Diamond Offshore Drilling (DODRW) 10-K 24 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 18, 2014	Jun. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'DO	'	'
Entity Registrant Name	'DIAMOND OFFSHORE DRILLING INC	'	'
Entity Central Index Key	'0000949039	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	139,035,448	'
Entity Public Float	'	'	$4,741,751,658

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$347,011	$335,432
Marketable securities	1,750,053	1,150,158
Accounts receivable, net of allowance for bad debts	469,355	499,660
Prepaid expenses and other current assets	143,997	136,099
Assets held for sale	7,694	11,594
Total current assets	2,718,110	2,132,943
Drilling and other property and equipment, net of accumulated depreciation	5,467,227	4,864,972
Other assets	206,097	237,371
Total assets	8,391,434	7,235,286
Current liabilities:	'	'
Accounts payable	94,151	96,631
Accrued liabilities	370,671	324,434
Taxes payable	30,806	64,481
Current portion of long-term debt	249,954	'
Total current liabilities	745,582	485,546
Long-term debt	2,244,189	1,496,066
Deferred tax liability	525,541	490,946
Other liabilities	238,864	186,334
Total liabilities	3,754,176	2,658,892
Commitments and contingencies (Note 11)	'	'
Stockholders' equity:	'	'
Preferred stock (par value $0.01, 25,000,000 shares authorized, none issued and outstanding)	'	'
Common stock (par value $0.01, 500,000,000 shares authorized; 143,952,248 shares issued and 139,035,448 shares outstanding at December 31, 2013; 143,948,370 shares issued and 139,031,570 shares outstanding at December 31, 2012)	1,440	1,439
Additional paid-in capital	1,988,720	1,983,957
Retained earnings	2,761,161	2,702,915
Accumulated other comprehensive gain (loss)	350	2,496
Treasury stock, at cost (4,916,800 shares of common stock at December 31, 2013 and 2012)	-114,413	-114,413
Total stockholders' equity	4,637,258	4,576,394
Total liabilities and stockholders' equity	$8,391,434	$7,235,286

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	143,952,248	143,948,370
Common stock, shares outstanding	139,035,448	139,031,570
Treasury stock, shares	4,916,800	4,916,800

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:	'	'	'
Contract drilling	$2,843,584	$2,936,066	$3,254,313
Revenues related to reimbursable expenses	76,837	50,442	68,106
Total revenues	2,920,421	2,986,508	3,322,419
Operating expenses:	'	'	'
Contract drilling, excluding depreciation	1,572,525	1,537,224	1,548,502
Reimbursable expenses	74,967	48,778	66,052
Depreciation	388,092	392,913	398,612
General and administrative	64,788	64,640	65,310
Impairment of assets	'	62,437	'
Bad debt expense (recovery)	22,513	-1,018	-6,713
Gain on disposition of assets	-4,070	-80,844	-4,758
Total operating expenses	2,118,815	2,024,130	2,067,005
Operating income	801,606	962,378	1,255,414
Other income (expense):	'	'	'
Interest income	701	4,910	6,668
Interest expense	-24,843	-46,216	-73,137
Foreign currency transaction loss	-4,915	-1,999	-8,588
Other, net	1,691	-992	-1,086
Income before income tax expense	774,240	918,081	1,179,271
Income tax expense	-225,554	-197,604	-216,729
Net income	$548,686	$720,477	$962,542
Earnings per share, Basic and Diluted	$3.95	$5.18	$6.92
Weighted-average shares outstanding:	'	'	'
Shares of common stock	139,035	139,029	139,027
Dilutive potential shares of common stock	29	19	11
Total weighted-average shares outstanding	139,064	139,048	139,038
Cash dividends declared per share of common stock	$3.50	$3.50	$3.50

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]	'	'	'
Net income	$548,686	$720,477	$962,542
Derivative financial instruments:	'	'	'
Unrealized holding (loss) gain	-6,833	4,237	-625
Reclassification adjustment for loss (gain) included in net income	4,840	2,733	-6,728
Investments in marketable securities:	'	'	'
Unrealized holding (loss) gain on investments	-6	124	-46
Reclassification adjustment for (gain) loss included in net income	-147	44	-384
Total other comprehensive (loss) gain	-2,146	7,138	-7,783
Comprehensive income	$546,540	$727,615	$954,759

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Gains (Losses) [Member]	Treasury Stock [Member]
In Thousands, except Share data
Beginning Balance at Dec. 31, 2010	$3,861,712	$1,439	$1,972,550	$1,998,995	$3,141	($114,413)
Beginning Balance, shares at Dec. 31, 2010	'	143,943,624	'	'	'	4,916,800
Net income	962,542	'	'	962,542	'	'
Dividends to stockholders ($3.50 per share)	-486,595	'	'	-486,595	'	'
Anti-dilution adjustment paid to stock plan participants ($3.00 per share)	-2,632	'	'	-2,632	'	'
Stock options exercised, shares	'	385	'	'	'	'
Stock-based compensation, net of tax	5,819	'	5,819	'	'	'
Net gain (loss) on derivative financial instruments	-7,353	'	'	'	-7,353	'
Net gain (loss) on investments	-430	'	'	'	-430	'
Ending Balance at Dec. 31, 2011	4,333,063	1,439	1,978,369	2,472,310	-4,642	-114,413
Ending Balance, Shares at Dec. 31, 2011	'	143,944,009	'	'	'	4,916,800
Net income	720,477	'	'	720,477	'	'
Dividends to stockholders ($3.50 per share)	-486,603	'	'	-486,603	'	'
Anti-dilution adjustment paid to stock plan participants ($3.00 per share)	-3,269	'	'	-3,269	'	'
Stock options exercised	148	'	148	'	'	'
Stock options exercised, shares	'	4,361	'	'	'	'
Stock-based compensation, net of tax	5,440	'	5,440	'	'	'
Net gain (loss) on derivative financial instruments	6,970	'	'	'	6,970	'
Net gain (loss) on investments	168	'	'	'	168	'
Ending Balance at Dec. 31, 2012	4,576,394	1,439	1,983,957	2,702,915	2,496	-114,413
Ending Balance, Shares at Dec. 31, 2012	'	143,948,370	'	'	'	4,916,800
Net income	548,686	'	'	548,686	'	'
Dividends to stockholders ($3.50 per share)	-486,620	'	'	-486,620	'	'
Anti-dilution adjustment paid to stock plan participants ($3.00 per share)	-3,820	'	'	-3,820	'	'
Stock options exercised	110	1	109	'	'	'
Stock options exercised, shares	15,091	3,878	'	'	'	'
Stock-based compensation, net of tax	4,654	'	4,654	'	'	'
Net gain (loss) on derivative financial instruments	-1,993	'	'	'	-1,993	'
Net gain (loss) on investments	-153	'	'	'	-153	'
Ending Balance at Dec. 31, 2013	$4,637,258	$1,440	$1,988,720	$2,761,161	$350	($114,413)
Ending Balance, Shares at Dec. 31, 2013	'	143,952,248	'	'	'	4,916,800

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (Retained Earnings [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Retained Earnings [Member]	'	'	'
Stockholders dividends per share	$3.50	$3.50	$3.50
Anti-dilution adjustment paid to stock plan participants per share	$3	$3	$3

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:	'	'	'
Net income	$548,686	$720,477	$962,542
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Depreciation	388,092	392,913	398,612
Impairment of assets	'	62,437	'
Gain on disposition of assets	-4,070	-80,844	-4,758
Bad debt expense (recovery)	22,513	-1,018	-6,713
Loss (gain) on foreign currency forward exchange contracts	6,501	4,302	-7,206
Deferred tax provision	34,101	-51,472	2,141
Accretion of discounts on marketable securities	-707	4,622	1,586
Stock-based compensation expense	3,573	4,357	4,956
Deferred income, net	-54,274	1,767	-32,219
Deferred expenses, net	25,604	67,824	53,317
Long-term employee remuneration programs	8,966	7,611	3,944
Other assets, noncurrent	-4,922	-2,794	2,220
Other liabilities, noncurrent	-5,296	3,614	6,921
(Payments of) proceeds from settlement of foreign currency forward exchange contracts designated as accounting hedges	-6,501	-4,302	7,206
Bank deposits denominated in nonconvertible currencies	-12,741	'	'
Other	1,954	1,258	319
Changes in operating assets and liabilities:	'	'	'
Accounts receivable	7,905	65,074	67,498
Prepaid expenses and other current assets	10,066	-8,960	-6,406
Accounts payable and accrued liabilities	46,752	10,354	-9,842
Taxes payable	49,786	114,049	-24,013
Net cash provided by operating activities	1,065,988	1,311,269	1,420,105
Investing activities:	'	'	'
Capital expenditures (including rig construction)	-957,598	-702,041	-774,756
Proceeds from disposition of assets, net of disposal costs	4,900	138,495	5,603
Proceeds from sale and maturities of marketable securities	4,650,085	2,725,118	5,362,138
Purchases of marketable securities	-5,249,462	-2,977,290	-5,653,665
Net cash used in investing activities	-1,552,075	-815,718	-1,060,680
Financing activities:	'	'	'
Issuance of senior notes	997,805	'	'
Debt issuance costs and arrangement fees	-9,973	-3,838	'
Payment of dividends	-490,331	-490,245	-490,057
Other	165	199	4
Net cash used in financing activities	497,666	-493,884	-490,053
Net change in cash and cash equivalents	11,579	1,667	-130,628
Cash and cash equivalents, beginning of year	335,432	333,765	464,393
Cash and cash equivalents, end of year	$347,011	$335,432	$333,765

General_Information

General Information	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
General Information	'
	1	General Information
	Diamond Offshore Drilling, Inc. is a leader in offshore drilling, providing contract drilling services to the energy industry around the globe with a fleet of 45 offshore drilling rigs, including five rigs under construction. Our fleet consists of 33 semisubmersibles, two of which are under construction, seven jack-ups, one of which is held for sale, and five dynamically positioned drillships, three of which are under construction. At December 31, 2013, one of our jack-up rigs, the Ocean Spartan, was reported as “Asset held for sale” in our Consolidated Balance Sheets. Unless the context otherwise requires, references in these Notes to “Diamond Offshore,” “we,” “us” or “our” mean Diamond Offshore Drilling, Inc. and our consolidated subsidiaries. We were incorporated in Delaware in 1989.
	As of February 18, 2014, Loews Corporation, or Loews, owned 50.4% of the outstanding shares of our common stock.
	Principles of Consolidation
	Our consolidated financial statements include the accounts of Diamond Offshore Drilling, Inc. and our subsidiaries after elimination of intercompany transactions and balances.
	Use of Estimates in the Preparation of Financial Statements
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States, or U.S., or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from those estimated.
	Reclassifications
	Certain amounts applicable to the prior periods have been reclassified to conform to the classifications currently followed. Such reclassifications did not affect earnings.
	Cash and Cash Equivalents
	We consider short-term, highly liquid investments that have an original maturity of three months or less and deposits in money market mutual funds that are readily convertible into cash to be cash equivalents. We had bank deposits denominated in Egyptian pounds totaling $14.3 million at December 31, 2013. However, the local currency is not readily convertible into U.S. dollars or other currencies at this time. While we believe that a portion of these amounts will be used to fund local operations and obligations in Egyptian pounds in the short term, we reclassified $12.7 million to “Other assets” in our Consolidated Balance Sheets at December 31, 2013.
	The effect of exchange rate changes on cash balances held in foreign currencies was not material for the years ended December 31, 2013, 2012 and 2011.
	Marketable Securities
	We classify our investments in marketable securities as available for sale and they are stated at fair value in our Consolidated Balance Sheets. Accordingly, any unrealized gains and losses, net of taxes, are reported in our Consolidated Balance Sheets in “Accumulated other comprehensive gain (loss)” until realized. The cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity and such adjustments are included in our Consolidated Statements of Operations in “Interest income.” The sale and purchase of securities are recorded on the date of the trade. The cost of debt securities sold is based on the specific identification method. Realized gains or losses, as well as any declines in value that are judged to be other than temporary, are reported in our Consolidated Statements of Operations in “Other income (expense) — Other, net.”
	Provision for Bad Debts
	We record a provision for bad debts on a case-by-case basis when facts and circumstances indicate that a customer receivable may not be collectible. In establishing these reserves, we consider historical and other factors that predict collectability, including write-offs, recoveries and the monitoring of credit quality. Such provision is reported as a component of “Operating expense” in our Consolidated Statements of Operations. See Note 2.
	Derivative Financial Instruments
	Our derivative financial instruments consist primarily of foreign currency forward exchange, or FOREX, contracts which we may designate as cash flow hedges. In accordance with GAAP, each derivative contract is stated in the balance sheet at its fair value with gains and losses reflected in the income statement except that, to the extent the derivative qualifies for and is designated as an accounting hedge, the gains and losses are reflected in income in the same period as offsetting gains and losses on the qualifying hedged positions. Designated hedges are expected to be highly effective, and therefore, adjustments to record the carrying value of the effective portion of our derivative financial instruments to their fair value are recorded as a component of “Accumulated other comprehensive gain (loss),” or AOCGL, in our Consolidated Balance Sheets. The effective portion of the cash flow hedge will remain in AOCGL until it is reclassified into earnings in the period or periods during which the hedged transaction affects earnings or it is determined that the hedged transaction will not occur. We report such realized gains and losses as a component of “Contract drilling, excluding depreciation” expense in our Consolidated Statements of Operations to offset the impact of foreign currency fluctuations in our expenditures in local foreign currencies in the countries in which we operate.
	Adjustments to record the carrying value of the ineffective portion of our derivative financial instruments to fair value and realized gains or losses upon settlement of derivative contracts not designated as cash flow hedges are reported as “Foreign currency transaction gain (loss)” in our Consolidated Statements of Operations. See Notes 6 and 7.
	Assets Held For Sale
	In 2012, our management adopted a plan to actively market for sale three mid-water semisubmersibles, the Ocean Epoch, the Ocean New Era and the Ocean Whittington, and one jack-up rig, the Ocean Spartan. This decision was based on management’s review of our drilling fleet at the end of 2012 and their assessment that three of these rigs had no short-term outlook for work due to their age and capabilities. These rigs were put on the market for sale at the end of 2012.
	In connection with the reclassification of these rigs to “Assets held for sale,” we measured the fair value of each rig in the disposal group using a probability-weighted cash flow analysis that utilized significant unobservable inputs, representing a Level 3 fair value measurement, which included assumptions for estimated proceeds that may be received upon disposition of the rig and estimated costs to sell. For our three mid-water semisubmersibles in the disposal group, we determined, at that time, that, due to the expected resale market for rigs of this type and age, the highest and best use of these rigs would be for sale as scrap. Based on our analyses, we determined that the carrying values of the mid-water semisubmersible rigs in the disposal group were impaired, as the carrying value for each exceeded its aggregate fair value, and recognized an impairment loss in the fourth quarter of 2012. We determined that the carrying value of the Ocean Spartan was not impaired.
	These rigs were not sold during 2013. The three mid-water semisubmersible rigs have been transferred to “Drilling and Other Property and Equipment” at their aggregate fair value of $3.9 million. Only the Ocean Spartan was reported as “Assets Held for Sale” at December 31, 2013. We reported “Assets held for sale” aggregating $7.7 million and $11.6 million in our Consolidated Balance Sheets at December 31, 2013 and 2012, respectively. See “Impairment of Long-Lived Assets” and Note 7.
	Drilling and Other Property and Equipment
	We carry our drilling and other property and equipment at cost. Maintenance and routine repairs are charged to income currently while replacements and betterments, which upgrade or increase the functionality of our existing equipment and that significantly extend the useful life of an existing asset, are capitalized. Significant judgments, assumptions and estimates may be required in determining whether or not such replacements and betterments meet the criteria for capitalization and in determining useful lives and salvage values of such assets. Changes in these judgments, assumptions and estimates could produce results that differ from those reported. Historically, the amount of capital additions requiring significant judgments, assumptions or estimates has not been significant. During the years ended December 31, 2013 and 2012, we capitalized $302.0 million and $220.3 million, respectively, in replacements and betterments of our drilling fleet, resulting from numerous projects ranging from $25,000 to $40 million per project.
	Costs incurred for major rig upgrades and/or the construction of rigs are accumulated in construction work-in-progress, with no depreciation recorded on the additions, until the month the upgrade or newbuild is completed and the rig is placed in service. Upon retirement or sale of a rig, the cost and related accumulated depreciation are removed from the respective accounts and any gains or losses are included in our results of operations as “Gain on disposition of assets.” Depreciation is recognized up to applicable salvage values by applying the straight-line method over the remaining estimated useful lives from the year the asset is placed in service. Drilling rigs and equipment are depreciated over their estimated useful lives ranging from 3 to 30 years.
	Capitalized Interest
	We capitalize interest cost for qualifying construction and upgrade projects. During the three years ended December 31, 2013, we capitalized interest on qualifying expenditures, primarily related to our rig construction projects. See Note 8.
	A reconciliation of our total interest cost to “Interest expense” as reported in our Consolidated Statements of Operations is as follows:
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Total interest cost including amortization of debt issuance costs		$	99,080		$	83,890		$	84,349
	Capitalized interest			(74,237	)		(37,674	)		(11,212	)
	Total interest expense as reported		$	24,843		$	46,216		$	73,137
	Asset Retirement Obligations
	At December 31, 2013 and 2012, we had no asset retirement obligations.
	Impairment of Long-Lived Assets
	We evaluate our property and equipment for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable (such as cold stacking a rig or excess spending over budget on a newbuild, construction project or major rig upgrade). We utilize an undiscounted probability-weighted cash flow analysis in testing an asset for potential impairment. Our assumptions and estimates underlying this analysis include the following:
		•		dayrate by rig;
		•		utilization rate by rig (expressed as the actual percentage of time per year that the rig would be used);
		•		the per day operating cost for each rig if active, warm stacked or cold stacked;
		•		the estimated annual cost for rig replacements and/or enhancement programs;
		•		the estimated maintenance, inspection or other costs associated with a rig returning to work;
		•		salvage value for each rig; and
		•		estimated proceeds that may be received on disposition of the rig.
	Based on these assumptions and estimates, we develop a matrix using several different utilization/dayrate scenarios, to each of which we have assigned a probability of occurrence. The sum of our utilization scenarios (which include active, warm stacked and cold stacked) and probability of occurrence scenarios both equal 100% in the aggregate. We reevaluate our cold-stacked rigs annually, by updating the matrices for each rig and modifying our assumptions, giving consideration to the length of time the rig has been cold stacked, the current and expected market for the type of rig and expectations of future oil and gas prices.
	At December 31, 2012, our four cold-stacked rigs were reported as “Assets held for sale” and had an aggregate net book value of $11.6 million. In connection with the presentation of these rigs as held for sale at the end of 2012, we recognized an impairment loss of $62.4 million. These four rigs remained cold stacked at December 31, 2013. We did not record any impairment with respect to our cold-stacked rigs at December 31, 2013. See “Assets Held for Sale.”
	Management’s assumptions are an inherent part of our asset impairment evaluation and the use of different assumptions could produce results that differ from those reported.
	Fair Value of Financial Instruments
	We believe that the carrying amount of our current financial instruments approximates fair value because of the short maturity of these instruments. For non-current financial instruments we use quoted market prices, when available, and discounted cash flows to estimate fair value. See Note 7.
	Debt Issuance Costs
	Debt issuance costs are included in our Consolidated Balance Sheets in “Other assets” and are amortized over the respective terms of the related debt.
	Income Taxes
	We account for income taxes in accordance with accounting standards that require the recognition of the amount of taxes payable or refundable for the current year and an asset and liability approach in recognizing the amount of deferred tax liabilities and assets for the future tax consequences of events that have been currently recognized in our financial statements or tax returns. In each of our tax jurisdictions we recognize a current tax liability or asset for the estimated taxes payable or refundable on tax returns for the current year and a deferred tax asset or liability for the estimated future tax effects attributable to temporary differences and carryforwards. Deferred tax assets are reduced by a valuation allowance, if necessary, which is determined by the amount of any tax benefits that, based on available evidence, are not expected to be realized under a “more likely than not” approach. We make judgments regarding future events and related estimates especially as they pertain to the forecasting of our effective tax rate, the potential realization of deferred tax assets such as utilization of foreign tax credits, and exposure to the disallowance of items deducted on tax returns upon audit.
	We record interest related to accrued unrecognized tax positions in interest expense and recognize penalties associated with uncertain tax positions in our tax expense. See Note 13.
	Treasury Stock
	Depending on market conditions, we may, from time to time, purchase shares of our common stock in the open market or otherwise. We account for the purchase of treasury stock using the cost method, which reports the cost of the shares acquired in “Treasury stock” as a deduction from stockholders’ equity in our Consolidated Balance Sheets. We did not repurchase any shares of our outstanding common stock during 2013, 2012 or 2011.
	Comprehensive Income (Loss)
	Comprehensive income (loss) is the change in equity of a business enterprise during a period from transactions and other events and circumstances except those transactions resulting from investments by owners and distributions to owners. Comprehensive income (loss) for the three years ended December 31, 2013, 2012 and 2011 includes net income (loss) and unrealized holding gains and losses on marketable securities and financial derivatives designated as cash flow accounting hedges. See Note 10.
	Foreign Currency
	Our functional currency is the U.S. dollar. Foreign currency transaction gains and losses are reported as “Foreign currency transaction gain (loss)” in our Consolidated Statements of Operations and include, when applicable, unrealized gains and losses to record the carrying value of our FOREX contracts not designated as accounting hedges, as well as realized gains and losses from the settlement of such contracts. For the years ended December 31, 2013, 2012 and 2011, we recognized aggregate net foreign currency gains (losses) of $(4.9) million, $(2.0) million and $(8.6) million, respectively. See Note 6.
	Revenue Recognition
We recognize revenue from dayrate drilling contracts as services are performed. In connection with such drilling contracts, we may receive fees (either lump-sum or dayrate) for the mobilization of equipment. We earn these fees as services are performed over the initial term of the related drilling contracts. We defer mobilization fees received, as well as direct and incremental mobilization costs incurred, and amortize each, on a straight-line basis, over the term of the related drilling contracts (which is the period we estimate to be benefited from the mobilization activity). Straight-line amortization of mobilization revenues and related costs over the term of the related drilling contracts (which generally range from 2 to 60 months) is consistent with the timing of net cash flows generated from the actual drilling services performed. Absent a contract, mobilization costs are recognized currently.
Some of our drilling contracts require downtime before the start of the contract to prepare the rig to meet customer requirements. At times, we may be compensated by the customer for such work (either lump-sum or dayrate). These fees are generally earned as services are performed over the initial term of the related drilling contracts. We defer contract preparation fees received, as well as direct and incremental costs associated with the contract preparation activities and amortize each, on a straight-line basis, over the term of the related drilling contracts (which we estimate to be benefited from the contract preparation activity).
From time to time, we may receive fees from our customers for capital improvements to our rigs (either lump-sum or dayrate). We defer such fees received in “Accrued liabilities” and “Other liabilities” in our Consolidated Balance Sheets and recognize these fees into income on a straight-line basis over the period of the related drilling contract. We capitalize the costs of such capital improvements and depreciate them over the estimated useful life of the improvement.
We record reimbursements received for the purchase of supplies, equipment, personnel services and other services provided at the request of our customers in accordance with a contract or agreement, for the gross amount billed to the customer, as “Revenues related to reimbursable expenses” in our Consolidated Statements of Operations.

Supplemental_Financial_Informa

Supplemental Financial Information	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Supplemental Financial Information	'
	2	Supplemental Financial Information
	Consolidated Balance Sheet Information
	Accounts receivable, net of allowance for bad debts, consists of the following:
			December 31,
			2013			2012
			(In thousands)
	Trade receivables		$	473,013		$	478,930
	Value added tax receivables			19,407			13,884
	Amounts held in escrow			3,066			11,555
	Interest receivable			7			6
	Related party receivables			587			527
	Other			615			216
				496,695			505,118
	Allowance for bad debts			(27,340	)		(5,458	)
	Total		$	469,355		$	499,660
	An analysis of the changes in our provision for bad debts for each of the three years ended December 31, 2013, 2012 and 2011 is as follows (see Note 7):
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Allowance for bad debts, beginning of year		$	5,458		$	6,867		$	31,908
	Bad debt expense:
	Provision for bad debts			22,513			—			5,688
	Recovery of bad debts			—			(1,018	)		(12,401	)
	Total bad debt expense (recovery)			22,513			(1,018	)		(6,713	)
	Write off of uncollectible accounts against reserve			(509	)		(391	)		(18,380	)
	Other(1)			(122	)		—			52
	Allowance for bad debts, end of year		$	27,340		$	5,458		$	6,867
	-1	Includes revaluation adjustments for non-U.S. dollar denominated receivables, which have been recorded as “Foreign currency transaction gain (loss)” in our Consolidated Statements of Operations.
	Prepaid expenses and other current assets consist of the following:
			December 31,
			2013			2012
			(In thousands)
	Rig spare parts and supplies		$	52,439		$	57,558
	Deferred mobilization costs			20,274			38,074
	Prepaid insurance			12,503			12,549
	Deferred tax assets			10,221			8,619
	Prepaid taxes			42,058			5,950
	FOREX contracts			1,562			3,627
	Other			4,940			9,722
	Total		$	143,997		$	136,099
	Accrued liabilities consist of the following:
			December 31,
			2013			2012
			(In thousands)
	Rig operating expenses		$	87,307		$	70,078
	Payroll and benefits			121,387			88,612
	Deferred revenue			26,975			71,699
	Accrued capital project/upgrade costs			86,274			56,595
	Interest payable			28,324			21,219
	Personal injury and other claims			9,687			10,312
	FOREX contracts			1,143			29
	Other			9,574			5,890
	Total		$	370,671		$	324,434
	Consolidated Statement of Cash Flows Information
	Noncash investing activities excluded from the Consolidated Statements of Cash Flows and other supplemental cash flow information is as follows:
			December 31,
			2013			2012			2011
			(In thousands)
	Accrued but unpaid capital expenditures at period end		$	86,274		$	56,595		$	37,325
	Income tax benefits related to exercise of stock options			1,081			1,083			863
	Cash interest payments(1)(2)			82,938			83,125			82,938
	Cash income taxes paid, net of refunds:
	U.S. federal			62,000			71,000			94,843
Foreign			78,041			72,249			150,465
State			190			243			210
-1	Interest payments, net of amounts capitalized, were $16.5 million, $46.2 million and $71.9 million for the years ended December 31, 2013, 2012 and 2011, respectively.
-2	Interest paid on Internal Revenue Service assessments was $0.2 million during the year ended December 31, 2012.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Compensation	'
	3	Stock-Based Compensation
	Our Second Amended and Restated 2000 Stock Option Plan, as amended, or Stock Plan, provides for the issuance of either incentive stock options or non-qualified stock options to our employees, consultants and non-employee directors. Our Stock Plan also authorizes the award of stock appreciation rights, or SARs, in tandem with stock options or separately. The maximum aggregate number of shares of our common stock for which stock options or SARs may be granted is 1,500,000 shares. The exercise price per share may not be less than the fair market value of the common stock on the date of grant. Generally, stock options and SARs vest ratably over a four year period and expire in ten years.
	Total compensation cost recognized for Stock Plan transactions, consisting solely of awards of SARs, for the years ended December 31, 2013, 2012 and 2011 was $3.9 million, $4.7 million and $5.0 million, respectively. Tax benefits recognized for the years ended December 31, 2013, 2012 and 2011 related thereto were $1.3 million, $1.6 million and $1.7 million, respectively.
	The fair value of SARs granted under the Stock Plan during each of the years ended December 31, 2013, 2012 and 2011 was estimated using the Black Scholes pricing model.
	The following are the weighted average assumptions used in estimating the fair value of our SARs:
			Year Ended December 31,
			2013			2012			2011
	Expected life of SARs (in years)			7			6			5
	Expected volatility			18.24	%		33.45	%		30.37	%
	Dividend yield			0.75	%		0.78	%		0.76	%
	Risk free interest rate			1.61	%		0.89	%		1.54	%
	Expected life of SARs is based on historical data as is the expected volatility. The dividend yield is based on the current approved regular dividend rate in effect and the current market price at the time of grant. Risk free interest rates are determined using the U.S. Treasury yield curve at time of grant with a term equal to the expected life of the SARs.
	A summary of activity under the Stock Plan as of December 31, 2013 and changes during the year then ended is as follows:
			Number of			Weighted-Average			Weighted-Average			Aggregate Intrinsic
			Awards			Exercise Price			Remaining			Value
									Contractual
									Term
									(Years)
												(In Thousands)
	Awards outstanding at January 1, 2013			1,229,480		$	80.32
	Granted			233,625		$	66.95
	Exercised			(15,091	)	$	59.58
	Forfeited			(24,283	)	$	67.51
	Expired			(31,072	)	$	94.01
	Awards outstanding at December 31, 2013			1,392,659		$	78.22			7		$	460
	Awards exercisable at December 31, 2013			973,918		$	83.32			6		$	438
	The weighted-average grant date fair values per share of awards granted during the years ended December 31, 2013, 2012 and 2011 were $13.74, $19.01 and $18.17, respectively. The total intrinsic value of awards exercised during the years ended December 31, 2013, 2012 and 2011 was $162,000, $147,000 and $28,000, respectively. The total fair value of awards vested during the years ended December 31, 2013, 2012 and 2011 was $4.1 million, $5.2 million and $5.4 million, respectively. As of December 31, 2013 there was $5.1 million of total unrecognized compensation cost related to nonvested stock awards granted under the Stock Plan which we expect to recognize over a weighted average period of 2.4 years.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	4	Earnings Per Share
	A reconciliation of the numerators and the denominators of the basic and diluted per-share computations follows:
			Year Ended December 31,
			2013		2012		2011
			(In thousands, except per share data)
	Net income — basic and diluted (numerator):		$	548,686	$	720,477	$	962,542
	Weighted-average shares — basic (denominator):			139,035		139,029		139,027
	Effect of dilutive potential shares
	Stock options and stock appreciation rights			29		19		11
	Weighted-average shares including conversions — diluted (denominator):			139,064		139,048		139,038
	Earnings per share:
	Basic		$	3.95	$	5.18	$	6.92
	Diluted		$	3.95	$	5.18	$	6.92
	The following table sets forth the share effects of stock options and the number of SARs excluded from our computations of diluted earnings per share, or EPS, as the inclusion of such potentially dilutive shares would have been antidilutive for the periods presented:
			Year Ended December 31,
			2013		2012		2011
			(In thousands)
	Employee and director:
	Stock options			18		18		19
	SARs			956		853		847

Marketable_Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]	'
Marketable Securities	'
	5. Marketable Securities
	We report our investments in marketable securities as current assets in our Consolidated Balance Sheets in “Marketable securities,” representing the investment of cash available for current operations. See Note 7.
	Our investments in marketable securities are classified as available for sale and are summarized as follows:
		December 31, 2013
		Amortized			Unrealized			Market
		Cost			Gain (Loss)			Value
		(In thousands)
	U.S. Treasury Bills and Notes (due within one year)	$	1,749,879		$	(22	)	$	1,749,857
	Mortgage-backed securities		188			8			196
	Total	$	1,750,067		$	(14	)	$	1,750,053
		December 31, 2012
		Amortized			Unrealized			Market
		Cost			Gain (Loss)			Value
		(In thousands)
	U.S. Treasury Bills and Notes (due within one year)	$	1,149,707		$	150		$	1,149,857
	Mortgage-backed securities		276			25			301
	Total	$	1,149,983		$	175		$	1,150,158
	Proceeds from maturities and sales of marketable securities and gross realized gains and losses are summarized as follows:
		Year Ended December 31,
		2013			2012			2011
		(In thousands)
	Proceeds from maturities	$	4,650,000		$	2,575,000		$	5,350,000
	Proceeds from sales		85			150,118			12,138
	Gross realized gains		—			—			784
	Gross realized losses		(1	)		(6	)		(5	)

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments	'
	6	Derivative Financial Instruments
	Foreign Currency Forward Exchange Contracts
	Our international operations expose us to foreign exchange risk associated with our costs payable in foreign currencies for employee compensation, foreign income tax payments and purchases from foreign suppliers. We may utilize FOREX contracts to manage our foreign exchange risk. Our FOREX contracts generally require us to net settle the spread between the contracted foreign currency exchange rate and the spot rate on the contract settlement date, which, for most of our contracts, is the average spot rate for the contract period.
	We enter into FOREX contracts when we believe market conditions are favorable to purchase contracts for future settlement with the expectation that such contracts, when settled, will reduce our exposure to foreign currency gains and losses on future foreign currency expenditures. The amount and duration of such contracts is based on our monthly forecast of expenditures in the significant currencies in which we do business and for which there is a financial market (i.e., Australian dollars, Brazilian reais, British pounds sterling, Mexican pesos and Norwegian kroner). These forward contracts are derivatives as defined by GAAP.
	During the years ended December 31, 2013, 2012 and 2011, we settled FOREX contracts with aggregate notional values of approximately $307.4 million, $305.6 million and $318.9 million, respectively, of which the entire aggregate amounts were designated as an accounting hedge. During the years ended December 31, 2013, 2012 and 2011, we did not enter into or settle any FOREX contracts that were not designated as accounting hedges.
	The following table presents the amounts recognized in our Consolidated Statements of Operations related to our FOREX contracts designated as hedging instruments for the years ended December 31, 2013, 2012 and 2011.
			Amount of (Loss) Gain Recognized in Income
			For the Years Ended December 31,
	Location of (Loss) Gain Recognized in Income		2013			2012			2011
			(In thousands)
	Contract drilling expense		$	(6,501	)	$	(4,302	)	$	7,206
	As of December 31, 2013, we had FOREX contracts outstanding in the aggregate notional amount of $114.1 million, consisting of $15.3 million in Australian dollars, $72.4 million in Brazilian reais, $14.2 million in British pounds sterling, $5.9 million in Mexican pesos and $6.3 million in Norwegian kroner. These contracts generally settle monthly through September 2014. As of December 31, 2013, all outstanding derivative contracts had been designated as cash flow hedges.
	We have International Swap Dealers Association, or ISDA, contracts, which are standardized master legal arrangements that establish key terms and conditions, which govern certain derivative transactions. Historically, our FOREX contracts have been with two counterparties and have been governed under such ISDA agreements. There are no requirements to post collateral under these contracts; however, they do contain credit-risk related contingent provisions including credit support provisions and the net settlement of amounts owed in the event of early terminations. Additionally, should our credit rating fall below a specified rating immediately following the merger of Diamond Offshore Drilling, Inc. with another entity, the counterparty may require all outstanding derivatives under the ISDA contract to be settled immediately at current market value. Our ISDA arrangements also include master netting agreements to further manage counterparty credit risk associated with our FOREX contracts. We have elected not to offset the fair value amounts recorded for our derivative contracts under these agreements in our Consolidated Balance Sheets as of December 31, 2013 and 2012; however, there would have been no significant differences in our Consolidated Balance Sheets if the estimated fair values were presented on a net basis for these periods.
	The following table presents the fair values of our FOREX contracts at December 31, 2013 and 2012.
	Balance Sheet Location		Fair Value						Balance Sheet Location		Fair Value
			December 31,			December 31,					December 31,			December 31,
			2013			2012					2013			2012
			(In thousands)								(In thousands)
	Prepaid expenses and other current assets		$	1,562		$	3,627			Accrued liabilities	$	(1,143	)	$	(29	)
	Treasury Lock Agreements
	In connection with the offering of our senior unsecured notes in 2013, we entered into two treasury lock agreements in October 2013 for notional amounts totaling $500 million and designated such contracts as cash flow hedges of interest rate risk. The agreements were settled in November 2013 upon the completion of the offering of the senior notes for a net gain of $26,728, before tax. The gain has been recorded as a component of AOCGL and is being amortized to interest expense over the terms of the respective unsecured senior notes. See Note 9.
	The following table presents the amounts recognized in our Consolidated Balance Sheets and Consolidated Statements of Operations related to our derivative contracts designated as cash flow hedges for the years ended December 31, 2013, 2012 and 2011.
			For the years ended December 31,
			2013			2012			2011
			(In thousands)
	FOREX contracts:
	Amount of (loss) gain recognized in AOCGL on derivative (effective portion)		$	(10,542)		$	6,519		$	(962)
	Location of (loss) gain reclassified from AOCGL into income (effective portion)			Contract drilling,			Contract drilling,			Contract drilling,
				excluding			excluding			excluding
				depreciation			depreciation			depreciation
	Amount of (loss) gain reclassified from AOCGL into income (effective portion)		$	-7,449		$	-4,205		$	10,351
	Location of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)			Foreign currency			Foreign currency			Foreign currency
				transaction gain			transaction gain			transaction gain
				(loss)			(loss)			(loss)
	Amount of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		$	-104		$	-17		$	-85
	Treasury lock agreements:
	Amount of gain recognized in AOCGL on derivative (effective portion)		$	27		$	—		$	—
	Location of gain reclassified from AOCGL into income (effective portion)			Interest expense			Interest expense			Interest expense
	Amount of gain reclassified from AOCGL into income (effective portion)		$	1		$	—		$	—
	As of December 31, 2013, the estimated amount of net unrealized gains associated with our FOREX contracts and treasury lock agreements that will be reclassified to earnings during the next twelve months was $0.5 million and $8,000, respectively. The net unrealized gains associated with our FOREX contracts will be reclassified to contract drilling expense to the extent fully effective. During the years ended December 30, 2013, 2012 and 2011 we did not reclassify any amounts from AOCGL due to the probability of an underlying forecasted transaction not occurring.

Financial_Instruments_and_Fair

Financial Instruments and Fair Value Disclosures	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Financial Instruments and Fair Value Disclosures	'
	7	Financial Instruments and Fair Value Disclosures
	Concentrations of Credit and Market Risk
	Financial instruments which potentially subject us to significant concentrations of credit or market risk consist primarily of periodic temporary investments of excess cash, trade accounts receivable and investments in debt securities, including mortgage-backed securities. We generally place our excess cash investments in U.S. government backed short-term money market instruments through several financial institutions. At times, such investments may be in excess of the insurable limit. We periodically evaluate the relative credit standing of these financial institutions as part of our investment strategy.
	Most of our investments in debt securities are U.S. government securities with minimal credit risk. However, we are exposed to market risk due to price volatility associated with interest rate fluctuations.
	Concentrations of credit risk with respect to our trade accounts receivable are limited primarily due to the entities comprising our customer base. Since the market for our services is the offshore oil and gas industry, this customer base consists primarily of major and independent oil and gas companies and government-owned oil companies. During 2013 and 2012, our largest customer in Brazil, Petróleo Brasileiro S.A. (a Brazilian multinational energy company that is majority-owned by the Brazilian government), accounted for $154.5 million and $116.4 million, or 35% and 24%, respectively, of our total consolidated gross trade accounts receivable balance. Our second largest customer in Brazil, OGX Petróleo e Gás Ltda. (a privately owned Brazilian oil and natural gas company that filed for bankruptcy in October 2013), or OGX, accounted for $80.3 million or 17% of our total consolidated gross trade accounts receivable balance at December 31, 2012. Our accounts receivable balance from OGX was fully reserved at December 31, 2013.
	In general, before working for a customer with whom we have not had a prior business relationship and/or whose financial stability may be uncertain to us, we perform a credit review on that company. Based on that analysis, we may require that the customer present a letter of credit, prepay or provide other credit enhancements. We record a provision for bad debts on a case-by-case basis when facts and circumstances indicate that a customer receivable may not be collectible and, historically, losses on our trade receivables have been infrequent occurrences.
	During 2013, based on our assessment of the financial condition of two of our customers, Niko Resources Ltd., or Niko, and OGX, and our expectations regarding the probability of collection of amounts due to us from them, we recorded $22.5 million in bad debt expense to fully reserve all outstanding receivables they owed us at June 30, 2013. With the exception of the settlement discussed below, we did not recognize revenue associated with these customers during the second half of 2013. See Note 2.
	In December 2013, we entered into a settlement agreement with Niko, which we refer to as the Settlement Agreement, whereby Niko will be released from certain obligations under the dayrate contracts for the Ocean Monarch and Ocean Lexington, subject to and effective upon the full payment of amounts owed to us under the Settlement Agreement and subject to its other conditions. In accordance with the terms of the Settlement Agreement, we received $25.0 million in cash during the fourth quarter of 2013, which we recognized as revenue against invoices due us. Niko is further obligated to make future periodic payments to us pursuant to the Settlement Agreement totaling an aggregate of $55.0 million, payable at various times through September 2017. We plan to recognize these amounts in revenue as they are received due to the uncertainty regarding their timing and collection.
	Fair Values
	Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy prescribed by GAAP requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value:
	Level 1		Quoted prices for identical instruments in active markets. Level 1 assets include short-term investments such as money market funds, U.S. Treasury Bills and Treasury notes. Our Level 1 assets at December 31, 2013 consisted of cash held in money market funds of $281.3 million, time deposits of $30.0 million and investments in U.S. Treasury securities of $1,749.9 million. Our Level 1 assets at December 31, 2012 consisted of cash held in money market funds of $264.9 million, time deposits of $20.0 million and investments in U.S. Treasury securities of $1,149.9 million.
	Level 2		Quoted market prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. Level 2 assets and liabilities include residential mortgage-backed securities and over-the-counter FOREX contracts. Our residential mortgage-backed securities were valued using a model-derived valuation technique based on the quoted closing market prices received from a financial institution. Our FOREX contracts are valued based on quoted market prices, which are derived from observable inputs including current spot and forward rates, less the contract rate multiplied by the notional amount. The inputs used in our valuation are obtained from a Bloomberg curve analysis which uses par coupon swap rates to calculate implied forward rates so that projected floating rate cash flows can be calculated. The valuation techniques underlying the models are widely accepted in the financial services industry and do not involve significant judgment.
	Level 3		Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Level 3 assets and liabilities generally include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation or for which there is a lack of transparency as to the inputs used. Our Level 3 assets at December 31, 2013 and 2012 consisted of nonrecurring measurements of certain rigs held for sale for which we recorded an impairment loss in 2012. The value of these rigs was determined using a present value technique which utilized unobservable inputs such as assumptions for estimated proceeds that may be received on disposition of each rig and estimated costs to sell. See Note 1.
	Market conditions could cause an instrument to be reclassified among Levels 1, 2 and 3. Our policy regarding fair value measurements of financial instruments transferred into and out of levels is to reflect the transfers as having occurred at the beginning of the reporting period. There were no transfers between fair value levels during the years ended December 31, 2013 and 2012.
	Certain of our assets and liabilities are required to be measured at fair value on a recurring basis in accordance with GAAP. In addition, certain assets and liabilities may be recorded at fair value on a nonrecurring basis. Generally, we record assets at fair value on a nonrecurring basis as a result of impairment charges. We did not record any impairment charges related to assets measured at fair value on a nonrecurring basis during the year ended December 31, 2013.
			December 31, 2013
			Fair Value Measurements Using							Assets at Fair			Total Losses
										Value			for Year
			Level 1		Level 2			Level 3					Ended
			(In thousands)
	Recurring fair value measurements:
	Assets:
	Short-term investments		$	2,061,154	$	—		$	—	$	2,061,154		$	—
	FOREX contracts			—		1,562			—		1,562			—
	Mortgage-backed securities			—		197			—		197			—
	Total assets		$	2,061,154	$	1,759		$	—	$	2,062,913		$	—
	Liabilities:
	FOREX contracts		$	—	$	(1,143	)	$	—	$	(1,143	)	$	—
	Nonrecurring fair value measurements:
	Assets:
	Impaired assets		$	—	$	—		$	3,900	$	3,900		$	—
			December 31, 2012
			Fair Value Measurements Using							Assets at Fair			Total Losses
										Value			for Year
			Level 1		Level 2			Level 3					Ended
			(In thousands)
	Recurring fair value measurements:
	Assets:
	Short-term investments		$	1,434,751	$	—		$	—	$	1,434,751		$	—
	FOREX contracts			—		3,627			—		3,627			—
	Mortgage-backed securities			—		301			—		301			—
	Total assets		$	1,434,751	$	3,928		$	—	$	1,438,679		$	—
	Liabilities:
	FOREX contracts		$	—	$	(29	)	$	—	$	(29	)	$	—
	Nonrecurring fair value measurements:
	Assets:
	Assets held for sale		$	—	$	—		$	3,900	$	3,900		$	(62,437	)
	We have presented the loss related to assets held for sale in “Impairment of assets” in our Consolidated Statements of Operations for the year ended December 31, 2012.
	We believe that the carrying amounts of our other financial assets and liabilities (excluding long-term debt), which are not measured at fair value in our Consolidated Balance Sheets, approximate fair value based on the following assumptions:
		•		Cash and cash equivalents — The carrying amounts approximate fair value because of the short maturity of these instruments.
		•		Accounts receivable and accounts payable — The carrying amounts approximate fair value based on the nature of the instruments.
	We consider our senior notes, including current maturities, to be Level 2 liabilities under the GAAP fair value hierarchy and, accordingly, the fair value of our senior notes was derived using a third-party pricing service at December 31, 2013 and 2012. We perform control procedures over information we obtain from pricing services and brokers to test whether prices received represent a reasonable estimate of fair value. These procedures include the review of pricing service or broker pricing methodologies and comparing fair value estimates to actual trade activity executed in the market for these instruments occurring generally within a 10-day window of the report date. Fair values and related carrying values (see Note 9) of our senior notes are shown below.
			December 31, 2013					December 31, 2012
			Fair Value		Carrying Value			Fair Value		Carrying Value
			(In millions)
	5.15% Senior Notes due 2014		$	257.4	$	250		$	269	$	249.9
	4.875% Senior Notes due 2015			265.7		249.9			275.5		249.8
	5.875% Senior Notes due 2019			578.1		499.6			617.1		499.5
	3.45% Senior Notes due 2023			241.4		249			—		—
	5.70% Senior Notes due 2039			543.1		496.9			641.4		496.9
	4.875% Senior Notes due 2043			736.1		748.8			—		—
	We have estimated the fair value amounts by using appropriate valuation methodologies and information available to management. Considerable judgment is required in developing these estimates, and accordingly, no assurance can be given that the estimated values are indicative of the amounts that would be realized in a free market exchange.

Drilling_and_Other_Property_an

Drilling and Other Property and Equipment	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Drilling and Other Property and Equipment	'
	8	Drilling and Other Property and Equipment
	Cost and accumulated depreciation of drilling and other property and equipment are summarized as follows:
			December 31,
			2013			2012
			(In thousands)
	Drilling rigs and equipment		$	7,412,066		$	7,107,279
	Construction work-in-progress			1,668,211			990,964
	Land and buildings			65,627			64,296
	Office equipment and other			65,799			60,239
	Cost			9,211,703			8,222,778
	Less accumulated depreciation			(3,744,476	)		(3,357,806	)
	Drilling and other property and equipment, net		$	5,467,227		$	4,864,972
	Construction work-in-progress, including capitalized interest, at December 31, 2013 and 2012 is summarized as follows:
			December 31,
			2013			2012
			(In thousands)
	Ultra-deepwater drillships		$	868,908		$	741,059
	Ultra-deepwater semisubmersible:
	Ocean GreatWhite			195,578			—
	Deepwater semisubmersibles:
	Ocean Onyx			339,129			167,403
	Ocean Apex			264,596			82,502
	Total construction work-in-progress		$	1,668,211		$	990,964
	During 2013, we entered into a shipyard contract for the construction of the Ocean GreatWhite, an ultra-deepwater, harsh environment semisubmersible. See Note 11.

Credit_Agreement_and_Senior_No

Credit Agreement and Senior Notes	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Credit Agreement and Senior Notes	'
	9	Credit Agreement and Senior Notes
	Credit Agreement
	We have a syndicated 5-Year Revolving Credit Agreement, or Credit Agreement, with Wells Fargo Bank, National Association, as administrative agent and swingline lender. Effective December 9, 2013, we entered into an extension agreement and amendment to the Credit Agreement, which, among other things, provided for a one-year extension with all of the existing lenders. The Credit Agreement provides for a $750 million senior unsecured revolving credit facility for general corporate purposes, maturing on September 28, 2018. The entire amount of the facility is available for revolving loans. Up to $250 million of the facility is available for the issuance of performance or other standby letters of credit and up to $75 million is available for swingline loans.
	Revolving loans under the Credit Agreement bear interest, at our option, at a rate per annum based on either an alternate base rate, or ABR, or a Eurodollar Rate, as defined in the Credit Agreement, plus the applicable interest margin for an ABR loan or a Eurodollar loan. The ABR is the greatest of (i) the prime rate, (ii) the federal funds rate plus 0.50% and (iii) the daily one-month Eurodollar Rate plus 1.00%. The applicable interest margin for ABR loans varies from 0% to 0.25%. The applicable interest margin for Eurodollar loans varies between 0.75% and 1.25%.
	Swingline loans bear interest, at our option, at a rate per annum equal to (i) the ABR plus the applicable interest margin for ABR loans or (ii) the daily one-month Eurodollar Rate plus the applicable interest margin for Eurodollar loans.
	Under our Credit Agreement, we also pay, based on our current credit ratings, and as applicable, other customary fees including, but not limited to, a commitment fee on the unused commitments under the Credit Agreement, varying between 0.06% and 0.20% per annum, and a fronting fee to the issuing bank for each letter of credit. Participation fees for letters of credit are dependent upon the type of letter of credit issued, varying between 0.375% and 0.625% per annum for performance letters of credit, and between 0.75% and 1.25% per annum for all other letters of credit. Changes in credit ratings could lower or raise the fees that we pay under the Credit Agreement.
	The Credit Agreement contains customary covenants including, but not limited to, maintenance of a ratio of consolidated indebtedness to total capitalization, as defined in the Credit Agreement, of not more than 60% at the end of each fiscal quarter, as well as limitations on liens; mergers, consolidations, liquidation and dissolution; changes in lines of business; swap agreements; transactions with affiliates; and subsidiary indebtedness.
	Based on our current credit ratings at December 31, 2013, the applicable margin on ABR loans and Eurodollar loans would have been 0.00% and 0.875%, respectively. As of December 31, 2013, there were no amounts outstanding under the Credit Agreement.
	Senior Notes
	At December 31, 2013, our senior notes were comprised of the following debt issues:
			Principal Amount					Interest Rate		Semiannual
										Interest Payment
	Debt Issue		(In millions)			Maturity Date		Coupon	Effective	Dates
	5.15% Senior Notes due 2014		$	250		September 1, 2014		5.15%	5.18%	March 1 and September 1
	4.875% Senior Notes due 2015		$	250		1-Jul-15		4.88%	4.90%	January 1 and July 1
	5.875% Senior Notes due 2019		$	500		1-May-19		5.88%	5.89%	May 1 and November 1
	3.45% Senior Notes due 2023		$	250		1-Nov-23		3.45%	3.50%	May 1 and November 1
	5.70% Senior Notes due 2039		$	500		15-Oct-39		5.70%	5.75%	April 15 and October 15
	4.875% Senior Notes due 2043		$	750		1-Nov-43		4.88%	4.89%	May 1 and November 1
	At December 31, 2013 and 2012, the carrying value of our senior notes was as follows:
			December 31,
			2013			2012
			(In thousands)
	5.15% Senior Notes due 2014		$	249,954		$	249,882
	4.875% Senior Notes due 2015			249,898			249,837
	5.875% Senior Notes due 2019			499,551			499,480
	3.45% Senior Notes due 2023			248,988			—
	5.70% Senior Notes due 2039			496,919			496,867
	4.875% Senior Notes due 2043			748,833			—
	Total senior notes, net of unamortized discount		$	2,494,143		$	1,496,066
	Less: Current portion of long-term debt			249,954			—
	Total Long-term debt		$	2,244,189		$	1,496,066
	As of December 31, 2013, the aggregate annual maturity of our senior notes was as follows:
			Aggregate
			Principal
			Amount
			(In thousands)
	Years Ending December 31,
	2014		$	250,000
	2015			250,000
	2016			—
	2017			—
	2018			—
	Thereafter			2,000,000
	Total maturities of senior notes			2,500,000
	Less: unamortized discounts			(5,857	)
	Total maturities of senior notes, net of unamortized discount		$	2,494,143
	2013 Debt Issues. On November 5, 2013, we completed the issuance of $1.0 billion aggregate principal amount of senior notes consisting of $250.0 million aggregate principal amount of 3.45% senior unsecured notes due 2023, or 2023 Notes, and $750.0 million aggregate principal amount of 4.875% senior unsecured notes due 2043, or 2043 Notes, and, collectively, the New Notes, for general corporate purposes, including redemption, repurchase or retirement of our 5.15% senior notes due September 1, 2014, or 2014 Notes, and our 4.875% senior notes due July 1, 2015, or 2015 Notes. The transaction resulted in net proceeds to us of $987.8 million after deducting underwriting discounts, commissions and estimated expenses.
	The 2023 Notes bear interest at 3.45% per year and mature on November 1, 2023. The 2043 Notes bear interest at 4.875% per year and mature on November 1, 2043. Interest on the New Notes is payable semiannually in arrears on May 1 and November 1 of each year, beginning May 1, 2014. The New Notes are unsecured and unsubordinated obligations of Diamond Offshore Drilling, Inc., and rank equally in right of payment to all of its existing and future unsecured and unsubordinated indebtedness, and are effectively subordinated to all existing and future obligations of our subsidiaries. We have the right to redeem all or a portion of the New Notes for cash at any time or from time to time, on at least 15 days but not more than 60 days prior written notice, at a make-whole redemption price specified in the governing indenture (if applicable) plus accrued and unpaid interest to, but excluding, the date of redemption.
	Other Debt. Our 2014 Notes, 2015 Notes, 5.875% Senior Notes due 2019 and 5.70% Senior Notes due 2039 are all unsecured and unsubordinated obligations of Diamond Offshore Drilling, Inc. and rank equal in right of payment to its existing and future unsecured and unsubordinated indebtedness, and are effectively subordinated to all existing and future obligations of our subsidiaries. We have the right to redeem all or a portion of these notes for cash at any time or from time to time, on at least 15 days but not more than 60 days prior written notice, at the redemption price specified in the governing indenture plus accrued and unpaid interest to the date of redemption.
	Our 2014 Notes, in the aggregate principal amount of $250.0 million, will mature on September 1, 2014. Accordingly, the aggregate $249.9 million accreted value of our 2014 Notes has been presented as “Current portion of long-term debt” in our Consolidated Balance Sheets at December 31, 2013.

Other_Comprehensive_Income_Los

Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Other Comprehensive Income (Loss)	'
	10	Other Comprehensive Income (Loss)
	The following table sets forth the components of “Other comprehensive income (loss)” and the related income tax effects thereon for the three years ended December 31, 2013 and the cumulative balances in AOCGL by component at December 31, 2013, 2012 and 2011.
			Unrealized Gain (Loss) on
			Derivative			Marketable			Total
			Financial			Securities			AOCGL
			Instruments
			(In thousands)
	Balance at January 1, 2011		$	2,733		$	408		$	3,141
	Unrealized gain (loss) before reclassifications, after tax of $337 and $15			(625	)		(46	)		(671	)
	Reclassification adjustments for items included in Net Income, after tax of $3,623 and $205			(6,728	)		(384	)		(7,112	)
	Total other comprehensive income (loss)			(7,353	)		(430	)		(7,783	)
	Balance at December 31, 2011			(4,620	)		(22	)		(4,642	)
	Unrealized gain (loss) before reclassifications, after tax of $(2,282) and $(28)			4,237			124			4,361
	Reclassification adjustments for items included in Net Income, after tax of $(1,472) and $(1)			2,733			44			2,777
	Total other comprehensive income (loss)			6,970			168			7,138
	Balance at December 31, 2012			2,350			146			2,496
	Unrealized gain (loss) before reclassifications, after tax of $3,682 and $18			(6,833	)		(6	)		(6,839	)
	Reclassification adjustments for items included in Net Income, after tax of $(2,608) and $18			4,840			(147	)		4,693
	Total other comprehensive income (loss)			(1,993	)		(153	)		(2,146	)
	Balance at December 31, 2013		$	357		$	(7	)	$	350
	The following table presents the line items in our Consolidated Statements of Operations affected by reclassification adjustments out of AOCGL.
	Major Components of AOCGL		Year Ended December 31,									Consolidated Statements of
												Operations Line Items
			2013			2012			2011
			(In thousands)
	Derivative financial instruments:		$	(7,449	)	$	(4,205	)	$	10,351		Contract drilling, excluding
	Unrealized (gain) loss on FOREX contracts											depreciation
	Unrealized loss (gain) on Treasury Lock Agreements			1			—			—		Interest expense
				2,608			1,472			(3,623	)	Income tax expense
			$	(4,840	)	$	(2,733	)	$	6,728		Net of tax
	Marketable securities:		$	165		$	(45	)	$	589		Other, net
	Unrealized (gain) loss on marketable securities
				(18	)		1			(205	)	Income tax expense
			$	147		$	(44	)	$	384		Net of tax

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	11	Commitments and Contingencies
	Various claims have been filed against us in the ordinary course of business, including claims by offshore workers alleging personal injuries. With respect to each claim or exposure, we have made an assessment, in accordance with GAAP, of the probability that the resolution of the matter would ultimately result in a loss. When we determine that an unfavorable resolution of a matter is probable and such amount of loss can be determined, we record a liability for the amount of the estimated loss at the time that both of these criteria are met. Our management believes that we have recorded adequate accruals for any liabilities that may reasonably be expected to result from these claims.
	Litigation. We are one of several unrelated defendants in lawsuits filed in state courts alleging that defendants manufactured, distributed or utilized drilling mud containing asbestos and, in our case, allowed such drilling mud to have been utilized aboard our offshore drilling rigs. The plaintiffs seek, among other things, an award of unspecified compensatory and punitive damages. The manufacture and use of asbestos-containing drilling mud had already ceased before we acquired any of the drilling rigs addressed in these lawsuits. We believe that we are not liable for the damages asserted and we expect to receive complete defense and indemnity with respect to a majority of the lawsuits from Murphy Exploration & Production Company pursuant to the terms of our 1992 asset purchase agreement with them. We also believe that we are not liable for the damages asserted in the remaining lawsuits pursuant to the terms of our 1989 asset purchase agreement with Diamond M Corporation, and we filed a declaratory judgment action in Texas state court against NuStar Energy LP, or NuStar, the successor to Diamond M Corporation, seeking a judicial determination that we did not assume liability for these claims. We obtained summary judgment on our claims in the declaratory judgment action, but NuStar appealed the trial court’s decision, and the appellate court has remanded the case to trial. We are unable to estimate our potential exposure, if any, to these lawsuits at this time but do not believe that ultimate liability, if any, resulting from this litigation will have a material effect on our consolidated financial condition, results of operations and cash flows.
	Various other claims have been filed against us in the ordinary course of business. In the opinion of our management, no pending or known threatened claims, actions or proceedings against us are expected to have a material adverse effect on our consolidated financial condition, results of operations and cash flows.
	We intend to defend these matters vigorously; however, we cannot predict with certainty the outcome or effect of any litigation matters specifically described above or any other pending litigation or claims. There can be no assurance as to the ultimate outcome of these lawsuits.
	NPI Arrangement. We received payments measured by a percentage net profits interest (of primarily 27%) under an overriding royalty interest in certain developmental oil-and-gas producing properties, or NPI, which we believe is a real property interest. Our drilling program related to the NPI was completed in 2011, and the balance of the amounts due to us under the NPI was received in 2013. However, the customer who conveyed the NPI to us filed a voluntary petition for reorganization under Chapter 11 of the Bankruptcy Code in August of 2012. Certain parties (including the debtor) in the bankruptcy proceedings have questioned whether our NPI, and certain amounts we received under it since the filing of the bankruptcy, should be included in the debtor’s estate under the bankruptcy proceeding. We filed a declaratory judgment action in the bankruptcy court seeking a declaration that our NPI, and payments that we received from it since the filing of the bankruptcy, are not part of the bankruptcy estate. Once discovery is concluded in the bankruptcy court, the federal district court will hold a trial to determine the nature of our NPI. We will vigorously defend our rights and pursue our interests in this matter.
	Personal Injury Claims. Our deductibles for marine liability insurance coverage, including personal injury claims, which primarily result from Jones Act liability in the Gulf of Mexico, are currently $10.0 million for the first occurrence, with no aggregate deductible, and vary in amounts ranging between $5.0 million and, if aggregate claims exceed certain thresholds, up to $100.0 million for each subsequent occurrence, depending on the nature, severity and frequency of claims which might arise during the policy year. The Jones Act is a federal law that permits seamen to seek compensation for certain injuries during the course of their employment on a vessel and governs the liability of vessel operators and marine employers for the work-related injury or death of an employee. We engage outside consultants to assist us in estimating our aggregate liability for personal injury claims based on our historical losses and utilizing various actuarial models. We allocate a portion of the aggregate liability to “Accrued liabilities” based on an estimate of claims expected to be paid within the next twelve months with the residual recorded as “Other liabilities.” At December 31, 2013, our estimated liability for personal injury claims was $35.5 million, of which $9.5 million and $26.0 million were recorded in “Accrued liabilities” and “Other liabilities,” respectively, in our Consolidated Balance Sheets. At December 31, 2012, our estimated liability for personal injury claims was $36.1 million, of which $9.9 million and $26.2 million were recorded in “Accrued liabilities” and “Other liabilities,” respectively, in our Consolidated Balance Sheets. The eventual settlement or adjudication of these claims could differ materially from our estimated amounts due to uncertainties such as:
		•	the severity of personal injuries claimed;
		•	significant changes in the volume of personal injury claims;
		•	the unpredictability of legal jurisdictions where the claims will ultimately be litigated;
		•	inconsistent court decisions; and
		•	the risks and lack of predictability inherent in personal injury litigation.
	Purchase Obligations.
	Ultra-Deepwater Floater Construction. In May 2013, we entered into an agreement with Hyundai Heavy Industries Co., Ltd., or Hyundai, for the construction of a 10,000 foot dynamically positioned, harsh environment semisubmersible drilling rig. The Ocean GreatWhite is under construction in South Korea at an estimated cost of $755 million, including commissioning, capital spares and project management costs. The contracted price to Hyundai, totaling $628.5 million, is payable in two installments, of which the first installment of $188.6 million was paid in 2013. The final installment of $439.9 million is due upon delivery of the rig, which is expected to occur in the first quarter of 2016.
	Drillship Construction. We are financially obligated under four separate turnkey construction contracts with Hyundai for the construction of four ultra-deepwater drillships. We expect the aggregate cost of the construction of our drillships, including commissioning, capital spares and project management costs, to be approximately $2.6 billion. The contracted price of each drillship is payable to Hyundai in two installments, with final payment due on delivery of each drillship. We have paid the first installment for each of the four drillships, aggregating $647.6 million. The Ocean Black Hawk, the first of our four drillships to be completed, was delivered in late January 2014, and we paid the final installment due to Hyundai of $396.1 million upon delivery of the drillship. The Ocean BlackHornet is expected to be delivered in the second quarter of 2014 at which time the second installment of approximately $394 million will be payable to Hyundai. The Ocean BlackRhino and Ocean BlackLion are expected to be delivered in the third quarter of 2014 and first quarter of 2015, respectively, at which times approximately $395 million will be payable to Hyundai for each rig.
	Ocean Onyx Construction. We were obligated under a vessel modification agreement with Keppel AmFELS, L.L.C., or Keppel, for the construction of the Ocean Onyx, a moored semisubmersible deepwater rig, which was delivered late in the fourth quarter of 2013. We estimate the aggregate cost for the construction of the Ocean Onyx to be approximately $366.0 million, including commissioning, capital spares and project management costs. The contracted price due to Keppel was payable in 11 installments based on the occurrence of certain events as detailed in the vessel modification agreement. As of December 31, 2013, we had paid the first ten installments, of which we paid $73.0 million and $65.7 million in 2013 and 2012, respectively. We paid the final installment payable to Keppel under the construction agreement of $7.3 million in January 2014.
	Ocean Apex Construction. We are obligated under a vessel modification agreement with Jurong Shipyard Pte Ltd, or Jurong, for the construction of the Ocean Apex, a moored semisubmersible deepwater rig, which is expected to be delivered in the third quarter of 2014 at an aggregate cost of approximately $370.0 million, including commissioning, capital spares and project management costs. The contracted price due to Jurong is payable in 12 installments based on the occurrence of certain events as detailed in the vessel modification agreement. We have paid the first seven installments, of which we paid $54.1 million and $27.0 million in 2013 and 2012, respectively. The remaining $54.1 million in aggregate milestone payments is payable to Jurong during 2014 as construction milestones are met.
	Ocean Patriot Enhancements. In February 2013, we entered into a vessel modification agreement with Keppel FELS Limited, or Keppel Singapore, for enhancements to the Ocean Patriot that will enable the rig to work in the North Sea. We estimate the cost of the enhancement project to be approximately $120.0 million, including shipyard costs, owner-furnished equipment and labor, commissioning and capital spares. Construction work commenced in Singapore in the fourth quarter of 2013 and is expected to be completed in the second quarter of 2014. The contracted price due Keppel Singapore is approximately $29.0 million, payable in seven installments based on the occurrence of certain events as detailed in the vessel modification agreement. We paid the first four installments due to Keppel Singapore aggregating $18.8 million in 2013. The remaining $10.2 million in aggregate milestone payments are payable to Keppel Singapore during 2014 as construction milestones are met.
	At December 31, 2013 and 2012, we had no other purchase obligations for major rig upgrades or any other significant obligations, except for those related to our direct rig operations, which arise during the normal course of business.
	Operating Leases. We lease office and yard facilities, housing, equipment and vehicles under operating leases, which expire at various times through the year 2018. Total rent expense amounted to $13.5 million, $10.8 million and $9.3 million for the years ended December 31, 2013, 2012 and 2011, respectively. Future minimum rental payments under leases are approximately $2.9 million and $1.6 million for the years 2014 and 2015, respectively, and $1.2 million in the aggregate for the years 2016 to 2018. There are no minimum future rental payments under operating leases after 2018.
	Letters of Credit and Other. We were contingently liable as of December 31, 2013 in the amount of $78.2 million under certain performance, bid, supersedeas, tax appeal and custom bonds and letters of credit. Agreements relating to approximately $67.4 million of performance, security, supersedeas and customs bonds can require collateral at any time. As of December 31, 2013, we had not been required to make any collateral deposits with respect to these agreements. The remaining agreements cannot require collateral except in events of default. On our behalf, banks have issued letters of credit securing certain of these bonds.

RelatedParty_Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	12. Related-Party Transactions
	Transactions with Loews. We are party to a services agreement with Loews, or the Services Agreement, pursuant to which Loews performs certain administrative and technical services on our behalf. Such services include personnel, internal auditing, accounting, and cash management services, in addition to advice and assistance with respect to preparation of tax returns and obtaining insurance. Under the Services Agreement, we are required to reimburse Loews for (i) allocated personnel costs (such as salaries, employee benefits and payroll taxes) of the Loews personnel actually providing such services and (ii) all out-of-pocket expenses related to the provision of such services. The Services Agreement may be terminated at our option upon 30 days’ notice to Loews and at the option of Loews upon six months’ notice to us. In addition, we have agreed to indemnify Loews for all claims and damages arising from the provision of services by Loews under the Services Agreement unless due to the gross negligence or willful misconduct of Loews. We were charged $1.0 million, $0.8 million and $1.1 million by Loews for these support functions during the years ended December 31, 2013, 2012 and 2011, respectively.
	Transactions with Other Related Parties. We hire marine vessels and helicopter transportation services at the prevailing market rate from subsidiaries of SEACOR Holdings Inc. and Era Group Inc. The Executive Chairman of the Board of Directors of SEACOR Holdings Inc. and the Non-Executive Chairman of the Board of Directors of Era Group Inc. is also a member of our Board of Directors. We paid $0.1 million in each of the three years ended December 31, 2013 for the hire of such vessels and such services.
	During the years ended December 31, 2013, 2012 and 2011, we made payments of $1.6 million, $1.0 million and $1.2 million, respectively, to Ernst & Young LLP for tax and other consulting services. The wife of our President and Chief Executive Officer is an audit partner at this firm.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	13	Income Taxes
	Our income tax expense is a function of the mix between our domestic and international pre-tax earnings or losses, as well as the mix of international tax jurisdictions in which we operate. Certain of our international rigs are owned and operated indirectly, by Diamond Offshore International Limited, or DOIL, a foreign subsidiary which we wholly own. It is our intention to indefinitely reinvest future earnings of DOIL and its foreign subsidiaries to finance foreign activities. Accordingly, we have not made a provision for U.S. income taxes on approximately $2.4 billion of undistributed foreign earnings and profits. Although we do not intend to repatriate the earnings of DOIL, and have not provided U.S. income taxes for such earnings, except to the extent that such earnings were immediately subject to U.S. income taxes, these earnings could become subject to U.S. income tax if remitted, or if deemed remitted as a dividend; however, it is not practical to estimate this potential liability.
	The components of income tax expense (benefit) are as follows:
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Federal — current		$	40,045		$	173,061		$	109,684
	State — current			69			267			264
	Foreign — current			151,339			75,748			104,640
	Total current			191,453			249,076			214,588
	Federal — deferred			46,767			(51,852	)		(1,023	)
	Foreign — deferred			(12,666	)		380			3,164
	Total deferred			34,101			(51,472	)		2,141
	Total		$	225,554		$	197,604		$	216,729
	The difference between actual income tax expense and the tax provision computed by applying the statutory federal income tax rate to income before taxes is attributable to the following:
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Income before income tax expense:
	U.S.		$	537,635		$	512,733		$	486,393
	Foreign			236,605			405,348			692,878
	Worldwide		$	774,240		$	918,081		$	1,179,271
	Expected income tax expense at federal statutory rate		$	270,984		$	321,328		$	412,745
	Foreign earnings of foreign subsidiaries (not taxed at the statutory federal income tax rate) net of related foreign taxes			(102,359	)		(166,251	)		(189,051	)
	Foreign earnings of foreign subsidiaries for which U.S. federal income taxes have been provided			805			28,252			(14,681	)
	Foreign taxes of domestic and foreign subsidiaries for which U.S. federal income taxes have also been provided			45,428			35,722			65,521
	Foreign tax credits			(46,524	)		(45,824	)		(67,232	)
	Interest capitalized by foreign subsidiaries			(18,391	)		(11,764	)		(3,924	)
	Reduction of deferred tax liability related to a goodwill deduction resulting from a prior period stock acquisition			—			—			(2,950	)
	Impact of American Taxpayer Relief Act of 2012			(27,509	)		—			—
	Uncertain tax positions			66,085			6,325			(7,733	)
	Amortization of deferred charges associated with intercompany rig sales to other tax jurisdictions			30,894			31,276			29,556
	Net expense (benefit) in connection with resolutions of tax issues and adjustments relating to prior years			4,804			(2,152	)		(6,085	)
	Other			1,337			692			563
	Income tax expense		$	225,554		$	197,604		$	216,729
	Deferred Income Taxes. Significant components of our deferred income tax assets and liabilities are as follows:
			December 31,
			2013			2012
			(In thousands)
	Deferred tax assets:
	Net operating loss carryforwards, or NOLs		$	12,038		$	24,067
	Worker’s compensation and other current accruals			17,269			16,929
	Disputed receivables reserved			3,516			956
	Deferred compensation			14,020			9,051
	Foreign contribution taxes			5,749			6,780
	Mobilization			1,673			4,736
	Nonqualified stock options and SARs			9,584			8,698
	Deferred deductions			8,577			—
	Interest -Uncertain Tax Positions			1,008			206
	Other			1,714			1,434
	Total deferred tax assets(1)			75,148			72,857
	Valuation allowance for NOLs			(7,321	)		(22,876	)
	Net deferred tax assets			67,827			49,981
	Deferred tax liabilities:
	Depreciation			(578,742	)		(526,606	)
	Unbilled revenue			(4,371	)		(5,649	)
	Undistributed earnings of foreign subsidiaries			(24	)		(24	)
	Other			(9	)		(29	)
	Total deferred tax liabilities			(583,146	)		(532,308	)
	Net deferred tax liability		$	(515,319	)	$	(482,327	)
	-1	$10.2 million and $8.6 million reflected in “Prepaid expenses and other current assets” in our Consolidated Balance Sheets at December 31, 2013 and 2012, respectively. See Note 2.
	We record a valuation allowance to derecognize a portion of our deferred tax assets, which we do not expect to be ultimately realized. A summary of changes in the valuation allowance is as follows:
			For the Year Ended December 31,
		2013			2012			2011
		(In thousands)
Valuation allowance as of January 1		$	22,876		$	26,353		$	32,102
Establishment of valuation allowances:
Foreign tax credits			—			—			(186	)
Net operating losses			25			946			1,844
Releases of valuation allowances in various jurisdictions			(15,580	)		(4,423	)		(7,407	)
Valuation allowance as of December 31		$	7,321		$	22,876		$	26,353
Net Operating Loss Carryforwards — As of December 31, 2013, we had recorded a deferred tax asset of $12.0 million for the benefit of NOL carryforwards related to our international operations. Approximately $11.2 million of this deferred tax asset relates to NOL carryforwards that have an indefinite life. The remaining $0.8 million relates to NOL carryforwards of our Mexican entities. Unless utilized, the tax benefits of these Mexican NOL carryforwards will expire between 2021 and 2023 as follows:
Year Expiring		Tax Benefit of
		NOL
		Carryforwards
		(In millions)
2021		$	0.2
2022			0.2
2023			0.4
Total		$	0.8
As of December 31, 2013, a valuation allowance of $7.3 million has been recorded for our NOLs as only $4.7 million of the deferred tax asset is more likely than not to be realized.
Unrecognized Tax Benefits. Our income tax returns are subject to review and examination in the various jurisdictions in which we operate and we are currently contesting various tax assessments. We accrue for income tax contingencies, or uncertain tax positions, that we believe are more likely than not exposures. A reconciliation of the beginning and ending amount of unrecognized tax benefits, gross of tax carryforwards and excluding interest and penalties, and is as follows:
		For the Year Ended December 31,
		2013			2012			2011
		(In thousands)
Balance, beginning of period		$	(67,150	)	$	(62,936	)	$	(75,311	)
Additions for current year tax positions			(1,724	)		(3,837	)		(913	)
Additions for prior year tax positions			(31,264	)		(5,136	)		—
Reductions for prior year tax positions			7,280			4,759			4,770
Reductions related to statute of limitation expirations			1,937			—			8,518
Balance, end of period		$	(90,921	)	$	(67,150	)	$	(62,936	)
At December 31, 2013, $6.3 million and $82.6 million of the net liability for uncertain tax positions were reflected in “Other assets” and “Other liabilities,” respectively. At December 31, 2012, $7.0 million and $55.4 million of the net liability for uncertain tax positions were reflected in “Other assets” and “Other liabilities,” respectively. Of the net unrecognized tax benefits at December 31, 2013, 2012 and 2011, all $76.3 million, $48.4 million and $41.2 million, respectively, would affect the effective tax rates if recognized.
The following table presents the amount of accrued interest and penalties at December 31, 2013 and 2012 related to uncertain tax positions:
		December 31,
		2013			2012
		(In thousands)
Uncertain tax positions net, excluding interest and penalties		$	(76,303	)	$	(48,353	)
Accrued interest on uncertain tax positions			(12,786	)		(7,029	)
Accrued penalties on uncertain tax positions			(59,797	)		(21,662	)
Uncertain tax positions net, including interest and penalties		$	(148,886	)	$	(77,044	)
We record interest related to accrued uncertain tax positions in interest expense and recognize penalties associated with uncertain tax positions in tax expense. Interest expense and penalties recognized during the three years ended December 31, 2013 related to uncertain tax positions are as follows:
		For the Year Ended December 31,
		2013			2012			2011
		(In thousands)
Net increase (decrease) in interest expense related to unrecognized tax positions		$	5,758		$	(1,902	)	$	245
Net increase (decrease) in penalties related to unrecognized tax positions			38,136			(787	)		(3,039	)
In several of the international locations in which we operate, certain of our wholly-owned subsidiaries enter into agreements with other of our wholly-owned subsidiaries to provide specialized services and equipment in support of our foreign operations. We apply a transfer pricing methodology to determine the amount to be charged for providing the services and equipment. In most cases, there are alternative transfer pricing methodologies that could be applied to these transactions and, if applied, could result in different chargeable amounts. Taxing authorities in the various foreign locations in which we operate could apply one of the alternative transfer pricing methodologies which could result in an increase to our income tax liabilities with respect to tax returns that remain subject to examination.
Tax Returns and Examinations. We file income tax returns in the U.S. federal jurisdiction, various state jurisdictions and various foreign jurisdictions. Tax years that remain subject to examination by these jurisdictions include years 2003 to 2012. We are currently under audit in several of these jurisdictions. We do not anticipate that any adjustments resulting from the tax audit of any of these years will have a material impact on our consolidated results of operations, financial condition and cash flows.
U.S. Tax Jurisdiction. In May 2013, we were notified by the Department of the Treasury that the Internal Revenue Service audit of our 2010 corporate tax return was completed without adjustment.
Brazil Tax Jurisdiction. In March 2013, the Brazilian tax authorities began an audit of our income tax returns for the years 2009 and 2010. In addition, we are continuing to defend tax assessments by the Brazilian tax authorities for the years 2000, 2004, 2005 and 2007.
In February 2012, the tax authorities concluded their audit of our income tax return for the 2007 tax year for which we received an assessment of R$35.1 million (approximately equal to USD $15 million at December 31, 2013) for income tax, including interest and penalties. We contested the assessment and a court in Brazil ruled to cancel the assessment. However, the Brazilian tax authorities have appealed the ruling, and we are awaiting the outcome of the appeal. We have not accrued any tax expense related to this assessment.
In December 2009, we received an assessment of approximately $26.0 million for the years 2004 and 2005, including interest and penalty. We contested the tax assessment in January 2010 and are awaiting the outcome of the appeal. As required by GAAP, only the portion of the tax benefit that has a greater than 50% likelihood of being realized upon settlement is to be recognized. Consequently, we have accrued approximately $9.9 million of expense attributable to the portion of the tax assessment we determined to be an uncertain tax position, of which approximately $3.4 million is interest related and approximately $2.8 million is penalty related.
In addition, the tax auditors have issued an assessment for tax year 2000 of approximately $1.5 million, including interest and penalty. We have appealed the tax assessment and are awaiting the outcome of the appeal.
During 2011, unrecognized tax benefits were reduced by approximately $6.8 million due to the lapse in the applicable statute of limitations for the 2006 tax year, of which $1.1 million was interest and $2.0 million was penalty.
Mexico Tax Jurisdiction. The tax authorities in Mexico previously audited our income tax returns for the years 2004 and 2006 and had issued assessments for tax years 2004 and 2006 of approximately $22.9 million and $24.4 million, respectively, including interest and penalties, which we had appealed. In 2013 the Mexican tax authorities initiated a tax amnesty program whereby income tax assessments, including penalties and interest, could be partially or completely waived. Under the tax amnesty, we were able to settle our tax liabilities for the years 2004 and 2006 for a net cash cost of $3.7 million. As a result of increases in uncertain tax positions for later years, we recorded an additional $13.2 million of expense, including $5.0 million of interest and $2.7 million of penalties.
Due to the expiration of the statute of limitations in Mexico for the 2007 tax year at the end of June 2013, during the second quarter of 2013, we reversed our $4.3 million accrual for this uncertain tax position, of which $1.5 million was interest and $0.6 million was penalty.
In addition, in August 2012, the Mexican tax authorities dismissed a claim against one of our Mexican subsidiaries and the 2004 tax year for that subsidiary is now closed. Consequently, during the third quarter of 2012, we reversed our $4.4 million accrual for this uncertain tax position, which included $0.2 million of penalty and $2.6 million of interest.
On June 13, 2013 we received official notification that the Mexican tax authorities will be auditing the 2008 income tax return of one of our Mexican subsidiaries.
Egypt Tax Jurisdiction. During 2013 we were under audit by the Egyptian tax authorities for the tax years 2006 through 2010. In December 2013, we received notification that the Egyptian government had concluded the income tax audit for the period 2006 to 2008 and a $1.2 billion increase to taxable income was proposed. We disagree with the tax audit findings and intend to vigorously pursue all legal remedies available to defend ourselves against any ensuing tax assessment. Due to the inherent uncertainties associated with the Egyptian income tax law, we have accrued approximately $56.9 million of expense for uncertain tax positions in Egypt, of which approximately $31.4 million is penalty related. We recently completed operating in Egypt and no longer have drilling operations there.
American Taxpayer Relief Act of 2012. The American Taxpayer Relief Act of 2012, or the Act, was signed into law on January 2, 2013. The Act extends through 2013 several expired or expiring temporary business provisions, commonly referred to as “extenders,” which are retroactively extended to the beginning of 2012. As required by GAAP, the effects of new legislation are recognized when signed into law. Consequently, we reduced our 2013 tax expense by $27.5 million as a result of recognizing the 2012 effect of the extenders.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]	'
Employee Benefit Plans	'
	14	Employee Benefit Plans
	Defined Contribution Plans
	We maintain defined contribution retirement plans for our U.S., United Kingdom, or U.K., and third-country national, or TCN, employees. The plan for our U.S. employees, or the 401k Plan, is designed to qualify under Section 401(k) of the Internal Revenue Code of 1986, as amended, or the Code. Under the 401k Plan, each participant may elect to defer taxation on a portion of his or her eligible earnings, as defined by the 401k Plan, by directing his or her employer to withhold a percentage of such earnings. A participating employee may also elect to make after-tax contributions to the 401k Plan. During each year ended December 31, 2013, 2012 and 2011, we made a 4% profit-share contribution of participants’ defined compensation and matched up to 6% of each employee’s compensation contributed to the 401k Plan. Participants are fully vested in the employer match immediately upon enrollment in the 401k Plan and subject to a three-year cliff vesting period for the profit sharing contribution. For the years ended December 31, 2013, 2012 and 2011, our provision for contributions was $29.6 million, $25.9 million and $21.5 million, respectively.
	The defined contribution retirement plan for our U.K. employees provides that we make annual contributions in an amount equal to the employee’s contributions generally up to a maximum percentage of the employee’s defined compensation per year. For the years ended December 31, 2013, 2012 and 2011, our contribution for employees working in the U.K. sector of the North Sea was up to a maximum of 10%, 10% and 5.25%, respectively, of the employee’s defined compensation. For the years ended December 31, 2013, 2012 and 2011, our contribution for U.K. nationals working in the Norwegian sector of the North Sea was up to a maximum of 15%, 15% and 9.0%, respectively, of the employee’s defined compensation. Our provision for contributions was $3.5 million, $2.7 million and $1.2 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	The defined contribution retirement plan for our TCN employees, or International Savings Plan, is similar to the 401k Plan. During each year ended December 31, 2013, 2012 and 2011, we contributed 4% of participants’ defined compensation and matched up to 6% of each employee’s compensation contributed to the International Savings Plan. Our provision for contributions was $3.1 million, $2.8 million and $2.9 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	Deferred Compensation and Supplemental Executive Retirement Plan
	Our Amended and Restated Diamond Offshore Management Company Supplemental Executive Retirement Plan, or Supplemental Plan, provides benefits to a select group of our management or other highly compensated employees to compensate such employees for any portion of our base salary contribution and/or matching contribution under the 401k Plan that could not be contributed to that plan because of limitations within the Code. Our provision for contributions to the Supplemental Plan for the years ended December 31, 2013, 2012 and 2011 was approximately $261,000, $256,000 and $245,000, respectively.

Segments_and_Geographic_Area_A

Segments and Geographic Area Analysis	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Segments and Geographic Area Analysis	'
	15	Segments and Geographic Area Analysis
	Although we provide contract drilling services with different types of offshore drilling rigs and also provide such services in many geographic locations, we have aggregated these operations into one reportable segment based on the similarity of economic characteristics due to the nature of the revenue earning process as it relates to the offshore drilling industry over the operating lives of our drilling rigs.
	Revenues from contract drilling services by equipment-type are listed below:
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Floaters:
	Ultra-Deepwater		$	854,515		$	902,793		$	841,565
	Deepwater			617,080			597,694			733,037
	Mid-Water			1,197,934			1,275,068			1,482,032
	Total Floaters			2,669,529			2,775,555			3,056,634
	Jack-ups			174,055			160,511			197,534
	Other			—			—			145
	Total contract drilling revenues			2,843,584			2,936,066			3,254,313
	Revenues related to reimbursable expenses			76,837			50,442			68,106
	Total revenues		$	2,920,421		$	2,986,508		$	3,322,419
	Geographic Areas
	Our drilling rigs are highly mobile and may be moved to other markets throughout the world in response to market conditions or customer needs. At December 31, 2013, our actively-marketed drilling rigs were en route to or located offshore 12 countries in addition to the United States. Revenues by geographic area are presented by attributing revenues to the individual country or areas where the services were performed.
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	United States		$	330,471		$	173,961		$	323,381
	International:
	South America			1,219,287			1,427,927			1,736,798
	Europe/Africa/Mediterranean			731,888			662,995			749,128
	Australia/Asia			438,814			524,957			451,364
	Mexico			199,961			196,668			61,748
				2,589,950			2,812,547			2,999,038
	Total revenues		$	2,920,421		$	2,986,508		$	3,322,419
	An individual international country may, from time to time, comprise a material percentage of our total contract drilling revenues from unaffiliated customers. For the years ended December 31, 2013, 2012 and 2011, individual countries that comprised 5% or more of our total contract drilling revenues from unaffiliated customers are listed below.
			Year Ended December 31,
			2013			2012			2011
	Brazil			38.3	%		46.1	%		49.4	%
	United Kingdom			7.9	%		6.9	%		4.6	%
	Australia			3.2	%		6.7	%		6.7	%
	Mexico			6.9	%		6.6	%		1.9	%
	Angola			3.8	%		2.7	%		9.6	%
	Indonesia			4.4	%		2.4	%		5	%
	The following table presents our long-lived tangible assets by geographic location as of December 31, 2013, 2012 and 2011. A substantial portion of our assets is comprised of rigs that are mobile, and therefore asset locations at the end of the period are not necessarily indicative of the geographic distribution of the earnings generated by such assets during the periods and may vary from period to period due to the relocation of rigs. In circumstances where our drilling rigs were in transit at the end of a calendar year, they have been presented in the tables below within the geographic area in which they were expected to operate.
			December 31,
			2013			2012			2011
			(In thousands)
	Drilling and other property and equipment, net:
	United States(1)		$	611,731		$	444,984		$	283,049
	International:
	Australia/Asia/Middle East(2)			2,078,348			1,474,999			1,212,461
	South America			1,690,976			1,827,247			1,979,303
	Europe/Africa/Mediterranean			793,097			799,194			852,300
	Mexico			293,075			318,548			340,356
				4,855,496			4,419,988			4,384,420
	Total		$	5,467,227		$	4,864,972		$	4,667,469
	-1	Long-lived tangible assets in the United States region as of December 31, 2013, 2012 and 2011 include $339.1 million, $167.4 million and $14.6 million, respectively, in construction work-in-progress for the Ocean Onyx under construction in Brownsville, Texas.
	-2	Long-lived tangible assets in the Australia/Asia/Middle East region include $1,064.5 million, $741.1 million and $490.2 million in construction work-in-progress for our four drillships and the Ocean GreatWhite under construction in South Korea as of December 31, 2013, 2012 and 2011, respectively, and $264.6 million and $82.5 million for the Ocean Apex under construction in Singapore as of December 31, 2013 and 2012, respectively.
	The following table presents the countries in which material concentrations of our long-lived tangible assets were located as of December 31, 2013, 2012 and 2011:
			December 31,
			2013			2012			2011
	Brazil			30.2	%		37.3	%		41.9	%
	South Korea			19.5	%		15.2	%		10.5	%
	United States			11.2	%		9.1	%		6.1	%
	Singapore			8.2	%		1.8	%		—
	Angola			6.3	%		—			8	%
	Mexico			5.4	%		6.5	%		7.3	%
	Indonesia			5.2	%		6.8	%		3.4	%
Egypt			4	%		4.7	%		5.5	%
Vietnam			0.6	%		1.4	%		6.6	%
Republic of Congo			—			7.4	%		—
As of December 31, 2013, 2012 and 2011, no other countries had more than a 5% concentration of our long-lived tangible assets.
Major Customers
Our customer base includes major and independent oil and gas companies and government-owned oil companies. Revenues from our major customers for the years ended December 31, 2013, 2012 and 2011 that contributed more than 10% of our total revenues are as follows:
		Year Ended December 31,
Customer		2013			2012			2011
Petróleo Brasileiro S.A.			33.6	%		33.3	%		35	%
OGX Petróleo e Gás Ltda.			2.4	%		12.5	%		14.1	%

Unaudited_Quarterly_Financial_

Unaudited Quarterly Financial Data	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Unaudited Quarterly Financial Data	'
	16	Unaudited Quarterly Financial Data
	Unaudited summarized financial data by quarter for the years ended December 31, 2013 and 2012 is shown below.
			First		Second		Third		Fourth
			Quarter		Quarter		Quarter		Quarter
			(In thousands, except per share data)
	2013
	Revenues		$	729,741	$	758,018	$	706,165	$	726,497
	Operating income			213,726		262,859		137,352		187,669
	Income before income tax expense			206,179		256,301		131,565		180,195
	Net income			175,989		185,334		94,748		92,615
	Net income per share, basic and diluted		$	1.27	$	1.33	$	0.68	$	0.67
	2012
	Revenues		$	768,642	$	738,188	$	729,141	$	750,537
	Operating income(a)			265,410		257,184		244,822		194,962
	Income before income tax expense			251,435		246,758		234,847		185,041
	Net income			185,169		201,461		178,186		155,661
	Net income per share, basic and diluted		$	1.33	$	1.45	$	1.28	$	1.12
	(a)	Results for the fourth quarter of 2012 include a $62.4 million impairment charge related to rigs transferred to “Assets held for sale” in our Consolidated Balance Sheets at December 31, 2012. See Note 1.

General_Information_Policies

General Information (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Principles of Consolidation	'
	Principles of Consolidation
	Our consolidated financial statements include the accounts of Diamond Offshore Drilling, Inc. and our subsidiaries after elimination of intercompany transactions and balances.
Use of Estimates in the Preparation of Financial Statements	'
	Use of Estimates in the Preparation of Financial Statements
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States, or U.S., or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from those estimated.
Reclassifications	'
	Reclassifications
	Certain amounts applicable to the prior periods have been reclassified to conform to the classifications currently followed. Such reclassifications did not affect earnings.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	We consider short-term, highly liquid investments that have an original maturity of three months or less and deposits in money market mutual funds that are readily convertible into cash to be cash equivalents. We had bank deposits denominated in Egyptian pounds totaling $14.3 million at December 31, 2013. However, the local currency is not readily convertible into U.S. dollars or other currencies at this time. While we believe that a portion of these amounts will be used to fund local operations and obligations in Egyptian pounds in the short term, we reclassified $12.7 million to “Other assets” in our Consolidated Balance Sheets at December 31, 2013.
	The effect of exchange rate changes on cash balances held in foreign currencies was not material for the years ended December 31, 2013, 2012 and 2011.
Marketable Securities	'
	Marketable Securities
	We classify our investments in marketable securities as available for sale and they are stated at fair value in our Consolidated Balance Sheets. Accordingly, any unrealized gains and losses, net of taxes, are reported in our Consolidated Balance Sheets in “Accumulated other comprehensive gain (loss)” until realized. The cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity and such adjustments are included in our Consolidated Statements of Operations in “Interest income.” The sale and purchase of securities are recorded on the date of the trade. The cost of debt securities sold is based on the specific identification method. Realized gains or losses, as well as any declines in value that are judged to be other than temporary, are reported in our Consolidated Statements of Operations in “Other income (expense) – Other, net.”
Provision for Bad Debts	'
	Provision for Bad Debts
	We record a provision for bad debts on a case-by-case basis when facts and circumstances indicate that a customer receivable may not be collectible. In establishing these reserves, we consider historical and other factors that predict collectability, including write-offs, recoveries and the monitoring of credit quality. Such provision is reported as a component of “Operating expense” in our Consolidated Statements of Operations. See Note 2.
Derivative Financial Instruments	'
	Derivative Financial Instruments
	Our derivative financial instruments consist primarily of foreign currency forward exchange, or FOREX, contracts which we may designate as cash flow hedges. In accordance with GAAP, each derivative contract is stated in the balance sheet at its fair value with gains and losses reflected in the income statement except that, to the extent the derivative qualifies for and is designated as an accounting hedge, the gains and losses are reflected in income in the same period as offsetting gains and losses on the qualifying hedged positions. Designated hedges are expected to be highly effective, and therefore, adjustments to record the carrying value of the effective portion of our derivative financial instruments to their fair value are recorded as a component of “Accumulated other comprehensive gain (loss),” or AOCGL, in our Consolidated Balance Sheets. The effective portion of the cash flow hedge will remain in AOCGL until it is reclassified into earnings in the period or periods during which the hedged transaction affects earnings or it is determined that the hedged transaction will not occur. We report such realized gains and losses as a component of “Contract drilling, excluding depreciation” expense in our Consolidated Statements of Operations to offset the impact of foreign currency fluctuations in our expenditures in local foreign currencies in the countries in which we operate.
	Adjustments to record the carrying value of the ineffective portion of our derivative financial instruments to fair value and realized gains or losses upon settlement of derivative contracts not designated as cash flow hedges are reported as “Foreign currency transaction gain (loss)” in our Consolidated Statements of Operations. See Notes 6 and 7.
Assets Held For Sale	'
	Assets Held For Sale
	In 2012, our management adopted a plan to actively market for sale three mid-water semisubmersibles, the Ocean Epoch, the Ocean New Era and the Ocean Whittington, and one jack-up rig, the Ocean Spartan. This decision was based on management’s review of our drilling fleet at the end of 2012 and their assessment that three of these rigs had no short-term outlook for work due to their age and capabilities. These rigs were put on the market for sale at the end of 2012.
	In connection with the reclassification of these rigs to “Assets held for sale,” we measured the fair value of each rig in the disposal group using a probability-weighted cash flow analysis that utilized significant unobservable inputs, representing a Level 3 fair value measurement, which included assumptions for estimated proceeds that may be received upon disposition of the rig and estimated costs to sell. For our three mid-water semisubmersibles in the disposal group, we determined, at that time, that, due to the expected resale market for rigs of this type and age, the highest and best use of these rigs would be for sale as scrap. Based on our analyses, we determined that the carrying values of the mid-water semisubmersible rigs in the disposal group were impaired, as the carrying value for each exceeded its aggregate fair value, and recognized an impairment loss in the fourth quarter of 2012. We determined that the carrying value of the Ocean Spartan was not impaired.
	These rigs were not sold during 2013. The three mid-water semisubmersible rigs have been transferred to “Drilling and Other Property and Equipment” at their aggregate fair value of $3.9 million. Only the Ocean Spartan was reported as “Assets Held for Sale” at December 31, 2013. We reported “Assets held for sale” aggregating $7.7 million and $11.6 million in our Consolidated Balance Sheets at December 31, 2013 and 2012, respectively. See “Impairment of Long-Lived Assets” and Note 7.
Drilling and Other Property and Equipment	'
	Drilling and Other Property and Equipment
	We carry our drilling and other property and equipment at cost. Maintenance and routine repairs are charged to income currently while replacements and betterments, which upgrade or increase the functionality of our existing equipment and that significantly extend the useful life of an existing asset, are capitalized. Significant judgments, assumptions and estimates may be required in determining whether or not such replacements and betterments meet the criteria for capitalization and in determining useful lives and salvage values of such assets. Changes in these judgments, assumptions and estimates could produce results that differ from those reported. Historically, the amount of capital additions requiring significant judgments, assumptions or estimates has not been significant. During the years ended December 31, 2013 and 2012, we capitalized $302.0 million and $220.3 million, respectively, in replacements and betterments of our drilling fleet, resulting from numerous projects ranging from $25,000 to $40 million per project.
	Costs incurred for major rig upgrades and/or the construction of rigs are accumulated in construction work-in-progress, with no depreciation recorded on the additions, until the month the upgrade or newbuild is completed and the rig is placed in service. Upon retirement or sale of a rig, the cost and related accumulated depreciation are removed from the respective accounts and any gains or losses are included in our results of operations as “Gain on disposition of assets.” Depreciation is recognized up to applicable salvage values by applying the straight-line method over the remaining estimated useful lives from the year the asset is placed in service. Drilling rigs and equipment are depreciated over their estimated useful lives ranging from 3 to 30 years.
Capitalized Interest	'
	Capitalized Interest
	We capitalize interest cost for qualifying construction and upgrade projects. During the three years ended December 31, 2013, we capitalized interest on qualifying expenditures, primarily related to our rig construction projects. See Note 8.
	A reconciliation of our total interest cost to “Interest expense” as reported in our Consolidated Statements of Operations is as follows:
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Total interest cost including amortization of debt issuance costs		$	99,080		$	83,890		$	84,349
	Capitalized interest			(74,237	)		(37,674	)		(11,212	)
	Total interest expense as reported		$	24,843		$	46,216		$	73,137
Asset Retirement Obligations	'
	Asset Retirement Obligations
	At December 31, 2013 and 2012, we had no asset retirement obligations.
Impairment of Long-Lived Assets	'
	Impairment of Long-Lived Assets
	We evaluate our property and equipment for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable (such as cold stacking a rig or excess spending over budget on a newbuild, construction project or major rig upgrade). We utilize an undiscounted probability-weighted cash flow analysis in testing an asset for potential impairment. Our assumptions and estimates underlying this analysis include the following:
		•		dayrate by rig;
		•		utilization rate by rig (expressed as the actual percentage of time per year that the rig would be used);
		•		the per day operating cost for each rig if active, warm stacked or cold stacked;
		•		the estimated annual cost for rig replacements and/or enhancement programs;
		•		the estimated maintenance, inspection or other costs associated with a rig returning to work;
		•		salvage value for each rig; and
		•		estimated proceeds that may be received on disposition of the rig.
	Based on these assumptions and estimates, we develop a matrix using several different utilization/dayrate scenarios, to each of which we have assigned a probability of occurrence. The sum of our utilization scenarios (which include active, warm stacked and cold stacked) and probability of occurrence scenarios both equal 100% in the aggregate. We reevaluate our cold-stacked rigs annually, by updating the matrices for each rig and modifying our assumptions, giving consideration to the length of time the rig has been cold stacked, the current and expected market for the type of rig and expectations of future oil and gas prices.
	At December 31, 2012, our four cold-stacked rigs were reported as “Assets held for sale” and had an aggregate net book value of $11.6 million. In connection with the presentation of these rigs as held for sale at the end of 2012, we recognized an impairment loss of $62.4 million. These four rigs remained cold stacked at December 31, 2013. We did not record any impairment with respect to our cold-stacked rigs at December 31, 2013. See “Assets Held for Sale.”
	Management’s assumptions are an inherent part of our asset impairment evaluation and the use of different assumptions could produce results that differ from those reported.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	We believe that the carrying amount of our current financial instruments approximates fair value because of the short maturity of these instruments. For non-current financial instruments we use quoted market prices, when available, and discounted cash flows to estimate fair value. See Note 7.
Debt Issuance Costs	'
	Debt Issuance Costs
	Debt issuance costs are included in our Consolidated Balance Sheets in “Other assets” and are amortized over the respective terms of the related debt.
Income Taxes	'
	Income Taxes
	We account for income taxes in accordance with accounting standards that require the recognition of the amount of taxes payable or refundable for the current year and an asset and liability approach in recognizing the amount of deferred tax liabilities and assets for the future tax consequences of events that have been currently recognized in our financial statements or tax returns. In each of our tax jurisdictions we recognize a current tax liability or asset for the estimated taxes payable or refundable on tax returns for the current year and a deferred tax asset or liability for the estimated future tax effects attributable to temporary differences and carryforwards. Deferred tax assets are reduced by a valuation allowance, if necessary, which is determined by the amount of any tax benefits that, based on available evidence, are not expected to be realized under a “more likely than not” approach. We make judgments regarding future events and related estimates especially as they pertain to the forecasting of our effective tax rate, the potential realization of deferred tax assets such as utilization of foreign tax credits, and exposure to the disallowance of items deducted on tax returns upon audit.
	We record interest related to accrued unrecognized tax positions in interest expense and recognize penalties associated with uncertain tax positions in our tax expense. See Note 13.
Treasury Stock	'
	Treasury Stock
	Depending on market conditions, we may, from time to time, purchase shares of our common stock in the open market or otherwise. We account for the purchase of treasury stock using the cost method, which reports the cost of the shares acquired in “Treasury stock” as a deduction from stockholders’ equity in our Consolidated Balance Sheets. We did not repurchase any shares of our outstanding common stock during 2013, 2012 or 2011.
Comprehensive Income (Loss)	'
	Comprehensive Income (Loss)
	Comprehensive income (loss) is the change in equity of a business enterprise during a period from transactions and other events and circumstances except those transactions resulting from investments by owners and distributions to owners. Comprehensive income (loss) for the three years ended December 31, 2013, 2012 and 2011 includes net income (loss) and unrealized holding gains and losses on marketable securities and financial derivatives designated as cash flow accounting hedges. See Note 10.
Foreign Currency	'
	Foreign Currency
	Our functional currency is the U.S. dollar. Foreign currency transaction gains and losses are reported as “Foreign currency transaction gain (loss)” in our Consolidated Statements of Operations and include, when applicable, unrealized gains and losses to record the carrying value of our FOREX contracts not designated as accounting hedges, as well as realized gains and losses from the settlement of such contracts. For the years ended December 31, 2013, 2012 and 2011, we recognized aggregate net foreign currency gains (losses) of $(4.9) million, $(2.0) million and $(8.6) million, respectively. See Note 6.
Revenue Recognition	'
	Revenue Recognition
	We recognize revenue from dayrate drilling contracts as services are performed. In connection with such drilling contracts, we may receive fees (either lump-sum or dayrate) for the mobilization of equipment. We earn these fees as services are performed over the initial term of the related drilling contracts. We defer mobilization fees received, as well as direct and incremental mobilization costs incurred, and amortize each, on a straight-line basis, over the term of the related drilling contracts (which is the period we estimate to be benefited from the mobilization activity). Straight-line amortization of mobilization revenues and related costs over the term of the related drilling contracts (which generally range from 2 to 60 months) is consistent with the timing of net cash flows generated from the actual drilling services performed. Absent a contract, mobilization costs are recognized currently.
	Some of our drilling contracts require downtime before the start of the contract to prepare the rig to meet customer requirements. At times, we may be compensated by the customer for such work (either lump-sum or dayrate). These fees are generally earned as services are performed over the initial term of the related drilling contracts. We defer contract preparation fees received, as well as direct and incremental costs associated with the contract preparation activities and amortize each, on a straight-line basis, over the term of the related drilling contracts (which we estimate to be benefited from the contract preparation activity).
	From time to time, we may receive fees from our customers for capital improvements to our rigs (either lump-sum or dayrate). We defer such fees received in “Accrued liabilities” and “Other liabilities” in our Consolidated Balance Sheets and recognize these fees into income on a straight-line basis over the period of the related drilling contract. We capitalize the costs of such capital improvements and depreciate them over the estimated useful life of the improvement.
	We record reimbursements received for the purchase of supplies, equipment, personnel services and other services provided at the request of our customers in accordance with a contract or agreement, for the gross amount billed to the customer, as “Revenues related to reimbursable expenses” in our Consolidated Statements of Operations.

General_Information_Tables

General Information (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Reconciliation of Total Interest Cost to Interest Expense	'
	A reconciliation of our total interest cost to “Interest expense” as reported in our Consolidated Statements of Operations is as follows:
		For the Year Ended December 31,
		2013			2012			2011
		(In thousands)
	Total interest cost including amortization of debt issuance costs	$	99,080		$	83,890		$	84,349
	Capitalized interest		(74,237	)		(37,674	)		(11,212	)
	Total interest expense as reported	$	24,843		$	46,216		$	73,137

Supplemental_Financial_Informa1

Supplemental Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Accounts Receivable, Net of Allowance for Doubtful Accounts	'
	Accounts receivable, net of allowance for bad debts, consists of the following:
			December 31,
			2013			2012
			(In thousands)
	Trade receivables		$	473,013		$	478,930
	Value added tax receivables			19,407			13,884
	Amounts held in escrow			3,066			11,555
	Interest receivable			7			6
	Related party receivables			587			527
	Other			615			216
				496,695			505,118
	Allowance for bad debts			(27,340	)		(5,458	)
	Total		$	469,355		$	499,660
Changes in Provision for Bad Debts	'
	An analysis of the changes in our provision for bad debts for each of the three years ended December 31, 2013, 2012 and 2011 is as follows (see Note 7):
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Allowance for bad debts, beginning of year		$	5,458		$	6,867		$	31,908
	Bad debt expense:
	Provision for bad debts			22,513			—			5,688
	Recovery of bad debts			—			(1,018	)		(12,401	)
	Total bad debt expense (recovery)			22,513			(1,018	)		(6,713	)
	Write off of uncollectible accounts against reserve			(509	)		(391	)		(18,380	)
	Other(1)			(122	)		—			52
	Allowance for bad debts, end of year		$	27,340		$	5,458		$	6,867
	(1)	Includes revaluation adjustments for non-U.S. dollar denominated receivables, which have been recorded as “Foreign currency transaction gain (loss)” in our Consolidated Statements of Operations.
Prepaid Expenses and Other Current Assets	'
	Prepaid expenses and other current assets consist of the following:
			December 31,
			2013			2012
			(In thousands)
	Rig spare parts and supplies		$	52,439		$	57,558
	Deferred mobilization costs			20,274			38,074
	Prepaid insurance			12,503			12,549
	Deferred tax assets			10,221			8,619
	Prepaid taxes			42,058			5,950
	FOREX contracts			1,562			3,627
	Other			4,940			9,722
	Total		$	143,997		$	136,099
Accrued Liabilities	'
	Accrued liabilities consist of the following:
			December 31,
			2013			2012
			(In thousands)
	Rig operating expenses		$	87,307		$	70,078
	Payroll and benefits			121,387			88,612
	Deferred revenue			26,975			71,699
	Accrued capital project/upgrade costs			86,274			56,595
	Interest payable			28,324			21,219
	Personal injury and other claims			9,687			10,312
	FOREX contracts			1,143			29
	Other			9,574			5,890
	Total		$	370,671		$	324,434
Noncash Investing and Financing Activities	'
	Noncash investing activities excluded from the Consolidated Statements of Cash Flows and other supplemental cash flow information is as follows:
			December 31,
			2013			2012			2011
			(In thousands)
	Accrued but unpaid capital expenditures at period end		$	86,274		$	56,595		$	37,325
	Income tax benefits related to exercise of stock options			1,081			1,083			863
	Cash interest payments(1)(2)			82,938			83,125			82,938
	Cash income taxes paid, net of refunds:
	U.S. federal			62,000			71,000			94,843
	Foreign			78,041			72,249			150,465
	State			190			243			210
	-1	Interest payments, net of amounts capitalized, were $16.5 million, $46.2 million and $71.9 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	-2	Interest paid on Internal Revenue Service assessments was $0.2 million during the year ended December 31, 2012.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Weighted Average Assumptions Used in Estimating Fair Value of Options and SARs	'
	The following are the weighted average assumptions used in estimating the fair value of our SARs:
		Year Ended December 31,
		2013			2012			2011
	Expected life of SARs (in years)		7			6			5
	Expected volatility		18.24	%		33.45	%		30.37	%
	Dividend yield		0.75	%		0.78	%		0.76	%
	Risk free interest rate		1.61	%		0.89	%		1.54	%
Summary of Activity Under Stock Plan	'
	A summary of activity under the Stock Plan as of December 31, 2013 and changes during the year then ended is as follows:
		Number of			Weighted-Average			Weighted-Average			Aggregate Intrinsic
		Awards			Exercise Price			Remaining			Value
								Contractual
								Term
								(Years)
											(In Thousands)
	Awards outstanding at January 1, 2013		1,229,480		$	80.32
	Granted		233,625		$	66.95
	Exercised		(15,091	)	$	59.58
	Forfeited		(24,283	)	$	67.51
	Expired		(31,072	)	$	94.01
	Awards outstanding at December 31, 2013		1,392,659		$	78.22			7		$	460
	Awards exercisable at December 31, 2013		973,918		$	83.32			6		$	438

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Reconciliation of Numerators and Denominators of Basic and Diluted Per-Share Computations	'
	A reconciliation of the numerators and the denominators of the basic and diluted per-share computations follows:
		Year Ended December 31,
		2013		2012		2011
		(In thousands, except per share data)
	Net income – basic and diluted (numerator):	$	548,686	$	720,477	$	962,542
	Weighted-average shares – basic (denominator):		139,035		139,029		139,027
	Effect of dilutive potential shares
	Stock options and stock appreciation rights		29		19		11
	Weighted-average shares including conversions – diluted (denominator):		139,064		139,048		139,038
	Earnings per share:
	Basic	$	3.95	$	5.18	$	6.92
	Diluted	$	3.95	$	5.18	$	6.92
Securities Excluded from Computation of Diluted Earning Per Share	'
	The following table sets forth the share effects of stock options and the number of SARs excluded from our computations of diluted earnings per share, or EPS, as the inclusion of such potentially dilutive shares would have been antidilutive for the periods presented:
		Year Ended December 31,
		2013		2012		2011
		(In thousands)
	Employee and director:
	Stock options		18		18		19
	SARs		956		853		847

Marketable_Securities_Tables

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]	'
Investments in Marketable Securities as Available for Sale	'
	Our investments in marketable securities are classified as available for sale and are summarized as follows:
		December 31, 2013
		Amortized			Unrealized			Market
		Cost			Gain (Loss)			Value
		(In thousands)
	U.S. Treasury Bills and Notes (due within one year)	$	1,749,879		$	(22	)	$	1,749,857
	Mortgage-backed securities		188			8			196
	Total	$	1,750,067		$	(14	)	$	1,750,053
		December 31, 2012
		Amortized			Unrealized			Market
		Cost			Gain (Loss)			Value
		(In thousands)
	U.S. Treasury Bills and Notes (due within one year)	$	1,149,707		$	150		$	1,149,857
	Mortgage-backed securities		276			25			301
	Total	$	1,149,983		$	175		$	1,150,158
Summary of Proceeds from Sales and Maturities of Marketable Securities and Gross Realized Gains and Losses	'
	Proceeds from maturities and sales of marketable securities and gross realized gains and losses are summarized as follows:
		Year Ended December 31,
		2013			2012			2011
		(In thousands)
	Proceeds from maturities	$	4,650,000		$	2,575,000		$	5,350,000
	Proceeds from sales		85			150,118			12,138
	Gross realized gains		—			—			784
	Gross realized losses		(1	)		(6	)		(5	)

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Amounts Recognized in Consolidated Statements of Operations Related to FOREX Contracts Designated as Hedging Instruments	'
	The following table presents the amounts recognized in our Consolidated Statements of Operations related to our FOREX contracts designated as hedging instruments for the years ended December 31, 2013, 2012 and 2011.
		Amount of (Loss) Gain
		Recognized in Income
		For the Years Ended December 31,
	Location of (Loss) Gain Recognized in Income	2013			2012			2011
		(In thousands)
	Contract drilling expense	$	(6,501	)	$	(4,302	)	$	7,206
Fair Values of FOREX Contracts	'
	The following table presents the fair values of our FOREX contracts at December 31, 2013 and 2012.
	Balance Sheet Location	Fair Value						Balance Sheet Location		Fair Value
		December 31,			December 31,					December 31,			December 31,
		2013			2012					2013			2012
		(In thousands)								(In thousands)
	Prepaid expenses and other current assets	$	1,562		$	3,627		Accrued liabilities		$	(1,143	)	$	(29	)
Amounts Recognized in Consolidated Balance Sheets and Consolidated Statements of Operations Related to Derivative Contracts Designated as Cash Flow Hedges	'
	The following table presents the amounts recognized in our Consolidated Balance Sheets and Consolidated Statements of Operations related to our derivative contracts designated as cash flow hedges for the years ended December 31, 2013, 2012 and 2011.
		For the years ended December 31,
		2013			2012			2011
		(In thousands)
	FOREX contracts:
	Amount of (loss) gain recognized in AOCGL on derivative (effective portion)	$	(10,542	)	$	6,519		$	(962	)
	Location of (loss) gain reclassified from AOCGL into income (effective portion)		Contract drilling,			Contract drilling,			Contract drilling,
			excluding			excluding			excluding
			depreciation			depreciation			depreciation
	Amount of (loss) gain reclassified from AOCGL into income (effective portion)	$	(7,449	)	$	(4,205	)	$	10,351
	Location of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		Foreign currency			Foreign currency			Foreign currency
			transaction gain			transaction gain			transaction gain
			(loss)			(loss)			(loss)
	Amount of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	$	(104	)	$	(17	)	$	(85	)
	Treasury lock agreements:
	Amount of gain recognized in AOCGL on derivative (effective portion)	$	27		$	—		$	—
	Location of gain reclassified from AOCGL into income (effective portion)		Interest expense			Interest expense			Interest expense
	Amount of gain reclassified from AOCGL into income (effective portion)	$	1		$	—		$	—

Financial_Instruments_and_Fair1

Financial Instruments and Fair Value Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Assets and Liabilities Measured at Fair Value on Recurring and Nonrecurring Basis	'
	December 31, 2013
		Fair Value Measurements Using							Assets at Fair			Total Losses
									Value			for Year
		Level 1		Level 2			Level 3					Ended
		(In thousands)
	Recurring fair value measurements:
	Assets:
	Short-term investments	$	2,061,154	$	—		$	—	$	2,061,154		$	—
	FOREX contracts		—		1,562			—		1,562			—
	Mortgage-backed securities		—		197			—		197			—
	Total assets	$	2,061,154	$	1,759		$	—	$	2,062,913		$	—
	Liabilities:
	FOREX contracts	$	—	$	(1,143	)	$	—	$	(1,143	)	$	—
	Nonrecurring fair value measurements:
	Assets:
	Impaired assets	$	—	$	—		$	3,900	$	3,900		$	—
		December 31, 2012
		Fair Value Measurements Using							Assets at Fair			Total Losses
									Value			for Year
		Level 1		Level 2			Level 3					Ended
		(In thousands)
	Recurring fair value measurements:
	Assets:
	Short-term investments	$	1,434,751	$	—		$	—	$	1,434,751		$	—
	FOREX contracts		—		3,627			—		3,627			—
	Mortgage-backed securities		—		301			—		301			—
	Total assets	$	1,434,751	$	3,928		$	—	$	1,438,679		$	—
	Liabilities:
	FOREX contracts	$	—	$	(29	)	$	—	$	(29	)	$	—
	Nonrecurring fair value measurements:
	Assets:
	Assets held for sale	$	—	$	—		$	3,900	$	3,900		$	(62,437	)
Fair Values and Related Carrying Values of Our Debt Instruments	'
	Fair values and related carrying values (see Note 9) of our senior notes are shown below.
		December 31, 2013					December 31, 2012
		Fair Value		Carrying Value			Fair Value		Carrying Value
		(In millions)
	5.15% Senior Notes due 2014	$	257.4	$	250		$	269	$	249.9
	4.875% Senior Notes due 2015		265.7		249.9			275.5		249.8
	5.875% Senior Notes due 2019		578.1		499.6			617.1		499.5
	3.45% Senior Notes due 2023		241.4		249			—		—
	5.70% Senior Notes due 2039		543.1		496.9			641.4		496.9
	4.875% Senior Notes due 2043		736.1		748.8			—		—

Drilling_and_Other_Property_an1

Drilling and Other Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Summary of Cost and Accumulated Depreciation of Drilling and Other Property and Equipment	'
	Cost and accumulated depreciation of drilling and other property and equipment are summarized as follows:
		December 31,
		2013			2012
		(In thousands)
	Drilling rigs and equipment	$	7,412,066		$	7,107,279
	Construction work-in-progress		1,668,211			990,964
	Land and buildings		65,627			64,296
	Office equipment and other		65,799			60,239
	Cost		9,211,703			8,222,778
	Less accumulated depreciation		(3,744,476	)		(3,357,806	)
	Drilling and other property and equipment, net	$	5,467,227		$	4,864,972
Summary of Construction Work-in-Progress, Including Capitalized Interest	'
	Construction work-in-progress, including capitalized interest, at December 31, 2013 and 2012 is summarized as follows:
		December 31,
		2013			2012
		(In thousands)
	Ultra-deepwater drillships	$	868,908		$	741,059
	Ultra-deepwater semisubmersible:
	Ocean GreatWhite		195,578			—
	Deepwater semisubmersibles:
	Ocean Onyx		339,129			167,403
	Ocean Apex		264,596			82,502
	Total construction work-in-progress	$	1,668,211		$	990,964

Credit_Agreement_and_Senior_No1

Credit Agreement and Senior Notes (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Summary of Senior Notes	'
	At December 31, 2013, our senior notes were comprised of the following debt issues:
		Principal Amount					Interest Rate		Semiannual
									Interest Payment
	Debt Issue	(In millions)			Maturity Date		Coupon	Effective	Dates
	5.15% Senior Notes due 2014	$	250		September 1, 2014		5.15%	5.18%	March 1 and September 1
	4.875% Senior Notes due 2015	$	250		1-Jul-15		4.88%	4.90%	January 1 and July 1
	5.875% Senior Notes due 2019	$	500		1-May-19		5.88%	5.89%	May 1 and November 1
	3.45% Senior Notes due 2023	$	250		1-Nov-23		3.45%	3.50%	May 1 and November 1
	5.70% Senior Notes due 2039	$	500		15-Oct-39		5.70%	5.75%	April 15 and October 15
	4.875% Senior Notes due 2043	$	750		1-Nov-43		4.88%	4.89%	May 1 and November 1
Summary of Carrying Value of Senior Notes	'
	At December 31, 2013 and 2012, the carrying value of our senior notes was as follows:
		December 31,
		2013			2012
		(In thousands)
	5.15% Senior Notes due 2014	$	249,954		$	249,882
	4.875% Senior Notes due 2015		249,898			249,837
	5.875% Senior Notes due 2019		499,551			499,480
	3.45% Senior Notes due 2023		248,988			—
	5.70% Senior Notes due 2039		496,919			496,867
	4.875% Senior Notes due 2043		748,833			—
	Total senior notes, net of unamortized discount	$	2,494,143		$	1,496,066
	Less: Current portion of long-term debt		249,954			—
	Total Long-term debt	$	2,244,189		$	1,496,066
Aggregate Maturities of Senior Notes	'
	As of December 31, 2013, the aggregate annual maturity of our senior notes was as follows:
		Aggregate
		Principal
		Amount
	Years Ending December 31,	(In thousands)
	2014	$	250,000
	2015		250,000
	2016		—
	2017		—
	2018		—
	Thereafter		2,000,000
	Total maturities of senior notes		2,500,000
	Less: unamortized discounts		(5,857	)
	Total maturities of senior notes, net of unamortized discount	$	2,494,143

Other_Comprehensive_Income_Los1

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Components of Other Comprehensive Income (Loss) and Associated Income Tax Effects	'
	The following table sets forth the components of “Other comprehensive income (loss)” and the related income tax effects thereon for the three years ended December 31, 2013 and the cumulative balances in AOCGL by component at December 31, 2013, 2012 and 2011 and.
		Unrealized Gain (Loss) on
		Derivative			Marketable			Total
		Financial			Securities			AOCGL
		Instruments
		(In thousands)
	Balance at January 1, 2011	$	2,733		$	408		$	3,141
	Unrealized gain (loss) before reclassifications, after tax of $337 and $15		(625	)		(46	)		(671	)
	Reclassification adjustments for items included in Net Income, after tax of $3,623 and $205		(6,728	)		(384	)		(7,112	)
	Total other comprehensive income (loss)		(7,353	)		(430	)		(7,783	)
	Balance at December 31, 2011		(4,620	)		(22	)		(4,642	)
	Unrealized gain (loss) before reclassifications, after tax of $(2,282) and $(28)		4,237			124			4,361
	Reclassification adjustments for items included in Net Income, after tax of $(1,472) and $(1)		2,733			44			2,777
	Total other comprehensive income (loss)		6,970			168			7,138
	Balance at December 31, 2012		2,350			146			2,496
	Unrealized gain (loss) before reclassifications, after tax of $3,682 and $18		(6,833	)		(6	)		(6,839	)
	Reclassification adjustments for items included in Net Income, after tax of $(2,608) and $18		4,840			(147	)		4,693
	Total other comprehensive income (loss)		(1,993	)		(153	)		(2,146	)
	Balance at December 31, 2013	$	357		$	(7	)	$	350
Components of Accumulated Other Comprehensive Gain Loss	'
	The following table presents the line items in our Consolidated Statements of Operations affected by reclassification adjustments out of AOCGL.
	Major Components of AOCGL	Year Ended December 31,									Consolidated Statements of
											Operations Line Items
		2013			2012			2011
		(In thousands)
	Derivative financial instruments:	$	(7,449	)	$	(4,205	)	$	10,351		Contract drilling, excluding
	Unrealized (gain) loss on FOREX contracts										depreciation
	Unrealized loss (gain) on Treasury Lock Agreements		1			—			—		Interest expense
			2,608			1,472			(3,623	)	Income tax expense
		$	(4,840	)	$	(2,733	)	$	6,728		Net of tax
	Marketable securities:	$	165		$	(45	)	$	589		Other, net
	Unrealized (gain) loss on marketable securities
			(18	)		1			(205	)	Income tax expense
		$	147		$	(44	)	$	384		Net of tax

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Components of Income Tax Expense (Benefit)	'
	The components of income tax expense (benefit) are as follows:
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Federal — current		$	40,045		$	173,061		$	109,684
	State — current			69			267			264
	Foreign — current			151,339			75,748			104,640
	Total current			191,453			249,076			214,588
	Federal — deferred			46,767			(51,852	)		(1,023	)
	Foreign — deferred			(12,666	)		380			3,164
	Total deferred			34,101			(51,472	)		2,141
	Total		$	225,554		$	197,604		$	216,729
Difference Between Actual Income Tax Expense and Tax Provision Computed by Applying Statutory Federal Income Tax Rate to Income Before Taxes	'
	The difference between actual income tax expense and the tax provision computed by applying the statutory federal income tax rate to income before taxes is attributable to the following:
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Income before income tax expense:
	U.S.		$	537,635		$	512,733		$	486,393
	Foreign			236,605			405,348			692,878
	Worldwide		$	774,240		$	918,081		$	1,179,271
	Expected income tax expense at federal statutory rate		$	270,984		$	321,328		$	412,745
	Foreign earnings of foreign subsidiaries (not taxed at the statutory federal income tax rate) net of related foreign taxes			(102,359	)		(166,251	)		(189,051	)
	Foreign earnings of foreign subsidiaries for which U.S. federal income taxes have been provided			805			28,252			(14,681	)
	Foreign taxes of domestic and foreign subsidiaries for which U.S. federal income taxes have also been provided			45,428			35,722			65,521
	Foreign tax credits			(46,524	)		(45,824	)		(67,232	)
	Interest capitalized by foreign subsidiaries			(18,391	)		(11,764	)		(3,924	)
	Reduction of deferred tax liability related to a goodwill deduction resulting from a prior period stock acquisition			—			—			(2,950	)
	Impact of American Taxpayer Relief Act of 2012			(27,509	)		—			—
	Uncertain tax positions			66,085			6,325			(7,733	)
	Amortization of deferred charges associated with intercompany rig sales to other tax jurisdictions			30,894			31,276			29,556
	Net expense (benefit) in connection with resolutions of tax issues and adjustments relating to prior years			4,804			(2,152	)		(6,085	)
	Other			1,337			692			563
	Income tax expense		$	225,554		$	197,604		$	216,729
Components of Deferred Income Tax Assets and Liabilities	'
	Significant components of our deferred income tax assets and liabilities are as follows:
			December 31,
			2013			2012
			(In thousands)
	Deferred tax assets:
	Net operating loss carryforwards, or NOLs		$	12,038		$	24,067
	Worker’s compensation and other current accruals			17,269			16,929
	Disputed receivables reserved			3,516			956
	Deferred compensation			14,020			9,051
	Foreign contribution taxes			5,749			6,780
	Mobilization			1,673			4,736
	Nonqualified stock options and SARs			9,584			8,698
	Deferred deductions			8,577			—
	Interest -Uncertain Tax Positions			1,008			206
	Other			1,714			1,434
	Total deferred tax assets (1)			75,148			72,857
	Valuation allowance for NOLs			(7,321	)		(22,876	)
	Net deferred tax assets			67,827			49,981
	Deferred tax liabilities:
	Depreciation			(578,742	)		(526,606	)
	Unbilled revenue			(4,371	)		(5,649	)
	Undistributed earnings of foreign subsidiaries			(24	)		(24	)
	Other			(9	)		(29	)
	Total deferred tax liabilities			(583,146	)		(532,308	)
	Net deferred tax liability		$	(515,319	)	$	(482,327	)
	-1	$10.2 million and $8.6 million reflected in “Prepaid expenses and other current assets” in our Consolidated Balance Sheets at December 31, 2013 and 2012, respectively. See Note 2.
Summary of Changes in Valuation Allowance	'
	A summary of changes in the valuation allowance is as follows:
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Valuation allowance as of January 1		$	22,876		$	26,353		$	32,102
	Establishment of valuation allowances:
	Foreign tax credits			—			—			(186	)
	Net operating losses			25			946			1,844
	Releases of valuation allowances in various jurisdictions			(15,580	)		(4,423	)		(7,407	)
	Valuation allowance as of December 31		$	7,321		$	22,876		$	26,353
Tax Benefits of these Mexican NOL Carryforwards	'
	Unless utilized, the tax benefits of these Mexican NOL carryforwards will expire between 2021 and 2023 as follows:
	Year Expiring		Tax Benefit of
			NOL
			Carryforwards
			(In millions)
	2021		$	0.2
	2022			0.2
	2023			0.4
	Total		$	0.8
Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits, Excluding Interest and Penalties	'
	A reconciliation of the beginning and ending amount of unrecognized tax benefits, gross of tax carryforwards and excluding interest and penalties, and is as follows:
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Balance, beginning of period		$	(67,150	)	$	(62,936	)	$	(75,311	)
	Additions for current year tax positions			(1,724	)		(3,837	)		(913	)
	Additions for prior year tax positions			(31,264	)		(5,136	)		—
	Reductions for prior year tax positions			7,280			4,759			4,770
	Reductions related to statute of limitation expirations			1,937			—			8,518
	Balance, end of period		$	(90,921	)	$	(67,150	)	$	(62,936	)
Schedule of Accrued Interest and Penalties	'
	The following table presents the amount of accrued interest and penalties at December 31, 2013 and 2012 related to uncertain tax positions:
			December 31,
			2013			2012
			(In thousands)
	Uncertain tax positions net, excluding interest and penalties		$	(76,303	)	$	(48,353	)
	Accrued interest on uncertain tax positions			(12,786	)		(7,029	)
	Accrued penalties on uncertain tax positions			(59,797	)		(21,662	)
	Uncertain tax positions net, including interest and penalties		$	(148,886	)	$	(77,044	)
Schedule of Interest Expense and Penalties	'
	Interest expense and penalties recognized during the three years ended December 31, 2013 related to uncertain tax positions are as follows:
			For the Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Net increase (decrease) in interest expense related to unrecognized tax positions		$	5,758		$	(1,902	)	$	245
	Net increase (decrease) in penalties related to unrecognized tax positions			38,136			(787	)		(3,039	)

Segments_and_Geographic_Area_A1

Segments and Geographic Area Analysis (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Revenues from Contract Drilling Services by Equipment Type	'
	Revenues from contract drilling services by equipment-type are listed below:
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	Floaters:
	Ultra-Deepwater		$	854,515		$	902,793		$	841,565
	Deepwater			617,080			597,694			733,037
	Mid-Water			1,197,934			1,275,068			1,482,032
	Total Floaters			2,669,529			2,775,555			3,056,634
	Jack-ups			174,055			160,511			197,534
	Other			—			—			145
	Total contract drilling revenues			2,843,584			2,936,066			3,254,313
	Revenues related to reimbursable expenses			76,837			50,442			68,106
	Total revenues		$	2,920,421		$	2,986,508		$	3,322,419
Revenues by Geographic Area Presented by Attributing Revenues to Individual Country	'
	Revenues by geographic area are presented by attributing revenues to the individual country or areas where the services were performed.
			Year Ended December 31,
			2013			2012			2011
			(In thousands)
	United States		$	330,471		$	173,961		$	323,381
	International:
	South America			1,219,287			1,427,927			1,736,798
	Europe/Africa/Mediterranean			731,888			662,995			749,128
	Australia/Asia			438,814			524,957			451,364
	Mexico			199,961			196,668			61,748
				2,589,950			2,812,547			2,999,038
	Total revenues		$	2,920,421		$	2,986,508		$	3,322,419
Individual Countries that Comprised 5% or More of Our Total Contract Drilling Revenues from Unaffiliated Customers	'
	For the years ended December 31, 2013, 2012 and 2011, individual countries that comprised 5% or more of our total contract drilling revenues from unaffiliated customers are listed below.
			Year Ended December 31,
			2013			2012			2011
	Brazil			38.3	%		46.1	%		49.4	%
	United Kingdom			7.9	%		6.9	%		4.6	%
	Australia			3.2	%		6.7	%		6.7	%
	Mexico			6.9	%		6.6	%		1.9	%
	Angola			3.8	%		2.7	%		9.6	%
	Indonesia			4.4	%		2.4	%		5	%
Long-Lived Tangible Assets by Geographic Location	'
	The following table presents our long-lived tangible assets by geographic location as of December 31, 2013, 2012 and 2011.
			December 31,
			2013			2012			2011
			(In thousands)
	Drilling and other property and equipment, net:
	United States(1)		$	611,731		$	444,984		$	283,049
	International:
	Australia/Asia/Middle East (2)			2,078,348			1,474,999			1,212,461
	South America			1,690,976			1,827,247			1,979,303
	Europe/Africa/Mediterranean			793,097			799,194			852,300
	Mexico			293,075			318,548			340,356
				4,855,496			4,419,988			4,384,420
	Total		$	5,467,227		$	4,864,972		$	4,667,469
	-1	Long-lived tangible assets in the United States region as of December 31, 2013, 2012, and 2011 include $339.1 million, $167.4 million and $14.6 million, respectively, in construction work-in-progress for the Ocean Onyx under construction in Brownsville, Texas.
	-2	Long-lived tangible assets in the Australia/Asia/Middle East region include $1,064.5 million, $741.1 million and $490.2 million in construction work-in-progress for our four drillships and the Ocean GreatWhite under construction in South Korea as of December 31, 2013, 2012, and 2011, respectively, and $264.6 million and $82.5 million for the Ocean Apex under construction in Singapore as of December 31, 2013 and 2012, respectively.
Countries Where Parent Company had Material Concentration of Operating Assets	'
	The following table presents the countries in which material concentrations of our long-lived tangible assets were located as of December 31, 2013, 2012 and 2011:
			December 31,
			2013			2012			2011
	Brazil			30.2	%		37.3	%		41.9	%
	South Korea			19.5	%		15.2	%		10.5	%
	United States			11.2	%		9.1	%		6.1	%
	Singapore			8.2	%		1.8	%		—
	Angola			6.3	%		—			8	%
	Mexico			5.4	%		6.5	%		7.3	%
	Indonesia			5.2	%		6.8	%		3.4	%
	Egypt			4	%		4.7	%		5.5	%
	Vietnam			0.6	%		1.4	%		6.6	%
	Republic of Congo			—			7.4	%		—
Revenues from Major Customers that Contributed More than 10% of Total Revenues	'
	Revenues from our major customers for the years ended December 31, 2013, 2012 and 2011 that contributed more than 10% of our total revenues are as follows:
			Year Ended December 31,
	Customer		2013			2012			2011
	Petróleo Brasileiro S.A.			33.6	%		33.3	%		35	%
	OGX Petróleo e Gás Ltda.			2.4	%		12.5	%		14.1	%

Unaudited_Quarterly_Financial_1

Unaudited Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Unaudited Quarterly Financial Data	'
	Unaudited summarized financial data by quarter for the years ended December 31, 2013 and 2012 is shown below.
			First		Second		Third		Fourth
			Quarter		Quarter		Quarter		Quarter
			(In thousands, except per share data)
	2013
	Revenues		$	729,741	$	758,018	$	706,165	$	726,497
	Operating income			213,726		262,859		137,352		187,669
	Income before income tax expense			206,179		256,301		131,565		180,195
	Net income			175,989		185,334		94,748		92,615
	Net income per share, basic and diluted		$	1.27	$	1.33	$	0.68	$	0.67
	2012
	Revenues		$	768,642	$	738,188	$	729,141	$	750,537
	Operating income(a)			265,410		257,184		244,822		194,962
	Income before income tax expense			251,435		246,758		234,847		185,041
	Net income			185,169		201,461		178,186		155,661
	Net income per share, basic and diluted		$	1.33	$	1.45	$	1.28	$	1.12
	(a)	Results for the fourth quarter of 2012 include a $62.4 million impairment charge related to rigs transferred to “Assets held for sale” in our Consolidated Balance Sheets at December 31, 2012. See Note 1.

General_Information_Additional

General Information - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
		Rigs
Property, Plant and Equipment [Line Items]	'	'	'	'
Number of offshore rigs owned	'	45	'	'
Number of offshore rigs held for sale	'	1	'	'
Number of rigs under construction	'	5	'	'
Outstanding common stock owned by Loews Corporation	'	50.40%	'	'
Period considered to treat short-term, highly liquid investments as cash equivalents	'	'Three months or less	'	'
Effect of exchange rate changes on cash balances held in foreign currencies	'	$0	$0	$0
Drilling and other property and equipment	4,864,972,000	5,467,227,000	4,864,972,000	4,667,469,000
Recoverable amount of assets held for sale	11,594,000	7,694,000	11,594,000	'
Amount capitalized for asset replacements and betterments	'	302,000,000	220,300,000	'
Sum and probability of occurrence scenarios	'	100.00%	100.00%	'
Net book value of cold stacked rigs	'	'	'	76,500,000
Impairment loss write down to the aggregate net book value	62,400,000	'	62,437,000	'
Gain (loss) on foreign currency transactions recognized in income	'	-4,900,000	-2,000,000	-8,600,000
Initial term of contracts minimum months	'	'2 months	'	'
Initial term of contracts maximum months	'	'60 months	'	'
Egyptian Pounds [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Bank deposits	'	14,300,000	'	'
Other Current Assets [Member] | Egyptian Pounds [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Bank deposits	'	12,700,000	'	'
Semisubmersibles [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number of offshore rigs owned	'	33	'	'
Number of rigs under construction	'	2	'	'
Jack-ups [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number of offshore rigs owned	'	7	'	'
Number of offshore rigs held for sale	1	1	1	'
Ultra-deepwater drillships [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number of offshore rigs owned	'	5	'	'
Number of rigs under construction	'	3	'	'
Mid-Water floaters [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Number of offshore rigs held for sale	3	'	3	'
Number of rigs in disposal group	3	'	3	'
Drilling and other property and equipment	'	3,900,000	'	'
Number of rigs transferred to drilling and other property and equipment	'	3	'	'
Cold-stacked rigs [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Recoverable amount of assets held for sale	11,594,000	'	11,594,000	'
Number of cold stacked rigs	4	4	4	'
Number of cold stacked rigs held for sale	4	1	4	'
Impairment loss write down to the aggregate net book value	'	'	62,437,000	'
Minimum [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Rig and equipment project costs	'	25,000	25,000	'
Estimated useful life for drilling rigs and equipment	'	'3 years	'	'
Maximum [Member]	'	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'	'
Rig and equipment project costs	'	$40,000,000	$40,000,000	'
Estimated useful life for drilling rigs and equipment	'	'30 years	'	'

General_Information_Reconcilia

General Information - Reconciliation of Total Interest Cost to Interest Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest Costs Incurred [Abstract]	'	'	'
Total interest cost including amortization of debt issuance costs	$99,080	$83,890	$84,349
Capitalized interest	-74,237	-37,674	-11,212
Total interest expense as reported	$24,843	$46,216	$73,137

Supplemental_Financial_Informa2

Supplemental Financial Information - Accounts Receivable, Net of Allowance for Doubtful Accounts (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'	'	'
Trade receivables	$473,013	$478,930	'	'
Value added tax receivables	19,407	13,884	'	'
Amounts held in escrow	3,066	11,555	'	'
Interest receivable	7	6	'	'
Related party receivables	587	527	'	'
Other	615	216	'	'
Receivables Gross Current, Total	496,695	505,118	'	'
Allowance for bad debts	-27,340	-5,458	-6,867	-31,908
Total	$469,355	$499,660	'	'

Supplemental_Financial_Informa3

Supplemental Financial Information - Changes in Provision for Bad Debts (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance For Doubtful Accounts Receivable Rollforward	'	'	'
Allowance for bad debts, beginning of year	$5,458	$6,867	$31,908
Provision for bad debts	22,513	'	5,688
Recovery of bad debts	'	-1,018	-12,401
Total bad debt expense (recovery)	22,513	-1,018	-6,713
Write off of uncollectible accounts against reserve	-509	-391	-18,380
Other	-122	'	52
Allowance for bad debts, end of year	$27,340	$5,458	$6,867

Supplemental_Financial_Informa4

Supplemental Financial Information - Prepaid Expenses and Other Current Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]	'	'
Rig spare parts and supplies	$52,439	$57,558
Deferred mobilization costs	20,274	38,074
Prepaid insurance	12,503	12,549
Deferred tax assets	10,221	8,619
Prepaid taxes	42,058	5,950
FOREX contracts	1,562	3,627
Other	4,940	9,722
Total	$143,997	$136,099

Supplemental_Financial_Informa5

Supplemental Financial Information - Accrued Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Rig operating expenses	$87,307	$70,078
Payroll and benefits	121,387	88,612
Deferred revenue	26,975	71,699
Accrued capital project/upgrade costs	86,274	56,595
Interest payable	28,324	21,219
Personal injury and other claims	9,687	10,312
FOREX contracts	1,143	29
Other	9,574	5,890
Total	$370,671	$324,434

Supplemental_Financial_Informa6

Supplemental Financial Information - Noncash Investing and Financing Activities (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'
Accrued but unpaid capital expenditures at period end	$86,274	$56,595	$37,325
Income tax benefits related to exercise of stock options	1,081	1,083	863
Cash interest payments	82,938	83,125	82,938
U.S federal [Member]	'	'	'
Cash income taxes paid, net of refunds:	'	'	'
Cash income taxes paid, net of refunds	62,000	71,000	94,843
Foreign [Member]	'	'	'
Cash income taxes paid, net of refunds:	'	'	'
Cash income taxes paid, net of refunds	78,041	72,249	150,465
State [Member]	'	'	'
Cash income taxes paid, net of refunds:	'	'	'
Cash income taxes paid, net of refunds	$190	$243	$210

Supplemental_Financial_Informa7

Supplemental Financial Information - Noncash Investing and Financing Activities (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'
Interest payments, net of amounts capitalized	$16,500,000	$46,200,000	$71,900,000
Interest paid	82,938,000	83,125,000	82,938,000
Internal Revenue Service [Member]	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'
Interest paid	'	$200,000	'

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'
Maximum aggregate number of shares of common stock for which stock options or SARs granted	1,500,000	'	'
Vesting period (in years, ratably over period)	'4 years	'	'
Expiration (in years)	'10 years	'	'
Compensation cost recognized for Stock Plan transactions	$3,900,000	$4,700,000	$5,000,000
Tax benefits recognized	1,300,000	1,600,000	1,700,000
Weighted-average grant date fair values of awards granted	$13.74	$19.01	$18.17
Intrinsic value of awards exercised	162,000	147,000	28,000
Fair value of awards vested	4,100,000	5,200,000	5,400,000
Unrecognized compensation cost related to nonvested stock options and SARs granted under the Stock Plan	$5,100,000	'	'
Expected weighted average period to recognize the compensation cost related to nonvested stock options and SARs granted under the Stock Plan	'2 years 4 months 24 days	'	'

StockBased_Compensation_Weight

Stock-Based Compensation - Weighted Average Assumptions Used in Estimating Fair Value of Options and SARs (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'
Expected life of SARs (in years)	'7 years	'6 years	'5 years
Expected volatility	18.24%	33.45%	30.37%
Dividend yield	0.75%	0.78%	0.76%
Risk free interest rate	1.61%	0.89%	1.54%

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Activity under Stock Plan (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Number of Awards Outstanding, Beginning Balance	1,229,480
Number of Awards, granted	233,625
Number of Awards, exercised	-15,091
Number of Awards, forfeited	-24,283
Number of Awards, expired	-31,072
Number of Awards, Outstanding, Ending Balance	1,392,659
Number of Awards, exercisable	973,918
Weighted-Average Exercise Price Outstanding, Beginning Balance	$80.32
Weighted-Average Exercise Price, granted	$66.95
Weighted-Average Exercise Price, exercised	$59.58
Weighted-Average Exercise Price, forfeited	$67.51
Weighted-Average Exercise Price, expired	$94.01
Weighted-Average Exercise Price Outstanding, Ending Balance	$78.22
Weighted-Average Exercise Price Outstanding, exercisable	$83.32
Weighted-Average Remaining Contractual Term, Ending Balance	'7 years
Weighted-Average Remaining Contractual Term, exercisable	'6 years
Aggregate Intrinsic Value, Ending Balance	$460
Aggregate Intrinsic Value, exercisable	$438

Earnings_Per_Share_Reconciliat

Earnings Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted Per-Share Computations (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net income - basic and diluted (numerator):	$92,615	$94,748	$185,334	$175,989	$155,661	$178,186	$201,461	$185,169	$548,686	$720,477	$962,542
Weighted-average shares - basic (denominator):	'	'	'	'	'	'	'	'	139,035	139,029	139,027
Effect of dilutive potential shares	'	'	'	'	'	'	'	'	'	'	'
Stock options and stock appreciation rights	'	'	'	'	'	'	'	'	29	19	11
Weighted-average shares including conversions - diluted (denominator):	'	'	'	'	'	'	'	'	139,064	139,048	139,038
Earnings per share:	'	'	'	'	'	'	'	'	'	'	'
Basic	'	'	'	'	'	'	'	'	$3.95	$5.18	$6.92
Diluted	'	'	'	'	'	'	'	'	$3.95	$5.18	$6.92

Earnings_Per_Share_Securities_

Earnings Per Share - Securities Excluded from Computation of Diluted Earning Per Share (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock options [Member]	'	'	'
Employee and director:	'	'	'
Securities excluded from computation of diluted earning per share	18	18	19
SARs [Member]	'	'	'
Employee and director:	'	'	'
Securities excluded from computation of diluted earning per share	956	853	847

Marketable_Securities_Investme

Marketable Securities - Investments in Marketable Securities as Available for Sale (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$1,750,067	$1,149,983
Unrealized Gain (Loss)	-14	175
Market Value	1,750,053	1,150,158
U.S. Treasury Bills and Notes (due within one year) [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	1,749,879	1,149,707
Unrealized Gain (Loss)	-22	150
Market Value	1,749,857	1,149,857
Mortgage-backed securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	188	276
Unrealized Gain (Loss)	8	25
Market Value	$196	$301

Marketable_Securities_Summary_

Marketable Securities - Summary of Proceeds from Sales and Maturities of Marketable Securities and Gross Realized Gains and Losses (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments Debt And Equity Securities [Abstract]	'	'	'
Proceeds from maturities	$4,650,000	$2,575,000	$5,350,000
Proceeds from sales	85	150,118	12,138
Gross realized gains	'	'	784
Gross realized losses	($1)	($6)	($5)

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Additional Information (Detail)

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

USD ($)

USD ($)

USD ($)

AUD

BRL

GBP (£)

MXN

NOK

Foreign currency transaction gain (loss) [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Treasury Lock Agreements [Member]

FOREX contracts [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Counterparty

Agreement

Derivative Instruments, Gain (Loss) [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Notional amount of foreign currency contracts settled

$307,400,000

$305,600,000

$318,900,000

'

'

'

'

'

'

'

'

'

'

'

Derivative contracts outstanding in the aggregate notional amount

114,100,000

'

'

15,300,000

72,400,000

14,200,000

5,900,000

6,300,000

'

'

'

'

500,000,000

'

Number of counterparties to FOREX contracts

'

'

'

'

'

'

'

'

'

'

'

'

'

2

Amount of (loss) gain recognized in AOCGL on derivative (effective portion)

26,728

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of treasury lock agreements

'

'

'

'

'

'

'

'

'

'

'

'

2

'

Net unrealized gains (losses) associated with FOREX contracts to be reclassified to earnings

'

'

'

'

'

'

'

'

500,000

'

'

'

8,000

'

Amount reclassified from AOCGL due to the probability of a forecasted transaction not occurring

'

'

'

'

'

'

'

'

'

$0

$0

$0

'

'

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Amounts Recognized in Consolidated Statements of Operations Related to FOREX Contracts Designated as Hedging Instruments (Detail) (Contract drilling expense [Member], Designated as hedging instrument [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Contract drilling expense [Member] | Designated as hedging instrument [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	($6,501)	($4,302)	$7,206

Derivative_Financial_Instrumen4

Derivative Financial Instruments - Fair Values of FOREX Contracts (Detail) (FOREX contracts [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accrued liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities designated as hedging instruments, current	($1,143)	($29)
Prepaid expenses and other current assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets designated as hedging instruments, current	$1,562	$3,627

Derivative_Financial_Instrumen5

Derivative Financial Instruments - Amounts Recognized in Consolidated Balance Sheets and Consolidated Statements of Operations Related to Derivative Contracts Designated as Cash Flow Hedges (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of (loss) gain recognized in AOCGL on derivative (effective portion)	$26,728	'	'
Derivative designated as accounting hedges [Member] | FOREX contracts [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of (loss) gain recognized in AOCGL on derivative (effective portion)	-10,542,000	6,519,000	-962,000
Derivative designated as accounting hedges [Member] | Treasury Lock Agreements [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of (loss) gain recognized in AOCGL on derivative (effective portion)	27,000	'	'
Contract drilling expense [Member] | Derivative designated as accounting hedges [Member] | FOREX contracts [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of (loss) gain reclassified from AOCGL into income (effective portion)	-7,449,000	-4,205,000	10,351,000
Foreign currency transaction gain (loss) [Member] | Derivative designated as accounting hedges [Member] | FOREX contracts [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	-104,000	-17,000	-85,000
Interest Expense [Member] | Derivative designated as accounting hedges [Member] | Treasury Lock Agreements [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of (loss) gain reclassified from AOCGL into income (effective portion)	$1,000	'	'

Financial_Instruments_and_Fair2

Financial Instruments and Fair Value Disclosures - Additional Information (Detail) (USD $)

12 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Sep. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Niko [Member]

Ogx and Niko Resources [Member]

Accounts Receivable [Member]

Accounts Receivable [Member]

Accounts Receivable [Member]

Cash Held in Money Market Funds [Member]

Cash Held in Money Market Funds [Member]

Time Deposits [Member]

Time Deposits [Member]

U.S. Treasury Bills [Member]

U.S. Treasury Bills [Member]

Customer

Petroleo Brasileiro S.A. [Member]

Petroleo Brasileiro S.A. [Member]

OGX Petroleo e Gas Ltda. [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accounts receivable due from major customer

$469,355,000

$499,660,000

'

'

'

'

'

'

'

'

'

$154,500,000

$116,400,000

$80,300,000

Percentage of accounts receivable due from major customer

'

'

'

'

'

'

'

'

'

'

'

35.00%

24.00%

17.00%

Number of customers

'

'

'

'

'

'

'

'

'

'

2

'

'

'

Bad debt expense

22,513,000

'

5,688,000

'

'

'

'

'

'

'

22,500,000

'

'

'

Cash received pursuant to Settlement Agreement

'

'

'

'

'

'

'

'

'

25,000,000

'

'

'

'

Anticipated future payments pursuant to Settlement Agreement

'

'

'

'

'

'

'

'

'

55,000,000

'

'

'

'

Fair value of investments

'

'

'

281,300,000

264,900,000

30,000,000

20,000,000

1,749,900,000

1,149,900,000

'

'

'

'

'

Transfers between fair value levels

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

Measurement period for determining fair value of debt instruments

'10 days

'

'

'

'

'

'

'

'

'

'

'

'

'

Financial_Instruments_and_Fair3

Financial Instruments and Fair Value Disclosures - Assets and Liabilities Measured at Fair Value on Recurring and Nonrecurring Basis (Detail) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Nonrecurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Fair Value Measurements, Recurring [Member]

Level 1 [Member]

Level 1 [Member]

Level 2 [Member]

Level 2 [Member]

Level 3 [Member]

Level 3 [Member]

Level 1 [Member]

Level 1 [Member]

Level 2 [Member]

Level 2 [Member]

Level 3 [Member]

Level 3 [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impaired assets/Assets held for sale, Total Losses for year

($62,400)

($62,437)

'

($62,437)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Assets:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Impaired assets

'

'

3,900

'

'

'

'

'

3,900

'

'

'

'

'

'

'

'

'

Assets held for sale

'

'

'

3,900

'

'

'

'

'

3,900

'

'

'

'

'

'

'

'

Impaired assets/Assets held for sale, Total Losses for year

-62,400

-62,437

'

-62,437

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Short-term investments

'

'

'

'

'

'

'

'

'

'

2,061,154

1,434,751

2,061,154

1,434,751

'

'

'

'

FOREX contracts

'

'

'

'

'

'

'

'

'

'

1,562

3,627

'

'

1,562

3,627

'

'

Mortgage-backed securities

'

'

'

'

'

'

'

'

'

'

197

301

'

'

197

301

'

'

Total assets

'

'

'

'

'

'

'

'

'

'

2,062,913

1,438,679

2,061,154

1,434,751

1,759

3,928

'

'

Liabilities:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

FOREX contracts

'

'

'

'

'

'

'

'

'

'

($1,143)

($29)

'

'

($1,143)

($29)

'

'

Financial_Instruments_and_Fair4

Financial Instruments and Fair Value Disclosures - Fair Value and Related Carrying Values of Our Debt Instruments (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
5.15% Senior Notes due 2014 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	$249,954,000	$249,882,000
5.15% Senior Notes due 2014 [Member] | Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fair Value	257,400,000	269,000,000
5.15% Senior Notes due 2014 [Member] | Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	250,000,000	249,900,000
4.875% Senior Notes due 2015 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	249,898,000	249,837,000
4.875% Senior Notes due 2015 [Member] | Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fair Value	265,700,000	275,500,000
4.875% Senior Notes due 2015 [Member] | Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	249,900,000	249,800,000
5.875% Senior Notes due 2019 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	499,551,000	499,480,000
5.875% Senior Notes due 2019 [Member] | Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fair Value	578,100,000	617,100,000
5.875% Senior Notes due 2019 [Member] | Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	499,600,000	499,500,000
3.45% Senior Notes due 2023 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	248,988,000	'
3.45% Senior Notes due 2023 [Member] | Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fair Value	241,400,000	'
3.45% Senior Notes due 2023 [Member] | Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	249,000,000	'
5.70% Senior Notes due 2039 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	496,919,000	496,867,000
5.70% Senior Notes due 2039 [Member] | Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fair Value	543,100,000	641,400,000
5.70% Senior Notes due 2039 [Member] | Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	496,900,000	496,900,000
4.875% Senior Notes due 2043 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	748,833,000	'
4.875% Senior Notes due 2043 [Member] | Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fair Value	736,100,000	'
4.875% Senior Notes due 2043 [Member] | Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	$748,800,000	'

Financial_Instruments_and_Fair5

Financial Instruments and Fair Value Disclosures - Fair Value and Related Carrying Values of Our Debt Instruments (Parenthetical) (Detail)	Dec. 31, 2013	Dec. 31, 2012
5.15% Senior Notes due 2014 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Interest rate of senior notes	5.15%	5.15%
4.875% Senior Notes due 2015 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Interest rate of senior notes	4.88%	4.88%
5.875% Senior Notes due 2019 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Interest rate of senior notes	5.88%	5.88%
3.45% Senior Notes due 2023 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Interest rate of senior notes	3.45%	'
5.70% Senior Notes due 2039 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Interest rate of senior notes	5.70%	5.70%
4.875% Senior Notes due 2043 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Interest rate of senior notes	4.88%	'

Drilling_and_Other_Property_an2

Drilling and Other Property and Equipment - Summary of Cost and Accumulated Depreciation of Drilling and Other Property and Equipment (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'	'
Property and equipment	$9,211,703	$8,222,778	'
Less: accumulated depreciation	-3,744,476	-3,357,806	'
Drilling and other property and equipment, net	5,467,227	4,864,972	4,667,469
Drilling rigs and equipment [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property and equipment	7,412,066	7,107,279	'
Construction work-in-progress [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property and equipment	1,668,211	990,964	'
Land and buildings [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property and equipment	65,627	64,296	'
Office equipment and other [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property and equipment	$65,799	$60,239	'

Drilling_and_Other_Property_an3

Drilling and Other Property and Equipment - Summary of Construction Work-in-Progress, Including Capitalized Interest (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	$1,668,211	$990,964
Ultra-deepwater drillships [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	868,908	741,059
Ocean GreatWhite [Member] | Ultra-deepwater semisubmersible [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	195,578	'
Ocean Onyx [Member] | Deepwater semisubmersibles [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	339,129	167,403
Ocean Apex [Member] | Deepwater semisubmersibles [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	$264,596	$82,502

Credit_Agreement_and_Senior_No2

Credit Agreement and Senior Notes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
Term of Credit agreement	'5 years	'
Initiation period of Credit agreement	28-Sep-12	'
Initial maturity date of Credit agreement	28-Sep-17	'
Amount available for general purposes	$750,000,000	'
Ratio of consolidated indebtedness to total capitalization	0.6	'
Amount outstanding under credit agreement	0	'
Issuance of senior notes	1,000,000,000	'
Date of issuance of long term debt	5-Nov-13	'
Proceeds from issuance	987,800,000	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
ABR Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest margin	0.00%	'
Eurodollar Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest margin	0.88%	'
Federal Funds Rate [Member]	'	'
Debt Instrument [Line Items]	'	'
Basis point increase	0.50%	'
One Month Eurodollar Rate [Member]	'	'
Debt Instrument [Line Items]	'	'
Basis point increase	1.00%	'
3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount of senior notes	250,000,000	'
Maturity Date	1-Nov-23	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
Accreted value of senior notes	248,988,000	'
4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount of senior notes	750,000,000	'
Maturity Date	1-Nov-43	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
Accreted value of senior notes	748,833,000	'
5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount of senior notes	250,000,000	'
Maturity Date	1-Sep-14	'
Semiannual Interest Payment Dates	'March 1 and September 1	'
Accreted value of senior notes	249,954,000	249,882,000
4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount of senior notes	250,000,000	'
Maturity Date	1-Jul-15	'
Semiannual Interest Payment Dates	'January 1 and July 1	'
Accreted value of senior notes	249,898,000	249,837,000
5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount of senior notes	500,000,000	'
Maturity Date	1-May-19	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
Accreted value of senior notes	499,551,000	499,480,000
5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount of senior notes	500,000,000	'
Maturity Date	15-Oct-39	'
Semiannual Interest Payment Dates	'April 15 and October 15	'
Accreted value of senior notes	496,919,000	496,867,000
Minimum [Member]	'	'
Debt Instrument [Line Items]	'	'
Commitment fee on unused commitments	0.06%	'
Minimum [Member] | ABR Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest margin	0.00%	'
Minimum [Member] | Eurodollar Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest margin	0.75%	'
Minimum [Member] | 3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'15 days	'
Minimum [Member] | 4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'15 days	'
Minimum [Member] | 5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'15 days	'
Minimum [Member] | 4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'15 days	'
Minimum [Member] | 5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'15 days	'
Minimum [Member] | 5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'15 days	'
Maximum [Member]	'	'
Debt Instrument [Line Items]	'	'
Commitment fee on unused commitments	0.20%	'
Maximum [Member] | ABR Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest margin	0.25%	'
Maximum [Member] | Eurodollar Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest margin	1.25%	'
Maximum [Member] | 3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'60 days	'
Maximum [Member] | 4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'60 days	'
Maximum [Member] | 5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'60 days	'
Maximum [Member] | 4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'60 days	'
Maximum [Member] | 5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'60 days	'
Maximum [Member] | 5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Notice period for redemption of senior notes	'60 days	'
Swingline Loan Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Amount available for general purposes	75,000,000	'
Swingline loans bear interest description	'Swingline loans bear interest, at our option, at a rate per annum equal to (i) the ABR plus the applicable interest margin for ABR loans or (ii) the daily one-month Eurodollar Rate plus the applicable interest margin for Eurodollar loans.	'
Performance Letters of Credit [Member] | Minimum [Member]	'	'
Debt Instrument [Line Items]	'	'
Participation fees for letters of credit	0.38%	'
Performance Letters of Credit [Member] | Maximum [Member]	'	'
Debt Instrument [Line Items]	'	'
Participation fees for letters of credit	0.63%	'
Letters of Credit [Member]	'	'
Debt Instrument [Line Items]	'	'
Amount available for general purposes	$250,000,000	'
Letters of Credit [Member] | Minimum [Member]	'	'
Debt Instrument [Line Items]	'	'
Participation fees for letters of credit	0.75%	'
Letters of Credit [Member] | Maximum [Member]	'	'
Debt Instrument [Line Items]	'	'
Participation fees for letters of credit	1.25%	'
Senior Unsecured Credit Facilities [Member]	'	'
Debt Instrument [Line Items]	'	'
Maturity period of Credit agreement	28-Sep-18	'

Credit_Agreement_and_Senior_No3

Credit Agreement and Senior Notes - Summary of Senior Notes (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount	$250	'
Maturity Date	1-Sep-14	'
Interest rate Coupon, senior notes	5.15%	5.15%
Interest rate Effective, senior notes	5.18%	'
Semiannual Interest Payment Dates	'March 1 and September 1	'
4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount	250	'
Maturity Date	1-Jul-15	'
Interest rate Coupon, senior notes	4.88%	4.88%
Interest rate Effective, senior notes	4.90%	'
Semiannual Interest Payment Dates	'January 1 and July 1	'
5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount	500	'
Maturity Date	1-May-19	'
Interest rate Coupon, senior notes	5.88%	5.88%
Interest rate Effective, senior notes	5.89%	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount	250	'
Maturity Date	1-Nov-23	'
Interest rate Coupon, senior notes	3.45%	'
Interest rate Effective, senior notes	3.50%	'
Semiannual Interest Payment Dates	'May 1 and November 1	'
5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount	500	'
Maturity Date	15-Oct-39	'
Interest rate Coupon, senior notes	5.70%	5.70%
Interest rate Effective, senior notes	5.75%	'
Semiannual Interest Payment Dates	'April 15 and October 15	'
4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate Principal Amount	$750	'
Maturity Date	1-Nov-43	'
Interest rate Coupon, senior notes	4.88%	'
Interest rate Effective, senior notes	4.89%	'
Semiannual Interest Payment Dates	'May 1 and November 1	'

Credit_Agreement_and_Senior_No4

Credit Agreement and Senior Notes - Summary of Senior Notes (Parenthetical) (Detail)	Dec. 31, 2013	Dec. 31, 2012
5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	5.15%	5.15%
4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	4.88%	4.88%
5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	5.88%	5.88%
3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	3.45%	'
5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	5.70%	5.70%
4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	4.88%	'

Credit_Agreement_and_Senior_No5

Credit Agreement and Senior Notes - Summary of Carrying Value of Senior Notes (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Total maturities of senior notes, net of unamortized discount	$2,494,143	$1,496,066
Less: Current portion of long-term debt	249,954	'
Total Long-term debt	2,244,189	1,496,066
5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior Notes	249,954	249,882
4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior Notes	249,898	249,837
5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior Notes	499,551	499,480
3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior Notes	248,988	'
5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior Notes	496,919	496,867
4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Senior Notes	$748,833	'

Credit_Agreement_and_Senior_No6

Credit Agreement and Senior Notes - Summary of Carrying Value of Senior Notes (Parenthetical) (Detail)	Dec. 31, 2013	Dec. 31, 2012
5.15% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	5.15%	5.15%
4.875% Senior Notes due 2015 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	4.88%	4.88%
5.875% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	5.88%	5.88%
3.45% Senior Notes due 2023 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	3.45%	'
5.70% Senior Notes due 2039 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	5.70%	5.70%
4.875% Senior Notes due 2043 [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate of senior notes	4.88%	'

Credit_Agreement_and_Senior_No7

Credit Agreement and Senior Notes - Aggregate Maturities of Senior Notes (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
2014	$250,000	'
2015	250,000	'
2016	'	'
2017	'	'
2018	'	'
Thereafter	2,000,000	'
Total maturities of senior notes	2,500,000	'
Less: unamortized discounts	-5,857	'
Total maturities of senior notes, net of unamortized discount	$2,494,143	$1,496,066

Other_Comprehensive_Income_Los2

Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) and Associated Income Tax Effects (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	$2,496	($4,642)	$3,141
Unrealized gain (loss) before reclassifications	-6,839	4,361	-671
Reclassification adjustments for items included in Net Income	4,693	2,777	-7,112
Total other comprehensive (loss) gain	-2,146	7,138	-7,783
Ending balance	350	2,496	-4,642
Derivative Financial Instrument [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	2,350	-4,620	2,733
Unrealized gain (loss) before reclassifications	-6,833	4,237	-625
Reclassification adjustments for items included in Net Income	4,840	2,733	-6,728
Total other comprehensive (loss) gain	-1,993	6,970	-7,353
Ending balance	357	2,350	-4,620
Marketable Securities [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning balance	146	-22	408
Unrealized gain (loss) before reclassifications	-6	124	-46
Reclassification adjustments for items included in Net Income	-147	44	-384
Total other comprehensive (loss) gain	-153	168	-430
Ending balance	($7)	$146	($22)

Other_Comprehensive_Income_Los3

Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) and Associated Income Tax Effects (Parenthetical) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity [Abstract]	'	'	'
Unrealized gain (loss) before reclassifications, tax (expense) benefit	$3,682	($2,282)	$337
Unrealized gain (loss) before reclassifications, tax (expense) benefit	18	-28	15
Reclassification adjustments for items included in Net Income, tax (expense) benefit	-2,608	-1,472	3,623
Reclassification adjustments for items included in Net Income, tax (expense) benefit	$18	($1)	$205

Other_Comprehensive_Income_Los4

Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Gain Loss (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Other, net	'	'	'	'	'	'	'	'	($1,691)	$992	$1,086
Contract drilling, excluding depreciation	'	'	'	'	'	'	'	'	1,572,525	1,537,224	1,548,502
Interest expense	'	'	'	'	'	'	'	'	-24,843	-46,216	-73,137
Income tax expense	'	'	'	'	'	'	'	'	225,554	197,604	216,729
Net of tax	-92,615	-94,748	-185,334	-175,989	-155,661	-178,186	-201,461	-185,169	-548,686	-720,477	-962,542
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member]	'	'	'	'	'	'	'	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Income tax expense	'	'	'	'	'	'	'	'	2,608	1,472	-3,623
Net of tax	'	'	'	'	'	'	'	'	-4,840	-2,733	6,728
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member] | FOREX contracts [Member]	'	'	'	'	'	'	'	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling, excluding depreciation	'	'	'	'	'	'	'	'	-7,449	-4,205	10,351
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member] | Treasury Lock Agreements [Member]	'	'	'	'	'	'	'	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Interest expense	'	'	'	'	'	'	'	'	1	'	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Marketable Securities [Member]	'	'	'	'	'	'	'	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Other, net	'	'	'	'	'	'	'	'	165	-45	589
Income tax expense	'	'	'	'	'	'	'	'	-18	1	-205
Net of tax	'	'	'	'	'	'	'	'	$147	($44)	$384

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)

12 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Jan. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Jan. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Total Contingent Liabilities Under Letters of Credit and Bonds [Member]

Collateralized Contingent Liabilities Under Letters of Credit and Bonds [Member]

Hyundai Heavy Industries, Co., Ltd. [Member]

Hyundai Heavy Industries, Co., Ltd. [Member]

Hyundai Heavy Industries, Co., Ltd. [Member]

Hyundai Heavy Industries, Co., Ltd. [Member]

Hyundai Heavy Industries, Co., Ltd. [Member]

Hyundai Heavy Industries, Co., Ltd. [Member]

Keppel AmFELS, L.L.C. [Member]

Keppel AmFELS, L.L.C. [Member]

Keppel AmFELS, L.L.C. [Member]

Jurong Shipyard Pte Ltd [Member]

Jurong Shipyard Pte Ltd [Member]

Keppel FELS Limited [Member]

Personal Injury Claims [Member]

Personal Injury Claims [Member]

Personal Injury Claims [Member]

Personal Injury Claims [Member]

Personal Injury Claims [Member]

Personal Injury Claims [Member]

Ultra-Deepwater Floater Construction [Member]

Ultra-deepwater drillships [Member]

Ultra-deepwater drillships [Member]

Ultra-deepwater drillships [Member]

Ultra-deepwater drillships [Member]

Ultra-deepwater drillships [Member]

Installment

First Quarter 2014 [Member]

Installment

Installment

Accrued Liabilities [Member]

Accrued Liabilities [Member]

Other Liabilities [Member]

Other Liabilities [Member]

Installment

Contract

Second Quarter of 2014 [Member]

Third Quarter 2014 [Member]

First Quarter 2015 [Member]

First Quarter 2014 [Member]

Subsequent Event [Member]

ft

Installment

Ocean BlackHornet [Member]

Ocean BlackRhino [Member]

Ocean BlackLion [Member]

Ocean Black Hawk [Member]

Subsequent Event [Member]

Contingencies And Commitments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net profits interest percent

27.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deductible for marine liability coverage including personal injury claims, per first occurrence

$10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Range of deductible for liability coverage for personal injury claims, lower limit

5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Range of deductible for liability coverage for personal injury claims, upper limit

100

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Personal injury claims recorded

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

35.5

36.1

9.5

9.9

26

26.2

Water depth of rig

'

'

'

'

'

10,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cost of enhancement of project

'

'

'

'

'

755

2,600

'

'

'

'

366

'

'

370

'

120

'

'

'

'

'

'

Total number of installments due under each turnkey construction agreements

'

'

'

'

'

2

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cost of construction per shipyard agreement

'

'

'

'

'

628.5

'

'

'

'

'

'

'

'

'

'

29

'

'

'

'

'

'

Construction installments paid

'

'

'

'

'

188.6

647.6

'

'

'

396.1

73

65.7

7.3

54.1

27

18.8

'

'

'

'

'

'

Final installment for Ultra-Deep water Floater Construction

'

'

'

'

'

439.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of turnkey contracts for drill ship construction

'

'

'

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected amount of second installments payable in next 12 months

'

'

'

'

'

'

'

394

395

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected amount of second installments payable in second year

'

'

'

'

'

'

'

'

'

395

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of installments due under each rig construction agreement

'

'

'

'

'

'

'

'

'

'

'

11

'

'

12

'

7

'

'

'

'

'

'

Number of installments paid

'

'

'

'

'

'

'

'

'

'

'

10

'

'

7

'

4

'

'

'

'

'

'

Construction agreement balance amount payable

'

'

'

'

'

'

'

'

'

'

'

'

'

'

54.1

'

10.2

'

'

'

'

'

'

Other purchase obligations

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rental expense under operating leases

13.5

10.8

9.3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future minimum rental payments under leases, in current years

2.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future minimum rental payments under leases, in two years

1.6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future minimum rental payments under leases , in years three through five following reporting period

1.2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future minimum rental payments under leases, thereafter

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Contingent liability under letters of credit and other bonds

'

'

'

$78.20

$67.40

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

RelatedParty_Transactions_Addi

Related-Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]	'	'	'
Terms and conditions of service agreement with Loews	'The Services Agreement may be terminated at our option upon 30 days' notice to Loews and at the option of Loews upon six months' notice to us.	'	'
Services Agreement with Loews [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Related party transaction expenses	$1	$0.80	$1.10
SEACOR Holdings Inc [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Related party transaction expenses	0.1	0.1	0.1
Ernst & Young LLP [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Related party transaction expenses	$1.60	$1	$1.20

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2013

Jun. 30, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Feb. 28, 2012

Dec. 31, 2009

Dec. 31, 2013

Other Assets [Member]

Other Assets [Member]

Other Liabilities [Member]

Other Liabilities [Member]

Mexico [Member]

2000 Tax Year [Member]

2006 Tax Year [Member]

2006 Tax Year [Member]

2007 Tax year [Member]

2004 Tax Year [Member]

2004 Tax Year [Member]

2007 Tax Year [Member]

2007 Tax Year [Member]

2004 & 2005 Tax Year [Member]

2006 through 2010 Tax Year [Member]

Brazil [Member]

Brazil [Member]

Mexico [Member]

Mexico [Member]

Mexico [Member]

Mexico [Member]

Brazil [Member]

Brazil [Member]

Brazil [Member]

Egypt [Member]

Income Tax Contingency [Line Items]

'

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'

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Amount of undistributed foreign earnings and profit

$2,400,000,000

'

'

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'

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'

'

'

'

'

'

Net operating loss carryforwards, or NOLs

12,038,000

24,067,000

'

'

'

'

'

'

800,000

'

'

'

'

'

'

'

'

'

'

Deferred tax asset relates to NOL carryforwards

11,200,000

'

'

'

'

'

'

'

'

'

'

'

'

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'

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'

'

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Valuation allowance of NOL

7,321,000

22,876,000

'

'

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'

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'

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'

'

'

'

'

'

Portion of operating loss carryforwards expected to be realized

4,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net liability for uncertain tax positions

90,921,000

67,150,000

62,936,000

75,311,000

6,300,000

7,000,000

82,600,000

55,400,000

'

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'

'

'

'

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'

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Net unrecognized tax benefits would affect the effective tax rate

76,300,000

48,400,000

41,200,000

'

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Total tax assessment including interest and penalty

'

'

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1,500,000

'

24,400,000

'

'

22,900,000

15,000,000

35,100,000

26,000,000

'

Recognition of tax benefits from uncertain tax positions

'

'

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'Greater than 50% likelihood of being realized upon settlement is to be recognized

'

Accrued expense related to income tax examination

'

'

'

'

'

'

'

'

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'

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'

9,900,000

56,900,000

Accrued interest related to income tax examination

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

3,400,000

'

Accrued penalties related to income tax examination

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,800,000

31,400,000

Reduction in uncertain tax positions related to statute of limitations expirations

1,937,000

'

8,518,000

'

'

'

'

'

'

'

6,800,000

'

4,300,000

4,400,000

'

'

'

'

'

Interest related to income tax examination

'

'

'

'

'

'

'

'

'

'

1,100,000

'

'

2,600,000

'

'

'

'

'

Penalties related to income tax examination

'

'

'

'

'

'

'

'

'

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2,000,000

'

'

200,000

'

'

'

'

'

Net cash cost on settlement of tax liability

'

'

'

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3,700,000

'

'

'

'

'

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'

'

'

'

Increase in uncertain tax position due to tax settlement

'

'

'

'

'

'

'

'

13,200,000

'

'

'

'

'

'

'

'

'

'

Change in interest on uncertain tax positions

5,758,000

-1,902,000

245,000

'

'

'

'

'

5,000,000

'

'

'

'

'

'

'

'

'

'

Change in penalties on uncertain tax positions

38,136,000

-787,000

-3,039,000

'

'

'

'

'

2,700,000

'

'

'

'

'

'

'

'

'

'

Reversal of accrued interest on uncertain tax position

'

'

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'

'

'

'

'

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1,500,000

'

'

'

'

'

'

Reversal of accrued penalty on uncertain tax position

'

'

'

'

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'

'

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600,000

'

'

'

'

'

'

Proposed increase to taxable income

'

'

'

'

'

'

'

'

'

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'

'

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'

1,200,000,000

Reduction in tax expense

$27,509,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income_Taxes_Components_of_Inc

Income Taxes - Components of Income Tax Expense (Benefit) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Federal - current	$40,045	$173,061	$109,684
State - current	69	267	264
Foreign - current	151,339	75,748	104,640
Total current	191,453	249,076	214,588
Federal - deferred	46,767	-51,852	-1,023
Foreign - deferred	-12,666	380	3,164
Total deferred	34,101	-51,472	2,141
Income tax expense	$225,554	$197,604	$216,729

Income_Taxes_Difference_Betwee

Income Taxes - Difference Between Actual Income Tax Expense and Tax Provision Computed by Applying Statutory Federal Income Tax Rate to Income Before Taxes (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income before income tax expense:	'	'	'	'	'	'	'	'	'	'	'
U.S.	'	'	'	'	'	'	'	'	$537,635	$512,733	$486,393
Foreign	'	'	'	'	'	'	'	'	236,605	405,348	692,878
Income before income tax expense	180,195	131,565	256,301	206,179	185,041	234,847	246,758	251,435	774,240	918,081	1,179,271
Expected income tax expense at federal statutory rate	'	'	'	'	'	'	'	'	270,984	321,328	412,745
Foreign earnings of foreign subsidiaries (not taxed at the statutory federal income tax rate) net of related foreign taxes	'	'	'	'	'	'	'	'	-102,359	-166,251	-189,051
Foreign earnings of foreign subsidiaries for which U.S. federal income taxes have been provided	'	'	'	'	'	'	'	'	805	28,252	-14,681
Foreign taxes of domestic and foreign subsidiaries for which U.S. federal income taxes have also been provided	'	'	'	'	'	'	'	'	45,428	35,722	65,521
Foreign tax credits	'	'	'	'	'	'	'	'	-46,524	-45,824	-67,232
Interest capitalized by foreign subsidiaries	'	'	'	'	'	'	'	'	-18,391	-11,764	-3,924
Reduction of deferred tax liability related to a goodwill deduction resulting from a prior period stock acquisition	'	'	'	'	'	'	'	'	'	'	-2,950
Impact of American Taxpayer Relief Act of 2012	'	'	'	'	'	'	'	'	-27,509	'	'
Uncertain tax positions	'	'	'	'	'	'	'	'	66,085	6,325	-7,733
Amortization of deferred charges associated with intercompany rig sales to other tax jurisdictions	'	'	'	'	'	'	'	'	30,894	31,276	29,556
Net expense (benefit) in connection with resolutions of tax issues and adjustments relating to prior years	'	'	'	'	'	'	'	'	4,804	-2,152	-6,085
Other	'	'	'	'	'	'	'	'	1,337	692	563
Income tax expense	'	'	'	'	'	'	'	'	$225,554	$197,604	$216,729

Income_Taxes_Components_of_Def

Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred tax assets:	'	'
Net operating loss carryforwards, or NOLs	$12,038	$24,067
Worker's compensation and other current accruals	17,269	16,929
Disputed receivables reserved	3,516	956
Deferred compensation	14,020	9,051
Foreign contribution taxes	5,749	6,780
Mobilization	1,673	4,736
Nonqualified stock options and SARs	9,584	8,698
Deferred deductions	8,577	'
Interest -Uncertain Tax Positions	1,008	206
Other	1,714	1,434
Total deferred tax assets	75,148	72,857
Valuation allowance for NOLs	-7,321	-22,876
Net deferred tax assets	67,827	49,981
Deferred tax liabilities:	'	'
Depreciation	-578,742	-526,606
Unbilled revenue	-4,371	-5,649
Undistributed earnings of foreign subsidiaries	-24	-24
Other	-9	-29
Total deferred tax liabilities	-583,146	-532,308
Net deferred tax liability	($515,319)	($482,327)

Income_Taxes_Components_of_Def1

Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Parenthetical) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Deferred Tax Asset on Worker's compensation and other current accruals included in prepaid expenses and other current assets	$10,221	$8,619

Income_Taxes_Summary_of_Change

Income Taxes - Summary of Changes in Valuation Allowance (Detail) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

In Thousands, unless otherwise specified

Foreign tax credits [Member]

Foreign tax credits [Member]

Foreign tax credits [Member]

Net operating losses [Member]

Net operating losses [Member]

Net operating losses [Member]

Releases of valuation allowances in various jurisdictions [Member]

Releases of valuation allowances in various jurisdictions [Member]

Releases of valuation allowances in various jurisdictions [Member]

Valuation Allowance [Line Items]

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Change in valuation allowance

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'

($186)

$25

$946

$1,844

($15,580)

($4,423)

($7,407)

Valuation allowance as of December 31

$7,321

$22,876

$26,353

$32,102

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'

'

'

Income_Taxes_Tax_Benefits_of_T

Income Taxes - Tax Benefits of These Mexican NOL Carryforwards (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Operating Loss Carryforwards [Line Items]	'	'
Net operating loss carryforwards, or NOLs	$12,038	$24,067
Mexico [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Net operating loss carryforwards, or NOLs	800	'
2021 [Member] | Mexico [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Net operating loss carryforwards, or NOLs	200	'
2022 [Member] | Mexico [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Net operating loss carryforwards, or NOLs	200	'
Two Thousands Twenty Three [Member] | Mexico [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Net operating loss carryforwards, or NOLs	$400	'

Income_Tax_Summary_of_Reconcil

Income Tax - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits, Excluding Interest and Penalties (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Balance, beginning of period	($67,150)	($62,936)	($75,311)
Additions for current year tax positions	-1,724	-3,837	-913
Additions for prior year tax positions	-31,264	-5,136	'
Reductions for prior year tax positions	7,280	4,759	4,770
Reductions related to statute of limitation expirations	1,937	'	8,518
Balance, end of period	($90,921)	($67,150)	($62,936)

Income_Taxes_Schedule_of_Accru

Income Taxes - Schedule of Accrued Interest and Penalties (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Uncertain tax positions net, excluding interest and penalties	($76,303)	($48,353)
Accrued interest on uncertain tax positions	-12,786	-7,029
Accrued penalties on uncertain tax positions	-59,797	-21,662
Uncertain tax positions net, including interest and penalties	($148,886)	($77,044)

Income_Tax_Schedule_of_Interes

Income Tax - Schedule of Interest Expense and Penalties (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Net increase (decrease) in interest expense related to unrecognized tax positions	$5,758	($1,902)	$245
Net increase (decrease) in penalties related to unrecognized tax positions	$38,136	($787)	($3,039)

Employee_Benefit_Plans_Additio

Employee Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Provision for contributions to the Supplemental Plan	$261,000	$256,000	$245,000
US Plan [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Contribution Plan, employer profit sharing contribution percent	4.00%	4.00%	4.00%
Vesting period for the profit sharing contribution	'3 years	'	'
Defined contribution plan, cost recognized	29,600,000	25,900,000	21,500,000
Defined Contribution Plan, Matching Contribution per employee by the company	6.00%	6.00%	6.00%
UK Plan [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined contribution plan, cost recognized	3,500,000	2,700,000	1,200,000
UK Plan [Member] | U. K. Sector of North Sea [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Contribution Plan, Matching Contribution by the company	10.00%	10.00%	5.25%
UK Plan [Member] | U.K. Norwegian Sector of North Sea [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Contribution Plan, Matching Contribution by the company	15.00%	15.00%	9.00%
International Savings Plan [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Contribution Plan, employer profit sharing contribution percent	4.00%	4.00%	4.00%
Defined contribution plan, cost recognized	$3,100,000	$2,800,000	$2,900,000
Defined Contribution Plan, Matching Contribution per employee by the company	6.00%	6.00%	6.00%

Segments_and_Geographic_Area_A2

Segments and Geographic Area Analysis - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]	'	'	'
Number of reportable segments	1	'	'
Number of countries with rigs	12	'	'
Geographic Concentration Risk [Member] | Long-lived tangible assets [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Concentration risk benchmark	'No other countries had more than a 5% concentration	'No other countries had more than a 5% concentration	'No other countries had more than a 5% concentration
Geographic Concentration Risk [Member] | Contract Drilling Revenues [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Concentration risk benchmark	'Individual countries that comprised 5% or more of our total contract drilling revenues	'Individual countries that comprised 5% or more of our total contract drilling revenues	'Individual countries that comprised 5% or more of our total contract drilling revenues
Customer Concentration Risk [Member] | Revenues [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Concentration risk benchmark	'Contributed more than 10% of our total revenues	'Contributed more than 10% of our total revenues	'Contributed more than 10% of our total revenues

Segments_and_Geographic_Area_A3

Segments and Geographic Area Analysis - Revenues from Contract Drilling Services by Equipment Type (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	$2,843,584	$2,936,066	$3,254,313
Revenues related to reimbursable expenses	'	'	'	'	'	'	'	'	76,837	50,442	68,106
Total revenues	726,497	706,165	758,018	729,741	750,537	729,141	738,188	768,642	2,920,421	2,986,508	3,322,419
Ultra-deepwater semisubmersible [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	854,515	902,793	841,565
Deepwater [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	617,080	597,694	733,037
Mid-Water [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	1,197,934	1,275,068	1,482,032
Total Floaters [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	2,669,529	2,775,555	3,056,634
Jack-ups [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	174,055	160,511	197,534
Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Contract drilling	'	'	'	'	'	'	'	'	'	'	$145

Segments_and_Geographic_Area_A4

Segments and Geographic Area Analysis - Revenues by Geographic Area Presented by Attributing Revenues to Individual Country (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	$726,497	$706,165	$758,018	$729,741	$750,537	$729,141	$738,188	$768,642	$2,920,421	$2,986,508	$3,322,419
United States [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	330,471	173,961	323,381
South America [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	1,219,287	1,427,927	1,736,798
Europe/Africa/Mediterranean [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	731,888	662,995	749,128
Australia/Asia [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	438,814	524,957	451,364
Mexico [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	199,961	196,668	61,748
International [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	$2,589,950	$2,812,547	$2,999,038

Segments_and_Geographic_Area_A5

Segments and Geographic Area Analysis - Individual Countries that Comprised 5% or More of Our Total Contract Drilling Revenues from Unaffiliated Customers (Detail) (Revenues [Member], Geographic Concentration Risk [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Brazil [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of total drilling revenues from unaffiliated customers	38.30%	46.10%	49.40%
United Kingdom [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of total drilling revenues from unaffiliated customers	7.90%	6.90%	4.60%
Australia [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of total drilling revenues from unaffiliated customers	3.20%	6.70%	6.70%
Mexico [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of total drilling revenues from unaffiliated customers	6.90%	6.60%	1.90%
Angola [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of total drilling revenues from unaffiliated customers	3.80%	2.70%	9.60%
Indonesia [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Percentage of total drilling revenues from unaffiliated customers	4.40%	2.40%	5.00%

Segments_and_Geographic_Area_A6

Segments and Geographic Area Analysis - Long-Lived Tangible Assets by Geographic Location (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	$5,467,227	$4,864,972	$4,667,469
United States [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	611,731	444,984	283,049
Australia/Asia/Middle East [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	2,078,348	1,474,999	1,212,461
South America [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	1,690,976	1,827,247	1,979,303
Europe/Africa/Mediterranean [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	793,097	799,194	852,300
Mexico [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	293,075	318,548	340,356
International [Member]	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Drilling and other property and equipment, net	$4,855,496	$4,419,988	$4,384,420

Segments_and_Geographic_Area_A7

Segments and Geographic Area Analysis - Additional Information (Parenthetical) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]	'	'	'
Construction work-in-progress	$1,668,211	$990,964	'
United States [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Construction work-in-progress	339,100	167,400	14,600
Australia Asia Middle East [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Construction work-in-progress	1,064,500	741,100	490,200
Singapore [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Construction work-in-progress	$264,600	$82,500	'

Segments_and_Geographic_Area_A8

Segments and Geographic Area Analysis - Countries Where Parent Company had Material Concentration of Operating Assets (Detail) (Long-lived tangible assets [Member], Geographic Concentration Risk [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Brazil [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	30.20%	37.30%	41.90%
South Korea [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	19.50%	15.20%	10.50%
United States [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	11.20%	9.10%	6.10%
Singapore [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	8.20%	1.80%	'
Angola [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	6.30%	'	8.00%
Mexico [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	5.40%	6.50%	7.30%
Indonesia [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	5.20%	6.80%	3.40%
Egypt [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	4.00%	4.70%	5.50%
Vietnam [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of long-lived tangible assets	0.60%	1.40%	6.60%
Republic of Congo [Member]	'	'	'
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]	'	'	'
Percentage of material concentration of operating assets	'	7.40%	'

Segments_and_Geographic_Area_A9

Segments and Geographic Area Analysis - Revenues from Major Customers that Contributed More than 10% of Total Revenues (Detail) (Revenues [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Petrobras Brasileiro S.A. [Member]	'	'	'
Revenue, Major Customer [Line Items]	'	'	'
Percentage of revenues from major customers	33.60%	33.30%	35.00%
OGX Petroleo e Gas Ltda. [Member]	'	'	'
Revenue, Major Customer [Line Items]	'	'	'
Percentage of revenues from major customers	2.40%	12.50%	14.10%

Unaudited_Quarterly_Financial_2

Unaudited Quarterly Financial Data - Unaudited Quarterly Financial Data (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Quarterly Financial Information [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Revenues	$726,497	$706,165	$758,018	$729,741	$750,537	$729,141	$738,188	$768,642	$2,920,421	$2,986,508	$3,322,419
Operating income	187,669	137,352	262,859	213,726	194,962	244,822	257,184	265,410	801,606	962,378	1,255,414
Income before income tax expense	180,195	131,565	256,301	206,179	185,041	234,847	246,758	251,435	774,240	918,081	1,179,271
Net income	$92,615	$94,748	$185,334	$175,989	$155,661	$178,186	$201,461	$185,169	$548,686	$720,477	$962,542
Net income per share, basic and diluted	$0.67	$0.68	$1.33	$1.27	$1.12	$1.28	$1.45	$1.33	$3.95	$5.18	$6.92

Unaudited_Quarterly_Financial_3

Unaudited Quarterly Financial Data - Unaudited Quarterly Financial Data (Parenthetical) (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2012
Selected Quarterly Financial Information [Abstract]	'	'
Impairment charges related to rigs	$62,400	$62,437