Diamond Offshore Drilling (DODRW) 10-Q 2 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 26, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	DO
Entity Registrant Name	DIAMOND OFFSHORE DRILLING INC
Entity Central Index Key	949,039
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		137,158,706

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 141,131	$ 233,623
Marketable securities	13,621	16,033
Accounts receivable, net of allowance for bad debts	515,754	463,862
Prepaid expenses and other current assets	163,871	185,541
Assets held for sale	6,700
Total current assets	841,077	899,059
Drilling and other property and equipment, net of accumulated depreciation	6,888,248	6,945,953
Other assets	121,171	176,277
Total assets	7,850,496	8,021,289
Current liabilities:
Accounts payable	78,571	138,444
Accrued liabilities	285,304	426,592
Taxes payable	33,546	41,648
Short-term borrowings	492,996
Current portion of long-term debt		249,962
Total current liabilities	890,417	856,646
Long-term debt	1,994,710	1,994,526
Deferred tax liability	417,621	530,394
Other liabilities	171,595	188,160
Total liabilities	$ 3,474,343	$ 3,569,726
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock (par value $0.01, 25,000,000 shares authorized, none issued and outstanding)
Common stock (par value $0.01, 500,000,000 shares authorized; 143,978,877 shares issued and 137,158,706 shares outstanding at September 30, 2015; 143,960,260 shares issued and 137,147,899 shares outstanding at December 31, 2014)	$ 1,440	$ 1,440
Additional paid-in capital	1,998,281	1,993,898
Retained earnings	2,581,664	2,661,999
Accumulated other comprehensive gain (loss)	(2,827)	(3,605)
Treasury stock, at cost (6,820,171 and 6,812,361 shares of common stock at September 30, 2015 and December 31, 2014, respectively)	(202,405)	(202,169)
Total stockholders' equity	4,376,153	4,451,563
Total liabilities and stockholders' equity	$ 7,850,496	$ 8,021,289

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
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	143,978,877	143,960,260
Common stock, shares outstanding	137,158,706	137,147,899
Treasury stock, shares	6,820,171	6,812,361

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues:
Contract drilling	$ 599,036	$ 727,888	$ 1,816,055	$ 2,062,750
Revenues related to reimbursable expenses	10,706	9,794	47,775	76,600
Total revenues	609,742	737,682	1,863,830	2,139,350
Operating expenses:
Contract drilling, excluding depreciation	277,944	399,802	971,471	1,164,968
Reimbursable expenses	10,476	9,437	46,904	75,393
Depreciation	118,086	108,854	378,714	324,771
General and administrative	16,888	18,604	50,888	61,909
Impairment of assets	2,546	109,462	361,074	109,462
Restructuring and separation costs	1,574		8,735
Loss (gain) on disposition of assets	794	1,107	19	(7,612)
Total operating expenses	428,308	647,266	1,817,805	1,728,891
Operating income	181,434	90,416	46,025	410,459
Other income (expense):
Interest income	629	86	1,796	644
Interest expense, net of amounts capitalized	(21,350)	(9,378)	(70,800)	(46,056)
Foreign currency transaction gain (loss)	(1,163)	425	954	(3,724)
Other, net	217	90	702	598
Income (loss) before income tax (expense) benefit	159,767	81,639	(21,323)	361,921
Income tax expense	(23,345)	(28,994)	(7,578)	(73,753)
Net income (loss)	$ 136,422	$ 52,645	$ (28,901)	$ 288,168
Earnings (loss) per share, Basic and Diluted	$ 0.99	$ 0.38	$ (0.21)	$ 2.09
Weighted-average shares outstanding:
Shares of common stock	137,159	137,146	137,156	137,582
Dilutive potential shares of common stock	44	1		3
Total weighted-average shares outstanding	137,203	137,147	137,156	137,585
Cash dividends declared per share of common stock	$ 0.125	$ 0.875	$ 0.375	$ 2.625

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 136,422	$ 52,645	$ (28,901)	$ 288,168
Derivative financial instruments:
Unrealized holding (loss) gain	(40)	(4,229)	(1,574)	1,492
Reclassification adjustment for loss (gain) included in net income	268	(1,518)	5,085	(4,055)
Investments in marketable securities:
Unrealized holding (loss) gain	(2,440)	(3)	(2,733)	36
Reclassification adjustment for gain included in net income		(1)		(27)
Total other comprehensive (loss) gain	(2,212)	(5,751)	778	(2,554)
Comprehensive income (loss)	$ 134,210	$ 46,894	$ (28,123)	$ 285,614

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net (loss) income	$ (28,901)	$ 288,168
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	378,714	324,771
Loss on impairment of assets	361,074	109,462
Loss (gain) on disposition of assets	19	(7,612)
Loss (gain) on foreign currency forward exchange contracts	8,364	(6,736)
Deferred tax provision	(114,662)	(10,290)
Stock-based compensation expense	3,503	2,559
Deferred income, net	(24,735)	49,013
Deferred expenses, net	(42,261)	(79,907)
Long-term employee remuneration programs	(1,265)	(4,799)
Other assets, noncurrent	774	197
Other liabilities, noncurrent	(3,844)	672
(Payments for) proceeds from settlement of foreign currency forward exchange contracts designated as accounting hedges	(8,364)	6,736
Bank deposits denominated in nonconvertible currencies	992	6,009
Other	1,271	1,379
Changes in operating assets and liabilities:
Accounts receivable	(33,360)	(48,258)
Prepaid expenses and other current assets	10,979	(10,686)
Accounts payable and accrued liabilities	(112,206)	40,326
Taxes payable	70,585	21,832
Net cash provided by operating activities	466,677	682,836
Investing activities:
Capital expenditures (including rig construction)	(758,342)	(1,024,325)
Proceeds from disposition of assets, net of disposal costs	8,442	16,756
Proceeds from sale and maturities of marketable securities	34	7,125,045
Purchases of marketable securities		(5,974,861)
Net cash provided by (used in) investing activities	(749,866)	142,615
Financing activities:
Repayment of long-term debt	(250,000)	(250,000)
Payment of dividends	(52,287)	(365,290)
Net proceeds from short-term borrowings	492,996
Purchase of treasury stock		(87,756)
Other	(12)	(593)
Net cash provided by (used in) financing activities	190,697	(703,639)
Net change in cash and cash equivalents	(92,492)	121,812
Cash and cash equivalents, beginning of period	233,623	347,011
Cash and cash equivalents, end of period	$ 141,131	$ 468,823

General Information

General Information	9 Months Ended
	Sep. 30, 2015
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, 2014 (File No. 1-13926). As of October 26, 2015, Loews Corporation owned 53.3 % 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. 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. 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, 2015 and 2014. 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, 2015 and the year ended December 31, 2014, we capitalized $217.8 million and $546.0 million, respectively, in replacements and betterments of our drilling fleet, resulting from numerous projects ranging from $25,000 to $215 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 “Loss (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, but not limited to, 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 if active, warm stacked or cold stacked (expressed as the actual percentage of time per year that the rig would be used at certain dayrates); • 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 each rig. Based on these assumptions, we develop a matrix for each rig under evaluation using multiple utilization/dayrate scenarios, to each of which we have assigned a probability of occurrence. We arrive at a projected probability- weighted cash flow for each rig based on the respective matrix and compare such amount to the carrying value of the asset to assess recoverability. The underlying assumptions and assigned probabilities of occurrence for utilization and dayrate scenarios are developed using a methodology that examines historical data for each rig, which considers the rig’s age, rated water depth and other attributes and then assesses its future marketability in light of the current and projected market environment at the time of assessment. Other assumptions, such as operating, maintenance and inspection costs, are estimated using historical data adjusted for known developments and future events that are anticipated by management at the time of the assessment. Management’s assumptions are necessarily subjective and are an inherent part of our asset impairment evaluation , 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, net of amounts capitalized” as reported in our Consolidated Statements of Operations is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) Total interest cost, including amortization of debt issuance costs $ 23,830 $ 25,707 $ 84,254 $ 93,600 Capitalized interest (2,480 ) (16,329 ) (13,454 ) (47,544 ) Total interest expense as reported $ 21,350 $ 9,378 $ 70,800 $ 46,056 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, 2015, we recognized net foreign currency transaction gains (losses) of $(1.2) million and $1.0 million, respectively. 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. 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 July 2015, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606)

Asset Impairments

Asset Impairments	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Asset Impairments	2. Asset Impairments During the first quarter of 2015, in response to pending regulatory requirements in the U.S. Gulf of Mexico, as well as the continued deterioration of the market fundamentals in the oil and gas industry, including the dramatic decline in oil prices, significant cutbacks in customer capital spending plans and contract cancelations by customers, we evaluated all drilling rigs in our fleet with indications that their carrying amounts may not be recoverable (e.g., cold stacked or expected to be cold stacked in the near term; see Note 1). Using the undiscounted projected probability-weighted cash flow analysis described in Note 1, we determined that the carrying values of seven of our mid-water semisubmersibles, as well as our older, 7,875-foot water depth rated drillship were impaired at March 31, 2015. We determined the fair value of five of the rigs in the impairment group using a market approach, which utilized the most recent contracted sales price for another of our previously impaired mid-water semisubmersible rigs. We determined the fair value of the three remaining rigs (which were under contract with a customer at that time) using an income approach, which utilized significant unobservable inputs, including assumptions related to estimated dayrate revenue, rig utilization and anticipated costs for the remainder of the current contract, as well as estimated proceeds that may be received on disposition of each rig. We consider each of these methodologies to be Level 3 fair value measurements due to the significant level of estimation involved and the lack of transparency as to the inputs used. During the third quarter of 2015, we evaluated 13 drilling rigs with indications that their carrying amounts may not be recoverable and that were not previously impaired, including four additional rigs that did not have prior indicators of impairment as noted above, and determined that further impairment of our fleet had not occurred. However, after receipt of offers in October 2015 to sell three drilling rigs, consisting of one semisubmersible rig and our 7,875-foot water depth rated drillship, both of which were previously impaired, and one cold-stacked jack-up rig, we recorded an aggregate impairment loss of $2.6 million during the third quarter of 2015 to write down the carrying value of each of these rigs to their expected selling price, which we also consider to be Level 3 fair value measurements. The sale of these rigs is currently being negotiated. As a result of our valuations, we recognized impairment losses aggregating $361.1 million for the first nine months of 2015. Of the rigs impaired during 2015, four semisubmersible rigs have been sold for scrap and another three rigs are currently cold stacked. The two remaining rigs in the impairment group are under contract with customers and are expected to be sold for scrap at the end of their respective contracts. The aggregate fair value of the rigs in the impairment group was $8.7 million at September 30, 2015, of which $6.7 million is reported as “Asset held for sale” and $2.0 million is reported in “Drilling and other property and equipment, net of accumulated depreciation” in our Consolidated Balance Sheets. See Notes 8 and 9. During the three-month and nine-month periods ended September 30, 2014, we recognized an impairment loss of $109.5 million related to six mid-water semisubmersible rigs, for which we had initiated a plan to retire and scrap. All of these rigs were subsequently sold for scrap. Management’s assumptions are necessarily subjective and are an inherent part of our asset impairment evaluation. The use of different assumptions could produce results that differ from those reported. The actual amount realized upon disposition of our drilling rigs may vary if, or when, such rigs are sold.

Supplemental Financial Informat

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2015
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, consist of the following: September 30, December 31, 2015 2014 (In thousands) Trade receivables $ 479,408 $ 437,017 Income tax receivable 18,408 — Value added tax receivables 17,604 24,853 Amounts held in escrow 4,871 6,450 Related party receivables 107 339 Other 1,080 927 521,478 469,586 Allowance for bad debts (5,724 ) (5,724 ) Total $ 515,754 $ 463,862 Prepaid expenses and other current assets consist of the following: September 30, December 31, 2015 2014 (In thousands) Rig spare parts and supplies $ 49,003 $ 56,315 Deferred mobilization costs 71,242 53,206 Prepaid insurance 6,701 12,163 Deferred tax assets 15,612 15,612 Prepaid taxes 16,928 44,085 Other 4,385 4,160 Total $ 163,871 $ 185,541 Accrued liabilities consist of the following: September 30, December 31, 2015 2014 (In thousands) Rig operating expenses $ 74,506 $ 85,897 Payroll and benefits 63,950 131,664 Deferred revenue 47,135 63,209 Accrued capital project/upgrade costs 42,325 103,123 Interest payable 44,130 18,365 Personal injury and other claims 8,565 8,570 FOREX contracts — 5,439 Other 4,693 10,325 Total $ 285,304 $ 426,592 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, 2015 2014 (In thousands) Accrued but unpaid capital expenditures at period end $ 42,325 $ 102,340 Common stock withheld for payroll tax obligations (1) 236 — Cash interest payments (2) 57,625 76,092 Cash income taxes paid, net of (refunds): U.S. federal (3,344 ) — Foreign 53,292 59,299 State 150 149 (1) Represents the cost of 7,810 shares of common stock withheld to satisfy the payroll tax obligation incurred as a result of the vesting of restricted stock units in the first quarter of 2015. This cost is presented as a deduction from stockholders’ equity in “Treasury stock” in our Consolidated Balance Sheets at September 30, 2015. (2) Interest payments, net of amounts capitalized, were $48.7 million and $38.9 million for the nine months ended September 30, 2015 and 2014, respectively.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	4. Stock-Based Compensation In April 2015, we granted an aggregate of 311,145 restricted stock units, or RSUs, to employees under our Equity Incentive Compensation Plan, or Equity Plan, collectively referred to as the 2015 RSUs. RSUs are contractual rights to receive shares of our common stock in the future if the applicable vesting conditions are met. Our 2015 RSUs included both performance-vesting and time-vesting RSUs. Under the terms of the 2015 awards, the performance-vesting 2015 RSUs vest upon achievement of certain performance goals as set forth in the individual award agreements over the performance period from January 1, 2015 to December 31, 2017, and the shares of our common stock to be received upon the vesting of the performance-vesting RSUs will be delivered no later than March 15, 2018. 50% of the time-vesting 2015 RSUs will vest on April 1, 2017 and 50% will vest on April 1, 2018, conditioned upon continued employment through the applicable vesting date. 2015 RSUs awarded under the Equity Plan are summarized as follows: Award Type Number of RSUs Weighted Average Fair Performance-vesting (dividend entitled) 110,791 $ 26.69 Performance-vesting 56,162 $ 25.21 Time-vesting 144,192 $ 25.21 We recognized compensation expense of $0.8 million and $1.7 million for the three-month and nine-month periods ended September 30, 2015, respectively, in connection with RSUs awarded under our Equity Plan. In connection with RSUs awarded in 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. During the nine months ended September 30, 2015, we issued an aggregate of 107,750 stock appreciation rights to our board of directors and certain employees under the Equity Plan.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2015
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 September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands, except per share data) Net income (loss) — basic and diluted numerator $ 136,422 $ 52,645 $ (28,901 ) $ 288,168 Weighted average shares — basic (denominator): 137,159 137,146 137,156 137,582 Dilutive effect of stock-based awards 44 1 — 3 Weighted average shares including conversions — diluted (denominator) 137,203 137,147 137,156 137,585 Earnings (loss) per share: Basic $ 0.99 $ 0.38 $ (0.21 ) $ 2.09 Diluted $ 0.99 $ 0.38 $ (0.21 ) $ 2.09 The following table sets forth the share effects of stock-based awards 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 September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) Employee and director: Stock options 23 37 29 32 Stock appreciation rights 1,521 1,526 1,561 1,472 Restricted stock units 176 — 252 —

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2015
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, 2015 Amortized Unrealized Market (In thousands) Corporate bonds $ 16,359 $ (2,836 ) $ 13,523 Mortgage-backed securities 94 4 98 Total $ 16,453 $ (2,832 ) $ 13,621 December 31, 2014 Amortized Unrealized Market (In thousands) Corporate bonds $ 16,003 $ (104 ) $ 15,899 Mortgage-backed securities 130 4 134 Total $ 16,133 $ (100 ) $ 16,033 Proceeds from maturities and sales of marketable securities are summarized as follows: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 (In thousands) Proceeds from maturities $ — $ 1,325,000 $ — $ 7,125,000 Proceeds from sales 11 12 34 45 Gross realized gains and losses from the sale of marketable securities for the three-month and nine-month periods ended September 30, 2015 and 2014 were not significant.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2015
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. From time to time, 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. Historically we have entered into FOREX contracts for future delivery of Australian dollars, Brazilian reais, British pounds sterling, Mexican pesos and Norwegian kroner. These forward contracts are derivatives as defined by GAAP. During the nine months ended September 30, 2015 and 2014, we settled FOREX contracts with aggregate notional values of approximately $91.6 million and $233.9 million, respectively, of which the entire aggregate amounts were designated as a cash flow accounting hedge. There were no FOREX contracts outstanding at September 30, 2015. 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, 2015 and 2014. Three Months Ended September 30, Nine Months Ended September 30, Location of (Loss) Gain Recognized in Income 2015 2014 2015 2014 (In thousands) Contract drilling expense $ (440 ) $ 1,729 $ (8,364 ) $ 6,736 The following table presents the fair values of our derivative FOREX contracts designated as hedging instruments at September 30, 2015 and December 31, 2014. Balance Sheet Location Fair Value Balance Sheet Location Fair Value September 30, 2015 December 31, September 30, 2015 December 31, (In thousands) (In thousands) Prepaid expenses and other current assets $ — $ — Accrued liabilities $ — $ (5,439 ) 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, 2015 and 2014. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) FOREX contracts: Amount of (loss) gain recognized in AOCGL on derivative (effective portion) $ (61 ) $ (6,505 ) $ (2,420 ) $ 2,297 Location of (loss) gain reclassified from AOCGL into income (effective portion) Contract Contract Contract Contract Amount of (loss) gain reclassified from AOCGL into income (effective portion) $ (415 ) $ 2,333 $ (7,829 ) $ 6,232 Location of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing) Foreign Foreign Foreign Foreign Amount of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing) $ — $ (59 ) $ (1 ) $ (60 ) 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 Interest Interest Amount of gain reclassified from AOCGL into income (effective portion) $ 2 $ 2 $ 6 $ 6 As of September 30, 2015, the estimated amount of net unrealized gains associated with our treasury lock agreements that will be reclassified to interest expense during the next twelve months was $8,052. During the nine-month periods ended September 30, 2015 and 2014, 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, 2015
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 securitized corporate bonds whereby our credit risk is mitigated by the collateral. 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, 2015 and December 31, 2014, Petróleo Brasileiro S.A. (a Brazilian multinational energy company that is majority-owned by the Brazilian government), or Petrobras, accounted for $74.1 million and $123.3 million, or 16% and 29%, 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. 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, 2015 consisted of cash held in money market funds of $110.3 million and time deposits of $20.3 million. Our Level 1 assets at December 31, 2014 consisted of cash held in money market funds of $197.5 million and time deposits of $20.3 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, corporate bonds purchased in a private placement offering and over-the-counter FOREX contracts. Our residential mortgage-backed securities and corporate bonds 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, 2015 consisted of nonrecurring measurements of certain of our drilling rigs for which we recorded an impairment loss during the first nine months of 2015. 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 three-month and nine-month periods ended September 30, 2015 and 2014. 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 during the three-month and nine-month periods ended September 30, 2015 of $2.6 million and $361.1 million, respectively. 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, 2015 Fair Value Measurements Using Total Losses for Period Ended Level 1 Level 2 Level 3 Assets at Three Nine (In thousands) Recurring fair value measurements: Assets: Short-term investments $ 130,625 $ — $ — $ 130,625 Corporate bonds — 13,523 — 13,523 Mortgage-backed securities — 98 — 98 Total assets $ 130,625 $ 13,621 $ — $ 144,246 Nonrecurring fair value measurements: Assets: Impaired assets (1)(2) $ — $ — $ 8,650 $ 8,650 $ 2,546 $ 361,074 (1) Represents the carrying value as of September 30, 2015 of three mid-water semisubmersible rigs, one jack-up rig and one drillship, which were written down to their estimated recoverable amounts in 2015. See Note 2. (2) Excludes the fair values of the Ocean Saratoga, Ocean Yorktown Ocean Worker Ocean Lexington December 31, 2014 Fair Value Measurements Using Level 1 Level 2 Level 3 Assets at (In thousands) Recurring fair value measurements: Assets: Short-term investments $ 217,789 $ — $ — $ 217,789 Corporate bonds — 15,899 — 15,899 Mortgage-backed securities — 134 — 134 Total assets $ 217,789 $ 16,033 $ — $ 233,822 Liabilities: FOREX contracts $ — $ (5,439 ) $ — $ (5,439 ) Nonrecurring fair value measurements: Assets: Impaired assets (1) $ — $ — $ 9,421 $ 9,421 (1) Represents the book value as of December 31, 2014 of four of our mid-water semisubmersible rigs, which were written down to their estimated recoverable amounts in 2014. All four rigs were sold for scrap during the nine months ended September 30, 2015. 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 • Accounts receivable and accounts payable • Commercial paper 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, 2015 and December 31, 2014. 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, 2015 December 31, 2014 Fair Value Carrying Value Fair Value Carrying Value (In millions) 4.875% Senior Notes due 2015 $ — $ — $ 255.0 $ 250.0 5.875% Senior Notes due 2019 520.0 499.7 544.9 499.6 3.45% Senior Notes due 2023 230.0 249.1 232.0 249.1 5.70% Senior Notes due 2039 383.0 497.0 478.5 497.0 4.875% Senior Notes due 2043 490.5 748.9 638.9 748.8 We have estimated the fair value amounts by using appropriate valuation methodologies and information available to management. Considerable judgment is required in developing these estimates, and accordingly, no assurance can be given that the estimated values are indicative of the amounts that would be realized in a free market exchange.

Drilling and Other Property and

Drilling and Other Property and Equipment	9 Months Ended
	Sep. 30, 2015
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, (In thousands) Drilling rigs and equipment $ 10,113,847 $ 10,555,314 Construction work-in-progress 250,930 439,206 Land and buildings 65,785 66,989 Office equipment and other 71,255 70,591 Cost 10,501,817 11,132,100 Less: accumulated depreciation (3,613,569 ) (4,186,147 ) Drilling and other property and equipment, net $ 6,888,248 $ 6,945,953 During the nine months ended September 30, 2015, we sold eight rigs with an aggregate net book value of $4.4 million for scrap and recognized an aggregate gain on disposition of $0.2 million and $1.0 million for the three-month and nine-month periods ended September 30, 2015, respectively. In addition, during the nine-month period ended September 30, 2015, we recognized an impairment loss of $361.1 million. See Note 2. Construction work-in-progress, including capitalized interest, at September 30, 2015 and December 31, 2014 is summarized as follows: September 30, December 31, (In thousands) Ultra-deepwater semisubmersible — Ocean GreatWhite $ 250,930 $ 213,801 Ultra-deepwater drillship — Ocean BlackLion — 225,405 Total construction work-in-progress $ 250,930 $ 439,206 The Ocean BlackLion

Revolving Credit Facility, Comm

Revolving Credit Facility, Commercial Paper and Senior Notes	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Revolving Credit Facility, Commercial Paper and Senior Notes	10. Revolving Credit Facility, Commercial Paper and Senior Notes Revolving Credit Facility. Commercial Paper As of September 30, 2015, we had $493.0 million in commercial paper notes outstanding with a weighted average interest rate of 0.44% and a weighted average remaining term of two days. As of October 29, 2015, we had an additional $1.1 billion available under our Revolving Credit Facility to provide liquidity for our payment obligations with respect to the issuance of commercial paper. 4.875% Senior Notes due 2015

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
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 Other Litigation. NPI Arrangement. Personal Injury Claims 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, 2015 our estimated liability for personal injury claims was $43.4 million, of which $8.2 million and $35.2 million were recorded in “Accrued liabilities” and “Other liabilities,” respectively, in our Consolidated Balance Sheets. At December 31, 2014, our estimated liability for personal injury claims was $39.4 million, of which $8.2 million and $31.2 million were recorded in “Accrued liabilities” and “Other liabilities,” respectively, in our Consolidated Balance Sheets. The eventual settlement or adjudication of these claims could differ materially from our estimated amounts due to uncertainties such as: • the severity of personal injuries claimed; • significant changes in the volume of personal injury claims; • the unpredictability of legal jurisdictions where the claims will ultimately be litigated; • inconsistent court decisions; and • the risks and lack of predictability inherent in personal injury litigation. Purchase Obligations Ocean GreatWhite to Hyundai Heavy Industries Co., Ltd. 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 second quarter of 2016. At September 30, 2015, 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.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Gain (Loss)	9 Months Ended
	Sep. 30, 2015
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 (Loss) Gain on Derivative Marketable Total AOCGL (In thousands) Balance at January 1, 2015 $ (3,504 ) $ (101 ) $ (3,605 ) Change in other comprehensive (loss) gain before reclassifications, after tax of $846 and $(1) (1,574 ) (2,733 ) (4,307 ) Reclassification adjustments for items included in Net Income, after tax of $(2,738) and $0 5,085 — 5,085 Balance at September 30, 2015 $ 7 $ (2,834 ) $ (2,827 ) The following table presents the line items in our Consolidated Statements of Operations affected by reclassification adjustments out of AOCGL. Three Months Ended September 30, Nine Months Ended September 30, Consolidated Statements of Major Category of AOCGL 2015 2014 2015 2014 (In thousands) Derivative Financial Instruments: Unrealized loss (gain) on FOREX contracts $ 415 $ (2,333 ) $ 7,829 $ (6,232 ) Contract drilling, excluding depreciation Unrealized (gain) loss on treasury lock agreements (2 ) (2 ) (6 ) (6 ) Interest expense (145 ) 817 (2,738 ) 2,183 Income tax expense $ 268 $ (1,518 ) $ 5,085 $ (4,055 ) Net of tax Marketable Securities: Unrealized (gain) loss on marketable securities $ — $ (1 ) $ — $ (34 ) Other, net — — — 7 Income tax expense $ — $ (1 ) $ — $ (27 ) Net of tax

Restructuring and Separation Co

Restructuring and Separation Costs	9 Months Ended
	Sep. 30, 2015
Restructuring and Related Activities [Abstract]
Restructuring and Separation Costs	13. Restructuring and Separation Costs In response to the continuing decline in the offshore drilling market, we reviewed our cost and organization structure, and, as a result, our management approved and initiated a reduction in workforce at our onshore bases and corporate facilities, also referred to as the Corporate Reduction Plan, during the first nine months of 2015. As of September 30, 2015, appropriate communications have been made to substantially all impacted personnel, and we paid $1.6 million and $8.7 million in restructuring and employee separation related costs during the three-month and nine-month periods ended September 30, 2015, respectively. There were no accrued costs associated with the Corporate Reduction Plan as of September 30, 2015.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
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. U.S. Tax Jurisdiction. During 2015, the Internal Revenue Service began an audit of our corporate income tax return for the 2013 tax year. Australia Tax Jurisdiction. During 2015, the Australian Taxation Office began an audit of our income tax returns for the 2010 through 2013 tax years. Mexico Tax Jurisdiction. Due to the 2015 expiration of the statute of limitations in Mexico for the 2009 tax year for one of our subsidiaries operating in Mexico, we reversed our $10.7 million accrual for an uncertain tax position, of which $3.6 million is interest and $1.4 million is penalty. During 2015, one of our subsidiaries operating in Mexico received a tax assessment of $5.3 million from the Mexican tax authorities for the 2008 tax year, which we are appealing.

Segments and Geographic Area An

Segments and Geographic Area Analysis	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segments and Geographic Area Analysis	15. Segments and Geographic Area Analysis Although we provide contract drilling services with different types of offshore drilling rigs and also provide such services in many geographic locations, we have aggregated these operations into one reportable segment based on the similarity of economic characteristics due to the nature of the revenue earning process as it relates to the offshore drilling industry over the operating lives of our drilling rigs. Revenues from contract drilling services by equipment type are listed below: Three Months Ended Nine Months Ended 2015 2014 2015 2014 (In thousands) Floaters: Ultra-Deepwater $ 376,195 $ 313,124 $ 943,261 $ 701,574 Deepwater 136,668 111,372 456,542 378,470 Mid-Water 69,500 258,028 342,783 844,909 Total Floaters 582,363 682,524 1,742,586 1,924,953 Jack-ups 16,673 45,364 73,469 137,797 Total contract drilling revenues 599,036 727,888 1,816,055 2,062,750 Revenues related to reimbursable expenses 10,706 9,794 47,775 76,600 Total revenues $ 609,742 $ 737,682 $ 1,863,830 $ 2,139,350 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, 2015, our actively-marketed drilling rigs were en route to or located offshore seven 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 2015 2014 2015 2014 (In thousands) United States $ 140,898 $ 83,300 $ 330,765 $ 326,808 International: South America 222,717 294,246 654,432 844,242 Europe/Africa/Mediterranean 132,345 135,286 420,147 395,602 Australia/Asia 86,608 162,929 333,628 393,248 Mexico 27,174 61,921 124,858 179,450 Total revenues $ 609,742 $ 737,682 $ 1,863,830 $ 2,139,350

General Information (Policies)

General Information (Policies)	9 Months Ended
	Sep. 30, 2015
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.
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. 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, 2015 and 2014.
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, 2015 and the year ended December 31, 2014, we capitalized $217.8 million and $546.0 million, respectively, in replacements and betterments of our drilling fleet, resulting from numerous projects ranging from $25,000 to $215 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 “Loss (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, but not limited to, 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 if active, warm stacked or cold stacked (expressed as the actual percentage of time per year that the rig would be used at certain dayrates); • 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 each rig. Based on these assumptions, we develop a matrix for each rig under evaluation using multiple utilization/dayrate scenarios, to each of which we have assigned a probability of occurrence. We arrive at a projected probability- weighted cash flow for each rig based on the respective matrix and compare such amount to the carrying value of the asset to assess recoverability. The underlying assumptions and assigned probabilities of occurrence for utilization and dayrate scenarios are developed using a methodology that examines historical data for each rig, which considers the rig’s age, rated water depth and other attributes and then assesses its future marketability in light of the current and projected market environment at the time of assessment. Other assumptions, such as operating, maintenance and inspection costs, are estimated using historical data adjusted for known developments and future events that are anticipated by management at the time of the assessment. Management’s assumptions are necessarily subjective and are an inherent part of our asset impairment evaluation ,
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, net of amounts capitalized” as reported in our Consolidated Statements of Operations is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) Total interest cost, including amortization of debt issuance costs $ 23,830 $ 25,707 $ 84,254 $ 93,600 Capitalized interest (2,480 ) (16,329 ) (13,454 ) (47,544 ) Total interest expense as reported $ 21,350 $ 9,378 $ 70,800 $ 46,056
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, 2015, we recognized net foreign currency transaction gains (losses) of $(1.2) million and $1.0 million, respectively. 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. 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 July 2015, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606)

General Information (Tables)

General Information (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Reconciliation of Total Interest Cost to Interest Expense	A reconciliation of our total interest cost to “Interest expense, net of amounts capitalized” as reported in our Consolidated Statements of Operations is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) Total interest cost, including amortization of debt issuance costs $ 23,830 $ 25,707 $ 84,254 $ 93,600 Capitalized interest (2,480 ) (16,329 ) (13,454 ) (47,544 ) Total interest expense as reported $ 21,350 $ 9,378 $ 70,800 $ 46,056

Supplemental Financial Inform24

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts Receivable, Net of Allowance for Doubtful Accounts	Accounts receivable, net of allowance for bad debts, consist of the following: September 30, December 31, 2015 2014 (In thousands) Trade receivables $ 479,408 $ 437,017 Income tax receivable 18,408 — Value added tax receivables 17,604 24,853 Amounts held in escrow 4,871 6,450 Related party receivables 107 339 Other 1,080 927 521,478 469,586 Allowance for bad debts (5,724 ) (5,724 ) Total $ 515,754 $ 463,862
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following: September 30, December 31, 2015 2014 (In thousands) Rig spare parts and supplies $ 49,003 $ 56,315 Deferred mobilization costs 71,242 53,206 Prepaid insurance 6,701 12,163 Deferred tax assets 15,612 15,612 Prepaid taxes 16,928 44,085 Other 4,385 4,160 Total $ 163,871 $ 185,541
Accrued Liabilities	Accrued liabilities consist of the following: September 30, December 31, 2015 2014 (In thousands) Rig operating expenses $ 74,506 $ 85,897 Payroll and benefits 63,950 131,664 Deferred revenue 47,135 63,209 Accrued capital project/upgrade costs 42,325 103,123 Interest payable 44,130 18,365 Personal injury and other claims 8,565 8,570 FOREX contracts — 5,439 Other 4,693 10,325 Total $ 285,304 $ 426,592
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, 2015 2014 (In thousands) Accrued but unpaid capital expenditures at period end $ 42,325 $ 102,340 Common stock withheld for payroll tax obligations (1) 236 — Cash interest payments (2) 57,625 76,092 Cash income taxes paid, net of (refunds): U.S. federal (3,344 ) — Foreign 53,292 59,299 State 150 149 (1) Represents the cost of 7,810 shares of common stock withheld to satisfy the payroll tax obligation incurred as a result of the vesting of restricted stock units in the first quarter of 2015. This cost is presented as a deduction from stockholders’ equity in “Treasury stock” in our Consolidated Balance Sheets at September 30, 2015. (2) Interest payments, net of amounts capitalized, were $48.7 million and $38.9 million for the nine months ended September 30, 2015 and 2014, respectively.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of 2015 Restricted Stock Units Awarded Under Equity Plan	2015 RSUs awarded under the Equity Plan are summarized as follows: Award Type Number of RSUs Weighted Average Fair Performance-vesting (dividend entitled) 110,791 $ 26.69 Performance-vesting 56,162 $ 25.21 Time-vesting 144,192 $ 25.21

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2015
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 September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands, except per share data) Net income (loss) — basic and diluted numerator $ 136,422 $ 52,645 $ (28,901 ) $ 288,168 Weighted average shares — basic (denominator): 137,159 137,146 137,156 137,582 Dilutive effect of stock-based awards 44 1 — 3 Weighted average shares including conversions — diluted (denominator) 137,203 137,147 137,156 137,585 Earnings (loss) per share: Basic $ 0.99 $ 0.38 $ (0.21 ) $ 2.09 Diluted $ 0.99 $ 0.38 $ (0.21 ) $ 2.09
Securities Excluded from Computation of Diluted Earning Per Share	The following table sets forth the share effects of stock-based awards 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 September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) Employee and director: Stock options 23 37 29 32 Stock appreciation rights 1,521 1,526 1,561 1,472 Restricted stock units 176 — 252 —

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 Amortized Unrealized Market (In thousands) Corporate bonds $ 16,359 $ (2,836 ) $ 13,523 Mortgage-backed securities 94 4 98 Total $ 16,453 $ (2,832 ) $ 13,621 December 31, 2014 Amortized Unrealized Market (In thousands) Corporate bonds $ 16,003 $ (104 ) $ 15,899 Mortgage-backed securities 130 4 134 Total $ 16,133 $ (100 ) $ 16,033
Summary of Proceeds from Sales and Maturities of Marketable Securities	Proceeds from maturities and sales of marketable securities are summarized as follows: Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 (In thousands) Proceeds from maturities $ — $ 1,325,000 $ — $ 7,125,000 Proceeds from sales 11 12 34 45

Derivative Financial Instrume28

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 and 2014. Three Months Ended September 30, Nine Months Ended September 30, Location of (Loss) Gain Recognized in Income 2015 2014 2015 2014 (In thousands) Contract drilling expense $ (440 ) $ 1,729 $ (8,364 ) $ 6,736
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, 2015 and December 31, 2014. Balance Sheet Location Fair Value Balance Sheet Location Fair Value September 30, 2015 December 31, September 30, 2015 December 31, (In thousands) (In thousands) Prepaid expenses and other current assets $ — $ — Accrued liabilities $ — $ (5,439 )
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, 2015 and 2014. Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (In thousands) FOREX contracts: Amount of (loss) gain recognized in AOCGL on derivative (effective portion) $ (61 ) $ (6,505 ) $ (2,420 ) $ 2,297 Location of (loss) gain reclassified from AOCGL into income (effective portion) Contract Contract Contract Contract Amount of (loss) gain reclassified from AOCGL into income (effective portion) $ (415 ) $ 2,333 $ (7,829 ) $ 6,232 Location of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing) Foreign Foreign Foreign Foreign Amount of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing) $ — $ (59 ) $ (1 ) $ (60 ) 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 Interest Interest Amount of gain reclassified from AOCGL into income (effective portion) $ 2 $ 2 $ 6 $ 6

Financial Instruments and Fai29

Financial Instruments and Fair Value Disclosures (Tables)	9 Months Ended
	Sep. 30, 2015
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, 2015 Fair Value Measurements Using Total Losses for Period Ended Level 1 Level 2 Level 3 Assets at Three Nine (In thousands) Recurring fair value measurements: Assets: Short-term investments $ 130,625 $ — $ — $ 130,625 Corporate bonds — 13,523 — 13,523 Mortgage-backed securities — 98 — 98 Total assets $ 130,625 $ 13,621 $ — $ 144,246 Nonrecurring fair value measurements: Assets: Impaired assets (1)(2) $ — $ — $ 8,650 $ 8,650 $ 2,546 $ 361,074 (1) Represents the carrying value as of September 30, 2015 of three mid-water semisubmersible rigs, one jack-up rig and one drillship, which were written down to their estimated recoverable amounts in 2015. See Note 2. (2) Excludes the fair values of the Ocean Saratoga, Ocean Yorktown Ocean Worker Ocean Lexington December 31, 2014 Fair Value Measurements Using Level 1 Level 2 Level 3 Assets at (In thousands) Recurring fair value measurements: Assets: Short-term investments $ 217,789 $ — $ — $ 217,789 Corporate bonds — 15,899 — 15,899 Mortgage-backed securities — 134 — 134 Total assets $ 217,789 $ 16,033 $ — $ 233,822 Liabilities: FOREX contracts $ — $ (5,439 ) $ — $ (5,439 ) Nonrecurring fair value measurements: Assets: Impaired assets (1) $ — $ — $ 9,421 $ 9,421 (1) Represents the book value as of December 31, 2014 of four of our mid-water semisubmersible rigs, which were written down to their estimated recoverable amounts in 2014. All four rigs were sold for scrap during the nine months ended September 30, 2015.
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, 2015 December 31, 2014 Fair Value Carrying Value Fair Value Carrying Value (In millions) 4.875% Senior Notes due 2015 $ — $ — $ 255.0 $ 250.0 5.875% Senior Notes due 2019 520.0 499.7 544.9 499.6 3.45% Senior Notes due 2023 230.0 249.1 232.0 249.1 5.70% Senior Notes due 2039 383.0 497.0 478.5 497.0 4.875% Senior Notes due 2043 490.5 748.9 638.9 748.8

Drilling and Other Property a30

Drilling and Other Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2015
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, (In thousands) Drilling rigs and equipment $ 10,113,847 $ 10,555,314 Construction work-in-progress 250,930 439,206 Land and buildings 65,785 66,989 Office equipment and other 71,255 70,591 Cost 10,501,817 11,132,100 Less: accumulated depreciation (3,613,569 ) (4,186,147 ) Drilling and other property and equipment, net $ 6,888,248 $ 6,945,953
Summary of Construction Work-in-Progress, Including Capitalized Interest	Construction work-in-progress, including capitalized interest, at September 30, 2015 and December 31, 2014 is summarized as follows: September 30, December 31, (In thousands) Ultra-deepwater semisubmersible — Ocean GreatWhite $ 250,930 $ 213,801 Ultra-deepwater drillship — Ocean BlackLion — 225,405 Total construction work-in-progress $ 250,930 $ 439,206

Accumulated Other Comprehensi31

Accumulated Other Comprehensive Gain (Loss) (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Components of Accumulated Other Comprehensive Gain (Loss)	The components of our AOCGL and related changes thereto are as follows: Unrealized (Loss) Gain on Derivative Marketable Total AOCGL (In thousands) Balance at January 1, 2015 $ (3,504 ) $ (101 ) $ (3,605 ) Change in other comprehensive (loss) gain before reclassifications, after tax of $846 and $(1) (1,574 ) (2,733 ) (4,307 ) Reclassification adjustments for items included in Net Income, after tax of $(2,738) and $0 5,085 — 5,085 Balance at September 30, 2015 $ 7 $ (2,834 ) $ (2,827 )
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. Three Months Ended September 30, Nine Months Ended September 30, Consolidated Statements of Major Category of AOCGL 2015 2014 2015 2014 (In thousands) Derivative Financial Instruments: Unrealized loss (gain) on FOREX contracts $ 415 $ (2,333 ) $ 7,829 $ (6,232 ) Contract drilling, excluding depreciation Unrealized (gain) loss on treasury lock agreements (2 ) (2 ) (6 ) (6 ) Interest expense (145 ) 817 (2,738 ) 2,183 Income tax expense $ 268 $ (1,518 ) $ 5,085 $ (4,055 ) Net of tax Marketable Securities: Unrealized (gain) loss on marketable securities $ — $ (1 ) $ — $ (34 ) Other, net — — — 7 Income tax expense $ — $ (1 ) $ — $ (27 ) Net of tax

Segments and Geographic Area 32

Segments and Geographic Area Analysis (Tables)	9 Months Ended
	Sep. 30, 2015
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 2015 2014 2015 2014 (In thousands) Floaters: Ultra-Deepwater $ 376,195 $ 313,124 $ 943,261 $ 701,574 Deepwater 136,668 111,372 456,542 378,470 Mid-Water 69,500 258,028 342,783 844,909 Total Floaters 582,363 682,524 1,742,586 1,924,953 Jack-ups 16,673 45,364 73,469 137,797 Total contract drilling revenues 599,036 727,888 1,816,055 2,062,750 Revenues related to reimbursable expenses 10,706 9,794 47,775 76,600 Total revenues $ 609,742 $ 737,682 $ 1,863,830 $ 2,139,350
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 2015 2014 2015 2014 (In thousands) United States $ 140,898 $ 83,300 $ 330,765 $ 326,808 International: South America 222,717 294,246 654,432 844,242 Europe/Africa/Mediterranean 132,345 135,286 420,147 395,602 Australia/Asia 86,608 162,929 333,628 393,248 Mexico 27,174 61,921 124,858 179,450 Total revenues $ 609,742 $ 737,682 $ 1,863,830 $ 2,139,350

General Information - Additiona

General Information - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Oct. 26, 2015
Property, Plant and Equipment [Line Items]
Period considered to treat short-term, highly liquid investments as cash equivalents			Three months or less
Amount capitalized for asset replacements and betterments			$ 217,800,000		$ 546,000,000
Gain (loss) on foreign currency transactions recognized in income	$ (1,200,000)	$ 400,000	$ 1,000,000	$ (3,700,000)
Initial term of contracts minimum months			2 months
Initial term of contracts maximum months			60 months
Subsequent Event [Member]
Property, Plant and Equipment [Line Items]
Outstanding common stock owned by Loews Corporation						53.30%
Minimum [Member]
Property, Plant and Equipment [Line Items]
Rig and equipment project costs			$ 25,000		25,000
Estimated useful life for drilling rigs and equipment			3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Rig and equipment project costs			$ 215,000,000		$ 215,000,000
Estimated useful life for drilling rigs and equipment			30 years

General Information - Reconcili

General Information - Reconciliation of Total Interest Cost to Interest Expense, Net of Amounts Capitalized (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest Costs Incurred [Abstract]
Total interest cost, including amortization of debt issuance costs	$ 23,830	$ 25,707	$ 84,254	$ 93,600
Capitalized interest	(2,480)	(16,329)	(13,454)	(47,544)
Total interest expense as reported	$ 21,350	$ 9,378	$ 70,800	$ 46,056

Asset Impairments - Additional

Asset Impairments - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	Oct. 31, 2015Rigs	Sep. 30, 2015USD ($)Rigs	Mar. 31, 2015Rigsft	Sep. 30, 2014USD ($)Rigs	Sep. 30, 2015USD ($)Rigs	Sep. 30, 2014USD ($)Rigs
Schedule Of Asset Impairment Charges [Line Items]
Impairment of assets | $		$ 2,546		$ 109,462	$ 361,074	$ 109,462
Number of rigs sold for scrap					8
Impaired Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Impaired long-lived assets held and used, method for determining fair value					We determined the fair value of five of the rigs in the impairment group using a market approach, which utilized the most recent contracted sales price for another of our previously impaired mid-water semisubmersible rigs. We determined the fair value of the three remaining rigs (which were under contract with a customer at that time) using an income approach, which utilized significant unobservable inputs, including assumptions related to estimated dayrate revenue, rig utilization and anticipated costs for the remainder of the current contract, as well as estimated proceeds that may be received on disposition of each rig. We consider each of these methodologies to be Level 3 fair value measurements due to the significant level of estimation involved and the lack of transparency as to the inputs used.
Impairment of assets | $		$ 2,600			$ 361,100
Number of rigs with fair values estimated using market approach			5
Number of rigs with fair values estimated using income approach			3
Number of rigs sold for scrap					4
Number of rigs cold stacked		3			3
Number of rigs currently working		2			2
Number of rigs not previously impaired		13			13
Number of additional rigs not previously impaired		4			4
Aggregate book value of physical assets | $		$ 8,700			$ 8,700
Aggregate fair value of assets held for sale | $		6,700			6,700
Aggregate fair value of drilling and other property and equipment, net of accumulated depreciation | $		$ 2,000			$ 2,000
Mid-Water Semi Submersible Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of rigs impaired			7
Impairment of assets | $				$ 109,500		$ 109,500
Number of rigs subject to scrap				6		6
Ultra-deepwater Drillship [Member]
Schedule Of Asset Impairment Charges [Line Items]
Water depth rated capacity of impaired drillship | ft			7,875
Subsequent Event [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of drilling rigs to be sold	3
Subsequent Event [Member] | Mid-Water Semi Submersible Rigs [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of drilling rigs to be sold	1
Subsequent Event [Member] | Cold Stacked Jack-Up Rig [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of drilling rigs to be sold	1
Subsequent Event [Member] | Ultra-deepwater Drillship [Member]
Schedule Of Asset Impairment Charges [Line Items]
Number of drilling rigs to be sold	1

Supplemental Financial Inform36

Supplemental Financial Information - Accounts Receivable, Net of Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Receivables [Abstract]
Trade receivables	$ 479,408	$ 437,017
Income tax receivable	18,408
Value added tax receivables	17,604	24,853
Amounts held in escrow	4,871	6,450
Related party receivables	107	339
Other	1,080	927
Receivables Gross Current, Total	521,478	469,586
Allowance for bad debts	(5,724)	(5,724)
Total	$ 515,754	$ 463,862

Supplemental Financial Inform37

Supplemental Financial Information - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Rig spare parts and supplies	$ 49,003	$ 56,315
Deferred mobilization costs	71,242	53,206
Prepaid insurance	6,701	12,163
Deferred tax assets	15,612	15,612
Prepaid taxes	16,928	44,085
Other	4,385	4,160
Total	$ 163,871	$ 185,541

Supplemental Financial Inform38

Supplemental Financial Information - Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Rig operating expenses	$ 74,506	$ 85,897
Payroll and benefits	63,950	131,664
Deferred revenue	47,135	63,209
Accrued capital project/upgrade costs	42,325	103,123
Interest payable	44,130	18,365
Personal injury and other claims	8,565	8,570
FOREX contracts		5,439
Other	4,693	10,325
Total	$ 285,304	$ 426,592

Supplemental Financial Inform39

Supplemental Financial Information - Noncash Investing and Financing Activities (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Accrued but unpaid capital expenditures at period end	$ 42,325	$ 102,340
Common stock withheld for payroll tax obligations	236
Cash interest payments	57,625	76,092
U.S Federal [Member]
Cash income taxes paid, net of (refunds):
Cash income taxes paid, net of (refunds)	(3,344)
Foreign [Member]
Cash income taxes paid, net of (refunds):
Cash income taxes paid, net of refunds	53,292	59,299
State [Member]
Cash income taxes paid, net of (refunds):
Cash income taxes paid, net of refunds	$ 150	$ 149

Supplemental Financial Inform40

Supplemental Financial Information - Noncash Investing and Financing Activities (Parenthetical) (Detail) - USD ($) shares in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Interest payments, net of amounts capitalized	$ 48.7	$ 38.9
Restricted Stock [Member]
Condensed Financial Statements, Captions [Line Items]
Number of shares of common stock withheld	7,810

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				$ 3,503	$ 2,559
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Equity Instruments Awarded in Period	311,145
Stock-based compensation expense		$ 800	$ 200	$ 1,700	$ 500
Time-vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Equity Instruments Awarded in Period				144,192
Time-vesting RSUs [Member] | Vesting on April 1, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of RSUs vesting	50.00%
Time-vesting RSUs [Member] | Vesting on April 1, 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of RSUs vesting	50.00%
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Equity Instruments Awarded in Period				107,750

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of 2015 Restricted Stock Units Awarded Under Equity Plan (Detail)	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Performance-vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Equity Instruments Awarded in Period	56,162
Weighted Average Fair Value per RSU | $ / shares	$ 25.21
Time-vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Equity Instruments Awarded in Period	144,192
Weighted Average Fair Value per RSU | $ / shares	$ 25.21
Performance-vesting Dividend Entitled RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Equity Instruments Awarded in Period	110,791
Weighted Average Fair Value per RSU | $ / shares	$ 26.69

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted Per-Share Computations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net income (loss) - basic and diluted numerator	$ 136,422	$ 52,645	$ (28,901)	$ 288,168
Weighted average shares - basic (denominator):	137,159	137,146	137,156	137,582
Dilutive effect of stock-based awards	44	1		3
Weighted average shares including conversions - diluted (denominator)	137,203	137,147	137,156	137,585
Earnings (loss) per share:
Basic	$ 0.99	$ 0.38	$ (0.21)	$ 2.09
Diluted	$ 0.99	$ 0.38	$ (0.21)	$ 2.09

Earnings Per Share - Securities

Earnings Per Share - Securities Excluded from Computation of Diluted Earning Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stock Options [Member]
Employee and director:
Securities excluded from computation of diluted earning per share	23	37	29	32
Restricted Stock Units (RSUs) [Member]
Employee and director:
Securities excluded from computation of diluted earning per share	176		252
Stock Appreciation Rights (SARs) [Member]
Employee and director:
Securities excluded from computation of diluted earning per share	1,521	1,526	1,561	1,472

Marketable Securities - Investm

Marketable Securities - Investments in Marketable Securities as Available for Sale (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 16,453	$ 16,133
Unrealized Gain (Loss)	(2,832)	(100)
Market Value	13,621	16,033
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,359	16,003
Unrealized Gain (Loss)	(2,836)	(104)
Market Value	13,523	15,899
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	94	130
Unrealized Gain (Loss)	4	4
Market Value	$ 98	$ 134

Marketable Securities - Summary

Marketable Securities - Summary of Proceeds from Sales and Maturities of Marketable Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]
Proceeds from maturities		$ 1,325,000		$ 7,125,000
Proceeds from sales	$ 11	$ 12	$ 34	$ 45

Derivative Financial Instrume47

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of foreign currency contracts settled	$ 91,600,000	$ 233,900,000
Derivative contracts outstanding	0
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from AOCGL due to the probability of a forecasted transaction not occurring	0	$ 0
Treasury Lock Agreements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains associated with derivative financial instruments to be reclassified to interest expense	$ 8,052

Derivative Financial Instrume48

Derivative Financial Instruments - Amounts Recognized in Consolidated Statements of Operations Related to FOREX Contracts Designated as Accounting Hedges (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Income			$ (8,364)	$ 6,736
Contract Drilling Expense [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Income	$ (440)	$ 1,729	$ (8,364)	$ 6,736

Derivative Financial Instrume49

Derivative Financial Instruments - Fair Values of Forex Contracts Designated as Hedging Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative liabilities designated as hedging instruments, current		$ (5,439)
Prepaid Expenses and Other Current Assets [Member] | FOREX Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative assets designated as hedging instruments, current	$ 0	0
Accrued Liabilities [Member] | FOREX Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities designated as hedging instruments, current		$ (5,439)

Derivative Financial Instrume50

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 ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
FOREX Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain recognized in AOCGL on derivative (effective portion)	$ (61)	$ (6,505)	$ (2,420)	$ 2,297
Contract Drilling Expense [Member] | FOREX Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain reclassified from AOCGL into income (effective portion)	(415)	2,333	(7,829)	6,232
Foreign Currency Transaction Gain (Loss) [Member] | FOREX Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of loss recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		(59)	(1)	(60)
Interest Expense [Member] | Treasury Lock Agreements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain reclassified from AOCGL into income (effective portion)	$ 2	$ 2	$ 6	$ 6

Financial Instruments and Fai51

Financial Instruments and Fair Value Disclosures - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accounts receivable, net	$ 515,754,000		$ 515,754,000		$ 463,862,000
Transfers between fair value levels	0	$ 0	0	$ 0
Impairment of assets	2,546,000	$ 109,462,000	$ 361,074,000	$ 109,462,000
Measurement period for determining fair value of debt instruments			10 days
Accounts Receivable [Member] | Petroleo Brasileiro S.A. [Member] | Credit Concentration Risk [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accounts receivable, net	74,100,000		$ 74,100,000		$ 123,300,000
Percentage of accounts receivable due from major customer			16.00%		29.00%
Level 1 [Member] | Cash Held in Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments	110,300,000		$ 110,300,000		$ 197,500,000
Level 1 [Member] | Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments	$ 20,300,000		$ 20,300,000		$ 20,300,000

Financial Instruments and Fai52

Financial Instruments and Fair Value Disclosures - Assets and Liabilities Measured at Fair Value on Recurring and Nonrecurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Assets:
Loss on assets	$ 2,546	$ 109,462	$ 361,074	$ 109,462
Book Value of Assets	6,888,248		6,888,248		$ 6,945,953
Liabilities:
FOREX contracts					(5,439)
Fair Value Measurements, Recurring [Member]
Assets:
Total assets	144,246		144,246		233,822
Short-term investments	130,625		130,625		217,789
Corporate bonds	13,523		13,523		15,899
Mortgage-backed securities	98		98		134
Liabilities:
FOREX contracts					(5,439)
Fair Value Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Total assets	130,625		130,625		217,789
Short-term investments	130,625		130,625		217,789
Fair Value Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Total assets	13,621		13,621		16,033
Corporate bonds	13,523		13,523		15,899
Mortgage-backed securities	98		98		134
Liabilities:
FOREX contracts					(5,439)
Nonrecurring Fair Value Measurements [Member]
Assets:
Loss on assets	2,546		361,074
Book Value of Assets	8,650		8,650		9,421
Nonrecurring Fair Value Measurements [Member] | Level 3 [Member]
Assets:
Book Value of Assets	$ 8,650		$ 8,650		$ 9,421

Financial Instruments and Fai53

Financial Instruments and Fair Value Disclosures - Assets and Liabilities Measured at Fair Value on Recurring and Nonrecurring Basis (Parenthetical) (Detail) - Rigs	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of rigs sold for scrap			8
Mid-Water [Member] | Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of rigs sold for scrap	1	3	4
Mid-Water [Member] | First Quarter 2015 [Member] | Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of rigs impaired	3		3
Ultra-deepwater Drillship [Member] | First Quarter 2015 [Member] | Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of rigs impaired	1		1
Jack-ups [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of rigs impaired	1		1

Financial Instruments and Fai54

Financial Instruments and Fair Value Disclosures - Fair Value and Related Carrying Values of Our Debt Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
4.875% Senior Notes due 2015 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value		$ 255
Carrying Value		250
5.875% Senior Notes due 2019 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	$ 520	544.9
Carrying Value	499.7	499.6
3.45% Senior Notes due 2023 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	230	232
Carrying Value	249.1	249.1
5.70% Senior Notes due 2039 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	383	478.5
Carrying Value	497	497
4.875% Senior Notes due 2043 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	490.5	638.9
Carrying Value	$ 748.9	$ 748.8

Financial Instruments and Fai55

Financial Instruments and Fair Value Disclosures - Fair Value and Related Carrying Values of Our Debt Instruments (Parenthetical) (Detail)	Sep. 30, 2015	Dec. 31, 2014
4.875% Senior Notes due 2015 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate of senior notes	4.875%	4.875%
5.875% Senior Notes due 2019 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate of senior notes	5.875%	5.875%
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	4.875%	4.875%

Drilling and Other Property a56

Drilling and Other Property and Equipment - Summary of Cost and Accumulated Depreciation of Drilling and Other Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment	$ 10,501,817	$ 11,132,100
Less: accumulated depreciation	(3,613,569)	(4,186,147)
Drilling and other property and equipment, net	6,888,248	6,945,953
Drilling Rigs and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	10,113,847	10,555,314
Construction Work-in-Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	250,930	439,206
Land and Buildings [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	65,785	66,989
Office Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 71,255	$ 70,591

Drilling and Other Property a57

Drilling and Other Property and Equipment - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)Rigs	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Property, Plant and Equipment [Line Items]
Number of rigs sold for scrap | Rigs			8
Aggregate book value of physical assets	$ 6,888,248		$ 6,888,248		$ 6,945,953
Gain on disposition of physical asset	(794)	$ (1,107)	(19)	$ 7,612
Impairment of assets	2,546	$ 109,462	361,074	$ 109,462
Rigs [Member]
Property, Plant and Equipment [Line Items]
Aggregate book value of physical assets	4,400		4,400
Gain on disposition of physical asset	$ 200		$ 1,000

Drilling and Other Property a58

Drilling and Other Property and Equipment - Summary of Construction Work-in-Progress, Including Capitalized Interest (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Rig(s) Under Construction	$ 250,930	$ 439,206
Ultra-deepwater Semisubmersible [Member] | Ocean GreatWhite [Member]
Property, Plant and Equipment [Line Items]
Rig(s) Under Construction	$ 250,930	213,801
Ultra-deepwater Drillship [Member] | Ocean BlackLion [Member]
Property, Plant and Equipment [Line Items]
Rig(s) Under Construction		$ 225,405

Revolving Credit Facility, Co59

Revolving Credit Facility, Commercial Paper and Senior Notes - Additional Information (Detail) - USD ($)	Oct. 22, 2015	Sep. 30, 2015	Oct. 29, 2015	Jul. 01, 2015	Dec. 31, 2014
4.875% Senior Notes due 2015 [Member]
Debt Instrument [Line Items]
Aggregate principal amount				$ 250,000,000
Interest rate of senior notes		4.875%			4.875%
Senior notes maturity date		Jul. 1, 2015
Subsequent Event [Member] | Swingline Loans [Member]
Debt Instrument [Line Items]
Amount available for general purposes	$ 100,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Amount available for general purposes		$ 1,500,000,000
Revolving Credit Facility [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Maturity period of credit agreement	Oct. 22, 2020
Additional amount available under revolving credit facility	$ 500,000,000
Credit Agreement Commitments Mature on March 17, 2019 [Member]
Debt Instrument [Line Items]
Amount available for general purposes		$ 40,000,000
Maturity period of credit agreement		Mar. 17, 2019
Credit Agreement Commitments Mature on October 22, 2019 [Member]
Debt Instrument [Line Items]
Amount available for general purposes		$ 60,000,000
Maturity period of credit agreement		Oct. 22, 2019
Commercial Paper [Member]
Debt Instrument [Line Items]
Amount available for general purposes		$ 1,500,000,000
Notes outstanding		$ 493,000,000
Weighted average interest rate		0.44%
Weighted average remaining term		2 days
Commercial Paper [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Additional revolving credit facility			$ 1,100,000,000
Commercial Paper [Member] | Maximum [Member]
Debt Instrument [Line Items]
Notes maturity period		397 days
Letters of Credit [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Amount available for general purposes	$ 250,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015USD ($)Installmentft	Dec. 31, 2014USD ($)
Contingencies And Commitments [Line Items]
Net profits interest percent	27.00%
Deductible for marine liability coverage including personal injury claims, per first occurrence	$ 25,000,000
Range of deductible for liability coverage for personal injury claims, lower limit	5,000,000
Range of deductible for liability coverage for personal injury claims, upper limit	100,000,000
Other purchase obligations	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	71,300,000
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	$ 63,700,000
Hyundai Heavy Industries, Co., Ltd. [Member] | Ultra-Deepwater Floater Construction [Member]
Contingencies And Commitments [Line Items]
Water depth of rig | ft	10,000
Cost of enhancement of project	$ 764,000,000
Total number of installments due under each turnkey construction agreements | Installment	2
Cost of construction per shipyard agreement	$ 628,500,000
Construction installments paid	188,600,000
Final installment for Ultra-Deep water Floater Construction	439,900,000
NPI Arrangement [Member]
Contingencies And Commitments [Line Items]
Payments received from customer after bankruptcy filing	3,250,000
Payments received from customer before and after bankruptcy filing	30,000,000
Personal Injury Claims [Member]
Contingencies And Commitments [Line Items]
Personal injury claims recorded	43,400,000	$ 39,400,000
Personal Injury Claims [Member] | Accrued Liabilities [Member]
Contingencies And Commitments [Line Items]
Personal injury claims recorded	8,200,000	8,200,000
Personal Injury Claims [Member] | Other Liabilities [Member]
Contingencies And Commitments [Line Items]
Personal injury claims recorded	$ 35,200,000	$ 31,200,000

Accumulated Other Comprehensi61

Accumulated Other Comprehensive Gain (Loss) - Components of Accumulated Other Comprehensive Gain (Loss) (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (3,605)
Change in other comprehensive (loss) gain before reclassifications	(4,307)
Reclassification adjustments for items included in Net Income	5,085
Ending balance	(2,827)
Derivative Financial Instrument [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(3,504)
Change in other comprehensive (loss) gain before reclassifications	(1,574)
Reclassification adjustments for items included in Net Income	5,085
Ending balance	7
Marketable Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(101)
Change in other comprehensive (loss) gain before reclassifications	(2,733)
Ending balance	$ (2,834)

Accumulated Other Comprehensi62

Accumulated Other Comprehensive Gain (Loss) - Components of Accumulated Other Comprehensive Gain (Loss) (Parenthetical) (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Equity [Abstract]
Change in other comprehensive (loss) gain on derivatives, tax expense (benefit)	$ 846
Change in other comprehensive (loss) gain on marketable securities, tax (expense) benefit	(1)
Reclassification adjustments for items included in Net Income on derivatives, tax (expense) benefit	(2,738)
Reclassification adjustments for items included in Net Income on marketable securities, tax (expense) benefit	$ 0

Accumulated Other Comprehensi63

Accumulated Other Comprehensive Gain (Loss) - Items in Consolidated Statements of Operations Affected by Reclassification Adjustments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other, net	$ 217	$ 90	$ 702	$ 598
Contract drilling, excluding depreciation	(277,944)	(399,802)	(971,471)	(1,164,968)
Interest expense	(21,350)	(9,378)	(70,800)	(46,056)
Income tax expense	23,345	28,994	7,578	73,753
Net income (loss)	136,422	52,645	(28,901)	288,168
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	(145)	817	(2,738)	2,183
Net income (loss)	268	(1,518)	5,085	(4,055)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member] | FOREX Contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Contract drilling, excluding depreciation	415	(2,333)	7,829	(6,232)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member] | Treasury Lock Agreements [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (2)	(2)	$ (6)	(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)		(34)
Income tax expense				7
Net income (loss)		$ (1)		$ (27)

Restructuring and Separation 64

Restructuring and Separation Costs - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Restructuring and Related Activities [Abstract]
Restructuring and employee separation related costs	$ 1,574,000	$ 8,735,000
Accrued costs associated with Corporate Reduction Plan		$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - Mexico [Member] $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)
2009 Tax Year [Member]
Income Tax Contingency [Line Items]
Accrued liabilities related to income tax examination	$ 10.7
Reversal of accrued interest on uncertain tax position	3.6
Reversal of accrued penalty on uncertain tax position	1.4
2008 Tax Year [Member]
Income Tax Contingency [Line Items]
Accrued liabilities related to income tax examination	$ 5.3

Segments and Geographic Area 66

Segments and Geographic Area Analysis - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015CountrySegment
Segment Reporting [Abstract]
Number of reportable segments	1
Number of countries with rigs | Country	7

Segments and Geographic Area 67

Segments and Geographic Area Analysis - Revenues from Contract Drilling Services by Equipment Type (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Contract drilling	$ 599,036	$ 727,888	$ 1,816,055	$ 2,062,750
Revenues related to reimbursable expenses	10,706	9,794	47,775	76,600
Total revenues	609,742	737,682	1,863,830	2,139,350
Ultra-deepwater Semisubmersible [Member]
Segment Reporting Information [Line Items]
Contract drilling	376,195	313,124	943,261	701,574
Deepwater [Member]
Segment Reporting Information [Line Items]
Contract drilling	136,668	111,372	456,542	378,470
Mid-Water [Member]
Segment Reporting Information [Line Items]
Contract drilling	69,500	258,028	342,783	844,909
Total Floaters [Member]
Segment Reporting Information [Line Items]
Contract drilling	582,363	682,524	1,742,586	1,924,953
Jack-ups [Member]
Segment Reporting Information [Line Items]
Contract drilling	$ 16,673	$ 45,364	$ 73,469	$ 137,797

Segments and Geographic Area 68

Segments and Geographic Area Analysis - Revenues by Geographic Area Presented by Attributing Revenues to Individual Country (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 609,742	$ 737,682	$ 1,863,830	$ 2,139,350
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	140,898	83,300	330,765	326,808
South America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	222,717	294,246	654,432	844,242
Europe/Africa/Mediterranean [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	132,345	135,286	420,147	395,602
Australia/Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	86,608	162,929	333,628	393,248
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 27,174	$ 61,921	$ 124,858	$ 179,450