Diamond Offshore Drilling (DODRW) 10-Q 29 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 23, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'DO	'
Entity Registrant Name	'DIAMOND OFFSHORE DRILLING INC	'
Entity Central Index Key	'0000949039	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	137,147,764

CONSOLIDATED_BALANCE_SHEETS_Un

CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$468,823	$347,011
Marketable securities	600,143	1,750,053
Accounts receivable, net of allowance for bad debts	517,389	469,355
Prepaid expenses and other current assets	185,350	143,997
Asset held for sale	'	7,694
Total current assets	1,771,705	2,718,110
Drilling and other property and equipment, net of accumulated depreciation	6,071,935	5,467,227
Other assets	192,872	206,097
Total assets	8,036,512	8,391,434
Current liabilities:	'	'
Accounts payable	104,027	94,151
Accrued liabilities	466,618	370,671
Taxes payable	51,156	30,806
Current portion of long-term debt	249,946	249,954
Total current liabilities	871,747	745,582
Long-term debt	1,994,466	2,244,189
Deferred tax liability	513,881	525,541
Other liabilities	183,504	238,864
Total liabilities	3,563,598	3,754,176
Commitments and contingencies (Note 11)	'	'
Stockholders' equity:	'	'
Preferred stock (par value $0.01, 25,000,000 shares authorized, none issued and outstanding)	0	0
Common stock (par value $0.01, 500,000,000 shares authorized; 143,960,125 shares issued and 137,147,764 shares outstanding at September 30, 2014; 143,952,248 shares issued and 139,035,448 shares outstanding at December 31, 2013)	1,440	1,440
Additional paid-in capital	1,991,492	1,988,720
Retained earnings	2,684,355	2,761,161
Accumulated other comprehensive gain (loss)	-2,204	350
Treasury stock, at cost (6,812,361 and 4,916,800 shares of common stock at September 30, 2014 and December 31, 2013, respectively)	-202,169	-114,413
Total stockholders' equity	4,472,914	4,637,258
Total liabilities and stockholders' equity	$8,036,512	$8,391,434

CONSOLIDATED_BALANCE_SHEETS_Un1

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
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	143,960,125	143,952,248
Common stock, shares outstanding	137,147,764	139,035,448
Treasury stock, shares	6,812,361	4,916,800

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues:	'	'	'	'
Contract drilling	$727,888	$690,741	$2,062,750	$2,135,612
Revenues related to reimbursable expenses	9,794	15,424	76,600	58,312
Total revenues	737,682	706,165	2,139,350	2,193,924
Operating expenses:	'	'	'	'
Contract drilling, excluding depreciation	399,802	419,488	1,164,968	1,163,618
Reimbursable expenses	9,437	14,904	75,393	56,998
Depreciation	108,854	97,143	324,771	291,107
General and administrative	18,604	15,240	61,909	48,490
Bad debt expense	0	22,563	0	22,563
Impairment of assets	109,462	0	109,462	0
Loss (gain) on disposition of assets	1,107	-525	-7,612	-2,789
Total operating expenses	647,266	568,813	1,728,891	1,579,987
Operating income	90,416	137,352	410,459	613,937
Other income (expense):	'	'	'	'
Interest income	86	136	644	1,024
Interest expense	-9,378	-1,693	-46,056	-17,713
Foreign currency transaction gain (loss)	425	-4,556	-3,724	-3,949
Other, net	90	326	598	746
Income before income tax expense	81,639	131,565	361,921	594,045
Income tax expense	-28,994	-36,817	-73,753	-137,974
Net income	$52,645	$94,748	$288,168	$456,071
Earnings per share, Basic and Diluted	$0.38	$0.68	$2.09	$3.28
Weighted-average shares outstanding:	'	'	'	'
Shares of common stock	137,146	139,035	137,582	139,034
Dilutive potential shares of common stock	1	30	3	38
Total weighted-average shares outstanding	137,147	139,065	137,585	139,072
Cash dividends declared per share of common stock	$0.88	$0.88	$2.63	$2.63

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$52,645	$94,748	$288,168	$456,071
Derivative financial instruments:	'	'	'	'
Unrealized holding (loss) gain	-4,229	1,615	1,492	-4,901
Reclassification adjustment for (gain) loss included in net income	-1,518	3,622	-4,055	1,918
Investments in marketable securities:	'	'	'	'
Unrealized holding (loss) gain	-3	-2	36	7
Reclassification adjustment for gain included in net income	-1	-14	-27	-146
Total other comprehensive (loss) gain	-5,751	5,221	-2,554	-3,122
Comprehensive income	$46,894	$99,969	$285,614	$452,949

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities:	'	'
Net income	$288,168	$456,071
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	324,771	291,107
Loss on impairment of assets	109,462	0
Gain on disposition of assets	-7,612	-2,789
(Gain) loss on foreign currency forward exchange contracts	-6,736	2,246
Deferred tax provision	-10,290	43,414
Accretion of discounts on marketable securities	-257	-584
Stock-based compensation expense	2,559	2,627
Deferred income, net	49,013	-45,600
Deferred expenses, net	-79,907	20,441
Long-term employee remuneration programs	-4,799	6,617
Other assets, noncurrent	197	-4,487
Other liabilities, noncurrent	672	-51
Proceeds from (payments for) settlement of foreign currency forward exchange contracts designated as accounting hedges	6,736	-2,246
Bank deposits denominated in nonconvertible currencies	6,009	'
Other	1,636	1,418
Changes in operating assets and liabilities:	'	'
Accounts receivable	-48,258	74,965
Prepaid expenses and other current assets	-10,686	-327
Accounts payable and accrued liabilities	40,326	25,583
Taxes payable	21,832	-10,505
Net cash provided by operating activities	682,836	857,900
Investing activities:	'	'
Capital expenditures (including rig construction)	-1,024,325	-740,460
Proceeds from disposition of assets, net of disposal costs	16,756	3,357
Proceeds from sale and maturities of marketable securities	7,125,045	3,225,062
Purchases of marketable securities	-5,974,861	-2,874,689
Net cash provided by (used in) investing activities	142,615	-386,730
Financing activities:	'	'
Repayment of long-term debt	-250,000	'
Payment of dividends	-365,290	-367,945
Purchase of treasury stock	-87,756	'
Other	-593	137
Net cash used in financing activities	-703,639	-367,808
Net change in cash and cash equivalents	121,812	103,362
Cash and cash equivalents, beginning of period	347,011	335,432
Cash and cash equivalents, end of period	$468,823	$438,794

General_Information

General Information

9 Months Ended

Sep. 30, 2014

Accounting Policies [Abstract]

'

General Information

'

1. General Information

The unaudited consolidated financial statements of Diamond Offshore Drilling, Inc. and subsidiaries, which we refer to as “Diamond Offshore,” “we,” “us” or “our,” should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2013 (File No. 1-13926).

As of October 23, 2014, Loews Corporation owned 51.1 % of the outstanding shares of our common stock.

Interim Financial Information

The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the U.S., or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission. Accordingly, pursuant to such rules and regulations, they do not include all disclosures required by GAAP for complete financial statements. The consolidated financial information has not been audited but, in the opinion of management, includes all adjustments (consisting only of normal recurring accruals) necessary for a fair presentation of the consolidated balance sheets, statements of operations, statements of comprehensive income and statements of cash flows at the dates and for the periods indicated. Results of operations for interim periods are not necessarily indicative of results of operations for the respective full years.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with 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 do 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 $7.3 million and $14.3 million at September 30, 2014 and December 31, 2013, respectively. 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 obligations in Egyptian pounds in the short term, we have reported $6.7 million and $12.7 million as “Other assets” in our Consolidated Balance Sheets at September 30, 2014 and December 31, 2013, respectively.

The effect of exchange rate changes on cash balances held in foreign currencies was not material for each of the three-month and nine-month periods ended September 30, 2014 and 2013.

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),” or AOCGL, 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.” See Note 6.

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 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. See Note 12.

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 7 and 8.

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 nine months ended September 30, 2014 and the year ended December 31, 2013, we capitalized $364.1 million and $302.0 million, respectively, in replacements and betterments of our drilling fleet, resulting from numerous projects ranging from $25,000 to $100 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 ready for its intended use. 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 three to 30 years.

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, the expectation of cold stacking a rig in the near term, a decision to retire or scrap 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 equals 100% in the aggregate. We reevaluate these 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. See Note 2.

Treasury Stock

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. Depending on market conditions, we may, from time to time, purchase shares of our common stock in the open market or otherwise. During the nine months ended September 30, 2014, we repurchased 1,895,561 shares of common stock at a cost of $87.8 million.

Capitalized Interest

We capitalize interest cost for qualifying construction and upgrade projects. See Note 9. A reconciliation of our total interest cost to “Interest expense” as reported in our Consolidated Statements of Operations is as follows:

Three Months Ended

Nine Months Ended

September 30,

September 30,

2014

2013

2014

2013

(In thousands)

Total interest cost, including amortization of debt issuance costs

$

25,707

$

22,234

$

93,600

$

71,229

Capitalized interest

(16,329

)

(20,541

)

(47,544

)

(53,516

)

Total interest expense as reported

$

9,378

$

1,693

$

46,056

$

17,713

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 three-month and nine-month periods ended September 30, 2014, we recognized net foreign currency transaction gains (losses) of $0.4 million and $(3.7) million, respectively. For the three-month and nine-month periods ended September 30, 2013, we recognized net foreign currency transaction (losses) of $(4.6) million and $(3.9) million, respectively. See Note 7.

Revenue Recognition

We recognize revenue from dayrate drilling contracts as services are performed. In connection with such drilling contracts, we may receive fees (on either a lump-sum or dayrate basis) 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 two 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 (on either a lump-sum or dayrate basis). 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 (on either a lump-sum or dayrate basis). 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.

Recent Accounting Pronouncements

In June 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2014-12, Compensation—Stock Compensation (Topic 718), or ASU 2014-12. The new standard amends existing standards to provide specific guidance on how to account for share-based payment awards that provide for the achievement of a performance target after an employee completes the requisite service period (e.g., the employee is eligible to vest in the award regardless of whether the employee is rendering service on the date the performance target is achieved). ASU 2014-12 is effective for annual and interim periods within those annual periods beginning after December 15, 2015. Earlier adoption is permitted. We have completed our evaluation and have determined that the provisions of ASU 2014-12 do not apply to our current share-based compensation plans and adoption of ASU 2014-12 will not have an impact on our financial position, results of operations or cash flows.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or ASU 2014-09. The new standard supersedes the industry-specific standards that currently exist under GAAP and provides a framework to address revenue recognition issues comprehensively for all contracts with customers regardless of industry-specific or transaction-specific fact patterns. Under the new guidance, companies recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. ASU 2014-09 also provides for additional disclosure requirements. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, and may be adopted using a retrospective or modified retrospective approach. Early adoption is not permitted. We are currently evaluating the provisions of ASU 2014-09 and have not yet determined its impact on our financial position, results of operations or cash flows.

Asset_Impairments

Asset Impairments	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Asset Impairments	'
	2. Asset Impairments
	At September 30, 2014, we had four cold-stacked rigs, consisting of the Ocean New Era, the Ocean Epoch and the Ocean Whittington, all three of which were cold stacked and initially impaired in 2012, and the Ocean Vanguard, which was cold stacked in the third quarter of 2014. During the third quarter of 2014, we initiated a plan to retire and scrap the three rigs cold stacked in 2012, as well as the Ocean Concord and the Ocean Yatzy, which are currently idle in Brazil. We also initiated a plan to retire and scrap the Ocean Winner upon completion of its contract term in Brazil. In addition, we expect to cold stack the Ocean General and the Ocean Saratoga in the near term.
	Using the undiscounted probability-weighted cash flow analysis described in Note 1, we determined that the carrying values of the six rigs to be retired and scrapped, or the Retirement Group, were impaired and that the carrying values of the Ocean Vanguard, the Ocean General and the Ocean Saratoga were not impaired. With regard to the Retirement Group, the fair values of five of the rigs were determined based on discussions with and a nonbinding quote received from a rig broker to scrap two of the rigs. We consider this to be a Level 3 fair value measurement due to the nonbinding nature of the quote, the significant level of estimation involved and the lack of transparency as to the inputs used. The fair value of the sixth rig in the Retirement Group, the Ocean Winner (which is under contract through March 2015) was determined using an income approach, which utilized significant unobservable inputs, representative of a Level 3 fair value measurement, including assumptions related to estimated dayrate revenue, rig utilization and anticipated costs for the remainder of the current contract, as well as the aforementioned scrap value quote.
	As a result of our valuations, we recognized an impairment loss aggregating $109.5 million for the three-month and nine-month periods ended September 30, 2014. The aggregate fair value of the Retirement Group was $17.4 million at September 30, 2014 and is reported in “Drilling and other property and equipment, net of accumulated depreciation” in our Consolidated Balance Sheets. We did not record any impairment for the three-month and nine-month periods ended September 30, 2013. See Note 8.
	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.

Supplemental_Financial_Informa

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Supplemental Financial Information	'
	3. Supplemental Financial Information
	Consolidated Balance Sheets Information
	Accounts receivable, net of allowance for bad debts, consists of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	Trade receivables		$	519,796		$	473,013
	Value added tax receivables			15,184			19,407
	Amounts held in escrow			8,974			3,066
	Related party receivables			374			587
	Other			155			622
				544,483			496,695
	Allowance for bad debts			(27,094	)		(27,340	)
	Total		$	517,389		$	469,355
	We recorded $22.6 million in bad debt expense during the three-month and nine-month periods ended September 30, 2013, to reserve the outstanding accounts receivable balance for two of our customers. No additional allowances were deemed necessary for the three-month and nine-month periods ended September 30, 2014.
	Prepaid expenses and other current assets consist of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	Rig spare parts and supplies		$	54,466		$	52,439
	Deferred mobilization costs			49,690			20,274
	Prepaid insurance			20,251			12,503
	Deferred tax assets			10,222			10,221
	Prepaid taxes			44,376			42,058
	FOREX contracts			46			1,562
	Other			6,299			4,940
	Total		$	185,350		$	143,997
	Accrued liabilities consist of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	Rig operating expenses		$	106,417		$	87,307
	Payroll and benefits			119,042			121,387
	Deferred revenue			69,423			26,975
	Accrued capital project/upgrade costs			102,340			86,274
	Interest payable			47,177			28,324
	Personal injury and other claims			9,036			9,687
	FOREX contracts			3,518			1,143
	Other			9,665			9,574
	Total		$	466,618		$	370,671
	Consolidated Statements of Cash Flows Information
	Noncash investing activities excluded from the Consolidated Statements of Cash Flows and other supplemental cash flow information is as follows:
			Nine Months Ended
			September 30,
			2014			2013
			(In thousands)
	Accrued but unpaid capital expenditures at period end		$	102,340		$	74,308
	Cash interest payments(1)			76,092			54,000
	Cash income taxes paid, net of refunds:
	U.S. federal			—			47,000
	Foreign			59,299			62,951
	State			149			190
	(1)	Interest payments, net of amounts capitalized, were $38.9 million and $8.9 million for the nine months ended September 30, 2014 and 2013, respectively.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	4. Stock-Based Compensation
	In March 2014, our Board of Directors adopted our Equity Incentive Compensation Plan, or Equity Plan, which amended and restated our Second Amended and Restated 2000 Stock Option Plan, or Stock Plan. The Equity Plan was approved by our stockholders in May 2014.
	The Equity Plan amended the Stock Plan by, among other things:
		•	increasing the number of shares of our common stock available for issuance under the Equity Plan from 1,500,000 shares to 7,500,000 shares;
		•	increasing the annual limit on the number of shares of our common stock with respect to which awards may be granted to any single individual from 200,000 shares to 500,000 shares;
		•	providing performance goals upon which the awards under the Equity Plan may be conditioned; and
		•	providing for the grant of other stock-based awards (in addition to options and stock appreciation rights) that may be granted under the Equity Plan, including awards of restricted stock, restricted stock units, or RSUs, performance shares and units and other stock-based awards.
	In March 2014, we awarded 52,581 targeted performance RSUs, with a volume weighted average price of our common stock preceding the grant date of $47.52 per share, to our Chief Executive Officer, or CEO, in connection with his commencement of service with us on March 3, 2014, subject to stockholder approval of the Equity Plan. RSUs are contractual rights to receive shares of our common stock in the future if the applicable vesting conditions are met. Targeted RSUs will become earned RSUs upon achievement of certain performance goals as set forth in the award certificate. Earned RSUs granted to our CEO will vest in one-third increments annually, over three years, commencing on the first anniversary of his hire date, with the first year being prorated for the portion of 2014 during which he was employed.
	Because the stock-based compensation awarded to our CEO is a fixed monetary amount at the date of grant (the target value of $3.0 million on a prorated basis) with variances based on actual achievement of a performance goal, the award is being recorded as a share-based liability. Compensation cost will be recognized over the requisite service period as specified in the award. In connection with the targeted RSUs granted in March 2014, we recognized $0.2 million and $0.5 million in compensation expense for the three-month and nine-month periods ended September 30, 2014, respectively. As of September 30, 2014, the targeted performance goal, as set forth in the award certificate, had not been met, but its achievement was deemed probable.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	5. Earnings Per Share
	A reconciliation of the numerators and the denominators of our basic and diluted per-share computations follows:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands, except per share data)
	Net income – basic and diluted numerator	$	52,645	$	94,748	$	288,168	$	456,071
	Weighted average shares – basic (denominator):		137,146		139,035		137,582		139,034
	Effect of dilutive potential shares Stock options and stock appreciation rights		1		30		3		38
	Weighted average shares including conversions – diluted (denominator)		137,147		139,065		137,585		139,072
	Earnings per share:
	Basic	$	0.38	$	0.68	$	2.09	$	3.28
	Diluted	$	0.38	$	0.68	$	2.09	$	3.28
	The following table sets forth the share effects of stock options and the number of stock appreciation rights 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:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands)
	Employee and director:
	Stock options		37		18		32		18
	Stock appreciation rights		1,526		982		1,472		885

Marketable_Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Marketable Securities	'
	6. Marketable Securities
	We report our investments as current assets in our Consolidated Balance Sheets in “Marketable securities,” representing the investment of cash available for current operations. See Note 8.
	Our investments in marketable securities are classified as available for sale and are summarized as follows:
		September 30, 2014
		Amortized		Unrealized			Market
		Cost		Gain (Loss)			Value
		(In thousands)
	U.S. Treasury Bills and Notes (due within one year)	$	599,997	$	(2	)	$	599,995
	Mortgage-backed securities		142		6			148
	Total	$	600,139	$	4		$	600,143
		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
	Proceeds from maturities and sales of marketable securities and gross realized gains and losses are summarized as follows:
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2014		2013			2014		2013
		(In thousands)
	Proceeds from maturities	$	1,325,000	$	1,475,000		$	7,125,000	$	3,225,000
	Proceeds from sales		12		25			45		62
	Gross realized gains		—		—			—		—
	Gross realized losses		—		(1	)		—		(1	)

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments	'
	7. 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 are 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 each of the nine-month periods ended September 30, 2014 and 2013, we settled FOREX contracts with aggregate notional values of approximately $233.9 million, of which the entire aggregate amounts were designated as a cash flow accounting hedge. During the nine-month periods ended September 30, 2014 and 2013, we did not enter into or settle any FOREX contracts that were not designated as accounting hedges.
	The following table presents the aggregate amount of gain or loss recognized in our Consolidated Statements of Operations related to our FOREX contracts designated as accounting hedges for the three-month and nine-month periods ended September 30, 2014 and 2013.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
	Location of Gain (Loss) Recognized in Income	2014			2013			2014			2013
		(In thousands)
	Contract drilling expense	$	1,729		$	(5,018	)	$	6,736		$	(2,246	)
	As of September 30, 2014, we had FOREX contracts outstanding in the aggregate notional amount of $132.9 million, consisting of $16.1 million in Australian dollars, $41.9 million in Brazilian reais, $52.3 million in British pounds sterling, $19.0 million in Mexican pesos and $3.6 million in Norwegian kroner. These contracts generally settle monthly through June 2015. As of September 30, 2014, all outstanding derivative contracts had been designated as cash flow hedges. See Note 8.
	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. At September 30, 2014, all of our FOREX contracts were with two counterparties and were governed under such ISDA contracts. 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 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 FOREX contracts under these agreements in our Consolidated Balance Sheets as of September 30, 2014 and December 31, 2013; however, there would have been no significant difference 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 derivative FOREX contracts designated as hedging instruments at September 30, 2014 and December 31, 2013.
	Balance Sheet Location	Fair Value						Balance Sheet			Fair Value
								Location
		September 30,			December 31,						September 30,			December 31,
		2014			2013						2014			2013
		(In thousands)									(In thousands)
	Prepaid expenses and other current assets	$	46		$	1,562			Accrued liabilities		$	(3,518	)	$	(1,143	)
	The following table presents the amounts recognized in our Consolidated Balance Sheets and Consolidated Statements of Operations related to our derivative financial instruments designated as cash flow hedges for the three-month and nine-month periods ended September 30, 2014 and 2013.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(In thousands)
	FOREX contracts:
	Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	$	(6,505	)	$	2,486		$	2,297		$	(7,539	)
	Location of gain (loss) reclassified from AOCGL into income (effective portion)		Contract			Contract			Contract			Contract
			drilling			drilling			drilling			drilling
			expense			expense			expense			expense
	Amount of gain (loss) reclassified from AOCGL into income (effective portion)	$	2,333		$	(5,572	)	$	6,232		$	(2,951	)
	Location of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		Foreign			Foreign			Foreign			Foreign
			currency			currency			currency			currency
			transaction			transaction			transaction			transaction
			gain (loss)			gain (loss)			gain (loss)			gain (loss)
	Amount of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	$	(59	)	$	59		$	(60	)	$	(59	)
	Treasury lock agreements:
	Amount of gain recognized in AOCGL on derivative (effective portion)		—			—			—			—
	Location of gain reclassified from AOCGL into income (effective portion)		Interest			—			Interest			—
			Expense						Expense
	Amount of gain reclassified from AOCGL into income (effective portion)	$	2		$	—		$	6		$	—
	As of September 30, 2014, the estimated amount of net unrealized gains (losses) associated with our FOREX contracts and treasury lock agreements that will be reclassified to earnings during the next twelve months was $(3.4) million and $8,052, respectively. The net unrealized gains (losses) associated with these derivative financial instruments will be reclassified to contract drilling expense and interest expense, respectively. During the three-month and nine-month periods ended September 30, 2014 and 2013, 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	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Financial Instruments and Fair Value Disclosures	'
	8. Financial Instruments and Fair Value Disclosures
	Financial instruments that 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 residential 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. At September 30, 2014 and December 31, 2013, Petróleo Brasileiro S.A. (a Brazilian multinational energy company that is majority-owned by the Brazilian government), or Petrobras, accounted for $123.7 million and $154.5 million, or 25% and 35%, respectively, of our total consolidated net trade accounts receivable balance.
	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.
	In June 2014, we received $14.7 million from Niko Resources Ltd. pursuant to a settlement agreement entered into at the end of 2013 with respect to certain unpaid obligations under dayrate contracts. We recognized the entire $14.7 million as revenue in the second quarter of 2014, as revenue had not been previously recognized. At September 30, 2014, $40.3 million remained outstanding under the settlement agreement, payable at various times through March 2017.
	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 September 30, 2014 consisted of cash held in money market funds of $422.6 million, time deposits of $20.1 million and investments in U.S. Treasury securities of $600.0 million. 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.
	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 September 30, 2014 consisted of nonrecurring measurements of six mid-water semisubmersible rigs for which we recorded an impairment loss during the third quarter of 2014. See Notes 1 and 2.
	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 nine-month periods ended September 30, 2014 and 2013.
	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 recorded impairment charges related to assets measured at fair value on a nonrecurring basis of $109.5 million during the three-month and nine-month periods ended September 30, 2014.
	Assets and liabilities measured at fair value are summarized below:
			September 30, 2014
			Fair Value Measurements Using										Total Losses
													for Period Ended
													September 30, 2014
			Level 1		Level 2			Level 3		Assets at			Three		Nine
										Fair Value			Months		Months
			(In thousands)
	Recurring fair value measurements:
	Assets:
	Short-term investments		$	1,042,736	$	—		$	—	$	1,042,736
	FOREX contracts			—		46			—		46
	Mortgage-backed securities			—		148			—		148
	Total assets		$	1,042,736	$	194		$	—	$	1,042,930
	Liabilities:
	FOREX contracts		$	—	$	(3,518	)	$	—	$	(3,518	)
	Nonrecurring fair value measurements:
	Assets:
	Impaired assets		$	—	$	—		$	17,442	$	17,442		$	109,462	$	109,462
			December 31, 2013
			Fair Value Measurements Using
			Level 1		Level 2			Level 3		Assets at
										Fair Value
			(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	)
	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 September 30, 2014 and December 31, 2013. 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 period of the report date. Fair values and related carrying values of our senior notes are shown below.
			September 30, 2014					December 31, 2013
			Fair Value		Carrying Value			Fair Value		Carrying Value
			(In millions)
	5.15% Senior Notes due 2014		$	—	$	—		$	257.4	$	250
	4.875% Senior Notes due 2015			258.3		249.9			265.7		249.9
	5.875% Senior Notes due 2019			567.5		499.6			578.1		499.6
	3.45% Senior Notes due 2023			238.9		249.1			241.4		249
	5.70% Senior Notes due 2039			522.3		497			543.1		496.9
	4.875% Senior Notes due 2043			695.2		748.8			736.1		748.8
	See Note 10 for further discussion of our senior notes.
	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	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Abstract]	'
Drilling and Other Property and Equipment	'
	9. Drilling and Other Property and Equipment
	Cost and accumulated depreciation of drilling and other property and equipment are summarized as follows:
		September 30,			December 31,
		2014			2013
		(In thousands)
	Drilling rigs and equipment	$	8,681,571		$	7,412,066
	Construction work-in-progress		1,314,517			1,668,211
	Land and buildings		66,620			65,627
	Office equipment and other		69,673			65,799
	Cost		10,132,381			9,211,703
	Less: accumulated depreciation		(4,060,446	)		(3,744,476	)
	Drilling and other property and equipment, net	$	6,071,935		$	5,467,227
	Construction work-in-progress, including capitalized interest, at September 30, 2014 and December 31, 2013 is summarized as follows:
		September 30,			December 31,
		2014			2013
		(In thousands)
	Ultra-deepwater drillships	$	733,805		$	868,908
	Ultra-deepwater semisubmersible:
	Ocean GreatWhite		207,345			195,578
	Deepwater semisubmersibles:
	Ocean Onyx		—			339,129
	Ocean Apex		373,367			264,596
	Total construction work-in-progress	$	1,314,517		$	1,668,211
	At December 31, 2013, construction work-in-progress included an aggregate $583.3 million for the deepwater semisubmersible Ocean Onyx and the ultra-deepwater drillship Ocean Blackhawk, which were placed in service in January 2014 and February 2014, respectively, and are no longer reported as construction work-in-progress at September 30, 2014.

Credit_Agreement_and_Senior_No

Credit Agreement and Senior Notes	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Credit Agreement and Senior Notes	'
	10. Credit Agreement and Senior Notes
	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 October 22, 2014, we entered into a commitment increase and extension agreement and third amendment to the Credit Agreement which, among other things, increased the aggregate commitment under the Credit Agreement from $1.0 billion to $1.5 billion and provided for an approximately seven-month extension of the maturity date for most of the lenders. In addition, pursuant to such amendment, subject to the conditions specified in the Credit Agreement, we have the option to increase the revolving commitments under the Credit Agreement by up to an additional $500 million from time to time, upon receipt of additional commitments from new or existing lenders, and to request up to two additional one-year extensions of the maturity date. As so amended, the Credit Agreement provides for a $1.5 billion senior unsecured revolving credit facility for general corporate purposes, maturing on October 22, 2019, except for $40 million of commitments that mature on March 17, 2019. The entire amount of the facility is available, subject to its terms, for revolving loans. Up to $250 million of the facility may be used for the issuance of performance or other standby letters of credit and up to $100 million may be used for swingline loans.
	At September 30, 2014, we had no amounts outstanding under the Credit Agreement.
	In September 2014, we repaid $250.0 million in aggregate principal amount of our 5.15% Senior Notes due September 1, 2014. Our 4.875% Senior Notes due July 1, 2015, or 2015 Senior Notes, in the aggregate principal amount of $250.0 million will mature on July 1, 2015. Accordingly, the aggregate $249.9 million accreted value of our 2015 Senior Notes has been presented as “Current portion of long-term debt” in our Consolidated Balance Sheets at September 30, 2014.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
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.
	Asbestos Litigation. We are one of several unrelated defendants in lawsuits filed in Mississippi and Louisiana 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 many 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, and Kaneb Management Co., L.L.C., or Kaneb, the successors to Diamond M Corporation, seeking a judicial determination that we did not assume liability for these claims. We obtained summary judgment from the Texas court on our claims in the declaratory judgment action, but NuStar and Kaneb appealed the Texas court’s decision, and the appellate court has remanded the case to the Texas court. We have filed an additional summary judgment motion in the case, and it remains pending. We are unable to estimate our potential exposure, if any, to these lawsuits at this time but do not believe that our ultimate liability, if any, resulting from this litigation will have a material effect on our consolidated financial condition, results of operations or cash flows.
	We have been named in various other lawsuits or threatened actions that are incidental to the ordinary course of our business. We intend to defend these matters vigorously; however litigation is inherently unpredictable, and the ultimate outcome or effect of these lawsuits and actions cannot be predicted with certainty. As a result, there can be no assurance as to the ultimate outcome of these lawsuits. Any claims against us, whether meritorious or not, could be time-consuming, cause us to incur costs and expenses, require significant amounts of management time and result in the diversion of significant operational resources. 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 position, results of operations or cash flows.
	Brazilian Withholding Contingency. In July 2014, Petrobras notified us, along with other industry participants, that it is challenging assessments by Brazilian tax authorities of withholding taxes associated with the provision of drilling rigs for its operations in Brazil during the years 2008 and 2009. Petrobras has also notified us that, if Petrobras is ultimately assessed and must pay such withholding taxes, it will seek reimbursement from us for the portion allocable to our drilling rigs. We dispute any basis for Petrobras to obtain such reimbursement, and we have notified Petrobras of our position. If necessary, we intend to defend any reimbursement claims against us vigorously. We are currently unable to estimate the range of loss, if any, that we would incur if Petrobras is ultimately assessed such taxes and if it is determined that Petrobras is entitled to obtain reimbursement from us. If Petrobras is assessed such taxes and we are ultimately required to pay such reimbursement, the amount of such reimbursement could be substantial and could have a material adverse effect on our financial condition, results of operations and cash flows.
	NPI Arrangement. We received customer payments measured by a percentage net profits interest (primarily of 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 2012. Certain parties (including the debtor) in the bankruptcy proceedings 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. In 2013, 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. We agreed to a settlement with the company that purchased most of the debtor’s assets (including the debtor’s claims against our NPI) whereby the nature of our NPI will not be challenged by that party and our declaratory judgment action was dismissed. Absent any challenge by the bankruptcy trustee or certain intervenors, we expect the bankruptcy proceedings to be concluded with no further impact to us.
	Personal Injury Claims. Under our current insurance policies that expire on May 1, 2015, our deductibles for marine liability insurance coverage, including personal injury claims, which primarily result from Jones Act liability in the Gulf of Mexico, are $25.0 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 that 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 September 30, 2014, our estimated liability for personal injury claims was $38.1 million, of which $8.6 million and $29.5 million were recorded in “Accrued liabilities” and “Other liabilities,” respectively, in our Consolidated Balance Sheets. 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. 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. The Ocean GreatWhite, a 10,000 foot dynamically positioned, harsh environment semisubmersible drilling rig, is under construction in South Korea at an estimated cost of $755 million, including shipyard costs, capital spares, commissioning, project management and shipyard supervision. The contracted price to Hyundai Heavy Industries Co., Ltd., or Hyundai, totaling $628.5 million is payable in two installments, of which the first installment of $188.6 million has been paid. 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. At September 30, 2014, we had three remaining ultra-deepwater drillships under construction at Hyundai for an estimated aggregate cost of $1.9 billion, including shipyard costs, commissioning, capital spares and project management costs. 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 our drillships currently under construction, aggregating $493.2 million. The Ocean BlackHornet and Ocean BlackRhino are expected to be delivered in the fourth quarter of 2014, and the Ocean BlackLion is expected to be delivered in the first quarter of 2015, at which times approximately $390 million will be payable to Hyundai for each rig.
	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 fourth quarter of 2014 at an aggregate cost of approximately $370.0 million, including shipyard costs, 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 eight installments, in the aggregate amount of $87.8 million. The remaining $47.3 million in aggregate milestone payments are payable to Jurong during the remainder of 2014 as construction milestones are met. In addition, we have executed approximately $10.2 million in change orders to the shipyard contract, of which $8.3 million remains payable to Jurong during the remainder of 2014 as projects are completed.
	At September 30, 2014 and December 31, 2013, 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.
	Letters of Credit and Other. We were contingently liable as of September 30, 2014 in the amount of $99.7 million under certain performance, supersedeas and customs bonds and letters of credit. Agreements relating to approximately $92.0 million of performance, supersedeas and customs bonds can require collateral at any time. As of September 30, 2014, 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.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Gain (Loss)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Accumulated Other Comprehensive Gain (Loss)	'
	12. Accumulated Other Comprehensive Gain (Loss)
	The components of our AOCGL and related changes thereto are as follows:
		Unrealized Gain (Loss) on
		Derivative			Marketable			Total
		Financial			Securities			AOCGL
		Instruments
		(In thousands)
	Balance at January 1, 2014	$	357		$	(7	)	$	350
	Change in other comprehensive gain (loss) before reclassifications, after tax of $(805) and $(16)		1,492			36			1,528
	Reclassification adjustments for items included in Net Income, after tax of $2,183 and $7		(4,055	)		(27	)		(4,082	)
	Balance at September 30, 2014	$	(2,206	)	$	2		$	(2,204	)
	The following table presents the line items in our Consolidated Statements of Operations affected by reclassification adjustments out of AOCGL.
	Major Category of AOCGL	Three Months Ended						Nine Months Ended						Consolidated Statements of Operations Line Items
		September 30,						September 30,
		2014			2013			2014			2013
		(In thousands)
	Derivative Financial Instruments:
	Unrealized (gain) loss on FOREX	$	(2,333	)	$	5,572		$	(6,232	)	$	2,951		Contract drilling, excluding
	contracts													depreciation
	Unrealized (gain) loss on Treasury Lock Agreements		(2	)		—			(6	)		—		Interest expense
			817			(1,950	)		2,183			(1,033	)	Income tax expense
		$	(1,518	)	$	3,622		$	(4,055	)	$	1,918		Net of tax
	Marketable Securities:
	Unrealized (gain) loss on marketable securities	$	(1	)	$	(15	)	$	(34	)	$	(165	)	Other, net
			—			1			7			19		Income tax expense
		$	(1	)	$	(14	)	$	(27	)	$	(146	)	Net of tax

Segments_and_Geographic_Area_A

Segments and Geographic Area Analysis	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segments and Geographic Area Analysis	'
	13. 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:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands)
	Floaters:
	Ultra-Deepwater	$	313,124	$	195,215	$	701,574	$	617,673
	Deepwater		111,372		147,333		378,470		495,858
	Mid-Water		258,028		297,368		844,909		891,449
	Total Floaters		682,524		639,916		1,924,953		2,004,980
	Jack-ups		45,364		50,825		137,797		130,632
	Total contract drilling revenues		727,888		690,741		2,062,750		2,135,612
	Revenues related to reimbursable expenses		9,794		15,424		76,600		58,312
	Total revenues	$	737,682	$	706,165	$	2,139,350	$	2,193,924
	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 September 30, 2014, our actively-marketed drilling rigs were en route to or located offshore nine 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.
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands)
	United States	$	83,300	$	69,627	$	326,808	$	253,654
	International:
	South America		294,246		311,708		844,242		896,029
	Europe/Africa/Mediterranean		135,286		185,335		395,602		559,290
	Australia/Asia		162,929		88,054		393,248		333,728
	Mexico		61,921		51,441		179,450		151,223
	Total revenues	$	737,682	$	706,165	$	2,139,350	$	2,193,924

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	14. 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, directly or indirectly, by one of our wholly owned foreign subsidiaries. It is our intention to indefinitely reinvest future earnings of this subsidiary to finance foreign activities. Accordingly, we have not made a provision for U.S. income taxes on such earnings except to the extent that such earnings were immediately subject to U.S. income taxes.
	Tax Returns and Examinations. We file income tax returns in the U.S. federal jurisdiction, various state jurisdictions and various foreign jurisdictions. In several of these jurisdictions, tax years remain subject to examination and/or we are currently under audit or we have assessments that we are disputing.
	Egypt Tax Jurisdiction. During 2013, we were under audit by the Egyptian tax authorities for the tax years 2006 through 2010. In 2013, after receiving notification that the Egyptian government had concluded the income tax audit for the period 2006 to 2008 and proposed a $1.2 billion increase to taxable income, we accrued an additional $56.9 million of expense for uncertain tax positions in Egypt for all open years. During the first quarter of 2014, we settled certain disputes for the years 2006 through 2008 with the Egyptian tax authorities, which resulted in an aggregate $17.2 million reduction in tax expense, comprised of a $23.2 million reversal of uncertain tax positions, partially offset by $6.0 million in current income tax expense. One issue for the 2006 through 2008 period remains open, which we appealed. During the second quarter of 2014, the Appeals Committee in Egypt issued a decision regarding this open item, with which we disagree. We have filed an objection with the Egyptian courts and continue to dispute the matter. We have also sought assistance from an agency of the U.S. Treasury Department, pursuant to international tax treaties, and continue to believe that our position will, more likely than not, be sustained. However, if our position is not sustained, tax expense and related penalties would increase by approximately $50 million related to this issue for the 2006 through 2008 tax years as of September 30, 2014.
	Brazil Tax Jurisdiction. 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 2010 and, during the third quarter of 2014, received a favorable court decision resulting in the closure of the 2004 and 2005 tax years. As a consequence, we reversed our $14.0 million reserve for this uncertain tax position, of which $3.5 million is interest and $4.4 million is penalty.
	Mexico Tax Jurisdiction. Due to the 2014 expiration of the statute of limitations in Mexico for the 2008 tax year for one of our subsidiaries operating in Mexico, we reversed our $8.0 million accrual for an uncertain tax position, of which $2.7 million is interest and $1.1 million is penalty.
	Malaysia Tax Jurisdiction. During the third quarter of 2014 we received final approval from the Malaysian tax authorities for the settlement of tax liabilities and penalties for the years 2003 through 2008 resulting in the reversal of a $14.2 million reserve for uncertain tax positions for these years, of which $5.3 million is penalty.
	United Kingdom Tax Jurisdiction. The U.K. Finance Act of 2014, or the Finance Act, was enacted in July 2014 with an effective date retroactive to April 1, 2014. Certain provisions of the Finance Act will limit the amount of tax deductions available with respect to our rigs working in the United Kingdom, or U.K., under bareboat charter arrangements, which has caused our expected tax expense for the full year of 2014 to increase by approximately $26 million. We are actively reviewing various alternative arrangements under which our U.K. rigs could operate in order to minimize the impact of this legislative change in future years.

General_Information_Policies

General Information (Policies)

9 Months Ended

Sep. 30, 2014

Accounting Policies [Abstract]

'

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 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 do 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 $7.3 million and $14.3 million at September 30, 2014 and December 31, 2013, respectively. 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 obligations in Egyptian pounds in the short term, we have reported $6.7 million and $12.7 million as “Other assets” in our Consolidated Balance Sheets at September 30, 2014 and December 31, 2013, respectively.

The effect of exchange rate changes on cash balances held in foreign currencies was not material for each of the three-month and nine-month periods ended September 30, 2014 and 2013.

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),” or AOCGL, 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.” See Note 6.

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 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. See Note 12.

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 7 and 8.

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 nine months ended September 30, 2014 and the year ended December 31, 2013, we capitalized $364.1 million and $302.0 million, respectively, in replacements and betterments of our drilling fleet, resulting from numerous projects ranging from $25,000 to $100 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 ready for its intended use. 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 three to 30 years.

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, the expectation of cold stacking a rig in the near term, a decision to retire or scrap 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 equals 100% in the aggregate. We reevaluate these 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. See Note 2.

Treasury Stock

'

Treasury Stock

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. Depending on market conditions, we may, from time to time, purchase shares of our common stock in the open market or otherwise. During the nine months ended September 30, 2014, we repurchased 1,895,561 shares of common stock at a cost of $87.8 million.

Capitalized Interest

'

Capitalized Interest

We capitalize interest cost for qualifying construction and upgrade projects. See Note 9. A reconciliation of our total interest cost to “Interest expense” as reported in our Consolidated Statements of Operations is as follows:

Three Months Ended

Nine Months Ended

September 30,

September 30,

2014

2013

2014

2013

(In thousands)

Total interest cost, including amortization of debt issuance costs

$

25,707

$

22,234

$

93,600

$

71,229

Capitalized interest

(16,329

)

(20,541

)

(47,544

)

(53,516

)

Total interest expense as reported

$

9,378

$

1,693

$

46,056

$

17,713

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 three-month and nine-month periods ended September 30, 2014, we recognized net foreign currency transaction gains (losses) of $0.4 million and $(3.7) million, respectively. For the three-month and nine-month periods ended September 30, 2013, we recognized net foreign currency transaction (losses) of $(4.6) million and $(3.9) million, respectively. See Note 7.

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 (on either a lump-sum or dayrate basis) 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 two 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 (on either a lump-sum or dayrate basis). 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 (on either a lump-sum or dayrate basis). 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.

Recent Accounting Pronouncements

'

Recent Accounting Pronouncements

In June 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2014-12, Compensation—Stock Compensation (Topic 718), or ASU 2014-12. The new standard amends existing standards to provide specific guidance on how to account for share-based payment awards that provide for the achievement of a performance target after an employee completes the requisite service period (e.g., the employee is eligible to vest in the award regardless of whether the employee is rendering service on the date the performance target is achieved). ASU 2014-12 is effective for annual and interim periods within those annual periods beginning after December 15, 2015. Earlier adoption is permitted. We have completed our evaluation and have determined that the provisions of ASU 2014-12 do not apply to our current share-based compensation plans and adoption of ASU 2014-12 will not have an impact on our financial position, results of operations or cash flows.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or ASU 2014-09. The new standard supersedes the industry-specific standards that currently exist under GAAP and provides a framework to address revenue recognition issues comprehensively for all contracts with customers regardless of industry-specific or transaction-specific fact patterns. Under the new guidance, companies recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. ASU 2014-09 also provides for additional disclosure requirements. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, and may be adopted using a retrospective or modified retrospective approach. Early adoption is not permitted. We are currently evaluating the provisions of ASU 2014-09 and have not yet determined its impact on our financial position, results of operations or cash flows.

General_Information_Tables

General Information (Tables)	9 Months Ended
	Sep. 30, 2014
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:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(In thousands)
	Total interest cost, including amortization of debt issuance costs	$	25,707		$	22,234		$	93,600		$	71,229
	Capitalized interest		(16,329	)		(20,541	)		(47,544	)		(53,516	)
	Total interest expense as reported	$	9,378		$	1,693		$	46,056		$	17,713

Supplemental_Financial_Informa1

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Accounts Receivable, Net of Allowance for Doubtful Accounts	'
	Accounts receivable, net of allowance for bad debts, consists of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	Trade receivables		$	519,796		$	473,013
	Value added tax receivables			15,184			19,407
	Amounts held in escrow			8,974			3,066
	Related party receivables			374			587
	Other			155			622
				544,483			496,695
	Allowance for bad debts			(27,094	)		(27,340	)
	Total		$	517,389		$	469,355
Prepaid Expenses and Other Current Assets	'
	Prepaid expenses and other current assets consist of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	Rig spare parts and supplies		$	54,466		$	52,439
	Deferred mobilization costs			49,690			20,274
	Prepaid insurance			20,251			12,503
	Deferred tax assets			10,222			10,221
	Prepaid taxes			44,376			42,058
	FOREX contracts			46			1,562
	Other			6,299			4,940
	Total		$	185,350		$	143,997
Accrued Liabilities	'
	Accrued liabilities consist of the following:
			September 30,			December 31,
			2014			2013
			(In thousands)
	Rig operating expenses		$	106,417		$	87,307
	Payroll and benefits			119,042			121,387
	Deferred revenue			69,423			26,975
	Accrued capital project/upgrade costs			102,340			86,274
	Interest payable			47,177			28,324
	Personal injury and other claims			9,036			9,687
	FOREX contracts			3,518			1,143
	Other			9,665			9,574
	Total		$	466,618		$	370,671
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:
			Nine Months Ended
			September 30,
			2014			2013
			(In thousands)
	Accrued but unpaid capital expenditures at period end		$	102,340		$	74,308
	Cash interest payments(1)			76,092			54,000
	Cash income taxes paid, net of refunds:
	U.S. federal			—			47,000
	Foreign			59,299			62,951
	State			149			190
	(1)	Interest payments, net of amounts capitalized, were $38.9 million and $8.9 million for the nine months ended September 30, 2014 and 2013, respectively.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
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 our basic and diluted per-share computations follows:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands, except per share data)
	Net income – basic and diluted numerator	$	52,645	$	94,748	$	288,168	$	456,071
	Weighted average shares – basic (denominator):		137,146		139,035		137,582		139,034
	Effect of dilutive potential shares Stock options and stock appreciation rights		1		30		3		38
	Weighted average shares including conversions – diluted (denominator)		137,147		139,065		137,585		139,072
	Earnings per share:
	Basic	$	0.38	$	0.68	$	2.09	$	3.28
	Diluted	$	0.38	$	0.68	$	2.09	$	3.28
Securities Excluded from Computation of Diluted Earning Per Share	'
	The following table sets forth the share effects of stock options and the number of stock appreciation rights 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:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands)
	Employee and director:
	Stock options		37		18		32		18
	Stock appreciation rights		1,526		982		1,472		885

Marketable_Securities_Tables

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2014
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:
		September 30, 2014
		Amortized		Unrealized			Market
		Cost		Gain (Loss)			Value
		(In thousands)
	U.S. Treasury Bills and Notes (due within one year)	$	599,997	$	(2	)	$	599,995
	Mortgage-backed securities		142		6			148
	Total	$	600,139	$	4		$	600,143
		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
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:
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2014		2013			2014		2013
		(In thousands)
	Proceeds from maturities	$	1,325,000	$	1,475,000		$	7,125,000	$	3,225,000
	Proceeds from sales		12		25			45		62
	Gross realized gains		—		—			—		—
	Gross realized losses		—		(1	)		—		(1	)

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Amounts Recognized in Consolidated Statements of Operations Related to FOREX Contracts Designated as Accounting Hedges	'
	The following table presents the aggregate amount of gain or loss recognized in our Consolidated Statements of Operations related to our FOREX contracts designated as accounting hedges for the three-month and nine-month periods ended September 30, 2014 and 2013.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
	Location of Gain (Loss) Recognized in Income	2014			2013			2014			2013
		(In thousands)
	Contract drilling expense	$	1,729		$	(5,018	)	$	6,736		$	(2,246	)
Fair Values of FOREX Contracts Designated as Hedging Instruments	'
	The following table presents the fair values of our derivative FOREX contracts designated as hedging instruments at September 30, 2014 and December 31, 2013.
	Balance Sheet Location	Fair Value						Balance Sheet			Fair Value
								Location
		September 30,			December 31,						September 30,			December 31,
		2014			2013						2014			2013
		(In thousands)									(In thousands)
	Prepaid expenses and other current assets	$	46		$	1,562			Accrued liabilities		$	(3,518	)	$	(1,143	)
Amounts Recognized in Consolidated Balance Sheets and Consolidated Statements of Operations Related to Derivative Financial Instruments 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 financial instruments designated as cash flow hedges for the three-month and nine-month periods ended September 30, 2014 and 2013.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(In thousands)
	FOREX contracts:
	Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	$	(6,505	)	$	2,486		$	2,297		$	(7,539	)
	Location of gain (loss) reclassified from AOCGL into income (effective portion)		Contract			Contract			Contract			Contract
			drilling			drilling			drilling			drilling
			expense			expense			expense			expense
	Amount of gain (loss) reclassified from AOCGL into income (effective portion)	$	2,333		$	(5,572	)	$	6,232		$	(2,951	)
	Location of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		Foreign			Foreign			Foreign			Foreign
			currency			currency			currency			currency
			transaction			transaction			transaction			transaction
			gain (loss)			gain (loss)			gain (loss)			gain (loss)
	Amount of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	$	(59	)	$	59		$	(60	)	$	(59	)
	Treasury lock agreements:
	Amount of gain recognized in AOCGL on derivative (effective portion)		—			—			—			—
	Location of gain reclassified from AOCGL into income (effective portion)		Interest			—			Interest			—
			Expense						Expense
	Amount of gain reclassified from AOCGL into income (effective portion)	$	2		$	—		$	6		$	—

Financial_Instruments_and_Fair1

Financial Instruments and Fair Value Disclosures (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Assets and Liabilities Measured at Fair Value on Recurring and Nonrecurring Basis	'
	Assets and liabilities measured at fair value are summarized below:
		September 30, 2014
		Fair Value Measurements Using										Total Losses
												for Period Ended
												September 30, 2014
		Level 1		Level 2			Level 3		Assets at			Three		Nine
									Fair Value			Months		Months
		(In thousands)
	Recurring fair value measurements:
	Assets:
	Short-term investments	$	1,042,736	$	—		$	—	$	1,042,736
	FOREX contracts		—		46			—		46
	Mortgage-backed securities		—		148			—		148
	Total assets	$	1,042,736	$	194		$	—	$	1,042,930
	Liabilities:
	FOREX contracts	$	—	$	(3,518	)	$	—	$	(3,518	)
	Nonrecurring fair value measurements:
	Assets:
	Impaired assets	$	—	$	—		$	17,442	$	17,442		$	109,462	$	109,462
		December 31, 2013
		Fair Value Measurements Using
		Level 1		Level 2			Level 3		Assets at
									Fair Value
		(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	)
Fair Values and Related Carrying Values of Our Debt Instruments	'
	Fair values and related carrying values of our senior notes are shown below.
		September 30, 2014					December 31, 2013
		Fair Value		Carrying Value			Fair Value		Carrying Value
		(In millions)
	5.15% Senior Notes due 2014	$	—	$	—		$	257.4	$	250
	4.875% Senior Notes due 2015		258.3		249.9			265.7		249.9
	5.875% Senior Notes due 2019		567.5		499.6			578.1		499.6
	3.45% Senior Notes due 2023		238.9		249.1			241.4		249
	5.70% Senior Notes due 2039		522.3		497			543.1		496.9
	4.875% Senior Notes due 2043		695.2		748.8			736.1		748.8

Drilling_and_Other_Property_an1

Drilling and Other Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2014
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:
		September 30,			December 31,
		2014			2013
		(In thousands)
	Drilling rigs and equipment	$	8,681,571		$	7,412,066
	Construction work-in-progress		1,314,517			1,668,211
	Land and buildings		66,620			65,627
	Office equipment and other		69,673			65,799
	Cost		10,132,381			9,211,703
	Less: accumulated depreciation		(4,060,446	)		(3,744,476	)
	Drilling and other property and equipment, net	$	6,071,935		$	5,467,227
Summary of Construction Work-in-Progress, Including Capitalized Interest	'
	Construction work-in-progress, including capitalized interest, at September 30, 2014 and December 31, 2013 is summarized as follows:
		September 30,			December 31,
		2014			2013
		(In thousands)
	Ultra-deepwater drillships	$	733,805		$	868,908
	Ultra-deepwater semisubmersible:
	Ocean GreatWhite		207,345			195,578
	Deepwater semisubmersibles:
	Ocean Onyx		—			339,129
	Ocean Apex		373,367			264,596
	Total construction work-in-progress	$	1,314,517		$	1,668,211

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Gain (Loss) (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Components of Accumulated Other Comprehensive Gain (Loss)	'
	The components of our AOCGL and related changes thereto are as follows:
		Unrealized Gain (Loss) on
		Derivative			Marketable			Total
		Financial			Securities			AOCGL
		Instruments
		(In thousands)
	Balance at January 1, 2014	$	357		$	(7	)	$	350
	Change in other comprehensive gain (loss) before reclassifications, after tax of $(805) and $(16)		1,492			36			1,528
	Reclassification adjustments for items included in Net Income, after tax of $2,183 and $7		(4,055	)		(27	)		(4,082	)
	Balance at September 30, 2014	$	(2,206	)	$	2		$	(2,204	)
Items in Consolidated Statements of Operations Affected by Reclassification Adjustments	'
	The following table presents the line items in our Consolidated Statements of Operations affected by reclassification adjustments out of AOCGL.
	Major Category of AOCGL	Three Months Ended						Nine Months Ended						Consolidated Statements
		September 30,						September 30,						of Operations Line Items
		2014			2013			2014			2013
		(In thousands)
	Derivative Financial Instruments:
	Unrealized (gain) loss on FOREX contracts	$	(2,333	)	$	5,572		$	(6,232	)	$	2,951		Contract drilling, excluding
														depreciation
	Unrealized (gain) loss on Treasury Lock Agreements		(2	)		—			(6	)		—		Interest expense
			817			(1,950	)		2,183			(1,033	)	Income tax expense
		$	(1,518	)	$	3,622		$	(4,055	)	$	1,918		Net of tax
	Marketable Securities:
	Unrealized (gain) loss on marketable securities	$	(1	)	$	(15	)	$	(34	)	$	(165	)	Other, net
			—			1			7			19		Income tax expense
		$	(1	)	$	(14	)	$	(27	)	$	(146	)	Net of tax

Segments_and_Geographic_Area_A1

Segments and Geographic Area Analysis (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Revenues from Contract Drilling Services by Equipment Type	'
	Revenues from contract drilling services by equipment type are listed below:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands)
	Floaters:
	Ultra-Deepwater	$	313,124	$	195,215	$	701,574	$	617,673
	Deepwater		111,372		147,333		378,470		495,858
	Mid-Water		258,028		297,368		844,909		891,449
	Total Floaters		682,524		639,916		1,924,953		2,004,980
	Jack-ups		45,364		50,825		137,797		130,632
	Total contract drilling revenues		727,888		690,741		2,062,750		2,135,612
	Revenues related to reimbursable expenses		9,794		15,424		76,600		58,312
	Total revenues	$	737,682	$	706,165	$	2,139,350	$	2,193,924
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.
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
		(In thousands)
	United States	$	83,300	$	69,627	$	326,808	$	253,654
	International:
	South America		294,246		311,708		844,242		896,029
	Europe/Africa/Mediterranean		135,286		185,335		395,602		559,290
	Australia/Asia		162,929		88,054		393,248		333,728
	Mexico		61,921		51,441		179,450		151,223
	Total revenues	$	737,682	$	706,165	$	2,139,350	$	2,193,924

General_Information_Additional

General Information - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Oct. 23, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Egyptian Pounds [Member]

Egyptian Pounds [Member]

Subsequent Event [Member]

Other Assets [Member]

Other Assets [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Egyptian Pounds [Member]

Egyptian Pounds [Member]

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding common stock owned by Loews Corporation

'

'

'

'

'

'

'

51.10%

'

'

'

'

'

'

Period considered to treat short-term, highly liquid investments as cash equivalents

'

'

'Three months or less

'

'

'

'

'

'

'

'

'

'

'

Bank deposits

'

'

'

'

'

$7,300,000

$14,300,000

'

$6,700,000

$12,700,000

'

'

'

'

Amount capitalized for asset replacements and betterments

'

'

364,100,000

'

302,000,000

'

'

'

'

'

'

'

'

'

Rig and equipment project costs

'

'

'

'

'

'

'

'

'

'

25,000

25,000

100,000,000

100,000,000

Estimated useful life for drilling rigs and equipment

'

'

'

'

'

'

'

'

'

'

'3 years

'

'30 years

'

Sum and probability of occurrence scenarios

'

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

Repurchase of common stock, shares

'

'

1,895,561

'

'

'

'

'

'

'

'

'

'

'

Repurchase of common stock, cost

'

'

87,800,000

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) on foreign currency transactions recognized in income

$400,000

($4,600,000)

($3,700,000)

($3,900,000)

'

'

'

'

'

'

'

'

'

'

Initial term of contracts minimum months

'

'

'2 months

'

'

'

'

'

'

'

'

'

'

'

Initial term of contracts maximum months

'

'

'60 months

'

'

'

'

'

'

'

'

'

'

'

General_Information_Reconcilia

General Information - Reconciliation of Total Interest Cost to Interest Expense (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest Costs Incurred [Abstract]	'	'	'	'
Total interest cost, including amortization of debt issuance costs	$25,707	$22,234	$93,600	$71,229
Capitalized interest	-16,329	-20,541	-47,544	-53,516
Total interest expense as reported	$9,378	$1,693	$46,056	$17,713

Asset_Impairments_Additional_I

Asset Impairments - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2012	Sep. 30, 2014
					Level 3 [Member]	Cold-stacked Rigs [Member]	Cold-stacked Rigs [Member]	Cold-stacked Rigs [Member]
					Rigs	Rigs	Rigs	Retirement Group [Member]
								Rigs
Schedule Of Asset Impairment Charges [Line Items]	'	'	'	'	'	'	'	'
Number of rigs	'	'	'	'	'	4	'	'
Number of cold stacked rigs at period end, previously impaired	'	'	'	'	'	'	3	'
Number of Rigs to be Scrapped	'	'	'	'	'	3	'	6
Number of rigs with fair values estimated based on scrap quote	'	'	'	'	5	'	'	'
Number of rigs included in indicative bid	'	'	'	'	2	'	'	'
Impairment of assets	$109,462	$0	$109,462	$0	'	'	'	'
Aggregate fair value reported for Impaired Assets	$17,400	'	$17,400	'	'	'	'	'

Supplemental_Financial_Informa2

Supplemental Financial Information - Accounts Receivable, Net of Allowance for Doubtful Accounts (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'
Trade receivables	$519,796	$473,013
Value added tax receivables	15,184	19,407
Amounts held in escrow	8,974	3,066
Related party receivables	374	587
Other	155	622
Receivables Gross Current, Total	544,483	496,695
Allowance for bad debts	-27,094	-27,340
Total	$517,389	$469,355

Supplemental_Financial_Informa3

Supplemental Financial Information - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
		Customer		Customer
Receivables [Abstract]	'	'	'	'
Bad debt expense	$0	$22,563	$0	$22,563
Number of customers	'	2	'	2

Supplemental_Financial_Informa4

Supplemental Financial Information - Prepaid Expenses and Other Current Assets (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'	'
Rig spare parts and supplies	$54,466	$52,439
Deferred mobilization costs	49,690	20,274
Prepaid insurance	20,251	12,503
Deferred tax assets	10,222	10,221
Prepaid taxes	44,376	42,058
FOREX contracts	46	1,562
Other	6,299	4,940
Total	$185,350	$143,997

Supplemental_Financial_Informa5

Supplemental Financial Information - Accrued Liabilities (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]	'	'
Rig operating expenses	$106,417	$87,307
Payroll and benefits	119,042	121,387
Deferred revenue	69,423	26,975
Accrued capital project/upgrade costs	102,340	86,274
Interest payable	47,177	28,324
Personal injury and other claims	9,036	9,687
FOREX contracts	3,518	1,143
Other	9,665	9,574
Total	$466,618	$370,671

Supplemental_Financial_Informa6

Supplemental Financial Information - Noncash Investing and Financing Activities (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Condensed Financial Statements, Captions [Line Items]	'	'
Accrued but unpaid capital expenditures at period end	$102,340	$74,308
Cash interest payments	76,092	54,000
U.S federal [Member]	'	'
Cash income taxes paid, net of refunds:	'	'
Cash income taxes paid, net of refunds	'	47,000
Foreign [Member]	'	'
Cash income taxes paid, net of refunds:	'	'
Cash income taxes paid, net of refunds	59,299	62,951
State [Member]	'	'
Cash income taxes paid, net of refunds:	'	'
Cash income taxes paid, net of refunds	$149	$190

Supplemental_Financial_Informa7

Supplemental Financial Information - Noncash Investing and Financing Activities (Parenthetical) (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Supplemental Cash Flow Information [Abstract]	'	'
Interest payments, net of amounts capitalized	$38.90	$8.90

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	9 Months Ended			1 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2014	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 2014	Mar. 31, 2014
				Restricted Stock Units (RSUs) [Member]	Restricted Stock Units (RSUs) [Member]	Restricted Stock Units (RSUs) [Member]	Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'
Number of shares of common stock available for issuance	'	'	1,500,000	'	'	'	7,500,000
Annual limit on number of shares granted per individual	'	'	200,000	'	'	'	500,000
Targeted performance restricted stock units awarded	'	'	'	52,581	'	'	'
Weighted-average price of common stock grant date per share	'	'	'	$47.52	'	'	'
Restricted stock units, vesting period	'	'	'	'3 years	'	'	'
Target value of RSUs granted	'	'	'	$3,000,000	'	'	'
Stock-based compensation expense	$2,559,000	$2,627,000	'	'	$200,000	$500,000	'

Earnings_Per_Share_Reconciliat

Earnings Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted Per-Share Computations (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income - basic and diluted numerator	$52,645	$94,748	$288,168	$456,071
Weighted average shares - basic (denominator):	137,146	139,035	137,582	139,034
Effect of dilutive potential shares stock options and stock appreciation rights	1	30	3	38
Weighted average shares including conversions - diluted (denominator)	137,147	139,065	137,585	139,072
Earnings per share:	'	'	'	'
Basic	$0.38	$0.68	$2.09	$3.28
Diluted	$0.38	$0.68	$2.09	$3.28

Earnings_Per_Share_Securities_

Earnings Per Share - Securities Excluded from Computation of Diluted Earning Per Share (Detail)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock options [Member]	'	'	'	'
Employee and director:	'	'	'	'
Securities excluded from computation of diluted earning per share	37	18	32	18
Stock appreciation rights [Member]	'	'	'	'
Employee and director:	'	'	'	'
Securities excluded from computation of diluted earning per share	1,526	982	1,472	885

Marketable_Securities_Investme

Marketable Securities - Investments in Marketable Securities as Available for Sale (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$600,139	$1,750,067
Unrealized Gain (Loss)	4	-14
Market Value	600,143	1,750,053
U.S. Treasury Bills and Notes (due within one year) [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	599,997	1,749,879
Unrealized Gain (Loss)	-2	-22
Market Value	599,995	1,749,857
Mortgage-backed securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	142	188
Unrealized Gain (Loss)	6	8
Market Value	$148	$196

Marketable_Securities_Summary_

Marketable Securities - Summary of Proceeds from Sales and Maturities of Marketable Securities and Gross Realized Gains and Losses (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'	'	'	'
Proceeds from maturities	$1,325,000	$1,475,000	$7,125,000	$3,225,000
Proceeds from sales	12	25	45	62
Gross realized gains	'	'	'	'
Gross realized losses	'	($1)	'	($1)

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Additional Information (Detail)

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

USD ($)

USD ($)

AUD

BRL

GBP (£)

MXN

NOK

Reclassification out of Accumulated Other Comprehensive Income [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]

FOREX contracts [Member]

Treasury Lock Agreements [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Counterparty

Derivative Instruments, Gain (Loss) [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Notional amount of foreign currency contracts settled

$233,900,000

$233,900,000

'

'

'

'

'

'

'

'

'

'

'

Derivative contracts outstanding in the aggregate notional amount

132,900,000

'

16,100,000

41,900,000

52,300,000

19,000,000

3,600,000

'

'

'

'

'

'

Number of counterparties to FOREX contracts

'

'

'

'

'

'

'

'

'

'

'

2

'

Net unrealized gains (losses) associated with derivative financial instruments to be reclassified to earnings

'

'

'

'

'

'

'

'

'

'

'

-3,400,000

8,052

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

'

'

'

'

'

'

'

$0

$0

$0

$0

'

'

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Amounts Recognized in Consolidated Statements of Operations Related to FOREX Contracts Designated as Accounting Hedges (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain Recognized in Income	'	'	$6,736	($2,246)
Contract drilling expense [Member] | Designated as hedging instrument [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain Recognized in Income	$1,729	($5,018)	$6,736	($2,246)

Derivative_Financial_Instrumen4

Derivative Financial Instruments - Fair Values of Forex Contracts Designated as Hedging Instruments (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Derivative assets designated as hedging instruments, current	$46	$1,562
Derivative liabilities designated as hedging instruments, current	-3,518	-1,143
Accrued Liabilities [Member] | FOREX contracts [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative liabilities designated as hedging instruments, current	-3,518	-1,143
Prepaid expenses and other current assets [Member] | FOREX contracts [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets designated as hedging instruments, current	$46	$1,562

Derivative_Financial_Instrumen5

Derivative Financial Instruments - Amounts Recognized in Consolidated Balance Sheets and Consolidated Statements of Operations Related to Derivative Financial Instruments Designated as Cash Flow Hedges (Detail) (Derivative designated as accounting hedges [Member], USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
FOREX contracts [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	($6,505)	$2,486	$2,297	($7,539)
Treasury Lock Agreements [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of gain (loss) recognized in AOCGL on derivative (effective portion)	'	'	'	'
Contract drilling expense [Member] | FOREX contracts [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of gain (loss) reclassified from AOCGL into income (effective portion)	2,333	-5,572	6,232	-2,951
Foreign currency transaction gain (loss) [Member] | FOREX contracts [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	-59	59	-60	-59
Interest Expense [Member] | Treasury Lock Agreements [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of gain (loss) reclassified from AOCGL into income (effective portion)	$2	'	$6	'

Financial_Instruments_and_Fair2

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

3 Months Ended

9 Months Ended

1 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Settlement Agreement [Member]

Settlement Agreement [Member]

Settlement Agreement [Member]

Accounts Receivable [Member]

Accounts Receivable [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 1 [Member]

Level 3 [Member]

Niko [Member]

Niko [Member]

Niko [Member]

Petroleo Brasileiro S.A. or Petrobras [Member]

Petroleo Brasileiro S.A. or Petrobras [Member]

Cash held in money market funds [Member]

Cash held in money market funds [Member]

Time deposits [Member]

Time deposits [Member]

U.S. Treasury securities [Member]

U.S. Treasury securities [Member]

Mid-Water [Member]

Credit Concentration Risk [Member]

Credit Concentration Risk [Member]

Rigs

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

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accounts receivable due from major customer

$517,389,000

'

$517,389,000

'

$469,355,000

'

'

'

$123,700,000

$154,500,000

'

'

'

'

'

'

'

Percentage of accounts receivable due from major customer

'

'

'

'

'

'

'

'

25.00%

35.00%

'

'

'

'

'

'

'

Cash received pursuant to Settlement Agreement

'

'

'

'

'

14,700,000

'

'

'

'

'

'

'

'

'

'

'

Revenue

737,682,000

706,165,000

2,139,350,000

2,193,924,000

'

'

14,700,000

'

'

'

'

'

'

'

'

'

'

Anticipated future payments pursuant to Settlement Agreement

'

'

'

'

'

'

'

40,300,000

'

'

'

'

'

'

'

'

'

Fair value of investments

'

'

'

'

'

'

'

'

'

'

422,600,000

281,300,000

20,100,000

30,000,000

600,000,000

1,749,900,000

'

Number of Rigs to be Scrapped

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6

Transfers between fair value levels

'

'

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

Impairment of assets

$109,462,000

$0

$109,462,000

$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		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Assets:	'	'	'	'	'
Impaired assets	$109,462	$0	$109,462	$0	'
FOREX contracts	46	'	46	'	1,562
Total assets	17,400	'	17,400	'	'
Liabilities:	'	'	'	'	'
FOREX contracts	-3,518	'	-3,518	'	-1,143
Fair Value Measurements, Recurring [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Short-term investments	1,042,736	'	1,042,736	'	2,061,154
FOREX contracts	46	'	46	'	1,562
Mortgage-backed securities	148	'	148	'	197
Total assets	1,042,930	'	1,042,930	'	2,062,913
Liabilities:	'	'	'	'	'
FOREX contracts	-3,518	'	-3,518	'	-1,143
Fair Value Measurements, Recurring [Member] | Level 1 [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Short-term investments	1,042,736	'	1,042,736	'	2,061,154
FOREX contracts	'	'	'	'	'
Mortgage-backed securities	'	'	'	'	'
Total assets	1,042,736	'	1,042,736	'	2,061,154
Liabilities:	'	'	'	'	'
FOREX contracts	'	'	'	'	'
Fair Value Measurements, Recurring [Member] | Level 2 [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Short-term investments	'	'	'	'	'
FOREX contracts	46	'	46	'	1,562
Mortgage-backed securities	148	'	148	'	197
Total assets	194	'	194	'	1,759
Liabilities:	'	'	'	'	'
FOREX contracts	-3,518	'	-3,518	'	-1,143
Fair Value Measurements, Recurring [Member] | Level 3 [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Short-term investments	'	'	'	'	'
FOREX contracts	'	'	'	'	'
Mortgage-backed securities	'	'	'	'	'
Total assets	'	'	'	'	'
Liabilities:	'	'	'	'	'
FOREX contracts	'	'	'	'	'
Nonrecurring Fair Value Measurements [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Impaired assets	109,462	'	109,462	'	'
Total assets	17,442	'	17,442	'	'
Nonrecurring Fair Value Measurements [Member] | Level 1 [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Total assets	'	'	'	'	'
Nonrecurring Fair Value Measurements [Member] | Level 2 [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Total assets	'	'	'	'	'
Nonrecurring Fair Value Measurements [Member] | Level 3 [Member]	'	'	'	'	'
Assets:	'	'	'	'	'
Total assets	$17,442	'	$17,442	'	'

Financial_Instruments_and_Fair4

Financial Instruments and Fair Value Disclosures - Fair Value and Related Carrying Values of Our Debt Instruments (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
5.15% Senior Notes due 2014 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	'	$250
Fair Value	'	257.4
4.875% Senior Notes due 2015 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	249.9	249.9
Fair Value	258.3	265.7
5.875% Senior Notes due 2019 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	499.6	499.6
Fair Value	567.5	578.1
3.45% Senior Notes due 2023 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	249.1	249
Fair Value	238.9	241.4
5.70% Senior Notes due 2039 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	497	496.9
Fair Value	522.3	543.1
4.875% Senior Notes due 2043 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Carrying Value	748.8	748.8
Fair Value	$695.20	$736.10

Financial_Instruments_and_Fair5

Financial Instruments and Fair Value Disclosures - Fair Value and Related Carrying Values of Our Debt Instruments (Parenthetical) (Detail)	Sep. 30, 2014	Dec. 31, 2013
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%	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%	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 $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	$10,132,381	$9,211,703
Less: accumulated depreciation	-4,060,446	-3,744,476
Drilling and other property and equipment, net	6,071,935	5,467,227
Drilling rigs and equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	8,681,571	7,412,066
Construction work-in-progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	1,314,517	1,668,211
Land and buildings [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	66,620	65,627
Office equipment and other [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	$69,673	$65,799

Drilling_and_Other_Property_an3

Drilling and Other Property and Equipment - Summary of Construction Work-in-Progress, Including Capitalized Interest (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	$1,314,517	$1,668,211
Ultra-deepwater drillships [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	733,805	868,908
Ocean GreatWhite [Member] | Ultra-deepwater semisubmersible [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	207,345	195,578
Ocean Onyx [Member] | Deepwater semisubmersibles [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	'	339,129
Ocean Apex [Member] | Deepwater semisubmersibles [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Rig(s) Under Construction	$373,367	$264,596

Drilling_and_Other_Property_an4

Drilling and Other Property and Equipment - Additional Information (Detail) (Assets Placed In Service [Member], USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Assets Placed In Service [Member]	'
Property, Plant and Equipment [Line Items]	'
Construction work-in-progress	$583.30

Credit_Agreement_and_Senior_No1

Credit Agreement and Senior Notes - Additional Information (Detail) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 22, 2014

5.15% Senior Notes due 2014 [Member]

4.875% Senior Notes due 2015 [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Credit Agreement [Member]

Additional Commitments [Member]

Additional Commitments [Member]

Letters of Credit [Member]

Swingline Loan Facility [Member]

Minimum [Member]

Maximum [Member]

Senior Unsecured [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Term of Credit agreement

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

Amount available for general purposes

'

'

'

'

'

'

$1,000,000,000

$1,500,000,000

$1,500,000,000

'

$40,000,000

$250,000,000

$100,000,000

Additional amount available for general purposes

'

'

'

'

'

500,000,000

'

'

'

'

'

'

'

Extension of the maturity date under credit agreement

'

'

'

'

'up to two additional one-year extensions of the maturity date

'

'

'

'

'

'

'

'

Maturity period of credit agreement

'

'

'

'

22-Oct-19

'

'

'

'

17-Mar-19

'

'

'

Amounts outstanding under the Credit Agreement

0

'

'

'

'

'

'

'

'

'

'

'

'

Maturity date

'

'

1-Sep-14

1-Jul-15

'

'

'

'

'

'

'

'

'

Aggregate principal amount of senior notes

'

'

250,000,000

250,000,000

'

'

'

'

'

'

'

'

'

Current portion of long-term debt

$249,946,000

$249,954,000

'

$249,900,000

'

'

'

'

'

'

'

'

'

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Contingencies And Commitments [Line Items]	'	'
Net profits interest percent	27.00%	'
Deductible for marine liability coverage including personal injury claims, per first occurrence	$25	'
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	'
Other purchase obligations	0	0
Total Contingent Liabilities Under Letters of Credit and Bonds [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Contingent liability under letters of credit and other bonds	99.7	'
Potentially Collateralized Contingent Liability Under Letters of Credit and Bonds [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Contingent liability under letters of credit and other bonds	92	'
Hyundai Heavy Industries, Co., Ltd. [Member] | Ultra-Deepwater Floater Construction [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Water depth of rig	10,000	'
Cost of enhancement of project	755	'
Total number of installments due under each turnkey construction agreements	2	'
Cost of construction per shipyard agreement	628.5	'
Construction installments paid	188.6	'
Final installment for Ultra-Deep water Floater Construction	439.9	'
Hyundai Heavy Industries, Co., Ltd. [Member] | Ultra-deepwater drillships [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Cost of enhancement of project	1,900	'
Total number of installments due under each turnkey construction agreements	2	'
Construction installments paid	493.2	'
Number of ultra-deepwater drillships under construction	3	'
Hyundai Heavy Industries, Co., Ltd. [Member] | Ultra-deepwater drillships [Member] | Fourth Quarter 2014 [Member] | Ocean BlackHornet [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Construction agreement balance amount payable	390	'
Hyundai Heavy Industries, Co., Ltd. [Member] | Ultra-deepwater drillships [Member] | Fourth Quarter 2014 [Member] | Ocean BlackRhino [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Construction agreement balance amount payable	390	'
Hyundai Heavy Industries, Co., Ltd. [Member] | Ultra-deepwater drillships [Member] | First Quarter 2015 [Member] | Ocean BlackLion [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Construction agreement balance amount payable	390	'
Jurong Shipyard Pte Ltd [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Cost of enhancement of project	370	'
Construction installments paid	87.8	'
Construction agreement balance amount payable	47.3	'
Number of installments due under each rig construction agreement	12	'
Number of installments paid	8	'
Additional orders executed	10.2	'
Additional orders executed, balance amount payable	8.3	'
Brazil Tax Jurisdiction [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Unable to estimate the amount of loss or range of loss	'We are unable to estimate the amount of loss or range of loss, if any, at this time, should Petrobras ultimately be assessed such taxes and it be determined that Petrobras is entitled to obtain reimbursement from us. If we were required to pay such reimbursement, however, the amount of such reimbursement could be substantial and could have a material adverse effect on our financial condition, results of operations and cash flows.	'
Personal Injury Claims [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Personal injury claims recorded	38.1	35.5
Personal Injury Claims [Member] | Accrued Liabilities [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Personal injury claims recorded	8.6	9.5
Personal Injury Claims [Member] | Other Liabilities [Member]	'	'
Contingencies And Commitments [Line Items]	'	'
Personal injury claims recorded	$29.50	$26

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Gain (Loss) - Components of Accumulated Other Comprehensive Gain (Loss) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning balance	$350
Change in other comprehensive gain (loss) before reclassifications, after tax of $(805) and $(16)	1,528
Reclassification adjustments for items included in Net Income, after tax of $2,183 and $7	-4,082
Ending balance	-2,204
Derivative Financial Instruments [Member]	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning balance	357
Change in other comprehensive gain (loss) before reclassifications, after tax of $(805) and $(16)	1,492
Reclassification adjustments for items included in Net Income, after tax of $2,183 and $7	-4,055
Ending balance	-2,206
Marketable Securities [Member]	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning balance	-7
Change in other comprehensive gain (loss) before reclassifications, after tax of $(805) and $(16)	36
Reclassification adjustments for items included in Net Income, after tax of $2,183 and $7	-27
Ending balance	$2

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Gain (Loss) - Components of Accumulated Other Comprehensive Gain (Loss) (Parenthetical) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Equity [Abstract]	'
Change in other comprehensive gain (loss), tax (expense) benefit	($805)
Change in other comprehensive gain (loss), tax (expense) benefit	-16
Reclassification adjustments for items included in Net Income, tax (expense) benefit	2,183
Reclassification adjustments for items included in Net Income, tax (expense) benefit	$7

Accumulated_Other_Comprehensiv4

Accumulated Other Comprehensive Gain (Loss) - Items in Consolidated Statements of Operations Affected by Reclassification Adjustments (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Other, net	($90)	($326)	($598)	($746)
Contract drilling, excluding depreciation	399,802	419,488	1,164,968	1,163,618
Interest expense	9,378	1,693	46,056	17,713
Income tax expense	28,994	36,817	73,753	137,974
Net of tax	-52,645	-94,748	-288,168	-456,071
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Financial Instruments [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Income tax expense	817	-1,950	2,183	-1,033
Net of tax	-1,518	3,622	-4,055	1,918
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Financial Instruments [Member] | FOREX contracts [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Contract drilling, excluding depreciation	-2,333	5,572	-6,232	2,951
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Financial Instruments [Member] | Treasury Lock Agreements [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Interest expense	-2	'	-6	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Marketable Securities [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Other, net	-1	-15	-34	-165
Income tax expense	'	1	7	19
Net of tax	($1)	($14)	($27)	($146)

Segments_and_Geographic_Area_A2

Segments and Geographic Area Analysis - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2014
	Segment
	Country
Segment Reporting [Abstract]	'
Number of reportable segments	1
Number of countries with rigs	9

Segments_and_Geographic_Area_A3

Segments and Geographic Area Analysis - Revenues from Contract Drilling Services by Equipment Type (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Contract drilling	$727,888	$690,741	$2,062,750	$2,135,612
Revenues related to reimbursable expenses	9,794	15,424	76,600	58,312
Total revenues	737,682	706,165	2,139,350	2,193,924
Ultra-deepwater semisubmersible [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract drilling	313,124	195,215	701,574	617,673
Deepwater [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract drilling	111,372	147,333	378,470	495,858
Mid-Water [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract drilling	258,028	297,368	844,909	891,449
Total Floaters [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract drilling	682,524	639,916	1,924,953	2,004,980
Jack-ups [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract drilling	$45,364	$50,825	$137,797	$130,632

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		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total revenues	$737,682	$706,165	$2,139,350	$2,193,924
United States [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total revenues	83,300	69,627	326,808	253,654
South America [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total revenues	294,246	311,708	844,242	896,029
Europe/Africa/Mediterranean [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total revenues	135,286	185,335	395,602	559,290
Australia/Asia [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total revenues	162,929	88,054	393,248	333,728
Mexico [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total revenues	$61,921	$51,441	$179,450	$151,223

Income_Taxes_Additional_Inform

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

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

6 Months Ended

1 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Mar. 31, 2014

Jun. 30, 2014

Dec. 31, 2013

United Kingdom Tax Jurisdiction [Member]

2004 & 2005 Tax Years [Member]

2008 Tax Year [Member]

2003 through 2008 Tax Years [Member]

2006 through 2008 Tax Year [Member]

2006 through 2008 Tax Year [Member]

2006 through 2008 Tax Year [Member]

2006 through 2010 Tax Year [Member]

Brazil Tax Jurisdiction [Member]

Mexico [Member]

Malaysia Tax Jurisdiction [Member]

Egypt [Member]

Egypt [Member]

Egypt [Member]

Egypt [Member]

Appeals

Income Tax Contingency [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Proposed increase to taxable income

'

'

'

'

'

'

'

'

$1,200,000,000

'

'

'

Accrued liabilities related to income tax examination

'

'

'

'

'

14,000,000

'

'

'

'

50,000,000

56,900,000

Current income tax expense due to settlement

'

'

'

'

'

'

'

'

'

6,000,000

'

'

Reversal of uncertain tax positions due to settlement

'

'

'

'

'

'

'

'

'

23,200,000

'

'

Income tax (expense) benefit

-28,994,000

-36,817,000

-73,753,000

-137,974,000

'

'

'

'

'

17,200,000

'

'

Number of open tax issues

'

'

'

'

'

'

'

'

'

'

1

'

Total tax assessment including interest and penalty

'

'

'

'

'

26,000,000

'

14,200,000

'

'

'

'

Reversal of accrued interest on uncertain tax position

'

'

'

'

'

3,500,000

2,700,000

'

'

'

'

'

Reversal of accrued penalty on uncertain tax position

'

'

'

'

'

4,400,000

1,100,000

5,300,000

'

'

'

'

Reduction in uncertain tax positions related to statute of limitations expirations

'

'

'

'

'

'

8,000,000

'

'

'

'

'

Tax expense increase (decrease)

'

'

'

'

$26,000,000

'

'

'

'

'

'

'