Document and Entity Information [Abstract] Document and Entity Information. Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Document Fiscal Year Focus Document Fiscal Period Focus Current Fiscal Year End Date Entity Filer Category Entity Common Stock, Shares Outstanding Balance Sheets [Abstract] Consolidated Balance Sheets [Abstract] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents, end of period Cash and cash equivalents, beginning of period Total Receivables, Net, Current Total assets Assets LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Stockholders' Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accrued liabilities Total Other Liabilities, Current Total current liabilities Liabilities, Current Deferred tax liability Deferred Tax Liabilities, Noncurrent Total liabilities Liabilities Stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Common Stock, Value, Issued Common stock (par value $0.01, 500,000,000 shares authorized; 143,944,709 shares issued and 139,027,909 shares outstanding at March 31, 2012; 143,944,009 shares issued and 139,027,209 shares outstanding at December 31, 2011) Accumulated Other Comprehensive Income (Loss), Net of Tax Total other comprehensive income loss, ending balance Total other comprehensive income loss, beginning balance Accumulated other comprehensive gain (loss) Treasury Stock, Value Treasury stock, at cost (4,916,800 shares at March 31, 2012 and December 31, 2011) Total liabilities and stockholders' equity Liabilities and Stockholders' Equity Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Consolidated Statements of Operations [Abstract] Revenues: Revenues from contract drilling services by equipment-type Revenues [Abstract] Reimbursement Revenue Revenues related to reimbursable expenses Operating expenses: Operating Expenses [Abstract] Contract drilling, excluding depreciation Contract Revenue Cost Reimbursable expenses Cost of Reimbursable Expense Depreciation Cost of Services, Depreciation Provision for Doubtful Accounts Additional allowances deemed Bad debt recovery Total operating expenses Costs and Expenses Other income (expense): Nonoperating Income (Expense) [Abstract] Interest income Investment Income, Interest Interest Expense Non Operating Interest expense Total interest expense as reported The cost of borrowed funds accounted for as interest that was charged against earnings during the period. Also includes accrued interest on uncertain tax positions under FIN 48. Foreign Currency Transaction Gain (Loss), before Tax Foreign Currency Transaction Gain (Loss), before Tax, Total Foreign currency transaction loss Net Income (Loss) Attributable to Parent Net income Net income Net income - basic and diluted (numerator): Earnings Per Share [Abstract] Income per share: Earnings Per Share, Diluted Diluted Weighted-average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Consolidated Statements of Cash Flows [Abstract] Operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Gain on disposition of assets Gain (Loss) on Sale of Property Plant Equipment (Gain) loss on foreign currency forward exchange contracts Loss (gain) on foreign currency forward exchange contracts The aggregate unrealized foreign currency transaction gain or loss (pretax) related to foreign currency forward exchange derivative contracts included in determining net income for the reporting period. Stock-based compensation expense Share-based Compensation Deferred Income Net Deferred income, net The amount of deferred or unearned revenue received during the period, net of amortization of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to the receipt and amortization thereof of deferred mobilization and capital modification fees paid to the reporting entity. Deferred Expenses Net Deferred expenses, net The amount of deferred expenses incurred during the period, net of amortization of previously deferred charges that were recognized as expense during the period. For cash flows, this element primarily pertains to costs associated with the mobilization and/or contract preparation activities of drilling rigs in connection with a drilling contract to be amortized over the initial drilling contract period. Proceeds From Settlement Of Foreign Currency Forward Exchange Contracts Designated As Accounting Hedges (Payments of) proceeds from settlement of foreign currency forward exchange contracts designated as accounting hedges The net cash outflow (inflow) associated with derivative instruments, such as swaps, forwards, options, and so forth designated as hedges. Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Receivables Prepaid expenses and other current assets Increase (Decrease) in Prepaid, Deferred Expense and Other Assets Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Proceeds from disposition of assets, net of disposal costs Proceeds from Sale of Property, Plant, and Equipment Proceeds from sale and maturities of marketable securities Proceeds from Sale and Maturity of Marketable Securities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Payment of dividends Payments of Dividends, Common Stock Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities General Information [Abstract] General Information [Abstract] General Information. General Information And Significant Accounting Policies [Text Block] General Information Note to financial statements that describes (1) general nature of the business, (2) consolidation and basis of presentation, (3) use of estimates, (4) restatements, reclassifications and comparability of prior years' data (as applicable) and (5) significant accounting policies. Supplemental Financial Information [Abstract] Supplemental financial information. Supplemental Financial Information [Text Block] Supplemental Financial Information Supplemental financial information. Earnings Per Share Earnings Per Share [Text Block] Derivative Financial Instruments Derivative Financial Instruments Financial Instruments and Fair Value Disclosures Fair Value Disclosures [Text Block] Summary of Cost and accumulated depreciation of drilling and other property and equipment Drilling and Other Property and Equipment [Abstract] Drilling and Other Property and Equipment Property, Plant and Equipment Disclosure [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Segments and Geographic Area Analysis Segment Reporting Disclosure [Text Block] Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Unrealized holding gain/loss Net-of-Tax Unrealized holding gain Other Comprehensive Income, Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax Reclassification adjustment for loss (gain) included in net income Reclassification adjustment for gain included in net income Unrealized holding (loss) gain Other Comprehensive Income, Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Unrealized holding gain/loss Net-of-Tax Other Comprehensive Income, Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax Reclassification adjustment for loss (gain) included in net income Reclassification adjustment for gain (loss) included in net income Schedule of Property, Plant and Equipment [Table] Statement, Geographical [Axis] Segment, Geographical [Domain] Property, Plant and Equipment [Line Items] Number Of Cold Stacked Rigs Total number of cold stacked rigs Number of cold stacked rigs. General Information (Textual) [Abstract] General Information (Textual) [Abstract] General Information (Textual) [Abstract]. Majority Shareholder Outstanding Common Stock Owned Percentage Outstanding common stock owned by Loews Corporation Majority Shareholder Outstanding Common Stock Owned Percentage. Period Considered to Treat Short Term, Highly Liquid Investments as Cash Equivalents Period considered to treat short-term, highly liquid investments as cash equivalents Period considered to treat short-term, highly liquid investments as cash equivalents. Initial Term Of Contracts Minimum Months Initial term of contracts minimum months Minimum initial term of drilling contracts, in months. Initial Term Of Contracts Maximum Months Initial term of contracts maximum months Maximum initial term of drilling contracts, in months. Accounts receivable, net of provision for bad debts Receivables, Net, Current [Abstract] Trade receivables Accounts Receivable, Gross, Current Value added tax receivables Value Added Tax Receivable, Current Related party receivables Due from Related Parties, Current Receivables Gross Current Receivables gross current Receivables Gross Current. Prepaid Expenses And Other Current Assets [Abstract] Prepaid expenses and other current assets Prepaid Expenses and Other Current Assets. Rig Spare Parts And Supplies Rig spare parts and supplies Non-capitalized spare parts and supplies for use on drilling rigs. Deferred mobilization costs Other Deferred Costs, Net Prepaid insurance Prepaid Insurance Deposits Deposits Assets, Current Prepaid taxes Prepaid Taxes FOREX contracts Foreign Currency Cash Flow Hedge Asset at Fair Value Accrued Liabilities Accrued Liabilities [Abstract] Accrued Capital Project Or Upgrade Costs Accrued capital project/upgrade costs Accrued capital project/upgrade costs. Payroll and benefits Employee-related Liabilities, Current Deferred revenue Deferred Revenue, Current Rig Operating Expenses Rig operating expenses Accrued expenditures for direct rig operating costs, including catering, agency fees, fuel and equipment rental. Interest payable Interest Payable, Current Personal injury and other claims Workers' Compensation Liability, Current Accrued Drillship Construction Installment Construction milestone payments Amounts payable under construction contracts. Income Tax Authority [Domain] Foreign Country [Member] Foreign Country [Member] State And Local Jurisdiction [Member] Federal, State and Local Jurisdiction [Member] Income taxes paid, net Income Taxes Paid, Net Supplemental Financial Information (Textual) [Abstract] Supplemental financial information (Textual) [Abstract] Supplemental financial information. Recorded Unconditional Purchase Obligation Due within One Year First milestone payment related to Ocean Onyx Construction milestone payments Capital Expenditures Incurred but Not yet Paid Capital expenditures accrued but unpaid Unpaid accrued capital expenditures Reconciliation of the numerators and the denominators of basic and diluted per-share computations Earnings Per Share Reconciliation [Abstract] Effect of dilutive potential shares Dilutive Securities [Abstract] Incremental Common Shares Attributable to Share-based Payment Arrangements Stock options and stock appreciation rights Antidilutive Securities Excluded from Computation of Earnings Per Share, by Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Stock Appreciation Rights [Member] Stock appreciation rights [Member] Stock Appreciation Rights. Stock Options [Member] Stock options [Member] Securities excluded from computation of diluted earning per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule Of Available For Sale Securities [Table] United States Treasury Bills Due Within One Year [Member] U.S. Treasury Bills and Notes (due within one year) [Member] United states treasury bills due within one year. Schedule Of Available For Sale Securities [Line Items] Investments in marketable securities as available for sale Available-for-sale Securities [Abstract] Amortized Cost Available-for-sale Securities, Amortized Cost Proceeds From Sales And Maturities Of Marketable Securities And Gross Realized Gains And Losses [Abstract] Summary of proceeds from sales and maturities of marketable securities and gross realized gains and losses Proceeds From Sales And Maturities Of Marketable Securities And Gross Realized Gains And Losses. Proceeds from sales Proceeds from Sale of Available-for-sale Securities Proceeds from maturities Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Gross realized gains Available-for-sale Securities, Gross Realized Gains Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Derivative Contract Type [Domain] FOREX contracts [Member] Foreign Exchange Contract [Member] Derivative Instruments, Gain (Loss) by Income Statement Location [Axis] Income Statement and Other Comprehensive Income Location [Domain] Contract Revenue Cost [Member] Contract drilling, excluding depreciation [Member] Foreign currency transaction gain (loss) [Member] Foreign Currency Gain Loss [Member] Derivative Instruments, Gain (Loss) by Hedging Relationship [Axis] Hedging Relationship [Domain] Derivative designated as accounting hedges [Member] Cash Flow Hedging [Member] Derivative Instruments Gain Loss [Line Items] Derivative Instruments, Gain Recognized in Income, Net Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract] Derivative Instruments, Gain Recognized in Income Amount of Gain (Loss) Recognized in Income Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net [Abstract] Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract] Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Amount of (loss) gain reclassified from AOCGL into income (effective portion) Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net [Abstract] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Domain] Prepaid Expenses And Other Current Assets [Member] Prepaid expenses and other current assets [Member] Prepaid expenses and other current assets. Other Liabilities Current [Member] Accrued liabilities [Member] Derivatives, Fair Value [Line Items] Foreign Currency Accounting Hedges Foreign Currency Cash Flow Hedges [Abstract] Notional Amount Of Foreign Currency Contacts Settled Notional amount of foreign currency contracts settled Notional amount of foreign currency contacts designated as accounting hedges settled. Notional Amount Of Foreign Currency Contacts Not Designated As Hedges Settled Notional amount of foreign currency contracts not designated as accounting hedges settled Notional amount of foreign currency contracts not designated as accounting hedges settled. FOREX contracts outstanding in the aggregate notional amount Notional Amount of Foreign Currency Cash Flow Hedge Derivatives Reclassification unrealized gain (loss) associated with FOREX contracts Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months Fair Value By Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Fair Value, Disclosure Item Amounts [Domain] Carrying Reported Amount Fair Value Disclosure [Member] Carrying Value [Member] Portion At Fair Value Fair Value Disclosure [Member] Fair Value [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Senior Notes [Member] 5.15% Senior Notes [Member] Senior Notes Two [Member] 4.875% Senior Notes [Member] Senior Notes Two. Senior Notes Three [Member] 5.875% Senior Notes [Member] Senior Notes Three. Senior Notes Four [Member] 5.70% Senior Notes [Member] Senior Notes Four. Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] Fair values and related carrying values of our debt instruments [Abstract] Fair values and related carrying values of our debt instruments Fair values and related carrying values of our debt instruments Abstract. Debt Instrument, Fair Value Debt Instrument, Fair Value Senior notes Senior Notes Cash held in money market funds [Member] Money Market Funds [Member] U.S. Treasury Bills [Member] U.S. Treasury Bills [Member] Major Customers [Axis] Name of Major Customer [Domain] Petrobras [Member] Petroleo Brasileiro S.A. [Member] Petrobras [Member] Petrobras. OGX [Member] OGX [Member] OGX. Accounts receivable due from major customer Accounts receivable due from major customer Accounts receivable balance due from. Percentage of accounts receivable due from major customer Percentage of accounts receivable due from major customer Percentage of total consolidated trade accounts receivable balance due from a major customer. Financial Instruments and Fair Value Disclosures (Textual) [Abstract] Financial Instruments and Fair Value Disclosures (Textual) [Abstract] Financial Instruments and Fair Value Disclosures (Textual) [Abstract]. Net profits interest percent Net profits interest percent Percentage of net profits interest in oil and gas producing properties which is to be used to settle the remaining contractual day rate pertaining to a specific customer contract. Summary Of Cost And Accumulated Depreciation Of Drilling And Other Property And Equipment [Abstract] Summary of cost and accumulated depreciation of drilling and other property and equipment Summary of cost and accumulated depreciation of drilling and other property and equipment. Drilling rigs and equipment Machinery and Equipment, Gross Land and Buildings Land and buildings Land and Buildings. Commitments and Contingencies (Textual) [Abstract] Commitments and Contingencies (Textual) [Abstract] Commitments And Contingencies (Textual) [Abstract]. Deductible For Marine Liability Coverage Including Personal Injury Claims Per First Occurrence Deductible for marine liability coverage including personal injury claims, per first occurrence Deductible for marine liability coverage including personal injury claims, per first occurrence. Range of deductible for liability coverage for personal injury claims lower limit Range of deductible for liability coverage for personal injury claims, lower limit Range of deductible for liability coverage for personal injury claims, lower limit. Range of deductible for liability coverage for personal injury claims upper limit Range of deductible for liability coverage for personal injury claims, upper limit Range of deductible for liability coverage for personal injury claims, upper limit. Estimated liability for personal injury claims Loss Contingency, Estimate of Possible Loss Reserve for personal injury claims recorded in accrued liabilities Reserve for personal injury claims recorded in accrued liabilities Reserve for personal injury claims recorded in accrued liabilities. Reserve for personal injury claims recorded in other liabilities Reserve for personal injury claims recorded in other liabilities Reserve for personal injury claims recorded in other liabilities. First Installments on Drillships aggregate amount Purchase Obligations Other Purchase obligations Purchase obligations. Contingent liability under letters of credit and other bonds Contingent liability under letters of credit and other bonds Contingent liability under letters of credit and performance, bid, supersedes, tax appeal and customs bonds. Number of outstanding bonds purchased from related parties Number of outstanding bonds purchased from related parties Number of outstanding bonds purchased from related parties. Notional amount of outstanding bonds purchased from related parties Notional amount of outstanding bonds purchased from related parties Notional amount of outstanding bonds purchased from related parties. Schedule of Segment Reporting Information, by Segment [Table] Statement, Business Segments [Axis] Equipment Three [Member] Jack-ups [Member] Equipment Three Member. Other Equipment [Member] Other [Member] Other Equipment. Segment Reporting Information [Line Items] Country One [Member] United States [Member] Country One Member. South America [Member] South America [Member] Country Two [Member] Europe/Africa/Mediterranean [Member] Country Two Member. Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries, Amount Segments and Geographic Area Analysis (Textual) [Abstract] Segments and Geographic Area Analysis (Textual) [Abstract] Segments and geographic area analysis. Number Of Countries With Rigs Number of countries with rigs Number of countries with rigs. Commitments and contingencies (Note 8) Commitments and Contingencies Investments, Fair Value Disclosure Fair value of investments Derivative Instrument Risk [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Segment [Domain] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Revenues from External Customers and Long-Lived Assets [Line Items] Other Receivables, Gross, Current Other Income Tax Authority [Axis] Sum And Probability Of Occurrence Scenarios Sum and probability of occurrence scenarios. Sum and probability of occurrence scenarios Reduction In Assumed Dayrates For Cold Stacked Rigs Reduction in assumed dayrates for the cold-stacked rigs. Reduction in assumed dayrates for the cold-stacked rigs Designated as Hedging Instrument [Member] Designated as Hedging Instrument [Member] Foreign Currency Contract, Asset, Fair Value Disclosure FOREX contracts Assets, Fair Value Disclosure Total assets Fair Value by Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Marketable Securities Derivative Financial Instruments [Abstract] Financial Instruments and Fair Value Disclosures [Abstract] Segments and Geographic Area Analysis [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Accounts receivable, net of allowance for doubtful accounts Schedule of Accrued Liabilities [Table Text Block] Accrued liabilities Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block] Reconciliation of the numerators and the denominators of basic and diluted per-share computations Summary Of Proceeds From Sales And Maturities Of Marketable Securities And Gross Realized Gains And Losses [Table Text Block] Summary of proceeds from sales and maturities of marketable securities and gross realized gains and losses Summary of proceeds from sales and maturities of marketable securities and gross realized gains and losses. Amounts Recognized In Our Consolidated Statements Of Operations Related To Our FOREX Contracts Designated As Accounting Hedges [Table Text Block] Amounts recognized in our consolidated statements of operations related to our FOREX contracts designated as accounting hedges Amounts recognized in our consolidated statements of operations related to our FOREX contracts designated as accounting hedges. Long Term Debt Carrying Values And Fair Values [Table Text Block] Fair values and related carrying values of our debt instruments Long term debt carrying values and fair values. Revenues By Geographic Area Presented By Attributing Revenues To Individual Country [Table Text Block] Revenues by geographic area presented by attributing revenues to individual country Revenues by geographic area presented by attributing revenues to individual country. Derivative Asset, Fair Value, Net [Abstract] Derivative Liability, Fair Value, Net [Abstract] Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less: accumulated depreciation Other Assets, Current Other Allowance for Doubtful Accounts Receivable, Current Allowance for bad debts Provision for bad debts on trade receivables Other Accrued Liabilities, Current Other Foreign Currency Contracts, Liability, Fair Value Disclosure FOREX contracts Payments to Acquire Available-for-sale Securities Increase (Decrease) in Accrued Income Taxes Payable Taxes payable Furniture and Fixtures, Gross Office equipment and other Common Stock, Dividends, Per Share, Declared Cash dividends declared per share of common stock Revenue, Oil and Gas Services Contract drilling Earnings Per Share, Basic and Diluted [Abstract] Earnings per share: Earnings Per Share, Diluted, Other Disclosures [Abstract] Securities excluded from computation of diluted earning per share Marketable Securities [Abstract] Accounts Receivable Expected To Be Collected Within One Year Accounts receivable expected to be collected within one year Accounts receivable expected to be collected within one year. Assets, Current Total current assets Cash and Cash Equivalents, Period Increase (Decrease) Net change in cash and cash equivalents Property, Plant and Equipment, Gross Cost Net Book Value Of Cold Stacked Rigs Aggregate net book value Net book value of cold stacked rigs Net book value of cold stacked rigs. Cash Flow Hedge Derivative Instrument Assets at Fair Value Derivative assets designated as hedging instruments, current Cash Flow Hedge Derivative Instrument Liabilities at Fair Value Derivative liabilities designated as hedging instruments, current Mortgage-backed Securities Available-for-sale, Fair Value Disclosure Mortgage-backed securities Fair Value by Asset Class [Axis] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, by Asset Class [Domain] Accounts receivable, net of allowance for bad debts Accounts and Other Receivables, Net, Current Accounts receivable, net of allowance for bad debts Interest Expense, Long-term Debt Interest paid on long-term debt Property, Plant and Equipment by Type [Axis] Property, Plant and Equipment, Type [Domain] Income Tax Examination [Table] Income Tax Examination [Line Items] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Schedule of Available-for-sale Securities, Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Assets, Fair Value Disclosure [Abstract] Assets: Liabilities, Fair Value Disclosure [Abstract] Liabilities: Accounts Receivable By Major Customers [Table] Accounts receivable by major customers. Accounts Receivable By Major Customers [Line Items] Accounts receivable by major customers. Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Entity's Country of Domicile Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Entity's Country of Domicile Available-for-sale Securities, Gross Unrealized Gain (Loss) Unrealized Gain (Loss) Purchases of marketable securities Prepaid Expense and Other Assets, Current Total Prepaid expenses and other current assets Interest Costs Capitalized Capitalized interest Capitalized interest Interest Costs Incurred Total interest cost, including amortization of debt issuance costs Reconciliation Of Aggregate Interest Cost To Interest Expense [Table Text Block] Reconciliation of total interest cost to Interest expense Reconciliation of aggregate interest cost to interest expense. Reconciliation Of Aggregate Interest Cost To Interest Expense [Abstract] Reconciliation of total interest cost to interest expense Reconciliation of aggregate interest cost to interest expense. Fair Value Measurements Recurring [Member] Fair Value Measurements [Member] Construction In Progress Gross Construction work-in-progress Drilling And Other Property And Equipment (Textual) [Abstract] Drilling and Other Property and Equipment (Textual) [Abstract] Drilling and other property and equipment. Comprehensive Income, Net of Tax, Attributable to Parent Comprehensive income Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Text Block] Fair values of our derivative financial instruments Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Text Block] Amounts recognized in our Consolidated Balance Sheets and Consolidated Statements of Operations related to our FOREX contracts designated as cash flow hedges Fair Value, Measurement Inputs, Disclosure [Text Block] Assets and liabilities measured at fair value on a recurring basis Property, Plant and Equipment [Text Block] Summary of Cost and accumulated depreciation of drilling and other property and equipment Schedule of Segment Reporting Information, by Segment [Text Block] Revenues from contract drilling services by equipment-type Mortgage Backed Securities [Member] Mortgage-backed Securities [Member] Short-term Investments [Member] Short-term investments [Member] Number of drillships under construction Number of drillships under construction Number of drillships under construction. Accretion (Amortization) of Discounts and Premiums, Investments Accretion of discounts on marketable securities Increase (Decrease) in Other Noncurrent Assets Other assets, noncurrent Increase (Decrease) in Other Noncurrent Liabilities Other liabilities, noncurrent Proceeds from (Payments for) Other Financing Activities Other Amount Capitalized For Asset Replacements and Betterments Amount capitalized for asset replacements and betterments Amount capitalized for asset replacements and betterments. Range of Asset Project Costs Lower Limit Range of asset project costs, lower limit Range of asset project costs, lower limit Range of Asset Project Costs Upper Limit Range of asset project costs, upper limit Range of asset project costs, upper limit. Reserve For Bad Debts Recovered Recorded In Prior Period Amount of bad debts recorded in prior periods and subsequently recovered Amount of bad debts recorded in prior periods and subsequently recovered. Available-for-sale Securities, Debt Securities, Current Market Value Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Amount of gain recognized in AOCGL on derivative (effective portion) Consolidated Statements of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net of Tax Total other comprehensive gain Total other comprehensive gain/loss Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract] Foreign currency forward exchange contracts: Commitments and Contingencies [Abstract] Income Tax Disclosure [Text Block] Income Taxes Schedule of Temporary Impairment Losses, Investments [Table Text Block] Summary of cold stacked rigs evaluated for impairment Summary Of Cold Stacked Rigs Evaluated For Impairment [Abstract] Summary of cold stacked rigs evaluated for impairment Summary of cold stacked rigs evaluated for impairment. Mid Water Semisubmersibles [Member] Mid-Water floaters [Member] Mid-Water semisubmersibles. Effect of Exchange Rate on Cash and Cash Equivalents Effect of exchange rate changes on cash balances held in foreign currencies Property, Plant and Equipment, Useful Life, Minimum Estimated useful life for Drilling rigs and equipments, Minimum Property, Plant and Equipment, Useful Life, Maximum Estimated useful life for Drilling rigs and equipments, Maximum Cash Payments Of Capital Expenditures Accrued In Prior Year Cash payments of capital expenditures accrued in the prior year Cash payments of capital expenditures accrued in prior year. Weighted Average Number of Shares Outstanding, Diluted Weighted-average shares including conversions - diluted (denominator) Total weighted-average shares outstanding Notional Amount Of Foreign Currency Contacts Settled Designated As Hedging Instruments Notional amount of foreign currency contracts settled designated as hedging instruments Notional amount of foreign currency contracts settled designated as hedging instruments. Long-term Debt, Excluding Current Maturities Total Long-term debt Other Comprehensive Income, Available-for-sale Securities Adjustment, Net of Tax [Abstract] Investments in marketable securities: Investments in marketable securities: Number Of Turnkey Contracts Number of turnkey contracts for drillship construction Number of turnkey contracts for drillship construction. Deferred Income Tax Expense (Benefit) Total deferred Deferred tax provision Income Tax Expense (Benefit) Income tax expense Income tax expense, Total MEXICO Mexico [Member] BRAZIL Brazil [Member] Income Taxes [Abstract] Income Taxes (Textual) [Abstract] Income taxes. Income Taxes (Textual) [Abstract] Ultra Deepwater [Member] Ultra deepwater. Ultra Deepwater [Member] Deepwater [Member] Deepwater. Deepwater [Member] Mid Water [Member] Mid water Mid Water [Member] Revenues Total revenues Revenues Operating Income (Loss) Operating income Operating income Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Securities excluded from computation of diluted earning per share Available-for-sale Securities [Table Text Block] Investments in marketable securities as available for sale Stockholders' Equity Attributable to Parent Ending balance Beginning balance Total stockholders' equity Retained Earnings (Accumulated Deficit) Retained earnings Additional Paid in Capital Additional paid-in capital Other Liabilities, Noncurrent Other liabilities Taxes Payable, Current Taxes payable Accounts Payable, Current Accounts payable Other Assets, Noncurrent Other assets Property, Plant and Equipment, Net Total long lived tangible assets Drilling and other property and equipment, net Drilling and other property and equipment, net of accumulated depreciation Available-for-sale Securities, Current Marketable securities Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Common Stock, Shares, Issued Common stock, shares issued Common Stock, Shares, Outstanding Common stock, shares outstanding Treasury Stock, Shares Treasury stock, shares Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Cumulative Effects of Changes in Accounting Principles, Noncontrolling Interest Income before income tax expense Income before income tax expense General and Administrative Expense General and administrative Gain (Loss) on Disposition of Assets Gain on disposition of assets Other Nonoperating Income (Expense) Other, net Earnings Per Share, Basic Basic Weighted Average Number of Shares Outstanding, Basic Shares of common stock Weighted-average shares - basic (denominator): Weighted Average Number Diluted Shares Outstanding Adjustment Dilutive potential shares of common stock Deferred Tax Assets, Net, Current Deferred Tax Asset on Worker's compensation and other current accruals included in prepaid expenses and other current assets Deferred tax assets Available-for-sale Securities, Fair Value Disclosure Short-term investments Level 1 [Member] Level 1 [Member] Level 2 [Member] Level 2 [Member] Level 3 [Member] Level 3 [Member] Unrecorded Unconditional Purchase Obligation, Purchases Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive gains (losses), net of tax: Receivables, Long-term Contracts or Programs Interest Receivable Debt Instrument, Interest Rate, Stated Percentage Stated Interest Rate Interest rate of senior notes Payments to Acquire Property, Plant, and Equipment Capital expenditures (including rig construction) Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] Prepaid expenses and other current assets Available-for-sale Securities, Gross Realized Losses Gross realized losses Ocean Onyx [Member] Ocean Onyx. Ocean Onyx [Member] Income Tax Examination By Period [Axis] Income tax examination by period. Income Tax Examination By Period [Domain] Income tax examination by period. Geographic Areas, Revenues from External Customers [Abstract] Revenues by geographic area, presented by attributing revenues to the individual country Drillship [Member] Drillship. Drillship [Member] Number of rigs not subject to impairment Number of rigs not subject to impairment Number of rigs not subject to impairment. Foreign Currency Transaction Gain (Loss), Realized Gain (loss) on foreign currency transactions recognized in income Derivative Instruments, Loss Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing Amount of Loss Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Two Thousand Seven Tax Year [Member] 2007 Tax Year [Member] Two thousand seven tax year. Amount Of Tax Assessment Including Interest And Penalties Total tax assessment including interest and penalty Amount of tax assessment including interest and penalties. Segment Geographical Groups Of Countries Group One [Member] Australia/Asia [Member] Australia/Asia/Middle East [Member] Unconditional Purchase Obligation Total unconditional purchase obligation for Onyx Project The total amount of the long-term purchase obligation as of the balance sheet date, which equals the sum of all payments due for purchase, commissioning, spares and project management for the Onyx project. Unconditional Purchase Obligation Drillships Total unconditional purchase obligation for drillships The total amount of the long-term purchase obligation as of the balance sheet date, which equals the sum of all payments due for purchase, commissioning, spares and project management for drillship construction. Assets Held-for-sale, Current Transferred aggregate net book value of rig Assets held for sale Other Operating Activities, Cash Flow Statement Other Long Lived Assets Held-for-sale, Gain (Loss) on Sale Net gain on sale of rig Deposits received on assets held for sale Nonrefundable deposits received related to the potential sales of these assets Deposits received on sales of rigs Deposits received on assets held for sale. Cold Stacked Rigs [Member] Cold-stacked rigs. Cold-stacked rigs [Member] Net book value of asset retired Net book value of rigs retired Net book value of asset retired. Vessel Modification Agreement Payment During Period Vessel modification agreement Payment during the period Vessel modification agreement Payment during the period. Expected Period For Sale Of Assets Held For Sale Maximum Expected period for sale of assets held for sale, maximum. Expected period for sale of assets held for sale, maximum Floaters [Member] Total Floaters [Member] Total Floaters. Performance Bonds That May Require Collateral At Any Time Performance bonds that may require collateral at any time Performance bonds that may require collateral at any time. Total number of installments due under vessel modification agreement Total number of installments due under vessel modification agreement. Number Of Installments Due Under Vessel Modification Agreement Total number of installments due under each drillship turnkey construction agreement Total number of installment due under each drillship turnkey construction agreement. Number Of Installment Due Under Each Drillship Turnkey Construction Agreement Number Of Equipments Transferred At Net Book Value To Assets Held For Sale Number of Rigs transferred at net book value to Asset held for sale Number of equipments transferred at net book value to assets held for sale. EGYPT Other Customers Current [Member]