percent December2024 [Member] 6.25% Senior Notes due December 2024 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due7.50 Percent January2026 [Member] 7.50% Senior Notes due January 2026 A debt instrument, representing a financial security with a fixed interest rate and a stated maturity. Notes Due7.45 Percent April2027 [Member] 7.45% Notes due April 2027 A debt instrument, representing a financial security with a fixed interest rate and a stated maturity. Debentures Due8 Percent April2027 [Member] 8.00% Debentures due April 2027 A debt instrument, representing a financial security with a fixed interest rate and a stated maturity. Notes Due7 Percent June2028 [Member] 7.00% Notes due June 2028 A debt instrument, representing a financial security with a fixed interest rate and a stated maturity. Notes Due7.5 Percent April2031 [Member] 7.50% Notes due April 2031 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due6.80 Percent March2038 [Member] 6.80% Senior Notes due March 2038 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due7.35 Percent December2041 [Member] 7.35% Senior Notes due December 2041 Debt Instrument [Line Items] Debt Long-term Debt, Other Disclosures [Abstract] Principal amount Long-term Debt, Gross Total principal amount of debt Aggregate principal amount outstanding Current portion before unamortized (discount) premium and debt issuance costs, of long-term debt. Long-term Debt, Gross, Current Debt due within one year Non current portion before unamortized (discount) premium and debt issuance costs, of long-term debt. Long-term Debt, Gross, Non Current Long-term debt Long-term Debt, by Current and Noncurrent [Abstract] Carrying amount Long-term Debt and Capital Lease Obligations, Including Current Maturities Total debt Long-term debt, including current maturities Long-term Debt and Capital Lease Obligations, Current Debt due within one year Debt Instrument, Interest Rate, Stated Percentage Debt instrument interest rate stated percentage Maturities of Long-term Debt [Abstract] Scheduled maturities of debt Long-term Debt, Maturities, Repayments of Principal in Next Rolling Twelve Months 2021 Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two 2022 Long-term Debt, Maturities, Repayments of Principal in Rolling Year Three 2023 Long-term Debt, Maturities, Repayments of Principal in Rolling Year Four 2024 Long-term Debt, Maturities, Repayments of Principal in Rolling Year Five 2025 Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five Thereafter Debt Instrument, Unamortized Discount (Premium), Net Total debt-related balances, net Long-term Debt Total carrying amount of debt Debt Instrument, Interest Rate During Period Interest rate, as adjusted (as a percent) Line of Credit Facility, Maximum Borrowing Capacity Borrowing capacity, maximum Debt Instrument, Basis Spread on Variable Rate Spread on variable rate basis (as a percent) The percentage reduction to the calculated variable rate. Debt Instrument Reduction to Calculated Variable Rate Percentage Percentage reduction to the calculated variable rate Line of Credit Facility, Commitment Fee Percentage Commitment fee percentage at period end Long-term Line of Credit Credit facility amount outstanding Letters of Credit Outstanding, Amount Letters of credit issued and outstanding Line of Credit Facility, Current Borrowing Capacity Credit facility available borrowing capacity Debt Instrument, Face Amount Debt instrument face value Debt Instrument, Redemption Price, Percentage Redemption price of debt instrument (as a percent) Restricted Cash and Cash Equivalents Restricted cash and cash equivalents Debt Instrument, Convertible, Conversion Ratio Debt conversion ratio Debt Instrument, Convertible, Conversion Price Debt conversion (in dollars per share) Extinguishment of Debt, Amount Debt retirement Repayments of Debt Aggregate cash payment Effective Income Tax Rate Reconciliation, Percent Effective tax rate Tax Adjustments, Settlements, and Unusual Provisions Various discrete tax items expense (benefit) Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations, excluding discrete items. Effective Income Tax Rate Reconciliation, Excluding Discrete Items, Percent Annual effective tax rate excluding discrete items (as a percent) Income Tax Examination [Table] Income Tax Examination [Line Items] Income Tax Examination Income Tax Examination, Estimate of Possible Loss Net adjustments of additional taxes, including interest and penalties Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities Name [Domain] Antidilutive Securities, Name [Domain] Stock Compensation Plan [Member] Share-based awards Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Securities excluded from earnings per share calculation (in shares) Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Numerator for loss per share, basic Net Income (Loss) Available to Common Stockholders, Basic Net loss attributable to controlling interest Weighted Average Number of Shares Outstanding, Basic [Abstract] Denominator for loss per share, basic Weighted Average Number of Shares Issued, Basic Weighted-average shares outstanding Weighted Average Number of Shares, Contingently Issuable Effect of share-based awards and other equity instruments Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Numerator for loss per share, diluted Net Income (Loss) Available to Common Stockholders, Diluted Net loss attributable to controlling interest This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (diluted). Weighted Average Number of Shares Issued, Diluted Weighted-average shares outstanding Loss Contingencies [Table] Litigation Case [Axis] Litigation Case Type [Domain] Litigation Case [Domain] Represents the Macondo well incident action lawsuit filed against the entity. Macondo Well Incident [Member] Macondo well incident Represents information pertaining to BP and PSC settlements. B P And P S C Settlement Agreements [Member] BP and PSC Settlement Agreement Represents information pertaining to PSC Settlement Agreement. Psc Settlement Agreement [Member] PSC Settlement Agreement Represents the Asbestos litigation lawsuit filed against the entity. Asbestos Litigation [Member] Asbestos litigation Geographical [Axis] Segment Geographical [Domain] Geographical [Domain] L [A] LA Loss Contingencies [Line Items] Contingencies Loss Contingency, Estimate of Possible Loss Amount of fines, recoveries and civil penalties Contractual Obligation Settlement Agreement Represents the number of subsidiaries party to the agreement. Number of Subsidiaries Number of subsidiaries Loss Contingency, Pending Claims, Number Number of claims Number of classes of plaintiffs that have filed claims pertaining to a loss contingency. Loss Contingency, Number of Classes of Plaintiffs Number of classes of plaintiffs Escrow Deposit Cash payment into an escrow account pending approval by MDL Court Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Portion At Fair Value Fair Value Disclosure [Member] Portion at Fair Value Measurement [Member] Carrying Reported Amount Fair Value Disclosure [Member] Carrying amount Estimate Of Fair Value Fair Value Disclosure [Member] Fair value Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial instruments Cash and Cash Equivalents, Fair Value Disclosure Cash and cash equivalents Class of Stock [Axis] Class Of Stock [Domain] Class of Stock [Domain] Represents the 0.5% Senior Unsecured Exchangeable Bonds, which are exchangeable into shares of the entity's stock. Senior Unsecured Exchangeable Bonds0.5 Percent [Member] 0.50% Exchangeable Bonds due January 2023 Property, Plant and Equipment, Type [Axis] Property Plant And Equipment Type [Domain] Property, Plant and Equipment, Type [Domain] Represents information related to the ultra-deepwater floaters asset group. Ultra Deepwater Floaters [Member] Ultra-deepwater floaters Represents information related to the harsh environment floaters asset group. Harsh Environment Floaters [Member] Harsh environment floaters Investment, Name [Axis] Equity Method Investee Name [Domain] Investment, Name [Domain] Represents information related to Transocean Norge, a harsh environment semisubmersible. Transocean Norge [Member] Transocean Norge Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Measurement Input Discount Rate [Member] Discount rate Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Accounts Receivable [Member] Accounts receivable Other Noncurrent Assets [Member] Other assets U [S] U.S. N [O] Norway B [R] Brazil Represents a country or countries that are not otherwise specified. Other Geographical [Member] Other Product and Service [Axis] Products And Services [Domain] Product and Service [Domain] Represents Deepwater Floater asset group. Deepwater Floater Assets [Member] Deepwater floaters Details pertaining to Midwater Floater asset group. Midwater Floater Asset Group [Member] Midwater floaters Construction In Progress [Member] Construction in Progress Capital Additions [Member] New builds Other Capitalized Property Plant And Equipment [Member] Other property and equipment Impaired Long-Lived Assets Held and Used by Type [Axis] Impaired Long Lived Assets Held And Used Asset Name [Domain] Impaired Long-Lived Assets Held and Used, Asset Name [Domain] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group Disposed Of By Sale Not Discontinued Operations [Member] Assets sold, not discontinued operations Disposal Group Name [Axis] Disposal Groups Including Discontinued Operations Name [Domain] Disposal Groups, Including Discontinued Operations, Name [Domain] Represents the sale of rig(s) and related equipment. Rig Sales [Member] Rig sales Represents the 6.125% senior secured notes due August 2025. Senior Secured Note6.125 Percent Due August2025 [Member] 6.125% Senior Secured Notes due August 2025 Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders. Senior Notes Due7.25 Percent November2025 [Member] 7.25% Senior Notes due November 2025 Represents 6.875% senior secured notes due February 2027. Senior Secured Note6.875 Percent Due February2027 [Member] 6.875% Senior Secured Notes due February 2027 Represents 8.00% senior unsecured notes due February 2027. Senior Unsecured Notes8.00 Percent Due February2027 [Member] 8.00% Senior Unsecured Notes due February 2027 Revolving Credit Facility [Member] Five-Year Revolving Credit Facility Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] The adjusted London Interbank Offered Rate. Adjusted L I B O R [Member] Adjusted LIBOR Range [Axis] Range [Member] Range [Domain] Minimum [Member] Minimum Maximum [Member] Maximum Extinguishment of Debt [Axis] Extinguishment Of Debt Type [Domain] Extinguishment of Debt, Type [Domain] Represents debt purchased in connection with a tender offer. Debt Tender Offer [Member] Tendered Represents debt securities repurchased and redeemed. Debt Redeemed [Member] Repurchased