Noble (NE) 10-K 22 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2018	Feb. 19, 2019	Jun. 30, 2018
Document Information [Line Items]
Entity Registrant Name	Noble Corp plc
Trading Symbol	NE
Entity Central Index Key	1,458,891
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		248,704,351
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1.5
Noble Corp
Document Information [Line Items]
Entity Registrant Name	Noble Corporation
Entity Central Index Key	1,169,055
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		261,245,693

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 375,232	$ 662,829
Accounts receivable, net	200,722	204,696
Taxes receivable	20,498	105,345
Prepaid expenses and other current assets	62,604	66,105
Total current assets	659,056	1,038,975
Property and equipment, at cost	10,956,412	12,034,331
Accumulated depreciation	(2,475,694)	(2,545,091)
Property and equipment, net	8,480,718	9,489,240
Other assets	125,149	266,444
Total assets	9,264,923	10,794,659
Current liabilities
Current maturities of long-term debt	0	249,843
Accounts payable	125,557	84,032
Accrued payroll and related costs	50,284	54,904
Taxes payable	29,386	34,391
Interest payable	100,100	98,189
Other current liabilities	60,130	71,665
Total current liabilities	365,457	593,024
Long-term debt	3,877,402	3,795,867
Deferred income taxes	91,695	164,962
Other liabilities	275,795	290,178
Total liabilities	4,610,349	4,844,031
Commitments and contingencies
Shareholders' equity
Common stock	2,468	2,450
Additional paid-in capital	699,409	678,922
Retained earnings	3,608,366	4,637,677
Accumulated other comprehensive loss	(57,072)	(42,888)
Total shareholders' equity	4,253,171	5,276,161
Noncontrolling interests	401,403	674,467
Total equity	4,654,574	5,950,628
Total liabilities and equity	9,264,923	10,794,659
Noble Corp
Current assets
Cash and cash equivalents	374,375	662,011
Accounts receivable, net	200,722	204,696
Taxes receivable	20,498	105,345
Prepaid expenses and other current assets	61,917	65,441
Total current assets	657,512	1,037,493
Property and equipment, at cost	10,956,412	12,034,331
Accumulated depreciation	(2,475,694)	(2,545,091)
Property and equipment, net	8,480,718	9,489,240
Other assets	125,149	266,528
Total assets	9,263,379	10,793,261
Current liabilities
Current maturities of long-term debt	0	249,843
Accounts payable	125,237	83,873
Accrued payroll and related costs	50,284	54,904
Taxes payable	29,386	33,965
Interest payable	100,100	98,189
Other current liabilities	60,012	71,466
Total current liabilities	365,019	592,240
Long-term debt	3,877,402	3,795,867
Deferred income taxes	91,695	164,962
Other liabilities	275,795	290,178
Total liabilities	4,609,911	4,843,247
Commitments and contingencies
Shareholders' equity
Common stock	26,125	26,125
Additional paid-in capital	647,082	623,137
Retained earnings	3,635,930	4,669,173
Accumulated other comprehensive loss	(57,072)	(42,888)
Total shareholders' equity	4,252,065	5,275,547
Noncontrolling interests	401,403	674,467
Total equity	4,653,468	5,950,014
Total liabilities and equity	$ 9,263,379	$ 10,793,261

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2018	Dec. 31, 2017
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Ordinary shares, shares outstanding (in shares)	246,794	244,971
Noble Corp
Common stock, par value (usd per share)	$ 0.10	$ 0.10
Ordinary shares, shares outstanding (in shares)	261,246	261,246

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating revenues
Operating revenues	$ 309,892	$ 279,408	$ 258,369	$ 235,157	$ 329,585	$ 266,212	$ 278,142	$ 362,976	$ 1,082,826	$ 1,236,915	$ 2,302,065
Operating costs and expenses
Depreciation and amortization									486,530	547,990	611,067
General and administrative									73,216	71,634	69,258
Loss on impairment									802,133	121,639	1,458,749
Total operating costs and expenses									2,028,900	1,402,635	3,062,262
Operating loss	(21,745)	(21,843)	(845,606)	(56,880)	(110,294)	(56,604)	(44,285)	(45,463)	(946,074)	(165,720)	(760,197)
Other income (expense)
Interest expense, net of amount capitalized									(297,611)	(291,989)	(222,915)
Gain (loss) on extinguishment of debt, net									(1,793)	0	17,814
Interest income and other, net									8,302	7,897	(1,731)
Loss from continuing operations before income taxes									(1,237,176)	(449,812)	(967,029)
Income tax benefit (provision)									106,641	(42,629)	109,156
Net loss from continuing operations									(1,130,535)	(492,441)	(857,873)
Net loss from discontinued operations, net of tax									0	(1,486)	0
Net loss									(1,130,535)	(493,927)	(857,873)
Net (income) loss attributable to noncontrolling interests									245,485	(22,584)	(71,707)
Net income (loss) attributable to the company	(33,062)	(81,591)	(628,063)	(142,334)	(24,675)	(96,792)	(91,864)	(301,694)	(885,050)	(516,511)	(929,580)
Loss from continuing operations									(885,050)	(515,025)	(929,580)
Net loss from discontinued operations, net of tax					0	0	(1,486)	0	0	(1,486)	0
Net income (loss) attributable to the company	$ (33,062)	$ (81,591)	$ (628,063)	$ (142,334)	$ (24,675)	$ (96,792)	$ (91,864)	$ (301,694)	$ (885,050)	$ (516,511)	$ (929,580)
Basic:
Loss from continuing operations (usd per share)	$ (0.13)	$ (0.33)	$ (2.55)	$ (0.58)	$ (0.10)	$ (0.40)	$ (0.37)	$ (1.24)	$ (3.59)	$ (2.10)	$ (3.82)
Loss from discontinued operations (usd per share)					0	0	(0.01)	0	0	(0.01)	0
Net income (loss) (usd per share)									(3.59)	(2.11)	(3.82)
Diluted:
Loss from continuing operations (usd per share)	$ (0.13)	$ (0.33)	$ (2.55)	$ (0.58)	(0.10)	(0.40)	(0.37)	(1.24)	(3.59)	(2.10)	(3.82)
Loss from discontinued operations (usd per share)					$ 0	$ 0	$ (0.01)	$ 0	0	(0.01)	0
Net income (loss) (usd per share)									$ (3.59)	$ (2.11)	$ (3.82)
Weighted- Average Shares Outstanding
Basic (in shares)									246,614,000	244,743,000	243,127,000
Diluted (in shares)									246,614,000	244,743,000	243,127,000
Noble Corp
Operating revenues
Operating revenues									$ 1,082,826	$ 1,236,915	$ 2,302,765
Operating costs and expenses
Depreciation and amortization									482,660	543,119	611,013
General and administrative									38,203	41,087	46,045
Loss on impairment									802,133	121,639	1,458,749
Total operating costs and expenses									1,988,208	1,364,763	3,033,218
Operating loss									(905,382)	(127,848)	(730,453)
Other income (expense)
Interest expense, net of amount capitalized									(297,611)	(291,989)	(222,915)
Gain (loss) on extinguishment of debt, net									(1,793)	0	17,814
Interest income and other, net									8,282	7,733	(1,616)
Loss from continuing operations before income taxes									(1,196,504)	(412,104)	(937,170)
Income tax benefit (provision)									106,534	(42,595)	109,163
Net loss from continuing operations									(1,089,970)	(454,699)	(828,007)
Net loss from discontinued operations, net of tax									0	2,967	0
Net loss									(1,089,970)	(451,732)	(828,007)
Net (income) loss attributable to noncontrolling interests									245,485	(22,584)	(71,707)
Net income (loss) attributable to the company									(844,485)	(474,316)	(899,714)
Net income (loss) attributable to the company									(844,485)	(474,316)	(899,714)
Contract drilling services
Operating revenues
Operating revenues	$ 292,049								1,036,082	1,207,026	2,242,200
Operating costs and expenses
Cost of services									629,937	642,937	877,689
Contract drilling services | Noble Corp
Operating revenues
Operating revenues									1,036,082	1,207,026	2,242,200
Operating costs and expenses
Cost of services									628,128	640,483	871,912
Reimbursables and other
Operating revenues
Operating revenues									46,744	29,889	59,865
Operating costs and expenses
Cost of services									37,084	18,435	45,499
Reimbursables and other | Noble Corp
Operating revenues
Operating revenues									46,744	29,889	60,565
Operating costs and expenses
Cost of services									$ 37,084	$ 18,435	$ 45,499

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net loss	$ (1,130,535)	$ (493,927)	$ (857,873)
Other comprehensive income (loss)
Foreign currency translation adjustments	(2,729)	990	(19)
Net pension plan gain (loss) (net of tax provision (benefit) of ($1,828), $523 and ($1,828) for the year ended December 31, 2018, 2017 and 2016, respectively)	(7,099)	6,774	(8,237)
Amortization of deferred pension plan amounts (net of tax provision of $345, $623 and $1,635 for the year ended December 31, 2018, 2017 and 2016, respectively)	1,298	1,393	3,127
Net pension plan curtailment and settlement expense (net of tax provision of $28, zero and $7,218 for the year ended December 31, 2018, 2017 and 2016, respectively)	107	95	15,216
Prior service cost arising during the period (net of tax provision (benefit) of ($55), zero and $344 for the year ended December 31, 2018, 2017 and 2016, respectively)	(221)	0	948
Other comprehensive income (loss), net	(8,644)	9,252	11,035
Net comprehensive (income) loss attributable to noncontrolling interests	245,485	(22,584)	(71,707)
Comprehensive income (loss) attributable to the company	(893,694)	(507,259)	(918,545)
Noble Corp
Net loss	(1,089,970)	(451,732)	(828,007)
Other comprehensive income (loss)
Foreign currency translation adjustments	(2,729)	990	(19)
Net pension plan gain (loss) (net of tax provision (benefit) of ($1,828), $523 and ($1,828) for the year ended December 31, 2018, 2017 and 2016, respectively)	(7,099)	6,774	(8,237)
Amortization of deferred pension plan amounts (net of tax provision of $345, $623 and $1,635 for the year ended December 31, 2018, 2017 and 2016, respectively)	1,298	1,393	3,127
Net pension plan curtailment and settlement expense (net of tax provision of $28, zero and $7,218 for the year ended December 31, 2018, 2017 and 2016, respectively)	107	95	15,216
Prior service cost arising during the period (net of tax provision (benefit) of ($55), zero and $344 for the year ended December 31, 2018, 2017 and 2016, respectively)	(221)	0	948
Other comprehensive income (loss), net	(8,644)	9,252	11,035
Net comprehensive (income) loss attributable to noncontrolling interests	245,485	(22,584)	(71,707)
Comprehensive income (loss) attributable to the company	$ (853,129)	$ (465,064)	$ (888,679)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Benefit plans, before reclassifications, tax	$ (1,828)	$ 523	$ (1,828)
Benefit plans, reclassification adjustments, tax	345	623	1,635
Benefit plans, settlement for curtailments, tax	28	0	7,218
Benefit plans, prior service costs, tax	(55)	0	344
Noble Corp
Benefit plans, reclassification adjustments, tax	$ 345	$ 623	$ 1,635

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net loss	$ (1,130,535)	$ (493,927)	$ (857,873)
Adjustments to reconcile net loss to net cash flow from operating activities:
Depreciation and amortization	486,530	547,990	611,067
Loss on impairment	802,133	121,639	1,458,749
(Gain) loss on extinguishment of debt, net	1,793	0	(17,814)
Deferred income taxes	(68,416)	241,326	(189,897)
Amortization of share-based compensation	23,993	29,115	34,720
Other long-term asset write-off	0	29,032	0
Other costs, net	6,446	12,590	13,434
Change in taxes receivable	84,847	(49,865)	45
Net changes in other operating assets and liabilities	(34,940)	(21,225)	90,309
Net cash provided by operating activities	171,851	416,675	1,142,740
Cash flows from investing activities
Capital expenditures	(194,779)	(120,707)	(711,403)
Proceeds from disposal of assets	5,402	2,382	24,808
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
Cash flows from financing activities
Issuance of senior notes	750,000	0	980,100
Repayments of debt	(972,708)	(300,000)	(1,049,338)
Debt issuance costs on senior notes and credit facilities	(15,639)	(42)	(12,111)
Dividend payments	0	0	(47,534)
Dividends paid to noncontrolling interests	(27,579)	(56,881)	(85,944)
Tender offer premium	0	0	(24,649)
Taxes withheld on employee stock transactions	(3,470)	(4,320)	(3,192)
Net cash used in financing activities	(269,396)	(361,243)	(242,668)
Net increase (decrease) in cash, cash equivalents and restricted cash	(286,922)	(62,893)	213,477
Cash, cash equivalents and restricted cash, beginning of period	662,829	725,722	512,245
Cash, cash equivalents and restricted cash, end of period	375,907	662,829	725,722
Noble Corp
Cash flows from operating activities
Net loss	(1,089,970)	(451,732)	(828,007)
Adjustments to reconcile net loss to net cash flow from operating activities:
Depreciation and amortization	482,660	543,119	611,013
Loss on impairment	802,133	121,639	1,458,749
(Gain) loss on extinguishment of debt, net	1,793	0	(17,814)
Deferred income taxes	(68,416)	241,326	(189,897)
Amortization of share-based compensation	23,945	29,046	32,782
Other long-term asset write-off	0	29,030	0
Other costs, net	6,446	12,591	13,434
Change in taxes receivable	84,847	(49,865)	(38)
Net changes in other operating assets and liabilities	(30,679)	(20,080)	92,713
Net cash provided by operating activities	212,759	455,074	1,172,935
Cash flows from investing activities
Capital expenditures	(194,779)	(120,707)	(711,403)
Proceeds from disposal of assets	5,402	2,382	24,808
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
Cash flows from financing activities
Issuance of senior notes	750,000	0	980,100
Repayments of debt	(972,708)	(300,000)	(1,049,338)
Debt issuance costs on senior notes and credit facilities	(15,639)	(42)	(12,111)
Dividends paid to noncontrolling interests	(27,579)	(56,881)	(85,944)
Tender offer premium	0	0	(24,649)
Contributions (distributions) from (to) parent company, net	(44,417)	28,352	(152,360)
Net cash used in financing activities	(310,343)	(328,571)	(344,302)
Net increase (decrease) in cash, cash equivalents and restricted cash	(286,961)	8,178	142,038
Cash, cash equivalents and restricted cash, beginning of period	662,011	653,833	511,795
Cash, cash equivalents and restricted cash, end of period	$ 375,050	$ 662,011	$ 653,833

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands		Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests	Noble Corp	Noble CorpCommon Stock	Noble CorpAdditional Paid-in Capital	Noble CorpRetained Earnings	Noble CorpAccumulated Other Comprehensive Loss	Noble CorpNoncontrolling Interests
Beginning Balance (in shares) at Dec. 31, 2015			241,977,000						261,246,000
Beginning balance at Dec. 31, 2015		$ 7,422,230	$ 2,420	$ 628,483	$ 6,131,501	$ (63,175)	$ 723,001	$ 7,414,471	$ 26,125	$ 561,309	$ 6,167,211	$ (63,175)	$ 723,001
Employee related equity activity
Amortization of share-based compensation		34,720		34,720
Issuance of share-based compensation shares (in shares)			1,262,000
Issuance of share-based compensation shares		(3,613)	$ 12	(3,625)
Tax benefit of equity transactions		(5,410)		(5,410)
Distributions to parent company, net								(152,360)			(152,360)
Capital contribution by parent - share-based compensation								32,782		32,782
Net loss		(857,873)			(929,580)		71,707	(828,007)			(899,714)	0	71,707
Dividends paid to noncontrolling interests		(85,944)					(85,944)	(85,944)				0	(85,944)
Dividends equivalents		(47,700)			(47,700)
Other comprehensive income, net		11,035				11,035		11,035				11,035	0
Ending Balance at Dec. 31, 2016		6,467,445	$ 2,432	654,168	5,154,221	(52,140)	708,764	6,391,977	$ 26,125	594,091	5,115,137	(52,140)	708,764
Ending Balance (in shares) at Dec. 31, 2016			243,239,000						261,246,000
Employee related equity activity
Amortization of share-based compensation		29,115		29,115
Issuance of share-based compensation shares (in shares)			1,732,000
Issuance of share-based compensation shares		(5)	$ 18	(23)
Tax benefit of equity transactions		(4,338)		(4,338)
Contributions from parent company, net								28,352			28,352
Capital contribution by parent - share-based compensation								29,046		29,046
Net loss		(493,927)			(516,511)		22,584	(451,732)			(474,316)		22,584
Dividends paid to noncontrolling interests		(56,881)					(56,881)	(56,881)					(56,881)
Dividends equivalents		(33)			(33)
Other comprehensive income, net		9,252				9,252		9,252				9,252
Ending Balance at Dec. 31, 2017		$ 5,950,628	$ 2,450	678,922	4,637,677	(42,888)	674,467	$ 5,950,014	$ 26,125	623,137	4,669,173	(42,888)	674,467
Ending Balance (in shares) at Dec. 31, 2017		244,971,000	244,971,000					261,246,000	261,246,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, adjusted balance		$ 5,800,747	$ 2,450	678,922	4,493,336	(48,428)	674,467	$ 5,800,133	$ 26,125	623,137	4,524,832	(48,428)	674,467
Employee related equity activity
Adjustment for adopting the revenue recognition standard | Accounting Standards Update 2016-16		(148,393)			(148,393)			(148,393)			(148,393)
Adjustment for adopting the revenue recognition standard | Accounting Standards Update 2014-09 [Member]		(1,488)			(1,488)			$ (1,488)			(1,488)
Stranded tax effect resulting from the Act		$ (5,540)
Beginning Balance (in shares) at Dec. 31, 2017		244,971,000	244,971,000					261,246,000	261,246,000
Beginning balance at Dec. 31, 2017		$ 5,950,628	$ 2,450	678,922	4,637,677	(42,888)	674,467	$ 5,950,014	$ 26,125	623,137	4,669,173	(42,888)	674,467
Employee related equity activity
Amortization of share-based compensation		23,993		23,993
Issuance of share-based compensation shares (in shares)			1,823,000
Issuance of share-based compensation shares		0	$ 18	(18)
Tax benefit of equity transactions		(3,488)		(3,488)
Distributions to parent company, net								(44,417)			(44,417)
Capital contribution by parent - share-based compensation								23,945		23,945
Net loss		(1,130,535)			(885,050)		(245,485)	(1,089,970)			(844,485)		(245,485)
Stranded tax effect resulting from the Act					5,500
Dividends paid to noncontrolling interests		(27,579)					(27,579)	(27,579)					(27,579)
Dividends equivalents	[1]	80			80
Other comprehensive income, net		(8,644)				(8,644)		(8,644)				(8,644)
Ending Balance at Dec. 31, 2018		$ 4,654,574	$ 2,468	$ 699,409	$ 3,608,366	(57,072)	$ 401,403	$ 4,653,468	$ 26,125	$ 647,082	$ 3,635,930	$ (57,072)	$ 401,403
Ending Balance (in shares) at Dec. 31, 2018		246,794,000	246,794,000					261,246,000	261,246,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, adjusted balance						$ (48,428)
[1]	Activity associated with dividend equivalents, which are related to 2016 performance awards to be paid upon vesting.

Consolidated Joint Ventures

Consolidated Joint Ventures	12 Months Ended
	Dec. 31, 2018
Noncontrolling Interest [Abstract]
Consolidated Joint Ventures	Note 2— Consolidated Joint Ventures We maintain a 50 percent interest in two joint ventures, each with a subsidiary of Royal Dutch Shell plc (“Shell”), that own and operate the two Bully -class drillships. We have determined that we are the primary beneficiary of the joint ventures. Accordingly, we consolidate the entities in our consolidated financial statements after eliminating intercompany transactions. Shell’s equity interests are presented as noncontrolling interests on our Consolidated Balance Sheets. During the years ended December 31, 2018 , 2017 and 2016 , the Bully joint ventures approved and paid dividends totaling $55.2 million , $113.8 million and $171.9 million , respectively. Of these amounts, 50 percent was paid to our joint venture partner. The combined carrying amount of the Bully -class drillships at December 31, 2018 and 2017 totaled $0.7 billion and $1.3 billion , respectively. These assets were primarily funded through partner equity contributions. During the year ended December 31, 2018 , we recognized a $550.3 million impairment on the Noble Bully I , of which $250.3 million is attributable to our joint venture partner. See “ Note 6— Loss on Impairment ” for additional information. Cash held by the Bully joint ventures totaled approximately $45.2 million at December 31, 2018 as compared to approximately $41.6 million at December 31, 2017 .

Organization and Significant Ac

Organization and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Significant Accounting Policies	Note 1— Organization and Significant Accounting Policies Noble Corporation plc, a public limited company incorporated under the laws of England and Wales (“Noble-UK”), is a leading offshore drilling contractor for the oil and gas industry. We provide contract drilling services to the international oil and gas industry with our global fleet of mobile offshore drilling units. As of December 31, 2018 , our fleet of 24 drilling rigs consisted of eight drillships, four semisubmersibles and 12 jackups. We report our contract drilling operations as a single reportable segment, Contract Drilling Services, which reflects how we manage our business. The mobile offshore drilling units comprising our offshore rig fleet operate in a global market for contract drilling services and are often redeployed to different regions due to changing demands of our customers, which consist primarily of large, integrated, independent and government-owned or controlled oil and gas companies throughout the world. Noble Corporation, a Cayman Islands company (“Noble-Cayman”), is an indirect, wholly-owned subsidiary of Noble-UK, our publicly-traded parent company. Noble-UK’s principal asset is all of the shares of Noble-Cayman. Noble-Cayman has no public equity outstanding. The consolidated financial statements of Noble-UK include the accounts of Noble-Cayman, and Noble-UK conducts substantially all of its business through Noble-Cayman and its subsidiaries. Principles of Consolidation The consolidated financial statements include our accounts, those of our wholly-owned subsidiaries and entities in which we hold a controlling financial interest. Our consolidated financial statements also include the accounts of two joint ventures, in each of which we own a 50 percent interest. Our ownership interest meets the definition of variable interest under Financial Accounting Standards Board (“FASB”) codification and we have determined that we are the primary beneficiary. Intercompany balances and transactions have been eliminated in consolidation. The combined carrying amount of the Bully -class drillships at December 31, 2018 and 2017 totaled $0.7 billion and $1.3 billion , respectively. These assets were primarily funded through partner equity contributions. Cash held by the Bully joint ventures totaled approximately $45.2 million at December 31, 2018 as compared to approximately $41.6 million at December 31, 2017 . Revision of Prior Period Financial Statements During the preparation of our 2018 financial statements, we identified a computational error that resulted in misstatements of certain line items on the Consolidated Statements of Cash Flows for Noble Corporation plc and Noble Corporation (Cayman) for the years ended December 31, 2017 and 2016 . These errors did not impact our cash, cash equivalents and restricted cash balances. We assessed the materiality of the misstatements and concluded the misstatements were immaterial to the previously issued financial statements. We have revised the Consolidated Statements of Cash Flows for the years ended December 31, 2017 and 2016 . The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 16,038 $ (37,263 ) $ (21,225 ) $ 73,645 $ 16,664 $ 90,309 Net cash provided by operating activities 453,938 (37,263 ) 416,675 1,126,076 16,664 1,142,740 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 17,183 $ (37,263 ) $ (20,080 ) $ 76,049 $ 16,664 $ 92,713 Net cash provided by operating activities 492,337 (37,263 ) 455,074 1,156,271 16,664 1,172,935 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) Foreign Currency Translation Although we are a UK company, our functional currency is the U.S. dollar, and we define any non-U.S. dollar denominated currency as “foreign currencies.” In non-U.S. locations where the U.S. Dollar has been designated as the functional currency (based on an evaluation of factors including the markets in which the subsidiary operates, inflation, generation of cash flow, financing activities and intercompany arrangements), local currency transaction gains and losses are included in net income or loss. In non-U.S. locations where the local currency is the functional currency, assets and liabilities are translated at the rates of exchange on the balance sheet date, while statement of operations items are translated at average rates of exchange during the year. The resulting gains or losses arising from the translation of accounts from the functional currency to the U.S. Dollar are included in “Accumulated other comprehensive loss” in the Consolidated Balance Sheets. We did not recognize any material gains or losses on foreign currency transactions or translations during the three years ended December 31, 2018 . Cash and Cash Equivalents Cash and cash equivalents include cash on hand, demand deposits with banks and all highly liquid investments with original maturities of three months or less. Our cash, cash equivalents and short-term investments are subject to potential credit risk, and certain of our cash accounts carry balances greater than the federally insured limits. Cash and cash equivalents are primarily held by major banks or investment firms. Our cash management and investment policies restrict investments to lower risk, highly liquid securities and we perform periodic evaluations of the relative credit standing of the financial institutions with which we conduct business. Restricted Cash We classify restricted cash balances in current assets if the restriction is expected to expire or otherwise be resolved within one year and in other assets if the restriction is expected to expire or otherwise be resolved in more than one year. As of December 31, 2018 , our restricted cash balance consisted of $0.7 million of restricted cash accounts for interest payments associated with our financing of the Noble Johnny Whitstine , recorded in Prepaid expenses and other current assets. As of December 31, 2017 and 2016 , we had no restricted cash balances. Accounts Receivable We record accounts receivable at the amount we invoice our clients, net of allowance for doubtful accounts. We provide an allowance for uncollectible accounts, as necessary. Our allowance for doubtful accounts as of December 31, 2018 and 2017 was $2.2 million and $20.8 million , respectively. Property and Equipment Property and equipment is stated at cost, reduced by provisions to recognize economic impairment. Major replacements and improvements are capitalized. When assets are sold, retired or otherwise disposed of, the cost and related accumulated depreciation are eliminated from the accounts and the gain or loss is recognized. Drilling equipment and facilities are depreciated using the straight-line method over their estimated useful lives as of the date placed in service or date of major refurbishment. Estimated useful lives of our drilling equipment range from three to thirty years . Other property and equipment is depreciated using the straight-line method over useful lives ranging from two to forty years. Included in accounts payable were $52.1 million and $25.5 million of capital accruals as of December 31, 2018 and 2017 , respectively. Interest is capitalized on long-term construction project using the weighted average cost of debt outstanding during the period of construction. Scheduled maintenance of equipment is performed based on the number of hours operated in accordance with our preventative maintenance program. Routine repair and maintenance costs are charged to expense as incurred; however, the costs of the overhauls and asset replacement projects that benefit future periods and which typically occur every three to five years are capitalized when incurred and depreciated over an equivalent period. These overhauls and asset replacement projects are included in “Drilling equipment and facilities” in “ Note 5— Property and Equipment .” We evaluate our property and equipment for impairment whenever there are changes in facts which suggest that the value of the asset is not recoverable. For more detailed information, see “ Note 6— Loss on Impairment .” Fair Value Measurements We measure certain of our assets and liabilities based on a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The three-level hierarchy, from highest to lowest level of observable inputs, are as follows: Level 1 - Valuations based on quoted prices in active markets for identical assets; Level 2 - Valuations based on observable inputs that do not meet the criteria for Level 1, including quoted prices in inactive markets and quoted prices in active markets for similar but not identical instruments; and Level 3 - Valuations based on unobservable inputs. Revenue Recognition The activities that primarily drive the revenue earned in our drilling contracts include (i) providing a drilling rig and the crew and supplies necessary to operate the rig, (ii) mobilizing and demobilizing the rig to and from the drill site, and (iii) performing rig preparation activities and/or modifications required for the contract. Consideration received for performing these activities may consist of dayrate drilling revenue, mobilization and demobilization revenue, contract preparation revenue and reimbursement revenue. We account for these integrated services provided within our drilling contracts as a single performance obligation satisfied over time and comprised of a series of distinct time increments in which we provide drilling services. Our standard drilling contracts require that we operate the rig at the direction of the customer throughout the contract term (which is the period we estimate to benefit from the corresponding activities and generally ranges from two to 60 months). The activities performed and the level of service provided can vary hour to hour. Our obligation under a standard contract is to provide whatever level of service is required by the operator, or customer, over the term of the contract. We are, therefore, under a stand-ready obligation throughout the entire contract duration. Consideration for our stand-ready obligation corresponds to distinct time increments, though the rate may be variable depending on various factors, and is recognized in the period in which the services are performed. The total transaction price is determined for each individual contract by estimating both fixed and variable consideration expected to be earned over the term of the contract. We have elected to exclude from the transaction price measurement all taxes assessed by a governmental authority. See further discussion regarding the allocation of the transaction price to the remaining performance obligations below. The amount estimated for variable consideration may be subject to interrupted or restricted rates and is only included in the transaction price to the extent that it is probable that a significant reversal of previously recognized revenue will not occur throughout the term of the contract (“constrained revenue”). When determining if variable consideration should be constrained, management considers whether there are factors outside the Company’s control that could result in a significant reversal of revenue as well as the likelihood and magnitude of a potential reversal of revenue. These estimates are re-assessed each reporting period as required. Dayrate Drilling Revenue. Our drilling contracts generally provide for payment on a dayrate basis, with higher rates for periods when the drilling unit is operating and lower rates or zero rates for periods when drilling operations are interrupted or restricted. The dayrate invoices billed to the customer are typically determined based on the varying rates applicable to the specific activities performed on an hourly basis. Such dayrate consideration is allocated to the distinct hourly increment it relates to within the contract term, and therefore, recognized in line with the contractual rate billed for the services provided for any given hour. Mobilization/Demobilization Revenue. We may receive fees (on either a fixed lump-sum or variable dayrate basis) for the mobilization and demobilization of our rigs. These activities are not considered to be distinct within the context of the contract and, therefore, the associated revenue is allocated to the overall performance obligation and the associated pre-operating costs are deferred. We record a contract liability for mobilization fees received and a deferred asset for costs. Both revenue and pre-operating costs are recognized ratably over the initial term of the related drilling contract. In most contracts, there is uncertainty as to the amount of expected demobilization revenue due to contractual provisions that stipulate that certain conditions must be present at contract completion for such revenue to be received and as to the amount thereof, if any. For example, contractual provisions may require that a rig demobilize a certain distance before the demobilization revenue is payable or the amount may vary dependent upon whether or not the rig has additional contracted work within a certain distance from the wellsite. Therefore, the estimate for such revenue may be constrained, as described earlier, depending on the facts and circumstances pertaining to the specific contract. We assess the likelihood of receiving such revenue based on past experience and knowledge of the market conditions. In cases where demobilization revenue is expected to be received upon contract completion, it is estimated as part of the overall transaction price at contract inception and recognized in earnings ratably over the initial term of the contract with an offset to an accretive contract asset. Contract Preparation Revenue. 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 fixed lump-sum or variable dayrate basis). These activities are not considered to be distinct within the context of the contract and, therefore, the related revenue is allocated to the overall performance obligation and recognized ratably over the initial term of the related drilling contract. We record a contract liability for contract preparation fees received, which is amortized ratably to contract drilling revenue over the initial term of the related drilling contract. Bonuses, Penalties and Other Variable Consideration. We may receive bonus increases to revenue or penalty decreases to revenue. Based on historical data and ongoing communication with the operator/customer, we are able to reasonably estimate this variable consideration. We will record such estimated variable consideration and re-measure our estimates at each reporting date. For revenue estimated, but not received, we will record to “Prepaid expenses and other current assets” on our Consolidated Balance Sheets. Capital Modification Revenue . From time to time, we may receive fees from our customers for capital improvements to our rigs to meet contractual requirements (on either a fixed lump-sum or variable dayrate basis). Such revenue is allocated to the overall performance obligation and recognized ratably over the initial term of the related drilling contract as these activities are integral to our drilling activities and are not considered to be a stand-alone service provided to the customer within the context of our contracts. We record a contract liability for such fees and recognize them ratably as contract drilling revenue over the initial term of the related drilling contract. Revenues Related to Reimbursable Expenses . We generally receive reimbursements from our customers for the purchase of supplies, equipment, personnel services and other services provided at their request in accordance with a drilling contract or other agreement. Such reimbursable revenue is variable and subject to uncertainty, as the amounts received and timing thereof is highly dependent on factors outside of our influence. Accordingly, reimbursable revenue is constrained revenue and not included in the total transaction price until the uncertainty is resolved, which typically occurs when the related costs are incurred on behalf of a customer. We are generally considered a principal in such transactions and record the associated revenue at the gross amount billed to the customer as “Reimbursables and other” in our Consolidated Statements of Operations. Such amounts are recognized ratably over the period within the contract term during which the corresponding goods and services are to be consumed. Deferred revenues from drilling contracts totaled $80.8 million and $114.3 million at December 31, 2018 and 2017 , respectively. Such amounts are included in either “Other current liabilities” or “Other liabilities” in the accompanying Consolidated Balance Sheets, based upon our expected time of recognition. Related expenses deferred under drilling contracts totaled $47.7 million at December 31, 2018 as compared to $55.7 million at December 31, 2017 and are included in either “Prepaid expenses and other current assets,” “Other assets” or “Property and equipment, net” in the accompanying Consolidated Balance Sheets, based upon our expected time of recognition. We record reimbursements from customers for “out-of-pocket” expenses as revenues and the related direct cost as operating expenses. Income Taxes Income taxes are based on the laws and rates in effect in the countries in which operations are conducted or in which we or our subsidiaries are considered resident for income tax purposes. In certain circumstances, we expect that, due to changing demands of the offshore drilling markets and the ability to redeploy our offshore drilling units, certain of such units will not reside in a location long enough to give rise to future tax consequences. As a result, no deferred tax asset or liability has been recognized in these circumstances. Should our expectations change regarding the length of time an offshore drilling unit will be used in a given location, we will adjust deferred taxes accordingly. Deferred tax assets and liabilities are recognized for the anticipated future tax effects of temporary differences between the financial statement basis and the tax basis of our assets and liabilities using the applicable jurisdictional tax rates at year-end. A valuation allowance for deferred tax assets is recorded when it is more likely than not that the deferred tax asset will not be realized in a future period. We operate through various subsidiaries in numerous countries throughout the world, including the United States. Consequently, we are subject to changes in tax laws, treaties or regulations or the interpretation or enforcement thereof in the U.S., UK or jurisdictions in which we or any of our subsidiaries operate or are resident. Our income tax expense is based upon our interpretation of the tax laws in effect in various countries at the time that the expense was incurred. If the IRS or other taxing authorities do not agree with our assessment of the effects of such laws, treaties and regulations, this could have a material adverse effect on us including the imposition of a higher effective tax rate on our worldwide earnings or a reclassification of the tax impact of our significant corporate restructuring transactions. The Company has adopted an accounting policy to look through the outside basis of partnerships and all other flow-through entities and exclude these from the computation of deferred taxes. On December 22, 2017, the President of the United States signed into law legislation informally known as the Tax Cuts and Jobs Act (the “Act”). The Act represents major tax reform legislation that, among other provisions, reduces the U.S. corporate tax rate. The Company recognized the income tax effects of the Act in its 2017 financial statements, including $109.0 million of tax benefit related to the write-down of our net deferred tax liabilities, in accordance with Accounting Standards Codification (“ASC”) Topic 740, Income Taxes, in the reporting period in which the Act was enacted. During the fourth quarter of 2017, the Act resulted in the write-down of our U.S. net deferred tax liabilities. In accordance with the guidance issued in Staff Accounting Bulletin No. 118 (SAB No. 118), during the third quarter of 2018, we finalized our provisional amounts recorded as we completed our technical analysis, computations and tax law interpretations and filed our 2017 U.S. tax return. As a result, we recognized an additional tax benefit of $24.9 million . See “ Note 11— Income Taxes ,” for further information on the financial statement impact of the Act. The Act introduces a new anti-deferral provision, which subjects a U.S. parent shareholder to current tax on certain income referred to as Global Intangible Low-Taxed Income, of its foreign subsidiaries. The Company has adopted a policy to treat tax due on future U.S. inclusions in taxable income as period costs when incurred. Insurance Reserves We maintain various levels of self-insured retention for certain losses including property damage, loss of hire, employment practices liability, employers’ liability and general liability, among others. We accrue for property damage and loss of hire charges on a per event basis. Employment practices liability claims are accrued based on actual claims during the year. Maritime employer’s liability claims are generally estimated using actuarial determinations. General liability claims are estimated by our internal claims department by evaluating the facts and circumstances of each claim (including incurred but not reported claims) and making estimates based upon historical experience with similar claims. At December 31, 2018 and 2017 , loss reserves for personal injury and protection claims totaled $22.4 million and $22.0 million , respectively, and such amounts are included in “Other current liabilities” in the accompanying Consolidated Balance Sheets. Earnings per Share Our unvested share-based payment awards, which contain non-forfeitable rights to dividends, are participating securities and are included in the computation of earnings per share pursuant to the two-class method. The two-class method allocates undistributed earnings between common shares and participating securities. The diluted earnings per share calculation under the two-class method also includes the dilutive effect of potential shares issued in connection with stock options. The dilutive effect of stock options is determined using the treasury stock method. Share-Based Compensation Plans We record the grant date fair value of share-based compensation arrangements as compensation cost using a straight-line method over the service period. Share-based compensation is expensed or capitalized based on the nature of the employee’s activities. Litigation Contingencies We are involved in legal proceedings, claims, and regulatory, tax or government inquiries and investigations that arise in the ordinary course of business. Certain of these matters include speculative claims for substantial or indeterminate amounts of damages. We record a liability when we believe that it is both probable that a loss has been incurred and the amount can be reasonably estimated. If we determine that a loss is reasonably possible and the loss or range of loss can be estimated, we disclose the possible loss in the notes to the consolidated financial statements. We review the developments in our contingencies that could affect the amount of the provisions that has been previously recorded, and the matters and related possible losses disclosed. We make adjustments to our provisions and changes to our disclosures accordingly to reflect the impact of negotiations, settlements, rulings, advice of legal counsel, and updated information. Significant judgement is required to determine both the probability and the estimated amount. Discontinued Operations On August 1, 2014, Noble-UK completed the separation and spin-off of a majority of its standard specification offshore drilling business (the “Spin-off”) through a pro rata distribution of all of the ordinary shares of its wholly-owned subsidiary, Paragon Offshore plc (“Paragon Offshore”), to the holders of Noble’s ordinary shares. Paragon Offshore, which had been reflected as continuing operations in our consolidated financial statements prior to the Spin-off, meets the criteria for being reported as discontinued operations and has been reclassified as such in our results of operations. Prior to the completion of the Spin-off, Noble-UK and Paragon Offshore entered into a series of agreements to effect the separation and Spin-off and govern the relationship between the parties after the Spin-off (the “Separation Agreements”), including the Master Separation Agreement (the “MSA”) and the Tax Sharing Agreement (the “TSA”). During the year ended December 31, 2017 , we recorded a non-cash loss of $1.5 million in “Net loss from discontinued operations, net of tax” on our Consolidated Statement of Operations from the effects of Paragon Offshore's rejection of the Separation Agreements. For additional information related to the Spin-off, refer to “ Note 15— Commitments and Contingencies .” Certain Significant Estimates 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. Certain accounting policies involve judgments and uncertainties to such an extent that there is reasonable likelihood that materially different amounts could have been reported under different conditions, or if different assumptions had been used. We evaluate our estimates and assumptions on a regular basis. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates and assumptions used in preparation of our consolidated financial statements. Accounting Pronouncements Accounting Standards Adopted In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, which creates ASC Topic 606, “Revenue from Contracts with Customers,” and supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” including most industry-specific revenue recognition guidance throughout the Industry Topics of the Codification. In addition, ASU No. 2014-09 supersedes the cost guidance in Subtopic 605-35, “Revenue Recognition—Construction-Type and Production-Type Contracts,” and creates new Subtopic 340-40, “Other Assets and Deferred Costs—Contracts with Customers.” Under the new guidance, revenue is recognized when a customer obtains control of promised goods or services and in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. We adopted ASU 2014-09 and its related amendments, or collectively Topic 606, effective January 1, 2018 using the modified retrospective implementation method. Accordingly, we have applied the five-step method outlined in Topic 606 for determining when and how revenue is recognized to all contracts that were not completed as of the date of adoption. Revenues for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts have not been adjusted and continue to be reported under the previous revenue recognition guidance. For contracts that were modified before the effective date, we have considered the modification guidance within the new standard and determined that the revenue recognized and contract balances recorded prior to adoption for such contracts were not impacted. While Topic 606 requires additional disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, its adoption has not had a material impact on the measurement or recognition of our revenues. Our modified retrospective adoption, for which we were not required to make any material changes to the prior year presentation, did not have a material effect on our consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, which amends ASC Topic 740, “Income Taxes.” The amendments in this update improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. This standard is effective for interim and annual reporting periods beginning after December 15, 2017. We adopted the new standard effective January 1, 2018 under the modified retrospective approach. Accordingly, we recorded deferred charges of approximately $148.4 million to “Retained earnings” on our Consolidated Balance Sheets. In March 2017, the FASB issued ASU No. 2017-07, which amends ASC Topic 715, “Compensation —Retirement Benefits; Improving the Presentation of Net Periodic Pension Cost and Postretirement Benefits Cost.” The amendments in this update require that an employer disaggregate the service cost component from the other components of net benefit cost for an entity's defined benefit pension and other postretirement plans. The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement and allow only the service cost component of net benefit cost to be eligible for capitalization. The amendments in this update require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit costs, as defined in paragraphs 715-30-35-4 and 715-60-35-9, are required to be presented in the income statement separately from the service cost component and outside of income from operations. We adopted ASU No. 2017-07 effective January 1, 2018 and accordingly, we have made certain reclassifications between our “Contract drilling services” costs and “Interest income and other, net” on our Consolidated Statement of Operations. In February 2018 , the FASB issued ASU No. 2018 -02, which amends ASC Topic 220, “Income Statement—Reporting Comprehensive Income.” The amendments in this update allow for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Act. This standard is effective for interim and annual reporting periods beginning after December 15, 2018 with early application permitted. We elected to adopt the new standard effective January 1, 2018 under the modified retrospective approach. The amendment should be applied on a retrospective basis to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Act was recognized. As a result of the retrospective application, we reduced “Accumulated other comprehensive loss” in our Consolidated Balance Sheet with a cumulative adjustment to “Retained earnings” of approximately $5.5 million . In August 2018 , the FASB issued ASU No. 2018 -15, which amends ASC Subtopic 350-40, “Intangibles—Goodwill and Other—Internal—Use Software.” The amendments in this update require an entity in a hosting arrangement that is a service contract to capitalize implemen

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Loss Per Share	Note 3— Loss Per Share The following table presents the computation of basic and diluted loss per share for Noble-UK: Year Ended December 31, 2018 2017 2016 Numerator: Basic Net loss from continuing operations $ (885,050 ) $ (515,025 ) $ (929,580 ) Net loss from discontinued operations, net of tax — (1,486 ) — Net loss attributable to Noble Corporation plc $ (885,050 ) $ (516,511 ) $ (929,580 ) Diluted Net loss from continuing operations $ (885,050 ) $ (515,025 ) $ (929,580 ) Net loss from discontinued operations, net of tax — (1,486 ) — Net loss attributable to Noble Corporation plc $ (885,050 ) $ (516,511 ) $ (929,580 ) Denominator: Weighted average shares outstanding - basic 246,614 244,743 243,127 Weighted average shares outstanding - diluted 246,614 244,743 243,127 Loss per share Basic: Loss from continuing operations $ (3.59 ) $ (2.10 ) $ (3.82 ) Loss from discontinued operations — (0.01 ) — Net loss attributable to Noble Corporation plc $ (3.59 ) $ (2.11 ) $ (3.82 ) Diluted: Loss from continuing operations $ (3.59 ) $ (2.10 ) $ (3.82 ) Loss from discontinued operations — (0.01 ) — Net loss attributable to Noble Corporation plc $ (3.59 ) $ (2.11 ) $ (3.82 ) Dividends per share $ — $ — $ 0.20 Only those items having a dilutive impact on our basic loss per share are included in diluted loss per share. For the years ended December 31, 2018 , 2017 and 2016 , 12.5 million , 12.0 million and 9.9 million share-based awards, respectively, were excluded from the diluted loss per share since the effect would have been anti-dilutive.

Receivables from Customers

Receivables from Customers	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Receivables from Customers	Note 4— Receivables from Customers At December 31, 2016 , we had receivables of approximately $14.4 million related to the Noble Max Smith , which had been disputed by our former customer, Petróleos Mexicanos (“Pemex”) and were classified as long-term and included in “Other assets” on our Consolidated Balance Sheet. The receivables were related to lost revenues for downtime that occurred after our rig was damaged when one of Pemex's supply boats collided with our rig in 2010. A Mexican subsidiary of Paragon Offshore, which had operated the Noble Max Smith , had been prosecuting the claim against Pemex. As of December 31, 2017 , Paragon Offshore announced that, as part of its bankruptcy plan, it will liquidate the Mexican entity involved. While Noble owns all rights to amounts from that claim and will take available actions to recover such amounts, we believe the announced actions by Paragon Offshore create uncertainty relating to the prosecution of the claim and associated recovery, and accordingly, the disputed amounts of approximately $14.4 million were written off through “Contract drilling services” costs on our Consolidated Statements of Operations during the year ended December 31, 2017 .

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Note 5— Property and Equipment Property and equipment, at cost, for Noble-UK consisted of the following: Year Ended December 31, 2018 2017 Drilling equipment and facilities $ 10,546,376 $ 11,746,629 Construction in progress 209,091 83,509 Other 200,945 204,193 Property and equipment, at cost $ 10,956,412 $ 12,034,331 Capital expenditures, including capitalized interest, totaled $281.3 million , $111.1 million and $659.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. During the years ended December 31, 2018 , 2017 and 2016 , capitalized interest was $2.9 million , zero and $22.4 million , respectively. During the year ended December 31, 2017 , we recognized a $14.3 million charge in “Contract drilling services” costs related to damages sustained on the Noble Danny Adkins and Noble Jim Day during Hurricane Harvey in the U.S. Gulf of Mexico region. On September 21, 2018 , we purchased the Noble Johnny Whitstine, a new GustoMSC CJ46 design jackup rig, from the PaxOcean Group (“PaxOcean”) in connection with a concurrently awarded drilling contract in the Middle East region. We paid $93.8 million for the rig, with $33.8 million paid in cash and the remaining $60.0 million of the purchase price financed by the seller. See “ Note 7— Debt ” for additional information. During the years ended December 31, 2018 , 2017 and 2016 , we recognized a non-cash loss on impairment of $802.1 million , $121.6 million and $1.5 billion , respectively, related to our long-lived assets. See “ Note 6— Loss on Impairment ” for additional information.

Loss on Impairment

Loss on Impairment	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Loss on Impairment	Note 6— Loss on Impairment Asset Impairments In connection with the preparation of the consolidated financial statements included in this Annual Report, consistent with our accounting policies discussed in “ Note 1— Organization and Significant Accounting Policies ,” we evaluate our property and equipment for impairment whenever there are changes in facts which suggest that the value of the asset is not recoverable. In connection with the preparation of our financial statements for the year ended December 31, 2018 , we conducted a review of our fleet. The review included an assessment of certain assumptions, including future marketability of each unit in light of its current technical specifications. Assumptions used in our assessment included, but were not limited to, timing of future contract awards and expected operating dayrates, operating costs, utilization rates, discount rates, capital expenditures, reactivation costs, estimated economic useful lives and, in certain cases, our belief that a drilling unit is no longer marketable and is unlikely to return to service. During the years ended December 31, 2018 , 2017 , and 2016 , we recognized a non-cash loss on impairment of $802.1 million , $121.6 million and $1.5 billion , respectively, related to certain rigs and related capital spares. Based upon our impairment analysis, we impaired the carrying values to estimated fair values for the Noble Bully I, Noble Dave Beard, Noble Gene House, Noble Joe Beall, Noble Paul Romano, and certain capital spare equipment. During the year ended December 31, 2018 , impairment charges related to these units and certain capital spare equipment were approximately $802.1 million . For our impaired units, we estimated the fair values of these units by applying the income valuation approach utilizing significant unobservable inputs, representative of a Level 3 fair value measurement. During the year ended December 31, 2018 , we recognized a $550.3 million impairment on the Noble Bully I, of which $250.3 million is attributable to our joint venture partner. See “ Note 2— Consolidated Joint Ventures ” for additional information. During the year ended December 31, 2017 , we identified indicators that certain assets in our fleet might not be recoverable. Such indicators included additional customer suspensions of drilling programs, contract cancellations, a further reduction in the number of new contract opportunities, resulting in reduced drilling contracts, and our belief that a drilling unit is no longer marketable and is unlikely to return to service. As a result, we determined that the carrying amounts of the Noble Amos Runner, Noble Alan Hay , Noble David Tinsley and certain capital spares were impaired and recorded an impairment charge of approximately $121.6 million . During the year ended December 31, 2016 , in connection with our impairment analysis, we impaired the carrying values to estimated fair values for the Noble Amos Runne r, Noble Clyde Boudreaux and Noble Dave Beard and recorded a charge of $1.0 billion related to these units. In addition, we concluded that the semisubmersible, the Noble Homer Ferrington, and certain capital spare equipment would not be utilized in the foreseeable future, and we recognized impairment charges of approximately $120.1 million and $170.5 million , respectively. Further, we decided to retire our semisubmersible, Noble Max Smith , which was sold for $1.2 million after we recognized an impairment charge during the year of approximately $164.8 million .

Debt

Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Debt	Note 7— Debt Credit Facilities 2015 Credit Facility At December 31, 2017 , we had a five -year $2.4 billion senior unsecured credit facility that matures in January 2020 and is guaranteed by our indirect, wholly-owned subsidiaries, Noble Holding (U.S.) LLC (“NHUS”) and Noble Holding International Limited (“NHIL”) (the “2015 Credit Facility”). At December 31, 2017 , the 2015 Credit Facility also provided us with the ability to issue up to $500.0 million in letters of credit. On December 19, 2017, we entered into the First Amendment and Consent and Successor Agent Agreement (the “Amendment”) amending the 2015 Credit Facility. On January 3, 2018, the Amendment to the 2015 Credit Facility became fully effective. The Amendment caused, among other things, a reduction in the aggregate principal amount of commitments under the 2015 Credit Facility to $300.0 million and the termination of the 2015 Credit Facility's letter of credit sub-facility. The maturity of the 2015 Credit Facility remains January 2020. As a result of the 2015 Credit Facility's reduction in the aggregate principal amount of commitments, we recognized a net loss of approximately $2.3 million in the year ended December 31, 2018 . At December 31, 2018 , we had no borrowings outstanding or letters of credit issued under the 2015 Credit Facility. 2017 Credit Facility On December 21, 2017, Noble Cayman Limited, a Cayman Islands company and a wholly-owned indirect subsidiary of Noble-Cayman (“NCL”); Noble International Finance Company, a Cayman Islands company and a wholly-owned indirect subsidiary of Noble-Cayman (“NIFCO”); and Noble Holding UK Limited, a company incorporated under the laws of England and Wales and a wholly-owned direct subsidiary of Noble-UK (“NHUK”), as parent guarantor, entered into a new senior unsecured credit agreement (the “2017 Credit Facility” and, together with the 2015 Credit Facility, the “Credit Facilities”). The maximum aggregate amount of commitments under the 2017 Credit Facility is approximately $1.5 billion . Borrowings under the 2017 Credit Facility are subject to certain conditions precedent, including that there be no unused commitments to advance loans under the 2015 Credit Facility. The 2017 Credit Facility will mature in January 2023 . Borrowings may be used for working capital and other general corporate purposes. The 2017 Credit Facility provides for a letter of credit sub-facility currently in the amount of $15.0 million , with the ability to increase such amount up to $500.0 million with the approval of the lenders. At December 31, 2018 , we had $3.4 million of performance letters of credit outstanding under the 2017 Credit Facility. At December 31, 2018 , other than the performance letters of credit, we had no borrowings outstanding under the 2017 Credit Facility. Both of our Credit Facilities have provisions which vary the applicable interest rates for borrowings based upon our debt ratings. We also pay a facility fee under the 2015 Credit Facility on the full commitments thereunder (used or unused) and a commitment fee under the 2017 Credit Facility on the daily unused amount of the underlying commitments, in each case which varies depending on our credit ratings. At December 31, 2018 , the interest rates in effect under our Credit Facilities were the highest permitted interest rates under those agreements. Debt Issuance In January 2018, we issued $750.0 million aggregate principal amount of our Senior Notes due 2026 (the “2026 Notes”) through our indirect wholly-owned subsidiary, NHIL. The net proceeds of the offering of approximately $737.4 million , after expenses, were used to retire a portion of our near-term senior notes in a related tender offer. The indenture for the 2026 Notes contains certain covenants and restrictions, including, among others, restrictions on our subsidiaries’ ability to incur certain additional indebtedness. Additionally, the subsidiary guarantors must own, directly or indirectly, (i) assets comprising at least 85% of the revenue of Noble-Cayman and its subsidiaries on a consolidated basis and (ii) jackups, semisubmersibles, drillships, submersibles or other mobile offshore drilling units of material importance, the combined book value of which comprises at least 85% of the combined book value of all such assets of Noble-Cayman and its subsidiaries on a consolidated basis, in each case, with respect to the most recently completed fiscal year. Seller Financing of Rigs In September 2018, we purchased the Noble Johnny Whitstine for $93.8 million with a $60.0 million seller-financed secured loan (the “Seller Loan”). The Seller Loan has a term of four years and requires a 5% principal payment at the end of the third year with the remainder of the principal due at the end of the term. The Seller Loan bears a cash interest rate of 4.25% and the equivalent of a 1.25% interest rate paid-in-kind over the four year term of the Seller Loan. Based on the terms of the Seller Loan, the 1.25% paid-in-kind interest rate is accelerated into the first year, resulting in an overall first year interest rate of 8.91% , of which only 4.25% is payable in cash. Thereafter, the paid-in-kind interest ends and the cash interest rate of 4.25% is payable for the remainder of the term. The Seller Loan is guaranteed by Noble-Cayman and is secured by a mortgage on the Noble Johnny Whitstine and by the pledge of the shares of the single-purpose entity that owns the rig. The Seller Loan contains debt to total capitalization ratio and minimum liquidity financial covenants substantially similar to the 2017 Credit Facility, and an asset and revenue covenant substantially similar to the 2026 Notes as well as other covenants and provisions customarily found in secured transactions. The Seller Loan requires immediate repayment on the occurrence of certain events, including the termination of the drilling contract entered into at the time of the purchase of the rig. On February 14, 2019, we exercised our option to purchase a new jackup rig, to be known as the Noble Joe Knight , and we expect to complete the purchase in late February 2019. The purchase of the Noble Joe Knight will be partially funded with cash and seller loan on terms similar to the Noble Johnny Whitstine . Senior Notes Interest Rate Adjustments During 2016 and 2017, we experienced debt rating downgrades by Moody’s Investors Service and S&P Global Ratings, which reduced our debt ratings below investment grade. As a result of these downgrades, we experienced interest rate increases during 2016 and 2017 on our Senior Notes due 2018 (the “2018 Notes”), our Senior Notes due 2025 (the “2025 Notes”) and our Senior Notes due 2045 (the “2045 Notes”), all of which are subject to provisions that vary the applicable interest rates based on our debt rating. On October 18, 2017, S&P Global Ratings further reduced our debt rating, which increased the interest rates on the 2025 Notes and the 2045 Notes to 7.95% and 8.95% , respectively, effective April 2018. These senior notes have reached the contractually defined maximum interest rate set for each rating agency and no further interest rate increases are possible. The interest rates on these senior notes may be decreased if our debt ratings were to be raised by either rating agency above specified levels. Our other outstanding senior notes do not contain provisions varying applicable interest rates based upon our credit ratings. Debt Tender Offers, Repayments and Open Market Repurchases In January 2018, we commenced cash tender offers for the 2018 Notes, our Senior Notes due 2019 (the “ 2019 Notes”), our Senior Notes due 2020 , our Senior Notes due 2021 , our Senior Notes due 2022 and our Senior Notes due 2024 . In February 2018 , we purchased $754.2 million aggregate principal amount of these senior notes for $750.0 million , plus accrued interest, using the net proceeds of the 2026 Notes issuance and cash on hand. As a result of this transaction, we recognized a net loss of approximately $3.5 million . In February 2018, we redeemed the remaining principal amount of $61.9 million of the 2019 Notes for approximately $65.3 million , plus accrued interest. As a result of this transaction, we recognized a net loss of approximately $3.5 million . In March 2018, we repaid the remaining aggregate principal amount of $126.6 million of the 2018 Notes at maturity using cash on hand. In March 2018, we purchased $9.5 million aggregate principal amount of various tranches of our senior notes for approximately $8.7 million , plus accrued interest, as open market repurchases and recognized a net gain of approximately $0.5 million . In August 2018, we purchased $0.4 million aggregate principal amount of our Senior Notes due 2042 for approximately $0.3 million , plus accrued interest, as open market repurchases and recognized a net gain of approximately $0.1 million . In October 2018, we purchased $27.4 million aggregate principal amount of various tranches of our senior notes for approximately $20.2 million , plus accrued interest, as open market repurchases and recognized a net gain of approximately $6.9 million . Covenants The 2015 Credit Facility is guaranteed by NHUS and NHIL. The 2015 Credit Facility contains a covenant that limits our ratio of debt to total tangible capitalization, as defined in the 2015 Credit Facility, to 0.60 at the end of each fiscal quarter. The 2017 Credit Facility contains certain financial covenants applicable to NHUK and its subsidiaries, including (i) a covenant restricting debt to total tangible capitalization to not greater than 0.55 at the end of each fiscal quarter, (ii) a minimum Liquidity requirement of $300.0 million , (iii) a covenant that, beginning with the fiscal quarter ending March 31, 2018, the ratio of the Rig Value (as defined in the 2017 Credit Facility) of Marketed Rigs (as defined in the 2017 Credit Facility) to the sum of commitments under the 2017 Credit Facility plus indebtedness for borrowed money of the borrowers and guarantors, in each case, that directly own Marketed Rigs, is not less than 3:00 to 1:00 at the end of each fiscal quarter and (iv) a covenant that, beginning with the fiscal quarter ending March 31, 2018, the ratio of (A) the Rig Value of the Closing Date Rigs (as defined in the 2017 Credit Facility) that are directly wholly owned by the borrowers and guarantors to (B) the Rig Value of the Closing Date Rigs owned by NHUK, subsidiaries of NHUK and certain local content affiliates, is not less than 80% at the end of each fiscal quarter (such covenants described in (iii) and (iv) of this paragraph, the “Guarantor Ratio Covenants”). The 2017 Credit Facility also includes restrictions on borrowings if, after giving effect to any such borrowings and the application of the proceeds thereof, the aggregate amount of Available Cash (as defined in the 2017 Credit Facility) would exceed $200.0 million . NHUK has guaranteed the obligations of the borrowers under the 2017 Credit Facility. In addition, on January 19, 2018, certain indirect subsidiaries of Noble-UK became guarantors under the 2017 Credit Facility, including Noble Dave Beard Limited, Noble Drilling (TVL) Ltd., Noble Resources Limited, Noble SA Limited, Noble BD LLC, Noble Drilling Holding LLC, Noble Drilling International GmbH, Noble Leasing (Switzerland) GmbH, and Noble Leasing III (Switzerland) GmbH. Certain other subsidiaries of Noble-UK may be required from time to time to guarantee the obligations of the borrowers under the 2017 Credit Facility in order maintain compliance with the Guarantor Ratio Covenants. The 2017 Credit Facility contains additional restrictive covenants generally applicable to NHUK and its subsidiaries, including restrictions on the incurrence of liens and indebtedness, mergers and other fundamental changes, restricted payments, repurchases and redemptions of indebtedness with maturities outside of the maturity of the 2017 Credit Facility, sale and leaseback transactions and transactions with affiliates. In addition to the covenants from the Credit Facilities noted above, the covenants from the 2026 Notes described under “—Debt Issuance” above, and the covenant from the Seller Loan described under “—Seller Financing of Rig” above, the indentures governing our outstanding senior unsecured notes contain covenants that place restrictions on certain merger and consolidation transactions, unless we are the surviving entity or the other party assumes the obligations under the indenture, and on the ability to sell or transfer all or substantially all of our assets. There are also restrictions on incurring or assuming certain liens and on entering into sale and lease-back transactions. At December 31, 2018 , our debt to total tangible capitalization ratio under our 2017 Credit Facility was approximately 0.48 and we were in compliance with all applicable debt covenants. We continually monitor compliance with the covenants under our Credit Facilities, senior notes and Seller Loan and expect to remain in compliance throughout 2019. Five-year debt obligations At December 31, 2018 , aggregate principal repayments of total debt for the next five years and thereafter are as follows: 2019 2020 2021 2022 2023 Thereafter Total $ — $ 65,890 $ 96,142 $ 99,481 $ — $ 3,673,040 $ 3,934,553 Fair Value of Debt Fair value represents the amount at which an instrument could be exchanged in a current transaction between willing parties. The estimated fair value of our debt instruments was based on the quoted market prices for similar issues or on the current rates offered to us for debt of similar remaining maturities (Level 2 measurement). All remaining fair value disclosures are presented in “ Note 14— Fair Value of Financial Instruments .” The following table presents the carrying value, net of unamortized debt issuance costs and discounts, and the estimated fair value of our total debt, not including the effect of unamortized debt issuance costs, respectively: December 31, 2018 December 31, 2017 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Senior unsecured notes 5.75% Senior Notes due March 2018 $ — $ — $ 249,843 $ 250,830 7.50% Senior Notes due March 2019 — — 201,535 206,881 4.90% Senior Notes due August 2020 65,810 60,177 167,422 163,283 4.625% Senior Notes due March 2021 92,967 84,931 208,095 195,687 3.95% Senior Notes due March 2022 41,617 37,096 125,307 107,348 7.75% Senior Notes due January 2024 783,350 613,719 971,498 861,160 7.95% Senior Notes due April 2025 446,517 339,035 446,106 380,732 7.875% Senior Notes due February 2026 738,075 647,085 — — 6.20% Senior Notes due August 2040 390,454 245,242 396,738 274,988 6.05% Senior Notes due March 2041 389,693 247,171 394,514 273,988 5.25% Senior Notes due March 2042 477,996 277,056 494,063 315,430 8.95% Senior Notes due April 2045 390,672 311,392 390,589 320,396 Other: Seller-financed secured loan due September 2022 60,251 57,902 — — Total debt 3,877,402 2,920,806 4,045,710 3,350,723 Less: Current maturities of long-term debt — — 249,843 250,830 Long-term debt $ 3,877,402 $ 2,920,806 $ 3,795,867 $ 3,099,893

Equity

Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Equity	Note 8— Equity Share Capital As of December 31, 2018 , Noble-UK had approximately 246.8 million shares outstanding and trading as compared to approximately 245.0 million shares outstanding and trading at December 31, 2017 . At our 2018 Annual General Meeting, shareholders approved a proposal to allow our Board of Directors to increase share capital through the issuance of up to 82.2 million ordinary shares (at current nominal value of $0.01 per share) The right of our directors to allot shares will expire at the end of our 2019 Annual General Meeting unless we seek an extension from shareholders at that time. No shares were allotted during the year ended December 31, 2018 . The declaration and payment of dividends require the authorization of the Board of Directors of Noble-UK, provided that such dividends on issued share capital may be paid only out of Noble-UK’s “distributable reserves” on its statutory balance sheet in accordance with UK law. Therefore, Noble-UK is not permitted to pay dividends out of share capital, which includes share premium. Noble has not paid dividends since the third quarter of 2016. The payment of future dividends will depend on our results of operations, financial condition, cash requirements, future business prospects, contractual and indenture restrictions and other factors deemed relevant by our Board of Directors. Share Repurchases Under UK law, the Company is only permitted to purchase its own shares by way of an “off-market purchase” in a plan approved by shareholders. We currently do not have shareholder authority to repurchase shares. During the years ended December 31, 2018 , 2017 and 2016 , we did not repurchase any of our shares. Share-Based Compensation Plans Stock Plans During 2015, Noble Corporation plc shareholders approved a new equity plan, the Noble Corporation plc 2015 Omnibus Incentive Plan (the “2015 Incentive Plan”), which permits grants of options, stock appreciation rights (“SARs”), stock or stock unit awards or cash awards, any of which may be structured as a performance award, from time to time to employees who are to be granted awards under the 2015 Incentive Plan. Neither consultants nor non-employee directors are eligible for awards under the 2015 Incentive Plan. During 2018 , 2017 and 2016 , the 2015 Incentive Plan was restated and shareholders approved amendments, primarily to increase the number of ordinary shares available for issuance as long-term incentive compensation under the 2015 Incentive Plan by 5.0 million , 3.7 million and 9.5 million shares, respectively. The maximum aggregate number of ordinary shares that may be granted for any and all awards under the 2015 Incentive Plan will not exceed 25.5 million shares and at December 31, 2018 , we had 11.5 million shares remaining available for grants to employees. The Noble Corporation 1991 Stock Option and Restricted Stock Plan, as amended (the “1991 Plan”), provides for the granting of options to purchase our shares, with or without stock appreciation rights, and the awarding of restricted shares or units to selected employees. Upon shareholder approval of the 2015 Incentive Plan, as described above, the 1991 Plan was terminated and equity based awards to employees are now made only through the 2015 Incentive Plan. Equity based awards previously granted under the 1991 Plan remain outstanding in accordance with their terms, which include the 1991 Plan. Prior to 2017 , we used the Noble Corporation 1992 Nonqualified Stock Options and Share Plan for Non-Employee Directors (the “1992 Plan”), to issue stock awards to non-employee directors. During 2017 , upon shareholder approval, the Noble Corporation plc 2017 Director Omnibus Plan (the “Director Plan”) replaced the 1992 Plan. At the same time, the 1992 Plan was terminated and equity based awards to non-employee directors are now made only through the Director Plan. Stock Options Options have a term of 10 years , an exercise price equal to the fair market value of a share on the date of grant and generally vest over a three -year period. A summary of the status of stock options granted under both the 1991 Plan and 1992 Plan as of December 31, 2018 , 2017 and 2016 and the changes during the year ended on those dates is presented below: 2018 2017 2016 Number of Shares Underlying Options Weighted Average Exercise Price Number of Shares Underlying Options Weighted Average Exercise Price Number of Shares Underlying Options Weighted Average Exercise Price Outstanding at beginning of year 1,313,155 $ 29.51 1,420,175 $ 29.52 1,677,154 $ 29.48 Expired (209,913 ) 33.56 (107,020 ) 29.74 (256,979 ) 29.22 Outstanding at end of year (1) 1,103,242 28.74 1,313,155 29.51 1,420,175 29.52 Exercisable at end of year (1) 1,103,242 $ 28.74 1,313,155 $ 29.51 1,420,175 $ 29.52 (1) Options outstanding and exercisable at December 31, 2018 had no intrinsic value. The following table summarizes additional information about stock options outstanding at December 31, 2018 : Options Outstanding and Exercisable Number of Shares Underlying Options Weighted Average Remaining Life (Years) Weighted Average Exercise Price $20.49 to $25.41 290,962 0.69 $ 21.40 $25.42 to $30.59 334,958 3.10 30.59 $30.60 to $32.78 477,322 1.70 31.91 Total 1,103,242 1.86 $ 28.74 The fair value of each option is estimated on the date of grant using a Black-Scholes pricing model. The expected term of options granted represents the period of time that the options are expected to be outstanding and is derived from historical exercise behavior, current trends and values derived from lattice-based models. Expected volatilities are based on implied volatilities of traded options on our shares, historical volatility of our shares, and other factors. The expected dividend yield is based on historical yields on the date of grant. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant. There were no non-vested stock option balances at December 31, 2018 or any changes during the year ended December 31, 2018 . No new stock options were granted during the years ended December 31, 2018 , 2017 and 2016 . There was no compensation cost recognized during the years ended December 31, 2018 , 2017 and 2016 , respectively, related to stock options. Restricted Stock Units (“RSUs”) We have awarded both Time Vested RSUs (“TVRSUs”) and Performance Vested (“PVRSUs”) under the 1991 Plan and the 2015 Incentive Plan. The TVRSUs generally vest over a three -year period. The number of PVRSUs which vest will depend on the degree of achievement of specified corporate performance criteria over a three -year performance period. Depending on the date the PVRSU was awarded, these criteria consist of market based criteria or market and performance based criteria. The TVRSUs are valued on the date of award at our underlying share price. The total compensation for units that ultimately vest is recognized over the service period. The shares and related nominal value are recorded when the restricted stock unit vests and additional paid-in capital is adjusted as the share-based compensation cost is recognized for financial reporting purposes. The market-based PVRSUs are valued on the date of grant based on the estimated fair value. Estimated fair value is determined based on numerous assumptions, including an estimate of the likelihood that our stock price performance will achieve the targeted thresholds and the expected forfeiture rate. The fair value is calculated using a Monte Carlo Simulation Model. The assumptions used to value the PVRSUs include historical volatility and risk-free interest rates over a time period commensurate with the remaining term prior to vesting, as follows: 2018 2017 2016 Valuation assumptions: Expected volatility 61.8 % 56.4 % 40.7 % Expected dividend yield — % — % — % Risk-free interest rate 2.31 % 1.49 % 0.97 % Additionally, similar assumptions were made for each of the companies included in the defined index and the peer group of companies in order to simulate the future outcome using the Monte Carlo Simulation Model. A summary of the RSUs awarded for each of the years ended December 31, 2018 , 2017 and 2016 is as follows: 2018 2017 2016 TVRSU Units awarded 3,578,212 3,231,225 3,624,182 Weighted-average share price at award date $ 4.71 $ 6.96 $ 7.78 Weighted-average vesting period (years) 3.0 3.0 3.0 PVRSU Units awarded 2,733,906 2,474,978 2,914,044 Weighted-average share price at award date $ 4.55 $ 7.28 $ 7.79 Three-year performance period ended December 31 2020 2019 2018 Weighted-average award-date fair value $ 2.96 $ 4.37 $ 3.81 During the years ended December 31, 2018 , 2017 and 2016 , we awarded 267,204 , 197,316 and 227,937 shares, respectively, to our non-employee directors. A summary of the status of non-vested RSUs at December 31, 2018 and changes during the year ended December 31, 2018 is presented below: TVRSUs Outstanding Weighted Average Award-Date Fair Value PVRSUs Outstanding (1) Weighted Average Award-Date Fair Value Non-vested RSUs at January 1, 2018 5,043,502 $ 7.95 5,645,454 $ 4.98 Awarded 3,578,212 4.71 2,733,906 4.87 Vested (2,342,503 ) 8.67 (403,553 ) 9.12 Forfeited (1,054,808 ) 6.43 (1,784,740 ) 5.97 Non-vested RSUs at December 31, 2018 5,224,403 $ 5.71 6,191,067 $ 4.38 (1) The number of PVRSUs shown equals the units that would vest if the “maximum” level of performance is achieved. The minimum number of units is zero and the “target” level of performance is 50 percent of the amounts shown. At December 31, 2018 , there wa s $15.8 million of total unrecognized compensation cost related to the TVRSUs, which is expected to be recognized over a remaining weighted-average period of 1.6 years . The total award-date fair value of TVRSUs vested during the year ended December 31, 2018 was $20.3 million . At December 31, 2018 , there was $6.7 million of total unrecognized compensation cost related to the PVRSUs, which is expected to be recognized over a remaining weighted-average period of 1.1 years . The total potential compensation for PVRSUs is recognized over the service period regardless of whether the performance thresholds are ultimately achieved. In February 2019 , 1,450,802 PVRSUs f or the 2016-2018 performance period were forfeited. Share-based amortization recognized during the years ended December 31, 2018 , 2017 and 2016 related to all restricted stock totaled $24.0 million ( $21.9 million net of income tax), $29.1 million ( $26.3 million net of income tax) and $34.7 million ( $31.0 million net of income tax), respectively. During the years ended December 31, 2018 and 2017 , capitalized share-based amortization was zero . During the year ended December 31, 2016 , capitalized share-based amortization totaled approximately $0.2 million .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 9— Accumulated Other Comprehensive Income (Loss) The following table presents the changes in the accumulated balances for each component of AOCI for the years ended December 31, 2018 and 2017 . All amounts within the tables are shown net of tax. Unrealized Gains /(Losses) on Cash Flow Hedges (1) Defined Benefit Pension Items (2) Foreign Currency Items Total Balance at December 31, 2016 $ — $ (35,865 ) $ (16,275 ) $ (52,140 ) Activity during period: Other comprehensive income before reclassifications 1,239 6,630 990 8,859 Amounts reclassified from AOCI (1,239 ) 1,632 — 393 Net other comprehensive income — 8,262 990 9,252 Balance at December 31, 2017 $ — $ (27,603 ) $ (15,285 ) $ (42,888 ) Activity during period: Stranded tax effect resulting from the Act (Note 1) — (5,540 ) — (5,540 ) Balance at January 1, 2018 — (33,143 ) (15,285 ) (48,428 ) Activity during period: Other comprehensive income before reclassifications — — (2,729 ) (2,729 ) Amounts reclassified from AOCI — (5,915 ) — (5,915 ) Net other comprehensive loss — (5,915 ) (2,729 ) (8,644 ) Balance at December 31, 2018 $ — $ (39,058 ) $ (18,014 ) $ (57,072 ) (1) Unrealized losses on cash flow hedges are related to foreign currency forward contracts. Reclassifications from AOCI are recognized through “Contract drilling services” costs on our Consolidated Statements of Operations. See “ Note 13— Derivative Instruments and Hedging Activities ” for additional information. (2) Defined benefit pension items relate to actuarial changes and the amortization of prior service costs. Reclassifications from AOCI are recognized as expense on our Consolidated Statements of Operations through either “Contract drilling services” or “General and administrative.” See “ Note 12— Employee Benefit Plans ” for additional information.

Revenue and Customers

Revenue and Customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue and Customers	Note 10— Revenue and Customers Contract Balances Accounts receivable are recognized when the right to consideration becomes unconditional based upon contractual billing schedules. Payment terms on invoiced amounts are typically 30 days. Current contract asset and liability balances are included in “Prepaid expenses and other current assets” and “Other current liabilities,” respectively, and noncurrent contract assets and liabilities are included in “Other assets” and “Other liabilities,” respectively, on our Consolidated Balance Sheets. The following table provides information about contract assets and contract liabilities from contracts with customers: December 31, 2018 January 1, 2018 Current contract assets $ 25,298 $ 21,229 Noncurrent contract assets 22,366 34,520 Total contract assets 47,664 55,749 Current contract liabilities (deferred revenue) (32,906 ) (35,422 ) Noncurrent contract liabilities (deferred revenue) (47,847 ) (73,439 ) Total contract liabilities $ (80,753 ) $ (108,861 ) Significant changes in the remaining performance obligation contract assets and the contract liabilities balances for the year ended December 31, 2018 are as follows: Contract Assets Contract Liabilities Net balance at January 1, 2018 $ 55,749 $ (108,861 ) Amortization of deferred costs (32,420 ) — Additions to deferred costs 24,335 — Amortization of deferred revenue — 47,798 Additions to deferred revenue — (19,690 ) Total (8,085 ) 28,108 Net balance at December 31, 2018 $ 47,664 $ (80,753 ) We have elected, as a practical expedient, not to disclose significant changes in the remaining performance obligation for the year ended December 31, 2017 , which was before our adoption date of January 1, 2018. Contract Costs Certain direct and incremental costs incurred for upfront preparation, initial rig mobilization and modifications are costs of fulfilling a contract and are recoverable. These recoverable costs are deferred and amortized ratably to contract drilling expense as services are rendered over the initial term of the related drilling contract. Certain of our contracts include capital rig enhancements used to satisfy our performance obligations. These capital items are capitalized and depreciated in accordance with our existing property and equipment accounting policy. Costs incurred for the demobilization of rigs at contract completion are recognized as incurred during the demobilization process. Costs incurred for rig modifications or upgrades required for a contract, which are considered to be capital improvements, are capitalized as drilling and other property and equipment and depreciated over the estimated useful life of the improvement. Transaction Price Allocated to the Remaining Performance Obligations The following table reflects revenue expected to be recognized in the future related to unsatisfied performance obligations, by rig type, at the end of the reporting period: Year Ending December 31, 2019 2020 2021 2022 2023 and beyond Total Drillships $ 20,658 $ 15,677 $ 15,677 $ 9,266 $ 3,572 $ 64,850 Semisubmersibles 363 — — — — 363 Jackups 11,868 3,672 — — — 15,540 Total $ 32,889 $ 19,349 $ 15,677 $ 9,266 $ 3,572 $ 80,753 The revenue included above consists of expected mobilization, demobilization, and upgrade revenue for unsatisfied performance obligations. The amounts are derived from the specific terms within drilling contracts that contain such provisions, and the expected timing for recognition of such revenue is based on the estimated start date and duration of each respective contract based on information known at December 31, 2018 . The actual timing of recognition of such amounts may vary due to factors outside of our control. We have taken the optional exemption, permitted by accounting standards, to exclude disclosure of the estimated transaction price related to the variable portion of unsatisfied performance obligations at the end of the reporting period, as our transaction price is based on a single performance obligation consisting of a series of distinct hourly, or more frequent, periods, the variability of which will be resolved at the time of the future services. Our revenue recognition pattern under ASC 606 is materially equivalent to revenue recognition under the previous guidance. For the year ended December 31, 2018 , there were no material effects to our Consolidated Balance Sheets, Consolidated Statements of Operations, or Consolidated Statements of Cash Flows. Disaggregation of Revenue The following table provides information about contract drilling revenue by rig types: Three Months Ended December 31, 2018 Twelve Months Ended December 31, 2018 Drillships $ 155,305 $ 532,833 Semisubmersibles 10,344 28,992 Jackups 126,400 474,257 Total $ 292,049 $ 1,036,082

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 11— Income Taxes Noble-UK is a company which is a tax resident in the UK and, as such, will be subject to UK corporation tax on its taxable profits and gains. A UK tax exemption is available in respect of qualifying dividends income and capital gains related to the sale of qualifying participations. We operate in various countries throughout the world, including the United States. The income or loss of the non-UK subsidiaries is not expected to be subject to UK corporation tax. Prior to the redomiciliation, Noble-Swiss was the group holding company and was exempt from Swiss cantonal and communal income tax on its worldwide income or loss, and was also granted participation relief from Swiss federal tax for qualifying dividend income and capital gains related to the sale of qualifying participations. It is expected that the participation relief will result in a full exemption of participation income from Swiss federal income tax. We do not expect the redomiciliation from Switzerland to the UK to have a material impact on our effective tax rate. Consequently, we have taken account of those tax exemptions and provided for income taxes based on the laws and rates in effect in the countries in which operations are conducted, or in which we or our subsidiaries have a taxable presence for income tax purposes. On December 22, 2017, the President of the United States signed the Act into law. The Act makes significant changes to various areas of U.S. federal income tax law by, among other things, lowering corporate income tax rates, implementing the territorial tax system, and rules limiting base erosion, and imposing a repatriation tax on deemed repatriated earnings of foreign subsidiaries of U.S parent shareholders. During the fourth quarter of 2017, the Act resulted in the write-down of our U.S. net deferred tax liabilities. In accordance with the guidance issued in SAB No. 118, during the third quarter of 2018, we finalized our provisional amounts recorded as we completed our technical analysis, computations and tax law interpretations and filed our 2017 U.S. tax return. As a result, we recognized an additional tax benefit of $24.9 million . The Company has considered new provisions of The Act that became effective in 2018. Two such provisions, which had an impact on the Company’s financial results for the current period, are as follows: • The Act limits the deduction of interest paid or accrued on indebtedness. This limitation results in a deferral for U.S. federal income tax purposes and requires the recording of a deferred tax asset for the benefit of the interest deduction carryforward. The interest deduction carryforward has an indefinite life. • The Act eliminates the U.S. federal income tax carryback provision for net operating losses (“NOLs”) and limits the taxpayer’s ability to utilize NOL carryforwards to 80 percent of taxable income. The NOL carryforward has an indefinite life. The Act also introduces a new anti-deferral provision, which subjects a U.S. parent shareholder to current tax on certain income, referred to as Global Intangible Low-Taxed Income, of its foreign subsidiaries. The Company has adopted a policy to treat tax due on future U.S. inclusions in taxable income as period costs when incurred. The Company continues to monitor developments in regulations. The components of the net deferred taxes are as follows: 2018 2017 Deferred tax assets United States Net operating loss carry forwards $ 95,577 $ — Disallowed interest deduction carryforwards 51,423 — Deferred pension plan amounts 11,887 10,758 Accrued expenses not currently deductible 9,688 11,585 Other 1,936 2,150 Non-U.S. Net operating loss carry forwards 26,441 — Disallowed interest deduction carryforwards 6,254 — Deferred pension plan amounts 670 134 Other — 14,085 Deferred tax assets 203,876 38,712 Less: valuation allowance (12,306 ) — Net deferred tax assets $ 191,570 $ 38,712 Deferred tax liabilities United States Excess of net book basis over remaining tax basis $ (254,669 ) $ (182,401 ) Other (6,482 ) (6,652 ) Non-U.S. Excess of net book basis over remaining tax basis (1,066 ) — Other (1,596 ) (402 ) Deferred tax liabilities (263,813 ) (189,455 ) Net deferred tax liabilities $ (72,243 ) $ (150,743 ) Income (loss) from continuing operations before income taxes consists of the following: Year Ended December 31, 2018 2017 2016 United States $ (136,083 ) $ (81,329 ) $ (428,087 ) Non-U.S. (1,101,093 ) (368,485 ) (538,942 ) Total $ (1,237,176 ) $ (449,814 ) $ (967,029 ) The income tax provision (benefit) for continuing operations consists of the following: Year Ended December 31, 2018 2017 2016 Current- United States $ (56,574 ) $ (227,707 ) $ 61,928 Current- Non-U.S. 18,348 29,010 18,813 Deferred- United States (67,371 ) 257,432 (189,880 ) Deferred- Non-U.S. (1,044 ) (16,106 ) (17 ) Total $ (106,641 ) $ 42,629 $ (109,156 ) The following is a reconciliation of our reserve for uncertain tax positions, excluding interest and penalties. In 2016, we released an uncertain tax position in Libya in the gross amount of $40 million coupled with a related tax benefit of $13 million . 2018 2017 2016 Gross balance at January 1, $ 174,437 $ 159,826 $ 169,687 Additions based on tax positions related to current year 97 14,187 15,665 Additions for tax positions of prior years 25 1,284 18,662 Reductions for tax positions of prior years (12,806 ) (860 ) (43,701 ) Expiration of statutes (497 ) — (487 ) Tax settlements — — — Gross balance at December 31, 161,256 174,437 159,826 Related tax benefits (1,008 ) (1,008 ) (1,008 ) Net reserve at December 31, $ 160,248 $ 173,429 $ 158,818 The liabilities related to our reserve for uncertain tax positions are comprised of the following: 2018 2017 Reserve for uncertain tax positions, excluding interest and penalties $ 160,248 $ 173,429 Interest and penalties included in “Other liabilities” 23,538 18,431 Reserve for uncertain tax positions, including interest and penalties $ 183,786 $ 191,860 At December 31, 2018 , the reserves for uncertain tax positions totaled $183.8 million (net of related tax benefits of 1.0 million ). If a portion or all of the December 31, 2018 reserves are not realized, the provision for income taxes could be reduced by up to $183.8 million . At December 31, 2017 , the reserves for uncertain tax positions totaled $191.9 million (net of related tax benefits of 1.0 million ). It is reasonably possible that our existing liabilities related to our reserve for uncertain tax positions may fluctuate in the next 12 months primarily due to the completion of open audits or the expiration of statutes of limitation. However, we cannot reasonably estimate a range of changes in our existing liabilities due to various uncertainties, such as the unresolved nature of various audits. We include, as a component of our “Income tax provision,” potential interest and penalties related to recognized tax contingencies within our global operations. Interest and penalties resulted in an income tax expense of $5.1 million in 2018 , an income tax expense of $4.7 million in 2017 and an income tax benefit of $2.7 million in 2016 . During the year ended December 31, 2018 , our income tax provision included non-cash items of $35.6 million related to the impairment of three rigs and certain capital spares. See “ Note 6— Loss on Impairment ” for additional information. We conduct business globally and, as a result, we file numerous income tax returns in U.S. and in non-U.S. jurisdictions. In the normal course of business we are subject to examination by taxing authorities throughout the world, including in jurisdictions such as Brazil, Brunei, Bulgaria, Canada, Cyprus, Egypt, Hungary, Malta, Mexico, Nigeria, Norway, Saudi Arabia, Argentina, Australia, Denmark, Gabon, Luxembourg, Malaysia, the Netherlands, Oman, Qatar, Tanzania, Singapore, Suriname, Switzerland, the United Kingdom and the United States. We are no longer subject to U.S. Federal income tax examinations for years before 2010 and non-U.S. income tax examinations for years before 2000. Noble-UK conducts substantially all of its business through Noble-Cayman and its subsidiaries. The income or loss of our non-UK subsidiaries is not subject to UK income tax. Earnings are taxable in the United Kingdom at the UK statutory rate of 19 percent . The ongoing consultative process in the United Kingdom and a possible change in law could materially impact our tax rate on operations in the United Kingdom continental shelf. A reconciliation of tax rates outside of the United Kingdom and the Cayman Islands to our Noble-UK effective rate for continuing operations is shown below: Year Ended December 31, 2018 2017 2016 Effect of: Tax rates which are different than the UK and Cayman Island rates 4.0 % 23.4 % 8.4 % Tax impact of asset impairment 2.9 % 11.7 % 3.9 % Tax impact of tax restructuring — % (76.1 )% — % Tax impact of the Act 2.1 % 33.4 % — % Reserve for (resolution of) tax authority audits (0.4 )% (1.9 )% (1.0 )% Total 8.6 % (9.5 )% 11.3 % Due to foreign tax credit limitation constraints, in 2018 , 2017 and 2016 , the Company has made the determination to take foreign tax expense as a deduction against U.S. taxable income. At December 31, 2018 , the Company asserted that the investment in foreign subsidiaries is permanent in nature, and estimated that there are no net cumulative earnings in its foreign subsidiaries. For interim and annual reporting periods beginning after December 15, 2017, ASU No. 2016-16 will be applied on a modified retrospective basis to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. As the result of the application of this standard, we recorded deferred charges of $148.4 million in to “Retained earnings” on our Consolidated Balance Sheets. During the fourth quarter of 2017, the Act resulted in the write-down of our U.S. net deferred tax liabilities. In accordance with the guidance issued in SAB No. 118, during the third quarter of 2018, we finalized our provisional amounts recorded as we completed our technical analysis, computations and tax law interpretations and filed our 2017 U.S. tax return. As a result, we recognized an additional tax benefit of $24.9 million .

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plans	Note 12— Employee Benefit Plans Defined Benefit Plans Noble Drilling (Land Support) Limited, an indirect, wholly-owned subsidiary of Noble-UK (“NDLS”), maintains a pension plan that covers all of its salaried, non-union employees, whose most recent date of employment is prior to April 1, 2014 (referred to as our “non-U.S. plan”). In addition to the non-U.S. plan discussed above, we have a U.S. noncontributory defined benefit pension plan that covers certain salaried employees and a U.S. noncontributory defined benefit pension plan that covers certain hourly employees, whose initial date of employment is prior to August 1, 2004 (collectively referred to as our “qualified U.S. plans”). These plans are governed by the Noble Drilling Employees’ Retirement Trust (the “Trust”). The benefits from these plans are based primarily on years of service and, for the salaried plan, employees' compensation near retirement. These plans are designed to qualify under the Employee Retirement Income Security Act of 1974 (“ERISA”), and our funding policy is consistent with funding requirements of ERISA and other applicable laws and regulations. We make cash contributions, or utilize credits available to us, for the qualified U.S. plans when required. The benefit amount that can be covered by the qualified U.S. plans is limited under ERISA and the Internal Revenue Code of 1986. Therefore, we maintain an unfunded, nonqualified excess benefit plan designed to maintain benefits for specified employees at the formula level in the qualified salaried U.S. plan. We refer to the qualified U.S. plans and the excess benefit plan collectively as the “U.S. plans.” During the fourth quarter of 2016, we approved amendments, effective as of December 31, 2016, to our non-U.S. and U.S. defined benefit plans. With these amendments, employees and alternate payees will accrue no future benefits under the plans after December 31, 2016. However, these amendments will not affect any benefits earned through that date. A reconciliation of the changes in projected benefit obligations (“PBO”) for our non-U.S. and U.S. plans is as follows: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Benefit obligation at beginning of year $ 61,952 $ 235,175 $ 72,347 $ 216,577 Service cost — — — — Interest cost 1,747 8,179 2,151 8,593 Actuarial loss (gain) (2,683 ) (20,673 ) (11,265 ) 19,113 Plan amendments 285 — — — Benefits paid (3,282 ) (7,218 ) (2,836 ) (6,795 ) Settlements and curtailments — (4,519 ) (4,825 ) (2,313 ) Foreign exchange rate changes (3,121 ) — 6,380 — Benefit obligation at end of year $ 54,898 $ 210,944 $ 61,952 $ 235,175 A reconciliation of the changes in fair value of plan assets is as follows: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Fair value of plan assets at beginning of year $ 77,141 $ 189,240 $ 71,286 $ 171,240 Actual return on plan assets (1,366 ) (16,326 ) 5,594 24,760 Employer contributions — 4,553 651 2,348 Benefits paid (3,282 ) (7,218 ) (2,836 ) (6,795 ) Settlement and curtailment — (4,519 ) (4,597 ) (2,313 ) Foreign exchange rate changes (3,896 ) — 7,043 — Fair value of plan assets at end of year $ 68,597 $ 165,730 $ 77,141 $ 189,240 The funded status of the plans is as follows: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Funded status $ 13,699 $ (45,214 ) $ 15,189 $ (45,935 ) Amounts recognized in the Consolidated Balance Sheets consist of: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Other assets (noncurrent) $ 13,699 $ — $ 15,189 $ — Other liabilities (current) — (1,062 ) — (2,312 ) Other liabilities (noncurrent) — (44,152 ) — (43,623 ) Net amount recognized $ 13,699 $ (45,214 ) $ 15,189 $ (45,935 ) Amounts recognized in AOCI consist of: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Net actuarial loss $ 3,622 $ 45,358 $ 2,258 $ 39,569 Prior service cost 273 — — — Deferred income tax asset (670 ) (9,524 ) (375 ) (13,849 ) Accumulated other comprehensive loss $ 3,225 $ 35,834 $ 1,883 $ 25,720 Pension costs include the following components: Years Ended December 31, 2018 2017 2016 Non-U.S. U.S. Non-U.S. U.S. Non-U.S. U.S. Service cost $ — $ — $ — $ — $ 2,914 $ 6,647 Interest cost 1,747 8,179 2,151 8,593 2,412 9,557 Return on plan assets (2,762 ) (11,914 ) (2,879 ) (11,764 ) (3,393 ) (12,389 ) Amortization of prior service cost — — — — 104 118 Recognized net actuarial loss — 1,642 743 1,464 142 4,398 Settlement and curtailment gains — 135 (838 ) 82 600 200 Net pension benefit cost (gain) $ (1,015 ) $ (1,958 ) $ (823 ) $ (1,625 ) $ 2,779 $ 8,531 There is less than $0.1 million and $2.8 million estimated net actuarial losses and prior service costs for the non-U.S. plan and the U.S. plans, respectively, that will be amortized from AOCI into net periodic pension cost in 2019 . During the years ended December 31, 2018 , 2017 and 2016 , we adopted the Retirement Plan (“RP”) mortality tables with the Mortality Projection (“MP”) scale as issued by the Society of Actuaries for each of the respective years. The RP 2018 , 2017 and 2016 mortality tables represent the new standard for defined benefit mortality assumptions due to adjusted life expectancies. The adoption of the updated mortality tables and the mortality improvement scales decreased our pension liability on our U.S. plans by approximately $0.6 million , $1.6 million and $2.9 million as of December 31, 2018 , 2017 and 2016 . During the fourth quarter of 2018, the UK High Court made a judgement confirming that UK pension schemes are required to equalize male and female members’ benefits for the effect of guaranteed minimum pensions (GMP). We have accounted for the impact of the GMP equalization as a plan amendment to our non-U.S. plan, and the impact is included as a prior service cost as of December 31, 2018 , which will be amortized over the average life expectancy of the members at that date. Defined Benefit Plans—Disaggregated Plan Information Disaggregated information regarding our non-U.S. and U.S. plans is summarized below: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Projected benefit obligation $ 54,898 $ 210,944 $ 61,952 $ 235,175 Accumulated benefit obligation 54,898 210,944 61,952 235,175 Fair value of plan assets 68,597 165,730 77,141 189,240 The following table provides information related to those plans in which the PBO exceeded the fair value of the plan assets at December 31, 2018 and 2017 . The PBO is the actuarially computed present value of earned benefits based on service to date and includes the estimated effect of any future salary increases. Employees and alternate payees have no longer accrued future benefits under the plans since December 31, 2016 . Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Projected benefit obligation $ — $ 210,944 $ — $ 235,175 Fair value of plan assets — 165,730 — 189,240 The PBO for the unfunded excess benefit plan was $10.5 million at December 31, 2018 as compared to $16.4 million in 2017 , and is included under “U.S.” in the above tables. The following table provides information related to those plans in which the accumulated benefit obligation (“ABO”) exceeded the fair value of plan assets at December 31, 2018 and 2017 . The ABO is the actuarially computed present value of earned benefits based on service to date, but differs from the PBO in that it is based on current salary levels. Employees and alternate payees have no longer accrued future benefits under the plans since December 31, 2016. Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Accumulated benefit obligation $ — $ 210,944 $ — $ 235,175 Fair value of plan assets — 165,730 — 189,240 The ABO for the unfunded excess benefit plan was $10.5 million at December 31, 2018 as compared to $16.4 million in 2017 , and is included under “U.S.” in the above tables. Defined Benefit Plans—Key Assumptions The key assumptions for the plans are summarized below: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Weighted-average assumptions used to determine benefit obligations: Discount Rate 2.90% 3.65% - 4.29% 2.60% 2.84% - 3.66% Rate of compensation increase N/A N/A N/A N/A Years Ended December 31, 2018 2017 2016 Non-U.S. U.S. Non-U.S. U.S. Non-U.S. U.S. Weighted-average assumptions used to determine periodic benefit cost: Discount Rate 2.60% 2.84% - 3.66% 2.48% - 2.70% 3.00% - 4.24% 2.15% - 3.90% 3.09% - 4.48% Expected long-term return on assets 3.70% 5.75% - 6.50% 4.10% 6.00% - 6.50% 1.60% - 5.00% 7.00% Rate of compensation increase N/A N/A N/A N/A 3.60% - 4.20% N/A The discount rates used to calculate the net present value of future benefit obligations for our U.S. plans is based on the average of current rates earned on long-term bonds that receive a Moody’s rating of “Aa” or better. We have determined that the timing and amount of expected cash outflows on our plans reasonably match this index. For our non-U.S. plan, the discount rate used to calculate the net present value of future benefit obligations is determined by using a yield curve of high quality bond portfolios with an average maturity approximating that of the liabilities. In developing the expected long-term rate of return on assets, we considered the current level of expected returns on risk free investments (primarily government bonds), the historical level of risk premium associated with the other asset classes in which the portfolio is invested and the expectations for future returns of each asset class. The expected return for each asset class was then weighted based on the target asset allocation to develop the expected long-term rate of return on assets for the portfolio. To assist us with this analysis, we employ third-party consultants for our U.S. and non-U.S. plans that use a portfolio return model. Defined Benefit Plans—Plan Assets Non-U.S. Plan The NDLS pension Scheme targets an asset allocation of 48.0% return-seeking securities (Growth) and 52.0% debt securities (Matching). The trustees have decided to implement a de-risking strategy whereby the level of investment risk reduces as the Scheme’s funding level improves. The overall investment objective of the Scheme, as adopted by the Scheme’s Trustees, is to reach a fully funded position on the agreed de-risking basis of Gilts - 0.45% per annum. The objectives within the Scheme’s overall investment strategy is to outperform the cash + 4% per annum long term objective for Growth assets and to sufficiently hedge interest rate and inflation risk within the Matching portfolio in relation to the Scheme’s liabilities. By achieving these objectives, the Trustees believe the Scheme will be able to avoid significant volatility in the contribution rate and provide sufficient assets to cover the Scheme’s benefit obligations. To achieve this the Trustees have given Mercer, the appointed investment manager, full discretion in the day-to-day management of the Scheme’s assets and implementation of the de-risking strategy, who in turn invests in multiple underlying investment managers where appropriate. The Trustees meet with Mercer periodically to review and discuss their investment performance. The actual fair values of the non-U.S. plan are as follows: Year Ended December 31, 2018 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 151 $ 151 $ — $ — Equity securities: International companies 25,585 25,585 — — Fixed income securities: Corporate bonds 42,861 42,861 — — Total $ 68,597 $ 68,597 $ — $ — Year Ended December 31, 2017 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 280 $ 280 $ — $ — Equity securities: International companies 54,145 54,145 — — Fixed income securities: Corporate bonds 22,716 22,716 — — Other — — — — Total $ 77,141 $ 77,141 $ — $ — U.S. Plans The fundamental objective of the Plan is to provide the capital assets necessary to meet the financial obligations made to Plan participants. In order to meet this objective, the Investment Policy Statement depicts how the investment assets of the Plan are to be managed in accordance with the overall target asset allocation of approximately 31.5% equity securities, 67.3% fixed income securities, and 1.2% in cash and equivalents. The target asset allocation is intended to generate sufficient capital to meet Plan obligations and provide a portfolio rate of return equal to or greater than the return realized using appropriate blended, market benchmark over a full market cycle (usually a three to five year time period). Actual allocations may deviate from the target range, however any deviation from the target range of asset allocations must be approved by the Trust’s governing committee. For investments in mutual funds, the assets of the Trust are subject to the guidelines and limits imposed by such mutual fund’s prospectus and the other governing documentation at the fund level. No shares of Noble were included in equity securities at either December 31, 2018 or 2017 . The actual fair values of U.S. plan assets are as follows: Year Ended December 31, 2018 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 4,801 $ 4,801 $ — $ — Equity securities: United States 47,950 16,775 31,175 — International 17,838 17,838 — — Fixed income securities: Corporate bonds 64,802 59,648 5,154 — Treasury bonds 30,339 30,339 — — Total $ 165,730 $ 129,401 $ 36,329 $ — Year Ended December 31, 2017 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 3,275 $ 3,275 $ — $ — Equity securities: United States 43,535 16,430 27,105 — International 17,712 17,712 — — Fixed income securities: Corporate bonds 40,793 40,793 — — Treasury bonds 83,925 83,925 — — Total $ 189,240 $ 162,135 $ 27,105 $ — As of December 31, 2018 , no single security made up more than 10 percent of total assets of either the U.S. or the non-U.S. plans. Defined Benefit Plans—Cash Flows In 2018 , we made no contributions to our non-U.S. plan and contributions of $4.6 million to our U.S. plans. In 2017 , we made total contributions of $0.7 million and $2.3 million to our non-U.S. and U.S. plans, respectively. In 2016 , we made total contributions of $2.8 million and $0.4 million to our non-U.S. and U.S. plans, respectively. We expect our aggregate minimum contributions to our non-U.S. and U.S. plans in 2019 , subject to applicable law, to be zero and $1.1 million , respectively. We continue to monitor and evaluate funding options based upon market conditions and may increase contributions at our discretion. The following table summarizes our estimated benefit payments at December 31, 2018 : Payments by Period Total 2019 2020 2021 2022 2023 Thereafter Estimated benefit payments Non-U.S. plans $ 38,334 $ 3,255 $ 3,372 $ 3,492 $ 3,617 $ 3,747 $ 20,851 U.S. plans 109,275 8,873 9,320 13,562 9,754 10,351 57,415 Total estimated benefit payments $ 147,609 $ 12,128 $ 12,692 $ 17,054 $ 13,371 $ 14,098 $ 78,266 Other Benefit Plans We sponsor a 401(k) Restoration Plan, which is a nonqualified, unfunded employee benefit plan under which specified employees may elect to defer compensation in excess of amounts deferrable under our 401(k) savings plan. The 401(k) Restoration Plan has no assets, and amounts withheld for the 401(k) Restoration Plan are kept by us for general corporate purposes. The investments selected by employees and associated returns are tracked on a phantom basis. Accordingly, we have a liability to the employee for amounts originally withheld plus phantom investment income or less phantom investment losses. We are at risk for phantom investment income and, conversely, benefit should phantom investment losses occur. At both December 31, 2018 and 2017 , our liability for the 401(k) Restoration Plan was $8.2 million and $8.8 million , respectively, and is included in “Accrued payroll and related costs.” In 2005, we enacted a profit sharing plan, the Noble Drilling Services Inc. Profit Sharing Plan, which covers eligible employees, as defined in the plan. Participants in the plan become fully vested in the plan after three years of service. Profit sharing contributions are discretionary, require Board of Directors approval and are made in the form of cash. Contributions recorded related to this plan totaled $2.3 million , $3.1 million and $6.0 million , respectively, for three years ended December 31, 2018 , 2017 and 2016 . We sponsor other retirement, health and welfare plans and a 401(k) savings plan for the benefit of our employees. The cost of maintaining these plans for continuing operations aggregated approximately $25.0 million , $27.6 million and $37.2 million in 2018 , 2017 and 2016 , respectively. We do not provide post-retirement benefits (other than pensions) or any post-employment benefits to our employees.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Note 13— Derivative Instruments and Hedging Activities We periodically enter into derivative instruments to manage our exposure to fluctuations in interest rates and foreign currency exchange rates. We have documented policies and procedures to monitor and control the use of derivative instruments. We do not engage in derivative transactions for speculative or trading purposes, nor are we a party to leveraged derivatives. For foreign currency forward contracts, hedge effectiveness is evaluated at inception based on the matching of critical terms between derivative contracts and the hedged item. Any change in fair value resulting from ineffectiveness is recognized immediately in earnings. On May 10, 2016, Freeport-McMoRan Inc. (“Freeport”), Freeport-McMoRan Oil & Gas LLC and one of our subsidiaries entered into an agreement terminating the contracts on the Noble Sam Croft and Noble Tom Madden (“FCX Settlement”), which were scheduled to end in July 2017 and November 2017, respectively. The FCX Settlement included two contingent payments, which are further discussed below. We accounted for these contingent payments as derivative instruments that did not qualify under the FASB standards for hedge accounting treatment, and therefore, changes in fair values were recognized as a loss in our accompanying Consolidated Statements of Operations. Cash Flow Hedges Several of our regional shorebases have a significant amount of their cash operating expenses payable in local currencies. To limit the potential risk of currency fluctuations, we periodically enter into forward contracts, which have historically settled monthly in the operations’ respective local currencies. All of these contracts had a maturity of less than 12 months. There were no foreign currency forward contracts outstanding or entered into during the year ended December 31, 2018 . FCX Settlement Pursuant to the FCX Settlement, Noble could have received contingent payments from the FCX Settlement on September 30, 2017, depending on the average price of oil over a 12 -month period from June 30, 2016 through June 30, 2017. The average price of oil was calculated using the daily closing price of West Texas Intermediate crude oil (“WTI”) (CL1) on the New York Mercantile Exchange for the period of June 30, 2016 through June 30, 2017. If the price of WTI averaged more than $50 per barrel during such period, Freeport would have paid $25.0 million to Noble. In addition to the $25.0 million contingent payment, if the price of WTI averaged more than $65 per barrel during such period, Freeport would have paid an additional $50.0 million to Noble. These contingent payments did not qualify for hedge accounting treatment under FASB standards, and therefore, the change in fair value was recognized as a loss in our Consolidated Statements of Operations. These contingent payments are referred to as non-designated derivatives in the following table. The price of WTI did not average more than $50 per barrel during the 12-month period. As of June 30, 2017, the fair value of these contingent payments was reduced to zero , as the period for earning the contingent payments had ended. Financial Statement Presentation The following table, together with “ Note 14— Fair Value of Financial Instruments ,” summarizes the recognized gains and losses of cash flow hedges and non-designated derivatives through AOCI or as “Contract drilling services” revenue or costs for the years ended December 31, 2018 and 2017 : Year Ended December 31, 2018 2017 2018 2017 2018 2017 Unrealized gain/(loss) recognized through AOCI Gain/(loss) reclassified from AOCI to “ Contract drilling services ” costs Gain/(loss) recognized through “ Contract drilling services ” revenue Cash flow hedges Foreign currency forward contracts $ — $ (1,239 ) $ — $ — $ — $ 1,239 Non-designated derivatives FCX Settlement $ — $ — $ — $ — $ — $ (14,400 ) There were no foreign currency forward contracts outstanding or entered into during the year ended December 31, 2018 .

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Note 14— Fair Value of Financial Instruments The following tables present the carrying amount and estimated fair value of our financial instruments recognized at fair value on a recurring basis: December 31, 2018 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets - Marketable securities $ 8,659 $ 8,659 $ — $ — December 31, 2017 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets - Marketable securities $ 7,321 $ 7,321 $ — $ — Our cash and cash equivalents, and restricted cash, accounts receivable, marketable securities and accounts payable are by their nature short-term. As a result, the carrying values included in our Consolidated Balance Sheets approximate fair value.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 15— Commitments and Contingencies Transocean Ltd. In January 2017, a subsidiary of Transocean Ltd. (“Transocean”) filed suit against us and certain of our subsidiaries for patent infringement in a Texas federal court. The suit claims that five of our newbuild rigs that operated in the U.S. Gulf of Mexico violated Transocean patents relating to what is generally referred to as dual-activity drilling. We were aware of the patents when we constructed the rigs. The patents are now expired in the United States and most other countries. While there is inherent risk in litigation, we do not believe that our rigs infringe the Transocean patents. Transocean also recently added another claim alleging that we breached a 2007 settlement agreement we entered into with Transocean relating to patent claims in respect of another Noble rig. We also do not believe there has been any breach of the 2007 agreement. The litigation continues, and we believe the court could set a trial date for the third quarter of 2019. We continue to defend ourselves vigorously against this claim. Brazil commercial agent We previously used a commercial agent in Brazil in connection with our Petróleo Brasileiro S.A. (“Petrobras”) drilling contracts. This agent represented a number of different companies in Brazil over many years, including several offshore drilling contractors. In November 2015, this agent pled guilty in Brazil in connection with the award of a drilling contract to a competitor and implicated a Petrobras official as part of a wider investigation of Petrobras’ business practices. Following news reports relating to the agent’s involvement in the Brazil investigation in connection with his activities with other companies, we conducted a review, which was substantially completed in 2017, of our relationship with the agent and with Petrobras. We have been in contact and cooperated with the SEC, the Brazilian federal prosecutor’s office and the U.S. Department of Justice (“DOJ”) about this matter, and in December 2018, the SEC and the DOJ each advised us that they had closed their file on this matter. We have remained in contact with the Brazilian federal prosecutor’s office, who is aware of our internal review, and continue to cooperate with any questions or requests they may have. To our knowledge, neither the agent, nor the government authorities investigating the matter, has alleged that the agent or Noble acted improperly in connection with our contracts with Petrobras. Paragon Offshore On August 1, 2014, Noble-UK completed the Spin-off of a majority of its standard specification offshore drilling business through a pro rata distribution of all of the ordinary shares of its wholly-owned subsidiary, Paragon Offshore, to the holders of Noble’s ordinary shares. In February 2016, Paragon Offshore sought approval of a pre-negotiated plan of reorganization (the “Prior Plan”) by filing for voluntary relief under Chapter 11 of the United States Bankruptcy Code. As part of the Prior Plan, we entered into a settlement agreement with Paragon Offshore (the “Settlement Agreement”). The Prior Plan was rejected by the bankruptcy court in October 2016. In April 2017, Paragon Offshore filed a revised plan of reorganization (the “New Plan”) in its bankruptcy proceeding. Under the New Plan, Paragon Offshore no longer need the Mexican tax bonding that Noble-UK was to provide under the Settlement Agreement. Consequently, Paragon Offshore abandoned the Settlement Agreement as part of the New plan, and the Settlement Agreement was terminated at the time of the filing of the New Plan. On May 2, 2017, Paragon Offshore announced that it had reached an agreement in principle with both its secured and unsecured creditors to revise the New Plan to, among other things, create and fund a $10.0 million . litigation trust to pursue litigation against us. On June 7, 2017, the revised New Plan was approved by the bankruptcy court and Paragon Offshore emerged from bankruptcy on July 18, 2017. On December 15, 2017, the litigation trust filed claims relating to the Spin-off against us and certain of our current and former officers and directors in the Delaware bankruptcy court that heard Paragon Offshore’s bankruptcy. The complaint alleges claims of alleged actual and constructive fraudulent conveyance, unjust enrichment and recharacterization of intercompany notes as equity claims against Noble and claims of breach of fiduciary duty and aiding and abetting breach of fiduciary duty against the officer and director defendants. The complaint states that the litigation trust is seeking damages of approximately $1.7 billion from the Company, an amount equal to the amount borrowed by Paragon Offshore immediately prior to the Spin-off, as well as unspecified amounts in respect of the claims against the officer and director defendants, all of whom have indemnification agreements with us. We requested that the court dismiss the claims of breach of fiduciary duty, aiding and abetting breach of fiduciary duty and unjust enrichment, and require such claims to be arbitrated under the MSA entered into between Noble and Paragon Offshore at the time of the Spin-off, as well as stay the other proceedings during the pendency of the arbitration. The court ruled that the unjust enrichment claim be arbitrated and that the other claims proceed in bankruptcy court. We and the litigation trust have mutually agreed to drop our respective appeals of the arbitration ruling and now all matters will be heard in court, which will streamline the case. Discovery continues and the court has approved a litigation schedule, which could result in all pre-trial activity being completed by the end of 2019. A trial date has not yet been set. We believe that Paragon Offshore, at the time of the Spin-off, was properly funded, solvent and had appropriate liquidity and that the claims brought by the litigation trust are without merit. We intend to defend ourselves vigorously. However, there is inherent risk and substantial expense in litigation, and the amount of damages the plaintiff is seeking is substantial. If any of the litigation trust’s claims are successful, or if we elect to settle any claims (in part to reduce or eliminate the ongoing cost of defending the litigation and eliminate any risk of a larger judgment against us), any damages or other amounts we would be required to or agree to pay could have a material adverse effect on our business, financial condition and results of operations. Because of our view of the merits of the claims and the significant discovery still to be conducted in the litigation, we are not currently able to make a reasonable estimation of the amount of possible loss we may incur, if any. Subsequent developments in the litigation may make such an estimation possible, in which case we may record a charge against our income when a loss is reasonably estimable. This may occur even though the litigation may still be ongoing. Any charge could be material and could have a material adverse effect on our financial condition and results of operations. It may also be materially different than any amount we are required to pay once the litigation is concluded. We have directors’ and officers’ indemnification coverage for the officers and directors who have been sued by the litigation trust. The insurers have accepted coverage for the director and officer claims and we are continuing to discuss with them the scope of their reimbursement of litigation expenses. In addition, at the time of the Spin-off, we had entity coverage, or “Side C” coverage, which was meant to cover certain litigation claims up to the coverage limit of $150.0 million , including litigation expenses. We have made a claim for coverage of the litigation trust’s claims against Noble under such entity insurance. The insurers have rejected coverage for these claims. We cannot predict the amount of claims and expenses we may incur, pay or settle in the Paragon Offshore litigation that such insurance will cover, if any. Prior to the completion of the Spin-off, Noble-UK and Paragon Offshore entered into the Separation Agreements to effect the separation and Spin-off and govern the relationship between the parties after the Spin-off, including the MSA and the TSA. As part of its final bankruptcy plan, Paragon Offshore rejected the Separation Agreements. Accordingly, the indemnity obligations that Paragon Offshore potentially would have owed us under the Separation Agreements have now terminated, including indemnities arising under the MSA and the TSA in respect of obligations related to Paragon Offshore’s business that were incurred through Noble-retained entities prior to the Spin-off. Likewise, any potential indemnity obligations that we would have owed Paragon Offshore under the Separation Agreements, including those under the MSA and the TSA in respect of Noble-UK’s business that was conducted prior to the Spin-off through Paragon Offshore-retained entities, are now also extinguished. In the absence of the Separation Agreements, liabilities relating to the respective parties will be borne by the owner of the legal entity or asset at issue and neither party will look to an allocation based on the historic relationship of an entity or asset to one of the party’s business, as had been the case under the Separation Agreements. The rejection and ultimate termination of the indemnity and related obligations under the Separation Agreements resulted in a number of accounting charges and benefits during the year ended December 31, 2017, and such termination may continue to affect us in the future as liabilities arise for which we would have been indemnified by Paragon Offshore or would have had to indemnify Paragon Offshore. We do not expect that, overall, the rejection of the Separation Agreements by Paragon Offshore will have a material adverse effect on our financial condition or liquidity. However, any loss we experience with respect to which we would have been able to secure indemnification from Paragon Offshore under one or more of the Separation Agreements could have an adverse impact on our results of operations in any period, which impact may be material depending on our results of operations during this down-cycle. During the year ended December 31, 2017, we recognized net charges of $15.9 million , with a non-cash loss of $1.5 million recorded in “Net loss from discontinued operations, net of tax” on our Consolidated Statement of Operations relating to Paragon Offshore’s emergence from bankruptcy.” Tax matters During 2014 , the Internal Revenue Service (“IRS”) began its examination of our tax reporting in the U.S. for the taxable years ended December 31, 2010 and 2011 . The IRS examination team has completed its examination of our 2010 and 2011 U.S. tax returns and proposed adjustments and deficiencies with respect to certain items that were reported by us for the 2010 and 2011 tax year. On December 19, 2016, we received the Revenue Agent Report from the IRS. We believe that we have accurately reported all amounts in our tax returns, and have submitted administrative protests with the IRS Office of Appeals contesting the examination team’s proposed adjustments. We intend to vigorously defend our reported positions, and believe the ultimate resolution of the adjustments proposed by the IRS examination team will not have a material adverse effect on our consolidated financial statements. During the third quarter of 2017, the IRS initiated its examination of our 2012 , 2013 , 2014 and 2015 tax returns. Audit claims of approximately $50.7 million attributable to income and other business taxes were assessed against Noble entities in Mexico related to tax years 2005 and 2007. We intend to vigorously defend our reported positions, and believe the ultimate resolution of the audit claims will not have a material adverse effect on our consolidated financial statements. We operate in a number of countries throughout the world and our tax returns filed in those jurisdictions are subject to review and examination by tax authorities within those jurisdictions. We recognize uncertain tax positions that we believe have a greater than 50 percent likelihood of being sustained. We cannot predict or provide assurance as to the ultimate outcome of any existing or future assessments. Other contingencies We have entered into agreements with certain of our executive officers, as well as certain other employees. These agreements become effective upon a change of control of Noble-UK (within the meaning set forth in the agreements) or a termination of employment in connection with or in anticipation of a change of control, and remain effective for three years thereafter. These agreements provide for compensation and certain other benefits under such circumstances. We are a defendant in certain claims and litigation arising out of operations in the ordinary course of business, including personal injury claims, the resolution of which, in the opinion of management, will not be material to our financial position, results of operations or cash flows. There is inherent risk in any litigation or dispute and no assurance can be given as to the outcome of these claims. We lease certain office space and warehouse facilities under cancelable and non-cancelable leases. Rent expense under these arrangements totaled $7.5 million , $8.3 million and $7.8 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The table below depicts future minimum rental commitments under our operating leases as of December 31, 2018 : 2019 2020 2021 2022 2023 Thereafter Total (1) $ 15,213 $ 7,913 $ 5,522 $ 1,821 $ 695 $ 5,724 $ 36,888 (1) In February 2019, we amended the lease of our Sugar Land office to extend the lease for an additional ten years and to reduce the rented space. The above table does not include this lease amendment.

Segment and Related Information

Segment and Related Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment and Related Information	Note 16— Segment and Related Information We report our contract drilling operations as a single reportable segment, Contract Drilling Services, which reflects how we manage our business. The mobile offshore drilling units comprising our offshore rig fleet operate in a global market for contract drilling services and are often redeployed to different regions due to changing demands of our customers, which consist primarily of large, integrated, independent and government-owned or controlled oil and gas companies throughout the world. As of December 31, 2018 , our contract drilling services segment conducts contract drilling operations in Canada, Far East Asia, the Middle East, the North Sea, Oceania, the Black Sea, South America and the U.S. Gulf of Mexico. The following table presents revenues and identifiable assets by country based on the location of the service provided: Revenues for Year Ended December 31, Identifiable Assets as of December 31, 2018 2017 2016 2018 2017 Argentina $ — $ — $ 51,627 $ — $ — Australia — 12,262 89,847 243,388 257,415 Brazil — — 27,640 13,299 25,645 Brunei 3,080 45,450 42,710 — 119 Bulgaria 84,757 55,145 78,985 645,689 657,806 Canada 47,085 1,639 — 219,421 238,902 Curacao — — — 82,521 647,554 Denmark 35,855 44,671 46,342 242,831 250,851 East Timor 33,733 — — — — Egypt 112,473 — — 689,965 — Gabon — — 23,385 8,065 8,378 Guyana 50,839 — — 1,250,390 — Malaysia 91,052 131,696 168,826 665,822 293,297 Mexico — — — 27,542 27,391 Myanmar 16,572 — — 152,629 — Qatar 35,180 16,488 608 478,708 — Saudi Arabia 156,989 140,453 120,132 380,421 455,296 Singapore 1,769 — — 125,574 911,515 South Africa — 48,228 1,803 — — Suriname (3 ) 13,034 — — — Tanzania 381 1,526 48,394 — — The Netherlands — — 42 — — Turkey — (3 ) — — — United Arab Emirates (17 ) 99,825 86,446 45,205 590,863 United Kingdom 194,602 209,338 95,621 1,152,596 894,902 United States 218,479 417,163 1,404,365 2,840,857 5,534,725 Other — — 15,292 — — Total $ 1,082,826 $ 1,236,915 $ 2,302,065 $ 9,264,923 $ 10,794,659

Supplemental Financial Informat

Supplemental Financial Information	12 Months Ended
	Dec. 31, 2018
Supplemental Financial Information [Abstract]
Supplemental Financial Information	Note 17— Supplemental Financial Information Consolidated Balance Sheets Information Deferred revenues from drilling contracts totaled $80.8 million and $114.3 million at December 31, 2018 and 2017 , respectively. Such amounts are included in either “Other current liabilities” or “Other liabilities” in the accompanying Consolidated Balance Sheets, based upon our expected time of recognition. Related expenses deferred under drilling contracts totaled $47.7 million at December 31, 2018 as compared to $55.7 million at December 31, 2017 , and are included in either “Prepaid expenses and other current assets,” “Other assets” or “Property and equipment, net” in the accompanying Consolidated Balance Sheets, based upon our expected time of recognition. Consolidated Statements of Cash Flows Information Operating cash activities The net effect of changes in other assets and liabilities on cash flows from operating activities is as follows: Noble-UK Noble-Cayman December 31, December 31, 2018 2017 2016 2018 2017 2016 Accounts receivable $ 3,974 $ 114,456 $ 179,779 $ 3,974 $ 114,456 $ 179,779 Other current assets (2,722 ) 26,155 81,657 (2,700 ) 23,309 79,720 Other assets (10,378 ) (89,021 ) 138,210 (6,424 ) (91,236 ) 136,130 Accounts payable 14,955 (14,625 ) (68,209 ) 14,795 (14,429 ) (66,421 ) Other current liabilities (13,940 ) 33,906 (209,739 ) (13,495 ) 35,033 (203,763 ) Other liabilities (26,829 ) (92,096 ) (31,389 ) (26,829 ) (87,213 ) (32,732 ) Total net change in assets and liabilities $ (34,940 ) $ (21,225 ) $ 90,309 $ (30,679 ) $ (20,080 ) $ 92,713 Non-cash investing and financing activities Additions to property and equipment, at cost for which we had accrued a corresponding liability in accounts payable as of December 31, 2018 , December 31, 2017 and December 31, 2016 were $52.1 million , $25.5 million and $35.1 million , respectively. We entered into a $60.0 million Seller Loan to finance a portion of the purchase price for the Noble Johnny Whitstine in September 2018 . See “ Note 7— Debt ” for additional information. Additional cash flow information is as follows: Noble - UK Noble - Cayman December 31, December 31, 2018 2017 2016 2018 2017 2016 Cash paid during the period for: Interest, net of amounts capitalized $ 286,506 $ 246,960 $ 232,907 $ 286,506 $ 246,960 $ 232,907 Income taxes (net of refunds) (107,554 ) 30,590 100,544 (107,554 ) 30,590 100,717 Non-cash activities during the period: Spin-off of Paragon Offshore N/A N/A N/A N/A N/A N/A In accordance with our adoption of ASU No. 2016-09, prior period excess tax benefits, which were previously classified as a financing activity in “Employee stock transactions,” are now classified as an operating activity in “Net change in other assets and liabilities” on our Consolidated Statement of Cash Flows and current period excess tax benefits are now recognized in our Consolidated Statement of Operations through income taxes. Additionally, shares withheld for taxes on employee stock transactions, which were previously classified as an operating activity in “Net change in other assets and liabilities,” are now classified as a financing activity in “Employee stock transactions” on our Consolidated Statement of Cash Flows. Revision of Prior Period Financial Statements During the preparation of our 2018 financial statements, we identified a computational error that resulted in misstatements of certain line items on the Consolidated Statements of Cash Flows for Noble Corporation plc and Noble Corporation (Cayman) for the years ended December 31, 2017 and 2016 . These errors did not impact our cash, cash equivalents and restricted cash balances. We assessed the materiality of the misstatements and concluded the misstatements were immaterial to the previously issued financial statements. We have revised the Consolidated Statements of Cash Flows for the years ended December 31, 2017 and 2016 . The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,638 $ (37,263 ) $ (14,625 ) $ (84,873 ) $ 16,664 $ (68,209 ) Net effect of changes in other assets and liabilities 16,038 (37,263 ) (21,225 ) 73,645 16,664 90,309 Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,834 $ (37,263 ) $ (14,429 ) $ (83,085 ) $ 16,664 $ (66,421 ) Net effect of changes in other assets and liabilities 17,183 (37,263 ) (20,080 ) 76,049 16,664 92,713

Condensed Consolidating Financi

Condensed Consolidating Financial Information	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Consolidating Financial Information	Note 18— Condensed Consolidating Financial Information Guarantees of Registered Securities Noble-Cayman, or one or more 100 percent owned subsidiaries of Noble-Cayman, is an issuer, co-issuer or full and unconditional guarantor or otherwise obligated as of December 31, 2018 with respect to registered securities as follows (see “ Note 7— Debt ” for additional information): Issuer Notes (1) (Co-Issuer(s)) Guarantor 5.75% Senior Notes due 2018 NHIL Noble-Cayman 7.50% Senior Notes due 2019 (2) NHUS Noble-Cayman Noble Drilling Holding, LLC (“NDH”) Noble Drilling Services 6 LLC (“NDS6”) 4.90% Senior Notes due 2020 NHIL Noble-Cayman 4.625% Senior Notes due 2021 NHIL Noble-Cayman 3.95% Senior Notes due 2022 NHIL Noble-Cayman 7.75% Senior Notes due 2024 NHIL Noble-Cayman 7.95% Senior Notes due 2025 NHIL Noble-Cayman 6.20% Senior Notes due 2040 NHIL Noble-Cayman 6.05% Senior Notes due 2041 NHIL Noble-Cayman 5.25% Senior Notes due 2042 NHIL Noble-Cayman 8.95% Senior Notes due 2045 NHIL Noble-Cayman (1) Our 2026 Notes are excluded from this list as they are unregistered securities issued in a non-public offering. (2) In February 2018 , the entire remaining principal amount of 2019 Notes were redeemed and, as a result, we have prospectively eliminated NHUS, NDH, and NDS6 as guarantors in the current year presentation of the Condensed Consolidating Financial Information. However, prior year information is presented as previously reported. The following condensed consolidating financial statements of Noble-Cayman, NHUS, NDH, NHIL, NDS6 and all other subsidiaries present investments in both consolidated and unconsolidated affiliates using the equity method of accounting. NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2018 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble - NHIL Other Consolidating Total ASSETS Current assets Cash and cash equivalents $ — $ 17,818 $ 356,557 $ — $ 374,375 Accounts receivable — — 200,722 — 200,722 Taxes receivable — — 20,498 — 20,498 Short-term notes receivable from affiliates — — 3,175,662 (3,175,662 ) — Accounts receivable from affiliates 275,726 61,046 4,823,902 (5,160,674 ) — Prepaid expenses and other current assets — — 61,917 — 61,917 Total current assets 275,726 78,864 8,639,258 (8,336,336 ) 657,512 Property and equipment, at cost — — 10,956,412 — 10,956,412 Accumulated depreciation — — (2,475,694 ) — (2,475,694 ) Property and equipment, net — — 8,480,718 — 8,480,718 Notes receivable from affiliates 5,145 — — (5,145 ) — Investments in affiliates 7,716,068 12,300,840 — (20,016,908 ) — Other assets 609 — 124,540 — 125,149 Total assets $ 7,997,548 $ 12,379,704 $ 17,244,516 $ (28,358,389 ) $ 9,263,379 LIABILITIES AND EQUITY Current liabilities Short-term notes payables to affiliates $ — $ 3,175,662 $ — $ (3,175,662 ) $ — Accounts payable 45 — 125,192 — 125,237 Accrued payroll and related costs — — 50,284 — 50,284 Accounts payable to affiliates 3,725,506 1,098,395 336,773 (5,160,674 ) — Taxes payable — — 29,386 — 29,386 Interest payable 3 99,997 100 — 100,100 Other current liabilities — — 60,012 — 60,012 Total current liabilities 3,725,554 4,374,054 601,747 (8,336,336 ) 365,019 Long-term debt — 3,817,153 60,249 — 3,877,402 Notes payable to affiliates — — 5,145 (5,145 ) — Deferred income taxes — — 91,695 — 91,695 Other liabilities 19,929 — 255,866 — 275,795 Total liabilities 3,745,483 8,191,207 1,014,702 (8,341,481 ) 4,609,911 Commitments and contingencies Total shareholder equity 4,252,065 4,188,497 15,828,411 (20,016,908 ) 4,252,065 Noncontrolling interests — — 401,403 — 401,403 Total equity 4,252,065 4,188,497 16,229,814 (20,016,908 ) 4,653,468 Total liabilities and equity $ 7,997,548 $ 12,379,704 $ 17,244,516 $ (28,358,389 ) $ 9,263,379 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2017 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total ASSETS Current assets Cash and cash equivalents $ 11 $ — $ 23,160 $ 29,324 $ — $ 609,516 $ — $ 662,011 Accounts receivable — — 24,722 — — 179,974 — 204,696 Taxes receivable — 93,302 3 — — 12,040 — 105,345 Short-term notes receivable from affiliates — — 119,476 — 2,373,452 — (2,492,928 ) — Accounts receivable from affiliates 594,456 1,454 144,367 60,945 465,749 5,813,846 (7,080,817 ) — Prepaid expenses and other current assets — — 1,477 — 1 63,963 — 65,441 Total current assets 594,467 94,756 313,205 90,269 2,839,202 6,679,339 (9,573,745 ) 1,037,493 Property and equipment, at cost — — 857,784 — — 11,176,547 — 12,034,331 Accumulated depreciation — — (110,005 ) — — (2,435,086 ) — (2,545,091 ) Property and equipment, net — — 747,779 — — 8,741,461 — 9,489,240 Notes receivable from affiliates 3,177,248 — 1,199,815 — 3,943,299 1,175,300 (9,495,662 ) — Investments in affiliates 4,933,978 4,550,358 5,252,135 12,560,598 7,237,474 — (34,534,543 ) — Other assets 2,663 16,775 8,372 — — 238,718 — 266,528 Total assets $ 8,708,356 $ 4,661,889 $ 7,521,306 $ 12,650,867 $ 14,019,975 $ 16,834,818 $ (53,603,950 ) $ 10,793,261 LIABILITIES AND EQUITY Current liabilities Short-term notes payables to affiliates $ — $ 1,605,243 $ — $ — $ — $ 887,685 $ (2,492,928 ) $ — Current maturities of long-term debt — — — 249,843 — — — 249,843 Accounts payable — — 1,467 — — 82,406 — 83,873 Accrued payroll and related costs — — 4,780 — — 50,124 — 54,904 Accounts payable to affiliates 3,410,669 393,073 1,770,066 661,375 — 845,634 (7,080,817 ) — Taxes payable — — — — — 33,965 — 33,965 Interest payable 2,211 — — 83,960 12,018 — — 98,189 Other current liabilities — — 5,169 — — 66,297 — 71,466 Total current liabilities 3,412,880 1,998,316 1,781,482 995,178 12,018 1,966,111 (9,573,745 ) 592,240 Long-term debt — — — 3,594,332 201,535 — — 3,795,867 Notes payable to affiliates — 700,000 474,637 3,175,663 — 5,145,362 (9,495,662 ) — Deferred income taxes — — 5 — — 164,957 — 164,962 Other liabilities 19,929 — 30,330 — — 239,919 — 290,178 Total liabilities 3,432,809 2,698,316 2,286,454 7,765,173 213,553 7,516,349 (19,069,407 ) 4,843,247 Commitments and contingencies Total shareholder equity 5,275,547 1,963,573 5,234,852 4,885,694 13,806,422 8,644,002 (34,534,543 ) 5,275,547 Noncontrolling interests — — — — — 674,467 — 674,467 Total equity 5,275,547 1,963,573 5,234,852 4,885,694 13,806,422 9,318,469 (34,534,543 ) 5,950,014 Total liabilities and equity $ 8,708,356 $ 4,661,889 $ 7,521,306 $ 12,650,867 $ 14,019,975 $ 16,834,818 $ (53,603,950 ) $ 10,793,261 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS and COMPREHENSIVE INCOME (LOSS) Year Ended December 31, 2018 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHIL Other Consolidating Total Operating revenues Contract drilling services $ — $ — $ 1,036,082 $ — $ 1,036,082 Reimbursables and other — — 46,744 — 46,744 Total operating revenues — — 1,082,826 — 1,082,826 Operating costs and expenses Contract drilling services 2 (22 ) 628,148 — 628,128 Reimbursables — — 37,084 — 37,084 Depreciation and amortization — — 482,660 — 482,660 General and administrative 57 214 37,932 — 38,203 Loss on impairment — — 802,133 — 802,133 Total operating costs and expenses 59 192 1,987,957 — 1,988,208 Operating loss (59 ) (192 ) (905,131 ) — (905,382 ) Other income (expense) Income (loss) of unconsolidated affiliates - continuing operations (2,738,475 ) (258,687 ) — 2,997,162 — Interest expense, net of amounts capitalized (1,324 ) (449,824 ) (1,911,822 ) 2,065,359 (297,611 ) Gain (loss) on extinguishment of debt, net (2,336 ) 12,651 (12,108 ) — (1,793 ) Interest income and other, net 1,897,709 (74 ) 176,006 (2,065,359 ) 8,282 Income (loss) before income taxes (844,485 ) (696,126 ) (2,653,055 ) 2,997,162 (1,196,504 ) Income tax benefit (provision) — — 106,534 — 106,534 Net income (loss) (844,485 ) (696,126 ) (2,546,521 ) 2,997,162 (1,089,970 ) Net income attributable to noncontrolling interests — — 245,485 — 245,485 Net income (loss) attributable to Noble Corporation (844,485 ) (696,126 ) (2,301,036 ) 2,997,162 (844,485 ) Other comprehensive income (loss), net (8,644 ) — (8,644 ) 8,644 (8,644 ) Comprehensive income (loss) attributable to Noble Corporation $ (853,129 ) $ (696,126 ) $ (2,309,680 ) $ 3,005,806 $ (853,129 ) NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS and COMPREHENSIVE INCOME (LOSS) Year Ended December 31, 2017 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Operating revenues Contract drilling services $ — $ — $ 168,592 $ — $ — $ 1,086,320 $ (47,886 ) $ 1,207,026 Reimbursables and other — — 3,443 — — 26,446 — 29,889 Total operating revenues — — 172,035 — — 1,112,766 (47,886 ) 1,236,915 Operating costs and expenses Contract drilling services 304 12,090 43,161 3,115 — 629,699 (47,886 ) 640,483 Reimbursables — — 1,992 — — 16,443 — 18,435 Depreciation and amortization — — 58,236 — — 484,883 — 543,119 General and administrative 129 5,761 — 1,588 9 33,600 — 41,087 Loss on impairment — — 45,012 — — 76,627 — 121,639 Total operating costs and expenses 433 17,851 148,401 4,703 9 1,241,252 (47,886 ) 1,364,763 Operating income (loss) (433 ) (17,851 ) 23,634 (4,703 ) (9 ) (128,486 ) — (127,848 ) Other income (expense) Income (loss) of unconsolidated affiliates - continuing operations (476,382 ) (528,702 ) 82,596 188,809 17,874 — 715,805 — Income (loss) of unconsolidated affiliates - discontinued operations, net of tax 2,967 4,566 — — — — (7,533 ) — Interest expense, net of amounts capitalized (10,951 ) (32,838 ) (13,493 ) (430,580 ) (15,288 ) (130,442 ) 341,603 (291,989 ) Interest income and other, net 10,483 (141 ) 87,287 4,771 224,772 22,164 (341,603 ) 7,733 Income (loss) before income taxes (474,316 ) (574,966 ) 180,024 (241,703 ) 227,349 (236,764 ) 708,272 (412,104 ) Income tax benefit (provision) — 241,960 (440 ) — — (284,115 ) — (42,595 ) Net income (loss) from continuing operations (474,316 ) (333,006 ) 179,584 (241,703 ) 227,349 (520,879 ) 708,272 (454,699 ) Net income (loss) from discontinuing operations, net of tax — (1,598 ) — — — 4,565 — 2,967 Net income (loss) (474,316 ) (334,604 ) 179,584 (241,703 ) 227,349 (516,314 ) 708,272 (451,732 ) Net income attributable to noncontrolling interests — — — — — (20,589 ) (1,995 ) (22,584 ) Net income (loss) attributable to Noble Corporation (474,316 ) (334,604 ) 179,584 (241,703 ) 227,349 (536,903 ) 706,277 (474,316 ) Other comprehensive income (loss), net 9,252 — — — — 9,252 (9,252 ) 9,252 Comprehensive income (loss) attributable to Noble Corporation $ (465,064 ) $ (334,604 ) $ 179,584 $ (241,703 ) $ 227,349 $ (527,651 ) $ 697,025 $ (465,064 ) NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF INCOME and COMPREHENSIVE INCOME (LOSS) Year Ended December 31, 2016 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Operating revenues Contract drilling services $ — $ — $ 250,049 $ — $ — $ 2,086,848 $ (94,697 ) $ 2,242,200 Reimbursables and other — — 9,190 — — 51,375 — 60,565 Total operating revenues — — 259,239 — — 2,138,223 (94,697 ) 2,302,765 Operating costs and expenses Contract drilling services 4,532 18,902 70,801 84,309 — 788,065 (94,697 ) 871,912 Reimbursables — — 8,231 — — 37,268 — 45,499 Depreciation and amortization — — 91,802 — — 519,211 — 611,013 General and administrative 1,264 8,716 — 40,082 1 (4,018 ) — 46,045 Loss on impairment — — — — — 1,458,749 — 1,458,749 Total operating costs and expenses 5,796 27,618 170,834 124,391 1 2,799,275 (94,697 ) 3,033,218 Operating income (loss) (5,796 ) (27,618 ) 88,405 (124,391 ) (1 ) (661,052 ) — (730,453 ) Other income (expense) Income (loss) of unconsolidated affiliates (962,662 ) (257,142 ) (980,099 ) (333,446 ) 515,518 — 2,017,831 — Interest expense, net of amounts capitalized (27,891 ) (70,494 ) (11,461 ) (228,423 ) (15,117 ) (122,345 ) 252,816 (222,915 ) Gain on extinguishment of debt, net — — — 17,814 — — — 17,814 Interest income and other, net 96,635 120 12,616 20,412 15,058 106,359 (252,816 ) (1,616 ) Income (loss) before income taxes (899,714 ) (355,134 ) (890,539 ) (648,034 ) 515,458 (677,038 ) 2,017,831 (937,170 ) Income tax benefit (provision) — (42,522 ) 163 — — 151,522 — 109,163 Net income (loss) (899,714 ) (397,656 ) (890,376 ) (648,034 ) 515,458 (525,516 ) 2,017,831 (828,007 ) Net (income) loss attributable to noncontrolling interests — — — — — (39,294 ) (32,413 ) (71,707 ) Net income (loss) attributable to Noble Corporation (899,714 ) (397,656 ) (890,376 ) (648,034 ) 515,458 (564,810 ) 1,985,418 (899,714 ) Other comprehensive income (loss), net 11,035 — — — — 11,035 (11,035 ) 11,035 Comprehensive income (loss) attributable to Noble Corporation $ (888,679 ) $ (397,656 ) $ (890,376 ) $ (648,034 ) $ 515,458 $ (553,775 ) $ 1,974,383 $ (888,679 ) NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2018 (Unless otherwise indicated, dollar amounts in tables are in thousands) Noble- NHIL Other Consolidating Total Cash flows from operating activities Net cash provided by (used in) operating activities $ 1,920,724 $ (426,298 ) $ (1,281,667 ) $ — $ 212,759 Cash flows from investing activities Capital expenditures — — (194,779 ) — (194,779 ) Proceeds from disposal of assets — — 5,402 — 5,402 Net cash used in investing activities — — (189,377 ) — (189,377 ) Cash flows from financing activities Issuance of senior notes — 750,000 — — 750,000 Repayment of long-term debt — (759,053 ) (213,655 ) — (972,708 ) Debt issuance costs (845 ) (13,027 ) (1,767 ) — (15,639 ) Dividends paid to noncontrolling interests — — (27,579 ) — (27,579 ) Distribution to parent company, net (44,417 ) — — — (44,417 ) Advances (to) from affiliates (1,875,473 ) 436,872 1,438,601 — — Net cash provided by (used in) financing activities (1,920,735 ) 414,792 1,195,600 — (310,343 ) Net change in cash, cash equivalents and restricted cash (11 ) (11,506 ) (275,444 ) — (286,961 ) Cash, cash equivalents and restricted cash, beginning of period 11 29,324 632,676 — 662,011 Cash, cash equivalents and restricted cash, end of period $ — $ 17,818 $ 357,232 $ — $ 375,050 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2017 (Unless otherwise indicated, dollar amounts in tables are in thousands) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Cash flows from operating activities Net cash provided by (used in) operating activities $ 32,195 $ 100,883 $ 209,898 $ (403,391 ) $ 217,080 $ 298,409 $ — $ 455,074 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (117,085 ) — (120,707 ) Proceeds from disposal of assets — — 46 — — 2,336 — 2,382 Net cash used in investing activities — — (3,576 ) — — (114,749 ) — (118,325 ) Cash flows from financing activities Repayment of long-term debt — — — (300,000 ) — — — (300,000 ) Debt issuance costs on senior notes and credit facilities — — — (42 ) — — — (42 ) Dividends paid to noncontrolling interests — — — — — (56,881 ) — (56,881 ) Contributions from parent company, net 28,352 — — — — — — 28,352 Advances (to) from affiliates (63,073 ) (100,883 ) (194,017 ) 732,757 (217,080 ) (157,704 ) — — Net cash provided by (used in) financing activities (34,721 ) (100,883 ) (194,017 ) 432,715 (217,080 ) (214,585 ) — (328,571 ) Net change in cash, cash equivalents and restricted cash (2,526 ) — 12,305 29,324 — (30,925 ) — 8,178 Cash, cash equivalents and restricted cash, beginning of period 2,537 — 10,855 — — 640,441 — 653,833 Cash, cash equivalents and restricted cash, end of period $ 11 $ — $ 23,160 $ 29,324 $ — $ 609,516 $ — $ 662,011 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2016 (Unless otherwise indicated, dollar amounts in tables are in thousands) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Cash flows from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,421,023 $ — $ 1,172,935 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (218,418 ) — (711,403 ) Proceeds from disposal of assets — — — — — 24,808 — 24,808 Net cash provided by (used in) investing activities — — (492,985 ) — — (193,610 ) — (686,595 ) Cash flows from financing activities Repayment of long-term debt — — — (1,049,338 ) — — — (1,049,338 ) Issuance of senior notes — — — 980,100 — — — 980,100 Tender offer premium — — — (24,649 ) — — — (24,649 ) Debt issuance costs on senior notes and credit facilities — — — (12,111 ) — — — (12,111 ) Dividends paid to noncontrolling interests — — — — — (85,944 ) — (85,944 ) Distributions to parent company, net (152,360 ) — — — — — — (152,360 ) Advances (to) from affiliates 55,882 150,735 352,308 450,110 60 (1,009,095 ) — — Net cash provided by (used in) financing activities (96,478 ) 150,735 352,308 344,112 60 (1,095,039 ) — (344,302 ) Net change in cash, cash equivalents and restricted cash 910 — 8,754 — — 132,374 — 142,038 Cash, cash equivalents and restricted cash, beginning of period 1,627 — 2,101 — — 508,067 — 511,795 Cash, cash equivalents and restricted cash, end of period $ 2,537 $ — $ 10,855 $ — $ — $ 640,441 $ — $ 653,833 Revision of Prior Period Financial Statements During the preparation of our 2018 financial statements, we identified a computational error that resulted in misstatements of certain line items on the Consolidated Statements of Cash Flows for Noble Corporation (Cayman) for the years ended December 31, 2017 and 2016 . These errors did not impact our cash, cash equivalents and restricted cash balances. We assessed the materiality of the misstatements and concluded the misstatements were immaterial to the previously issued financial statements. We have revised the Consolidated Statements of Cash Flows for the years ended December 31, 2017 and 2016 . The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Year Ended December 31, 2017 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 32,195 $ 100,883 $ 209,898 $ (403,391 ) $ 217,080 $ 335,672 $ — $ 492,337 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (154,348 ) — (157,970 ) Net cash used in investing activities — — (3,576 ) — — (152,012 ) — (155,588 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities — — — — — (37,263 ) — (37,263 ) Cash flows from investing activities Capital expenditures — — — — — 37,263 — 37,263 Net cash used in investing activities — — — — — 37,263 — 37,263 As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities 32,195 100,883 209,898 (403,391 ) 217,080 298,409 — 455,074 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (117,085 ) — (120,707 ) Net cash used in investing activities — — (3,576 ) — — (114,749 ) — (118,325 ) Year Ended December 31, 2016 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,404,359 $ — $ 1,156,271 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (201,754 ) — (694,739 ) Net cash used in investing activities — — (492,985 ) — — (176,946 ) — (669,931 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ — $ — $ — $ — $ — $ 16,664 $ — $ 16,664 Cash flows from investing activities Capital expenditures — — — — — (16,664 ) — (16,664 ) Net cash used in investing activities — — — — — (16,664 ) — (16,664 ) As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,421,023 $ — $ 1,172,935 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (218,418 ) — (711,403 ) Net cash used in investing activities — — (492,985 ) — — (193,610 ) — (686,595 )

Unaudited Interim Financial Dat

Unaudited Interim Financial Data	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Unaudited Interim Financial Data	Note 19— Unaudited Interim Financial Data Unaudited interim consolidated financial information from continuing operations for Noble-UK is as follows: Quarters Ended March 31 June 30 September 30 December 31 2018 Operating revenues $ 235,157 $ 258,369 $ 279,408 $ 309,892 Operating loss (56,880 ) (845,606 ) (21,843 ) (21,745 ) Net loss from continuing operations (142,334 ) (628,063 ) (81,591 ) (33,062 ) Net loss per share from continuing operations attributable to Noble-UK (1) Basic Loss from continuing operations (0.58 ) (2.55 ) (0.33 ) (0.13 ) Diluted Loss from continuing operations (0.58 ) (2.55 ) (0.33 ) (0.13 ) Quarter Ended March 31 June 30 September 30 December 31 2017 Operating revenues $ 362,976 $ 278,142 $ 266,212 $ 329,585 Operating loss (45,463 ) (44,285 ) (56,604 ) (110,294 ) Net loss from continuing operations (301,694 ) (91,864 ) (96,792 ) (24,675 ) Net loss from discontinued operations, net of tax — (1,486 ) — — Net loss per share from continuing operations attributable to Noble-UK (1) Basic Loss from continuing operations (1.24 ) (0.37 ) (0.40 ) (0.10 ) Loss from discontinued operations — (0.01 ) — — Diluted Loss from continuing operations (1.24 ) (0.37 ) (0.40 ) (0.10 ) Loss from discontinued operations — (0.01 ) — — (1) Net loss per share is computed independently for each of the quarters presented. Therefore, the sum of the quarters’ net loss per share may not equal the total computed for the year.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 20— Subsequent Events Purchase of Noble Joe Knight On February 14, 2019, we exercised an option to purchase another GustoMSC CJ46 rig, to be known as the Noble Joe Knight , and we expect to close the purchase agreement in late February 2019. The purchase of the Noble Joe Knight is expected to be $83.8 million , of which, $30.1 million will be funded with cash and $53.8 million will be funded with seller financing on terms similar to the Noble Johnny Whitstine .

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Noble Corporation plc, a public limited company incorporated under the laws of England and Wales (“Noble-UK”), is a leading offshore drilling contractor for the oil and gas industry. We provide contract drilling services to the international oil and gas industry with our global fleet of mobile offshore drilling units. As of December 31, 2018 , our fleet of 24 drilling rigs consisted of eight drillships, four semisubmersibles and 12 jackups. We report our contract drilling operations as a single reportable segment, Contract Drilling Services, which reflects how we manage our business. The mobile offshore drilling units comprising our offshore rig fleet operate in a global market for contract drilling services and are often redeployed to different regions due to changing demands of our customers, which consist primarily of large, integrated, independent and government-owned or controlled oil and gas companies throughout the world. Noble Corporation, a Cayman Islands company (“Noble-Cayman”), is an indirect, wholly-owned subsidiary of Noble-UK, our publicly-traded parent company. Noble-UK’s principal asset is all of the shares of Noble-Cayman. Noble-Cayman has no public equity outstanding. The consolidated financial statements of Noble-UK include the accounts of Noble-Cayman, and Noble-UK conducts substantially all of its business through Noble-Cayman and its subsidiaries.
Principles of Consolidation	The consolidated financial statements include our accounts, those of our wholly-owned subsidiaries and entities in which we hold a controlling financial interest. Our consolidated financial statements also include the accounts of two joint ventures, in each of which we own a 50 percent interest. Our ownership interest meets the definition of variable interest under Financial Accounting Standards Board (“FASB”) codification and we have determined that we are the primary beneficiary. Intercompany balances and transactions have been eliminated in consolidation.
Prior Period Adjustment	During the preparation of our 2018 financial statements, we identified a computational error that resulted in misstatements of certain line items on the Consolidated Statements of Cash Flows for Noble Corporation plc and Noble Corporation (Cayman) for the years ended December 31, 2017 and 2016 . These errors did not impact our cash, cash equivalents and restricted cash balances. We assessed the materiality of the misstatements and concluded the misstatements were immaterial to the previously issued financial statements.
Foreign Currency Translation	Although we are a UK company, our functional currency is the U.S. dollar, and we define any non-U.S. dollar denominated currency as “foreign currencies.” In non-U.S. locations where the U.S. Dollar has been designated as the functional currency (based on an evaluation of factors including the markets in which the subsidiary operates, inflation, generation of cash flow, financing activities and intercompany arrangements), local currency transaction gains and losses are included in net income or loss. In non-U.S. locations where the local currency is the functional currency, assets and liabilities are translated at the rates of exchange on the balance sheet date, while statement of operations items are translated at average rates of exchange during the year. The resulting gains or losses arising from the translation of accounts from the functional currency to the U.S. Dollar are included in “Accumulated other comprehensive loss” in the Consolidated Balance Sheets.
Cash and Cash Equivalents	Cash and cash equivalents include cash on hand, demand deposits with banks and all highly liquid investments with original maturities of three months or less. Our cash, cash equivalents and short-term investments are subject to potential credit risk, and certain of our cash accounts carry balances greater than the federally insured limits. Cash and cash equivalents are primarily held by major banks or investment firms. Our cash management and investment policies restrict investments to lower risk, highly liquid securities and we perform periodic evaluations of the relative credit standing of the financial institutions with which we conduct business.
Restricted Cash	We classify restricted cash balances in current assets if the restriction is expected to expire or otherwise be resolved within one year and in other assets if the restriction is expected to expire or otherwise be resolved in more than one year.
Accounts Receivable	We record accounts receivable at the amount we invoice our clients, net of allowance for doubtful accounts. We provide an allowance for uncollectible accounts, as necessary.
Property and Equipment	Property and equipment is stated at cost, reduced by provisions to recognize economic impairment. Major replacements and improvements are capitalized. When assets are sold, retired or otherwise disposed of, the cost and related accumulated depreciation are eliminated from the accounts and the gain or loss is recognized. Drilling equipment and facilities are depreciated using the straight-line method over their estimated useful lives as of the date placed in service or date of major refurbishment. Estimated useful lives of our drilling equipment range from three to thirty years . Other property and equipment is depreciated using the straight-line method over useful lives ranging from two to forty years. Included in accounts payable were $52.1 million and $25.5 million of capital accruals as of December 31, 2018 and 2017 , respectively. Interest is capitalized on long-term construction project using the weighted average cost of debt outstanding during the period of construction. Scheduled maintenance of equipment is performed based on the number of hours operated in accordance with our preventative maintenance program. Routine repair and maintenance costs are charged to expense as incurred; however, the costs of the overhauls and asset replacement projects that benefit future periods and which typically occur every three to five years are capitalized when incurred and depreciated over an equivalent period. These overhauls and asset replacement projects are included in “Drilling equipment and facilities” in “ Note 5— Property and Equipment .” We evaluate our property and equipment for impairment whenever there are changes in facts which suggest that the value of the asset is not recoverable.
Fair Value Measurements	We measure certain of our assets and liabilities based on a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The three-level hierarchy, from highest to lowest level of observable inputs, are as follows: Level 1 - Valuations based on quoted prices in active markets for identical assets; Level 2 - Valuations based on observable inputs that do not meet the criteria for Level 1, including quoted prices in inactive markets and quoted prices in active markets for similar but not identical instruments; and Level 3 - Valuations based on unobservable inputs.
Revenue Recognition	The activities that primarily drive the revenue earned in our drilling contracts include (i) providing a drilling rig and the crew and supplies necessary to operate the rig, (ii) mobilizing and demobilizing the rig to and from the drill site, and (iii) performing rig preparation activities and/or modifications required for the contract. Consideration received for performing these activities may consist of dayrate drilling revenue, mobilization and demobilization revenue, contract preparation revenue and reimbursement revenue. We account for these integrated services provided within our drilling contracts as a single performance obligation satisfied over time and comprised of a series of distinct time increments in which we provide drilling services. Our standard drilling contracts require that we operate the rig at the direction of the customer throughout the contract term (which is the period we estimate to benefit from the corresponding activities and generally ranges from two to 60 months). The activities performed and the level of service provided can vary hour to hour. Our obligation under a standard contract is to provide whatever level of service is required by the operator, or customer, over the term of the contract. We are, therefore, under a stand-ready obligation throughout the entire contract duration. Consideration for our stand-ready obligation corresponds to distinct time increments, though the rate may be variable depending on various factors, and is recognized in the period in which the services are performed. The total transaction price is determined for each individual contract by estimating both fixed and variable consideration expected to be earned over the term of the contract. We have elected to exclude from the transaction price measurement all taxes assessed by a governmental authority. See further discussion regarding the allocation of the transaction price to the remaining performance obligations below. The amount estimated for variable consideration may be subject to interrupted or restricted rates and is only included in the transaction price to the extent that it is probable that a significant reversal of previously recognized revenue will not occur throughout the term of the contract (“constrained revenue”). When determining if variable consideration should be constrained, management considers whether there are factors outside the Company’s control that could result in a significant reversal of revenue as well as the likelihood and magnitude of a potential reversal of revenue. These estimates are re-assessed each reporting period as required. Dayrate Drilling Revenue. Our drilling contracts generally provide for payment on a dayrate basis, with higher rates for periods when the drilling unit is operating and lower rates or zero rates for periods when drilling operations are interrupted or restricted. The dayrate invoices billed to the customer are typically determined based on the varying rates applicable to the specific activities performed on an hourly basis. Such dayrate consideration is allocated to the distinct hourly increment it relates to within the contract term, and therefore, recognized in line with the contractual rate billed for the services provided for any given hour. Mobilization/Demobilization Revenue. We may receive fees (on either a fixed lump-sum or variable dayrate basis) for the mobilization and demobilization of our rigs. These activities are not considered to be distinct within the context of the contract and, therefore, the associated revenue is allocated to the overall performance obligation and the associated pre-operating costs are deferred. We record a contract liability for mobilization fees received and a deferred asset for costs. Both revenue and pre-operating costs are recognized ratably over the initial term of the related drilling contract. In most contracts, there is uncertainty as to the amount of expected demobilization revenue due to contractual provisions that stipulate that certain conditions must be present at contract completion for such revenue to be received and as to the amount thereof, if any. For example, contractual provisions may require that a rig demobilize a certain distance before the demobilization revenue is payable or the amount may vary dependent upon whether or not the rig has additional contracted work within a certain distance from the wellsite. Therefore, the estimate for such revenue may be constrained, as described earlier, depending on the facts and circumstances pertaining to the specific contract. We assess the likelihood of receiving such revenue based on past experience and knowledge of the market conditions. In cases where demobilization revenue is expected to be received upon contract completion, it is estimated as part of the overall transaction price at contract inception and recognized in earnings ratably over the initial term of the contract with an offset to an accretive contract asset. Contract Preparation Revenue. 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 fixed lump-sum or variable dayrate basis). These activities are not considered to be distinct within the context of the contract and, therefore, the related revenue is allocated to the overall performance obligation and recognized ratably over the initial term of the related drilling contract. We record a contract liability for contract preparation fees received, which is amortized ratably to contract drilling revenue over the initial term of the related drilling contract. Bonuses, Penalties and Other Variable Consideration. We may receive bonus increases to revenue or penalty decreases to revenue. Based on historical data and ongoing communication with the operator/customer, we are able to reasonably estimate this variable consideration. We will record such estimated variable consideration and re-measure our estimates at each reporting date. For revenue estimated, but not received, we will record to “Prepaid expenses and other current assets” on our Consolidated Balance Sheets. Capital Modification Revenue . From time to time, we may receive fees from our customers for capital improvements to our rigs to meet contractual requirements (on either a fixed lump-sum or variable dayrate basis). Such revenue is allocated to the overall performance obligation and recognized ratably over the initial term of the related drilling contract as these activities are integral to our drilling activities and are not considered to be a stand-alone service provided to the customer within the context of our contracts. We record a contract liability for such fees and recognize them ratably as contract drilling revenue over the initial term of the related drilling contract. Revenues Related to Reimbursable Expenses . We generally receive reimbursements from our customers for the purchase of supplies, equipment, personnel services and other services provided at their request in accordance with a drilling contract or other agreement. Such reimbursable revenue is variable and subject to uncertainty, as the amounts received and timing thereof is highly dependent on factors outside of our influence. Accordingly, reimbursable revenue is constrained revenue and not included in the total transaction price until the uncertainty is resolved, which typically occurs when the related costs are incurred on behalf of a customer. We are generally considered a principal in such transactions and record the associated revenue at the gross amount billed to the customer as “Reimbursables and other” in our Consolidated Statements of Operations. Such amounts are recognized ratably over the period within the contract term during which the corresponding goods and services are to be consumed. Deferred revenues from drilling contracts totaled $80.8 million and $114.3 million at December 31, 2018 and 2017 , respectively. Such amounts are included in either “Other current liabilities” or “Other liabilities” in the accompanying Consolidated Balance Sheets, based upon our expected time of recognition. Related expenses deferred under drilling contracts totaled $47.7 million at December 31, 2018 as compared to $55.7 million at December 31, 2017 and are included in either “Prepaid expenses and other current assets,” “Other assets” or “Property and equipment, net” in the accompanying Consolidated Balance Sheets, based upon our expected time of recognition. We record reimbursements from customers for “out-of-pocket” expenses as revenues and the related direct cost as operating expenses.
Income Taxes	Income taxes are based on the laws and rates in effect in the countries in which operations are conducted or in which we or our subsidiaries are considered resident for income tax purposes. In certain circumstances, we expect that, due to changing demands of the offshore drilling markets and the ability to redeploy our offshore drilling units, certain of such units will not reside in a location long enough to give rise to future tax consequences. As a result, no deferred tax asset or liability has been recognized in these circumstances. Should our expectations change regarding the length of time an offshore drilling unit will be used in a given location, we will adjust deferred taxes accordingly. Deferred tax assets and liabilities are recognized for the anticipated future tax effects of temporary differences between the financial statement basis and the tax basis of our assets and liabilities using the applicable jurisdictional tax rates at year-end. A valuation allowance for deferred tax assets is recorded when it is more likely than not that the deferred tax asset will not be realized in a future period. We operate through various subsidiaries in numerous countries throughout the world, including the United States. Consequently, we are subject to changes in tax laws, treaties or regulations or the interpretation or enforcement thereof in the U.S., UK or jurisdictions in which we or any of our subsidiaries operate or are resident. Our income tax expense is based upon our interpretation of the tax laws in effect in various countries at the time that the expense was incurred. If the IRS or other taxing authorities do not agree with our assessment of the effects of such laws, treaties and regulations, this could have a material adverse effect on us including the imposition of a higher effective tax rate on our worldwide earnings or a reclassification of the tax impact of our significant corporate restructuring transactions. The Company has adopted an accounting policy to look through the outside basis of partnerships and all other flow-through entities and exclude these from the computation of deferred taxes. On December 22, 2017, the President of the United States signed into law legislation informally known as the Tax Cuts and Jobs Act (the “Act”). The Act represents major tax reform legislation that, among other provisions, reduces the U.S. corporate tax rate. The Company recognized the income tax effects of the Act in its 2017 financial statements, including $109.0 million of tax benefit related to the write-down of our net deferred tax liabilities, in accordance with Accounting Standards Codification (“ASC”) Topic 740, Income Taxes, in the reporting period in which the Act was enacted. During the fourth quarter of 2017, the Act resulted in the write-down of our U.S. net deferred tax liabilities. In accordance with the guidance issued in Staff Accounting Bulletin No. 118 (SAB No. 118), during the third quarter of 2018, we finalized our provisional amounts recorded as we completed our technical analysis, computations and tax law interpretations and filed our 2017 U.S. tax return. As a result, we recognized an additional tax benefit of $24.9 million . See “ Note 11— Income Taxes ,” for further information on the financial statement impact of the Act. The Act introduces a new anti-deferral provision, which subjects a U.S. parent shareholder to current tax on certain income referred to as Global Intangible Low-Taxed Income, of its foreign subsidiaries. The Company has adopted a policy to treat tax due on future U.S. inclusions in taxable income as period costs when incurred.
Insurance Reserves	We maintain various levels of self-insured retention for certain losses including property damage, loss of hire, employment practices liability, employers’ liability and general liability, among others. We accrue for property damage and loss of hire charges on a per event basis. Employment practices liability claims are accrued based on actual claims during the year. Maritime employer’s liability claims are generally estimated using actuarial determinations. General liability claims are estimated by our internal claims department by evaluating the facts and circumstances of each claim (including incurred but not reported claims) and making estimates based upon historical experience with similar claims.
Earnings per Share	Our unvested share-based payment awards, which contain non-forfeitable rights to dividends, are participating securities and are included in the computation of earnings per share pursuant to the two-class method. The two-class method allocates undistributed earnings between common shares and participating securities. The diluted earnings per share calculation under the two-class method also includes the dilutive effect of potential shares issued in connection with stock options. The dilutive effect of stock options is determined using the treasury stock method.
Share-Based Compensation Plans	We record the grant date fair value of share-based compensation arrangements as compensation cost using a straight-line method over the service period. Share-based compensation is expensed or capitalized based on the nature of the employee’s activities.
Litigation Contingencies	We are involved in legal proceedings, claims, and regulatory, tax or government inquiries and investigations that arise in the ordinary course of business. Certain of these matters include speculative claims for substantial or indeterminate amounts of damages. We record a liability when we believe that it is both probable that a loss has been incurred and the amount can be reasonably estimated. If we determine that a loss is reasonably possible and the loss or range of loss can be estimated, we disclose the possible loss in the notes to the consolidated financial statements. We review the developments in our contingencies that could affect the amount of the provisions that has been previously recorded, and the matters and related possible losses disclosed. We make adjustments to our provisions and changes to our disclosures accordingly to reflect the impact of negotiations, settlements, rulings, advice of legal counsel, and updated information. Significant judgement is required to determine both the probability and the estimated amount.
Discontinued Operations	On August 1, 2014, Noble-UK completed the separation and spin-off of a majority of its standard specification offshore drilling business (the “Spin-off”) through a pro rata distribution of all of the ordinary shares of its wholly-owned subsidiary, Paragon Offshore plc (“Paragon Offshore”), to the holders of Noble’s ordinary shares. Paragon Offshore, which had been reflected as continuing operations in our consolidated financial statements prior to the Spin-off, meets the criteria for being reported as discontinued operations and has been reclassified as such in our results of operations. Prior to the completion of the Spin-off, Noble-UK and Paragon Offshore entered into a series of agreements to effect the separation and Spin-off and govern the relationship between the parties after the Spin-off (the “Separation Agreements”), including the Master Separation Agreement (the “MSA”) and the Tax Sharing Agreement (the “TSA”).
Certain Significant Estimates	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. Certain accounting policies involve judgments and uncertainties to such an extent that there is reasonable likelihood that materially different amounts could have been reported under different conditions, or if different assumptions had been used. We evaluate our estimates and assumptions on a regular basis. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates and assumptions used in preparation of our consolidated financial statements.
Accounting Pronouncements	Accounting Standards Adopted In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, which creates ASC Topic 606, “Revenue from Contracts with Customers,” and supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” including most industry-specific revenue recognition guidance throughout the Industry Topics of the Codification. In addition, ASU No. 2014-09 supersedes the cost guidance in Subtopic 605-35, “Revenue Recognition—Construction-Type and Production-Type Contracts,” and creates new Subtopic 340-40, “Other Assets and Deferred Costs—Contracts with Customers.” Under the new guidance, revenue is recognized when a customer obtains control of promised goods or services and in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. We adopted ASU 2014-09 and its related amendments, or collectively Topic 606, effective January 1, 2018 using the modified retrospective implementation method. Accordingly, we have applied the five-step method outlined in Topic 606 for determining when and how revenue is recognized to all contracts that were not completed as of the date of adoption. Revenues for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts have not been adjusted and continue to be reported under the previous revenue recognition guidance. For contracts that were modified before the effective date, we have considered the modification guidance within the new standard and determined that the revenue recognized and contract balances recorded prior to adoption for such contracts were not impacted. While Topic 606 requires additional disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, its adoption has not had a material impact on the measurement or recognition of our revenues. Our modified retrospective adoption, for which we were not required to make any material changes to the prior year presentation, did not have a material effect on our consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, which amends ASC Topic 740, “Income Taxes.” The amendments in this update improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. This standard is effective for interim and annual reporting periods beginning after December 15, 2017. We adopted the new standard effective January 1, 2018 under the modified retrospective approach. Accordingly, we recorded deferred charges of approximately $148.4 million to “Retained earnings” on our Consolidated Balance Sheets. In March 2017, the FASB issued ASU No. 2017-07, which amends ASC Topic 715, “Compensation —Retirement Benefits; Improving the Presentation of Net Periodic Pension Cost and Postretirement Benefits Cost.” The amendments in this update require that an employer disaggregate the service cost component from the other components of net benefit cost for an entity's defined benefit pension and other postretirement plans. The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement and allow only the service cost component of net benefit cost to be eligible for capitalization. The amendments in this update require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit costs, as defined in paragraphs 715-30-35-4 and 715-60-35-9, are required to be presented in the income statement separately from the service cost component and outside of income from operations. We adopted ASU No. 2017-07 effective January 1, 2018 and accordingly, we have made certain reclassifications between our “Contract drilling services” costs and “Interest income and other, net” on our Consolidated Statement of Operations. In February 2018 , the FASB issued ASU No. 2018 -02, which amends ASC Topic 220, “Income Statement—Reporting Comprehensive Income.” The amendments in this update allow for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Act. This standard is effective for interim and annual reporting periods beginning after December 15, 2018 with early application permitted. We elected to adopt the new standard effective January 1, 2018 under the modified retrospective approach. The amendment should be applied on a retrospective basis to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Act was recognized. As a result of the retrospective application, we reduced “Accumulated other comprehensive loss” in our Consolidated Balance Sheet with a cumulative adjustment to “Retained earnings” of approximately $5.5 million . In August 2018 , the FASB issued ASU No. 2018 -15, which amends ASC Subtopic 350-40, “Intangibles—Goodwill and Other—Internal—Use Software.” The amendments in this update require an entity in a hosting arrangement that is a service contract to capitalize implementation costs. Entities are to follow the guidance in ASC Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. The amendment also requires the entity to expense these capitalized implementation costs over the term of the hosting arrangement. We elected to early adopt ASU No. 2018 -15 effective September 30, 2018 , on a prospective basis. The adoption of this guidance did not have a material impact on our consolidated financial statements. Recently Issued Accounting Standards In February 2016, the FASB issued ASU No. 2016-02 (Topic 842, “Leases”), as amended, which generally requires lessees to recognize operating and financing lease liabilities and corresponding right-of-use assets on the balance sheet and to provide enhanced disclosures surrounding the amount, time and uncertainty of cash flows arising from lease agreements. We expect to adopt this standard, on a modified retrospective basis, effective January 1, 2019 and will not restate comparative periods. With respect to leases in which we are the lessee, we expect to recognize a lease liability and a corresponding right-of-use asset of approximately $28.0 million on our consolidated balance sheet as of January 1, 2019. We will elect the package of practical expedients that allows us to not reassess: (1) whether any expired or existing contracts are or contain leases, (2) lease classification for any expired or existing leases and (3) initial direct costs for any expired or existing leases. As lessee, we have taken the accounting policy election to not recognize an asset and liability for leases with a term of 12 months or less. We will recognize lease payments in the Consolidated Statements of Operations on a straight-line basis over the lease term. Our drilling contracts contain a lease component related to the underlying drilling equipment, in addition to the service component provided by our crews and our expertise to operate such drilling equipment. We have concluded that the non-lease service of operating our equipment and providing expertise in the drilling of the client's well is predominant in our drilling contracts. We expect to apply the practical expedient to account for the lease and associated non-lease operations as a single component. With the election of the practical expedient, we will continue to present a single performance obligation under the new revenue guidance in ASC 606. We are currently finalizing our evaluation of what other effect, if any, ASC 842 will have on our consolidated financial statements and related disclosures. We do not expect our adoption to materially affect our Consolidated Balance Sheet, Consolidated Statement of Operations, or Consolidated Statement of Cash Flows. In August 2018 , the FASB issued ASU No. 2018 -14, which amends ASC Subtopic 715-20, “Compensation — Retirement Benefits — Defined Benefit Plans — General.” This update applies to all employers that sponsor defined benefit pension or other postretirement plans and is part of the disclosure framework project to improve the effectiveness of disclosures in notes to the financial statements. The amendment is effective for fiscal years ending after December 15, 2020 and is required to be adopted on a retrospective basis for all periods presented. We do not expect the adoption of this guidance to materially affect our consolidated financial statements. With the exception of the updated standards discussed above, there have been no new accounting pronouncements not yet effective that have significance, or potential significance, to our consolidated financial statements.

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Prior Period Adjustments	The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 16,038 $ (37,263 ) $ (21,225 ) $ 73,645 $ 16,664 $ 90,309 Net cash provided by operating activities 453,938 (37,263 ) 416,675 1,126,076 16,664 1,142,740 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 17,183 $ (37,263 ) $ (20,080 ) $ 76,049 $ 16,664 $ 92,713 Net cash provided by operating activities 492,337 (37,263 ) 455,074 1,156,271 16,664 1,172,935 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,638 $ (37,263 ) $ (14,625 ) $ (84,873 ) $ 16,664 $ (68,209 ) Net effect of changes in other assets and liabilities 16,038 (37,263 ) (21,225 ) 73,645 16,664 90,309 Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,834 $ (37,263 ) $ (14,429 ) $ (83,085 ) $ 16,664 $ (66,421 ) Net effect of changes in other assets and liabilities 17,183 (37,263 ) (20,080 ) 76,049 16,664 92,713 The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Year Ended December 31, 2017 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 32,195 $ 100,883 $ 209,898 $ (403,391 ) $ 217,080 $ 335,672 $ — $ 492,337 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (154,348 ) — (157,970 ) Net cash used in investing activities — — (3,576 ) — — (152,012 ) — (155,588 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities — — — — — (37,263 ) — (37,263 ) Cash flows from investing activities Capital expenditures — — — — — 37,263 — 37,263 Net cash used in investing activities — — — — — 37,263 — 37,263 As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities 32,195 100,883 209,898 (403,391 ) 217,080 298,409 — 455,074 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (117,085 ) — (120,707 ) Net cash used in investing activities — — (3,576 ) — — (114,749 ) — (118,325 ) Year Ended December 31, 2016 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,404,359 $ — $ 1,156,271 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (201,754 ) — (694,739 ) Net cash used in investing activities — — (492,985 ) — — (176,946 ) — (669,931 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ — $ — $ — $ — $ — $ 16,664 $ — $ 16,664 Cash flows from investing activities Capital expenditures — — — — — (16,664 ) — (16,664 ) Net cash used in investing activities — — — — — (16,664 ) — (16,664 ) As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,421,023 $ — $ 1,172,935 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (218,418 ) — (711,403 ) Net cash used in investing activities — — (492,985 ) — — (193,610 ) — (686,595 )

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share for Noble-UK	The following table presents the computation of basic and diluted loss per share for Noble-UK: Year Ended December 31, 2018 2017 2016 Numerator: Basic Net loss from continuing operations $ (885,050 ) $ (515,025 ) $ (929,580 ) Net loss from discontinued operations, net of tax — (1,486 ) — Net loss attributable to Noble Corporation plc $ (885,050 ) $ (516,511 ) $ (929,580 ) Diluted Net loss from continuing operations $ (885,050 ) $ (515,025 ) $ (929,580 ) Net loss from discontinued operations, net of tax — (1,486 ) — Net loss attributable to Noble Corporation plc $ (885,050 ) $ (516,511 ) $ (929,580 ) Denominator: Weighted average shares outstanding - basic 246,614 244,743 243,127 Weighted average shares outstanding - diluted 246,614 244,743 243,127 Loss per share Basic: Loss from continuing operations $ (3.59 ) $ (2.10 ) $ (3.82 ) Loss from discontinued operations — (0.01 ) — Net loss attributable to Noble Corporation plc $ (3.59 ) $ (2.11 ) $ (3.82 ) Diluted: Loss from continuing operations $ (3.59 ) $ (2.10 ) $ (3.82 ) Loss from discontinued operations — (0.01 ) — Net loss attributable to Noble Corporation plc $ (3.59 ) $ (2.11 ) $ (3.82 ) Dividends per share $ — $ — $ 0.20

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment, at Cost	Property and equipment, at cost, for Noble-UK consisted of the following: Year Ended December 31, 2018 2017 Drilling equipment and facilities $ 10,546,376 $ 11,746,629 Construction in progress 209,091 83,509 Other 200,945 204,193 Property and equipment, at cost $ 10,956,412 $ 12,034,331

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Debt	At December 31, 2018 , aggregate principal repayments of total debt for the next five years and thereafter are as follows: 2019 2020 2021 2022 2023 Thereafter Total $ — $ 65,890 $ 96,142 $ 99,481 $ — $ 3,673,040 $ 3,934,553
Schedule of Debt	The following table presents the carrying value, net of unamortized debt issuance costs and discounts, and the estimated fair value of our total debt, not including the effect of unamortized debt issuance costs, respectively: December 31, 2018 December 31, 2017 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Senior unsecured notes 5.75% Senior Notes due March 2018 $ — $ — $ 249,843 $ 250,830 7.50% Senior Notes due March 2019 — — 201,535 206,881 4.90% Senior Notes due August 2020 65,810 60,177 167,422 163,283 4.625% Senior Notes due March 2021 92,967 84,931 208,095 195,687 3.95% Senior Notes due March 2022 41,617 37,096 125,307 107,348 7.75% Senior Notes due January 2024 783,350 613,719 971,498 861,160 7.95% Senior Notes due April 2025 446,517 339,035 446,106 380,732 7.875% Senior Notes due February 2026 738,075 647,085 — — 6.20% Senior Notes due August 2040 390,454 245,242 396,738 274,988 6.05% Senior Notes due March 2041 389,693 247,171 394,514 273,988 5.25% Senior Notes due March 2042 477,996 277,056 494,063 315,430 8.95% Senior Notes due April 2045 390,672 311,392 390,589 320,396 Other: Seller-financed secured loan due September 2022 60,251 57,902 — — Total debt 3,877,402 2,920,806 4,045,710 3,350,723 Less: Current maturities of long-term debt — — 249,843 250,830 Long-term debt $ 3,877,402 $ 2,920,806 $ 3,795,867 $ 3,099,893

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Summary of Stock Options Granted	A summary of the status of stock options granted under both the 1991 Plan and 1992 Plan as of December 31, 2018 , 2017 and 2016 and the changes during the year ended on those dates is presented below: 2018 2017 2016 Number of Shares Underlying Options Weighted Average Exercise Price Number of Shares Underlying Options Weighted Average Exercise Price Number of Shares Underlying Options Weighted Average Exercise Price Outstanding at beginning of year 1,313,155 $ 29.51 1,420,175 $ 29.52 1,677,154 $ 29.48 Expired (209,913 ) 33.56 (107,020 ) 29.74 (256,979 ) 29.22 Outstanding at end of year (1) 1,103,242 28.74 1,313,155 29.51 1,420,175 29.52 Exercisable at end of year (1) 1,103,242 $ 28.74 1,313,155 $ 29.51 1,420,175 $ 29.52 (1) Options outstanding and exercisable at December 31, 2018 had no intrinsic value.
Additional Information about Stock Options Outstanding	The following table summarizes additional information about stock options outstanding at December 31, 2018 : Options Outstanding and Exercisable Number of Shares Underlying Options Weighted Average Remaining Life (Years) Weighted Average Exercise Price $20.49 to $25.41 290,962 0.69 $ 21.40 $25.42 to $30.59 334,958 3.10 30.59 $30.60 to $32.78 477,322 1.70 31.91 Total 1,103,242 1.86 $ 28.74
Assumptions used to Value Performance-Vested Restricted Stock Awards	The assumptions used to value the PVRSUs include historical volatility and risk-free interest rates over a time period commensurate with the remaining term prior to vesting, as follows: 2018 2017 2016 Valuation assumptions: Expected volatility 61.8 % 56.4 % 40.7 % Expected dividend yield — % — % — % Risk-free interest rate 2.31 % 1.49 % 0.97 %
Summary of Restricted Share Awards	A summary of the RSUs awarded for each of the years ended December 31, 2018 , 2017 and 2016 is as follows: 2018 2017 2016 TVRSU Units awarded 3,578,212 3,231,225 3,624,182 Weighted-average share price at award date $ 4.71 $ 6.96 $ 7.78 Weighted-average vesting period (years) 3.0 3.0 3.0 PVRSU Units awarded 2,733,906 2,474,978 2,914,044 Weighted-average share price at award date $ 4.55 $ 7.28 $ 7.79 Three-year performance period ended December 31 2020 2019 2018 Weighted-average award-date fair value $ 2.96 $ 4.37 $ 3.81
Summary of Status of Non-Vested Restricted Shares	A summary of the status of non-vested RSUs at December 31, 2018 and changes during the year ended December 31, 2018 is presented below: TVRSUs Outstanding Weighted Average Award-Date Fair Value PVRSUs Outstanding (1) Weighted Average Award-Date Fair Value Non-vested RSUs at January 1, 2018 5,043,502 $ 7.95 5,645,454 $ 4.98 Awarded 3,578,212 4.71 2,733,906 4.87 Vested (2,342,503 ) 8.67 (403,553 ) 9.12 Forfeited (1,054,808 ) 6.43 (1,784,740 ) 5.97 Non-vested RSUs at December 31, 2018 5,224,403 $ 5.71 6,191,067 $ 4.38 (1) The number of PVRSUs shown equals the units that would vest if the “maximum” level of performance is achieved. The minimum number of units is zero and the “target” level of performance is 50 percent of the amounts shown.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Changes in AOCI by Component	The following table presents the changes in the accumulated balances for each component of AOCI for the years ended December 31, 2018 and 2017 . All amounts within the tables are shown net of tax. Unrealized Gains /(Losses) on Cash Flow Hedges (1) Defined Benefit Pension Items (2) Foreign Currency Items Total Balance at December 31, 2016 $ — $ (35,865 ) $ (16,275 ) $ (52,140 ) Activity during period: Other comprehensive income before reclassifications 1,239 6,630 990 8,859 Amounts reclassified from AOCI (1,239 ) 1,632 — 393 Net other comprehensive income — 8,262 990 9,252 Balance at December 31, 2017 $ — $ (27,603 ) $ (15,285 ) $ (42,888 ) Activity during period: Stranded tax effect resulting from the Act (Note 1) — (5,540 ) — (5,540 ) Balance at January 1, 2018 — (33,143 ) (15,285 ) (48,428 ) Activity during period: Other comprehensive income before reclassifications — — (2,729 ) (2,729 ) Amounts reclassified from AOCI — (5,915 ) — (5,915 ) Net other comprehensive loss — (5,915 ) (2,729 ) (8,644 ) Balance at December 31, 2018 $ — $ (39,058 ) $ (18,014 ) $ (57,072 ) (1) Unrealized losses on cash flow hedges are related to foreign currency forward contracts. Reclassifications from AOCI are recognized through “Contract drilling services” costs on our Consolidated Statements of Operations. See “ Note 13— Derivative Instruments and Hedging Activities ” for additional information. (2) Defined benefit pension items relate to actuarial changes and the amortization of prior service costs. Reclassifications from AOCI are recognized as expense on our Consolidated Statements of Operations through either “Contract drilling services” or “General and administrative.” See “ Note 12— Employee Benefit Plans ” for additional information.

Revenue and Customers (Tables)

Revenue and Customers (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset and Liability	The following table provides information about contract assets and contract liabilities from contracts with customers: December 31, 2018 January 1, 2018 Current contract assets $ 25,298 $ 21,229 Noncurrent contract assets 22,366 34,520 Total contract assets 47,664 55,749 Current contract liabilities (deferred revenue) (32,906 ) (35,422 ) Noncurrent contract liabilities (deferred revenue) (47,847 ) (73,439 ) Total contract liabilities $ (80,753 ) $ (108,861 ) Significant changes in the remaining performance obligation contract assets and the contract liabilities balances for the year ended December 31, 2018 are as follows: Contract Assets Contract Liabilities Net balance at January 1, 2018 $ 55,749 $ (108,861 ) Amortization of deferred costs (32,420 ) — Additions to deferred costs 24,335 — Amortization of deferred revenue — 47,798 Additions to deferred revenue — (19,690 ) Total (8,085 ) 28,108 Net balance at December 31, 2018 $ 47,664 $ (80,753 )
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The following table reflects revenue expected to be recognized in the future related to unsatisfied performance obligations, by rig type, at the end of the reporting period: Year Ending December 31, 2019 2020 2021 2022 2023 and beyond Total Drillships $ 20,658 $ 15,677 $ 15,677 $ 9,266 $ 3,572 $ 64,850 Semisubmersibles 363 — — — — 363 Jackups 11,868 3,672 — — — 15,540 Total $ 32,889 $ 19,349 $ 15,677 $ 9,266 $ 3,572 $ 80,753
Disaggregation of revenue by rig types	The following table provides information about contract drilling revenue by rig types: Three Months Ended December 31, 2018 Twelve Months Ended December 31, 2018 Drillships $ 155,305 $ 532,833 Semisubmersibles 10,344 28,992 Jackups 126,400 474,257 Total $ 292,049 $ 1,036,082

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of Net Deferred Taxes	The components of the net deferred taxes are as follows: 2018 2017 Deferred tax assets United States Net operating loss carry forwards $ 95,577 $ — Disallowed interest deduction carryforwards 51,423 — Deferred pension plan amounts 11,887 10,758 Accrued expenses not currently deductible 9,688 11,585 Other 1,936 2,150 Non-U.S. Net operating loss carry forwards 26,441 — Disallowed interest deduction carryforwards 6,254 — Deferred pension plan amounts 670 134 Other — 14,085 Deferred tax assets 203,876 38,712 Less: valuation allowance (12,306 ) — Net deferred tax assets $ 191,570 $ 38,712 Deferred tax liabilities United States Excess of net book basis over remaining tax basis $ (254,669 ) $ (182,401 ) Other (6,482 ) (6,652 ) Non-U.S. Excess of net book basis over remaining tax basis (1,066 ) — Other (1,596 ) (402 ) Deferred tax liabilities (263,813 ) (189,455 ) Net deferred tax liabilities $ (72,243 ) $ (150,743 )
Income (Loss) from Continuing Operations Before Income Taxes	Income (loss) from continuing operations before income taxes consists of the following: Year Ended December 31, 2018 2017 2016 United States $ (136,083 ) $ (81,329 ) $ (428,087 ) Non-U.S. (1,101,093 ) (368,485 ) (538,942 ) Total $ (1,237,176 ) $ (449,814 ) $ (967,029 )
Income Tax Provision for Continuing Operations	The income tax provision (benefit) for continuing operations consists of the following: Year Ended December 31, 2018 2017 2016 Current- United States $ (56,574 ) $ (227,707 ) $ 61,928 Current- Non-U.S. 18,348 29,010 18,813 Deferred- United States (67,371 ) 257,432 (189,880 ) Deferred- Non-U.S. (1,044 ) (16,106 ) (17 ) Total $ (106,641 ) $ 42,629 $ (109,156 )
Reconciliation of Reserve for Uncertain Tax Positions, Excluding Interest and Penalties	The following is a reconciliation of our reserve for uncertain tax positions, excluding interest and penalties. In 2016, we released an uncertain tax position in Libya in the gross amount of $40 million coupled with a related tax benefit of $13 million . 2018 2017 2016 Gross balance at January 1, $ 174,437 $ 159,826 $ 169,687 Additions based on tax positions related to current year 97 14,187 15,665 Additions for tax positions of prior years 25 1,284 18,662 Reductions for tax positions of prior years (12,806 ) (860 ) (43,701 ) Expiration of statutes (497 ) — (487 ) Tax settlements — — — Gross balance at December 31, 161,256 174,437 159,826 Related tax benefits (1,008 ) (1,008 ) (1,008 ) Net reserve at December 31, $ 160,248 $ 173,429 $ 158,818
Summary of Liabilities Related to Reserve for Uncertain Tax Positions	The liabilities related to our reserve for uncertain tax positions are comprised of the following: 2018 2017 Reserve for uncertain tax positions, excluding interest and penalties $ 160,248 $ 173,429 Interest and penalties included in “Other liabilities” 23,538 18,431 Reserve for uncertain tax positions, including interest and penalties $ 183,786 $ 191,860
Schedule of Effective Tax Rate Reconciliation	A reconciliation of tax rates outside of the United Kingdom and the Cayman Islands to our Noble-UK effective rate for continuing operations is shown below: Year Ended December 31, 2018 2017 2016 Effect of: Tax rates which are different than the UK and Cayman Island rates 4.0 % 23.4 % 8.4 % Tax impact of asset impairment 2.9 % 11.7 % 3.9 % Tax impact of tax restructuring — % (76.1 )% — % Tax impact of the Act 2.1 % 33.4 % — % Reserve for (resolution of) tax authority audits (0.4 )% (1.9 )% (1.0 )% Total 8.6 % (9.5 )% 11.3 %

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Reconciliation of Changes in Projected Benefit Obligations for our Non - U.S. and U.S. Plans	A reconciliation of the changes in projected benefit obligations (“PBO”) for our non-U.S. and U.S. plans is as follows: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Benefit obligation at beginning of year $ 61,952 $ 235,175 $ 72,347 $ 216,577 Service cost — — — — Interest cost 1,747 8,179 2,151 8,593 Actuarial loss (gain) (2,683 ) (20,673 ) (11,265 ) 19,113 Plan amendments 285 — — — Benefits paid (3,282 ) (7,218 ) (2,836 ) (6,795 ) Settlements and curtailments — (4,519 ) (4,825 ) (2,313 ) Foreign exchange rate changes (3,121 ) — 6,380 — Benefit obligation at end of year $ 54,898 $ 210,944 $ 61,952 $ 235,175
Reconciliation of Changes in Fair Value of Plan Assets	A reconciliation of the changes in fair value of plan assets is as follows: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Fair value of plan assets at beginning of year $ 77,141 $ 189,240 $ 71,286 $ 171,240 Actual return on plan assets (1,366 ) (16,326 ) 5,594 24,760 Employer contributions — 4,553 651 2,348 Benefits paid (3,282 ) (7,218 ) (2,836 ) (6,795 ) Settlement and curtailment — (4,519 ) (4,597 ) (2,313 ) Foreign exchange rate changes (3,896 ) — 7,043 — Fair value of plan assets at end of year $ 68,597 $ 165,730 $ 77,141 $ 189,240
Funded Status of Plans	The funded status of the plans is as follows: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Funded status $ 13,699 $ (45,214 ) $ 15,189 $ (45,935 )
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized in the Consolidated Balance Sheets consist of: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Other assets (noncurrent) $ 13,699 $ — $ 15,189 $ — Other liabilities (current) — (1,062 ) — (2,312 ) Other liabilities (noncurrent) — (44,152 ) — (43,623 ) Net amount recognized $ 13,699 $ (45,214 ) $ 15,189 $ (45,935 )
Amounts Recognized in Accumulated Other Comprehensive Loss	Amounts recognized in AOCI consist of: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Net actuarial loss $ 3,622 $ 45,358 $ 2,258 $ 39,569 Prior service cost 273 — — — Deferred income tax asset (670 ) (9,524 ) (375 ) (13,849 ) Accumulated other comprehensive loss $ 3,225 $ 35,834 $ 1,883 $ 25,720
Pension Costs	Pension costs include the following components: Years Ended December 31, 2018 2017 2016 Non-U.S. U.S. Non-U.S. U.S. Non-U.S. U.S. Service cost $ — $ — $ — $ — $ 2,914 $ 6,647 Interest cost 1,747 8,179 2,151 8,593 2,412 9,557 Return on plan assets (2,762 ) (11,914 ) (2,879 ) (11,764 ) (3,393 ) (12,389 ) Amortization of prior service cost — — — — 104 118 Recognized net actuarial loss — 1,642 743 1,464 142 4,398 Settlement and curtailment gains — 135 (838 ) 82 600 200 Net pension benefit cost (gain) $ (1,015 ) $ (1,958 ) $ (823 ) $ (1,625 ) $ 2,779 $ 8,531
Disaggregated Plan Information	Disaggregated information regarding our non-U.S. and U.S. plans is summarized below: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Projected benefit obligation $ 54,898 $ 210,944 $ 61,952 $ 235,175 Accumulated benefit obligation 54,898 210,944 61,952 235,175 Fair value of plan assets 68,597 165,730 77,141 189,240
Plans in which PBO Exceeded Fair Value	The following table provides information related to those plans in which the PBO exceeded the fair value of the plan assets at December 31, 2018 and 2017 . The PBO is the actuarially computed present value of earned benefits based on service to date and includes the estimated effect of any future salary increases. Employees and alternate payees have no longer accrued future benefits under the plans since December 31, 2016 . Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Projected benefit obligation $ — $ 210,944 $ — $ 235,175 Fair value of plan assets — 165,730 — 189,240
Plans in which Accumulated Benefit Obligation Exceeded Fair Value of Plan Assets	The following table provides information related to those plans in which the accumulated benefit obligation (“ABO”) exceeded the fair value of plan assets at December 31, 2018 and 2017 . The ABO is the actuarially computed present value of earned benefits based on service to date, but differs from the PBO in that it is based on current salary levels. Employees and alternate payees have no longer accrued future benefits under the plans since December 31, 2016. Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Accumulated benefit obligation $ — $ 210,944 $ — $ 235,175 Fair value of plan assets — 165,730 — 189,240
Defined Benefit Plans Key Assumptions	The key assumptions for the plans are summarized below: Years Ended December 31, 2018 2017 Non-U.S. U.S. Non-U.S. U.S. Weighted-average assumptions used to determine benefit obligations: Discount Rate 2.90% 3.65% - 4.29% 2.60% 2.84% - 3.66% Rate of compensation increase N/A N/A N/A N/A Years Ended December 31, 2018 2017 2016 Non-U.S. U.S. Non-U.S. U.S. Non-U.S. U.S. Weighted-average assumptions used to determine periodic benefit cost: Discount Rate 2.60% 2.84% - 3.66% 2.48% - 2.70% 3.00% - 4.24% 2.15% - 3.90% 3.09% - 4.48% Expected long-term return on assets 3.70% 5.75% - 6.50% 4.10% 6.00% - 6.50% 1.60% - 5.00% 7.00% Rate of compensation increase N/A N/A N/A N/A 3.60% - 4.20% N/A
Actual Fair Values of Defined Benefit Plans	The actual fair values of the non-U.S. plan are as follows: Year Ended December 31, 2018 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 151 $ 151 $ — $ — Equity securities: International companies 25,585 25,585 — — Fixed income securities: Corporate bonds 42,861 42,861 — — Total $ 68,597 $ 68,597 $ — $ — Year Ended December 31, 2017 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 280 $ 280 $ — $ — Equity securities: International companies 54,145 54,145 — — Fixed income securities: Corporate bonds 22,716 22,716 — — Other — — — — Total $ 77,141 $ 77,141 $ — $ — The actual fair values of U.S. plan assets are as follows: Year Ended December 31, 2018 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 4,801 $ 4,801 $ — $ — Equity securities: United States 47,950 16,775 31,175 — International 17,838 17,838 — — Fixed income securities: Corporate bonds 64,802 59,648 5,154 — Treasury bonds 30,339 30,339 — — Total $ 165,730 $ 129,401 $ 36,329 $ — Year Ended December 31, 2017 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents $ 3,275 $ 3,275 $ — $ — Equity securities: United States 43,535 16,430 27,105 — International 17,712 17,712 — — Fixed income securities: Corporate bonds 40,793 40,793 — — Treasury bonds 83,925 83,925 — — Total $ 189,240 $ 162,135 $ 27,105 $ —
Estimated Benefit Payments	The following table summarizes our estimated benefit payments at December 31, 2018 : Payments by Period Total 2019 2020 2021 2022 2023 Thereafter Estimated benefit payments Non-U.S. plans $ 38,334 $ 3,255 $ 3,372 $ 3,492 $ 3,617 $ 3,747 $ 20,851 U.S. plans 109,275 8,873 9,320 13,562 9,754 10,351 57,415 Total estimated benefit payments $ 147,609 $ 12,128 $ 12,692 $ 17,054 $ 13,371 $ 14,098 $ 78,266

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summarization of Recognized Gains and Losses of Cash Flow Hedges	The following table, together with “ Note 14— Fair Value of Financial Instruments ,” summarizes the recognized gains and losses of cash flow hedges and non-designated derivatives through AOCI or as “Contract drilling services” revenue or costs for the years ended December 31, 2018 and 2017 : Year Ended December 31, 2018 2017 2018 2017 2018 2017 Unrealized gain/(loss) recognized through AOCI Gain/(loss) reclassified from AOCI to “ Contract drilling services ” costs Gain/(loss) recognized through “ Contract drilling services ” revenue Cash flow hedges Foreign currency forward contracts $ — $ (1,239 ) $ — $ — $ — $ 1,239 Non-designated derivatives FCX Settlement $ — $ — $ — $ — $ — $ (14,400 )

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Carrying Amount and Estimated Fair Value of Financial Instruments	The following tables present the carrying amount and estimated fair value of our financial instruments recognized at fair value on a recurring basis: December 31, 2018 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets - Marketable securities $ 8,659 $ 8,659 $ — $ — December 31, 2017 Estimated Fair Value Measurements Carrying Amount Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets - Marketable securities $ 7,321 $ 7,321 $ — $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The table below depicts future minimum rental commitments under our operating leases as of December 31, 2018 : 2019 2020 2021 2022 2023 Thereafter Total (1) $ 15,213 $ 7,913 $ 5,522 $ 1,821 $ 695 $ 5,724 $ 36,888 (1) In February 2019, we amended the lease of our Sugar Land office to extend the lease for an additional ten years and to reduce the rented space. The above table does not include this lease amendment.

Segment and Related Informati_2

Segment and Related Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Revenues and Identifiable Assets by Country Based on the Location of the Service Provided	The following table presents revenues and identifiable assets by country based on the location of the service provided: Revenues for Year Ended December 31, Identifiable Assets as of December 31, 2018 2017 2016 2018 2017 Argentina $ — $ — $ 51,627 $ — $ — Australia — 12,262 89,847 243,388 257,415 Brazil — — 27,640 13,299 25,645 Brunei 3,080 45,450 42,710 — 119 Bulgaria 84,757 55,145 78,985 645,689 657,806 Canada 47,085 1,639 — 219,421 238,902 Curacao — — — 82,521 647,554 Denmark 35,855 44,671 46,342 242,831 250,851 East Timor 33,733 — — — — Egypt 112,473 — — 689,965 — Gabon — — 23,385 8,065 8,378 Guyana 50,839 — — 1,250,390 — Malaysia 91,052 131,696 168,826 665,822 293,297 Mexico — — — 27,542 27,391 Myanmar 16,572 — — 152,629 — Qatar 35,180 16,488 608 478,708 — Saudi Arabia 156,989 140,453 120,132 380,421 455,296 Singapore 1,769 — — 125,574 911,515 South Africa — 48,228 1,803 — — Suriname (3 ) 13,034 — — — Tanzania 381 1,526 48,394 — — The Netherlands — — 42 — — Turkey — (3 ) — — — United Arab Emirates (17 ) 99,825 86,446 45,205 590,863 United Kingdom 194,602 209,338 95,621 1,152,596 894,902 United States 218,479 417,163 1,404,365 2,840,857 5,534,725 Other — — 15,292 — — Total $ 1,082,826 $ 1,236,915 $ 2,302,065 $ 9,264,923 $ 10,794,659

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018
Supplemental Financial Information [Abstract]
Effect of Changes in Other Assets and Liabilities on Cash Flows from Operating Activities	The net effect of changes in other assets and liabilities on cash flows from operating activities is as follows: Noble-UK Noble-Cayman December 31, December 31, 2018 2017 2016 2018 2017 2016 Accounts receivable $ 3,974 $ 114,456 $ 179,779 $ 3,974 $ 114,456 $ 179,779 Other current assets (2,722 ) 26,155 81,657 (2,700 ) 23,309 79,720 Other assets (10,378 ) (89,021 ) 138,210 (6,424 ) (91,236 ) 136,130 Accounts payable 14,955 (14,625 ) (68,209 ) 14,795 (14,429 ) (66,421 ) Other current liabilities (13,940 ) 33,906 (209,739 ) (13,495 ) 35,033 (203,763 ) Other liabilities (26,829 ) (92,096 ) (31,389 ) (26,829 ) (87,213 ) (32,732 ) Total net change in assets and liabilities $ (34,940 ) $ (21,225 ) $ 90,309 $ (30,679 ) $ (20,080 ) $ 92,713
Additional Cash Flow Information	Additional cash flow information is as follows: Noble - UK Noble - Cayman December 31, December 31, 2018 2017 2016 2018 2017 2016 Cash paid during the period for: Interest, net of amounts capitalized $ 286,506 $ 246,960 $ 232,907 $ 286,506 $ 246,960 $ 232,907 Income taxes (net of refunds) (107,554 ) 30,590 100,544 (107,554 ) 30,590 100,717 Non-cash activities during the period: Spin-off of Paragon Offshore N/A N/A N/A N/A N/A N/A
Schedule of Prior Period Adjustments	The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 16,038 $ (37,263 ) $ (21,225 ) $ 73,645 $ 16,664 $ 90,309 Net cash provided by operating activities 453,938 (37,263 ) 416,675 1,126,076 16,664 1,142,740 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 17,183 $ (37,263 ) $ (20,080 ) $ 76,049 $ 16,664 $ 92,713 Net cash provided by operating activities 492,337 (37,263 ) 455,074 1,156,271 16,664 1,172,935 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,638 $ (37,263 ) $ (14,625 ) $ (84,873 ) $ 16,664 $ (68,209 ) Net effect of changes in other assets and liabilities 16,038 (37,263 ) (21,225 ) 73,645 16,664 90,309 Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,834 $ (37,263 ) $ (14,429 ) $ (83,085 ) $ 16,664 $ (66,421 ) Net effect of changes in other assets and liabilities 17,183 (37,263 ) (20,080 ) 76,049 16,664 92,713 The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Year Ended December 31, 2017 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 32,195 $ 100,883 $ 209,898 $ (403,391 ) $ 217,080 $ 335,672 $ — $ 492,337 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (154,348 ) — (157,970 ) Net cash used in investing activities — — (3,576 ) — — (152,012 ) — (155,588 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities — — — — — (37,263 ) — (37,263 ) Cash flows from investing activities Capital expenditures — — — — — 37,263 — 37,263 Net cash used in investing activities — — — — — 37,263 — 37,263 As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities 32,195 100,883 209,898 (403,391 ) 217,080 298,409 — 455,074 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (117,085 ) — (120,707 ) Net cash used in investing activities — — (3,576 ) — — (114,749 ) — (118,325 ) Year Ended December 31, 2016 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,404,359 $ — $ 1,156,271 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (201,754 ) — (694,739 ) Net cash used in investing activities — — (492,985 ) — — (176,946 ) — (669,931 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ — $ — $ — $ — $ — $ 16,664 $ — $ 16,664 Cash flows from investing activities Capital expenditures — — — — — (16,664 ) — (16,664 ) Net cash used in investing activities — — — — — (16,664 ) — (16,664 ) As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,421,023 $ — $ 1,172,935 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (218,418 ) — (711,403 ) Net cash used in investing activities — — (492,985 ) — — (193,610 ) — (686,595 )

Condensed Consolidating Finan_2

Condensed Consolidating Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Guarantor Obligations	Noble-Cayman, or one or more 100 percent owned subsidiaries of Noble-Cayman, is an issuer, co-issuer or full and unconditional guarantor or otherwise obligated as of December 31, 2018 with respect to registered securities as follows (see “ Note 7— Debt ” for additional information): Issuer Notes (1) (Co-Issuer(s)) Guarantor 5.75% Senior Notes due 2018 NHIL Noble-Cayman 7.50% Senior Notes due 2019 (2) NHUS Noble-Cayman Noble Drilling Holding, LLC (“NDH”) Noble Drilling Services 6 LLC (“NDS6”) 4.90% Senior Notes due 2020 NHIL Noble-Cayman 4.625% Senior Notes due 2021 NHIL Noble-Cayman 3.95% Senior Notes due 2022 NHIL Noble-Cayman 7.75% Senior Notes due 2024 NHIL Noble-Cayman 7.95% Senior Notes due 2025 NHIL Noble-Cayman 6.20% Senior Notes due 2040 NHIL Noble-Cayman 6.05% Senior Notes due 2041 NHIL Noble-Cayman 5.25% Senior Notes due 2042 NHIL Noble-Cayman 8.95% Senior Notes due 2045 NHIL Noble-Cayman (1) Our 2026 Notes are excluded from this list as they are unregistered securities issued in a non-public offering. (2) In February 2018 , the entire remaining principal amount of 2019 Notes were redeemed and, as a result, we have prospectively eliminated NHUS, NDH, and NDS6 as guarantors in the current year presentation of the Condensed Consolidating Financial Information. However, prior year information is presented as previously reported.
Condensed Consolidating Balance Sheet	NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2018 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble - NHIL Other Consolidating Total ASSETS Current assets Cash and cash equivalents $ — $ 17,818 $ 356,557 $ — $ 374,375 Accounts receivable — — 200,722 — 200,722 Taxes receivable — — 20,498 — 20,498 Short-term notes receivable from affiliates — — 3,175,662 (3,175,662 ) — Accounts receivable from affiliates 275,726 61,046 4,823,902 (5,160,674 ) — Prepaid expenses and other current assets — — 61,917 — 61,917 Total current assets 275,726 78,864 8,639,258 (8,336,336 ) 657,512 Property and equipment, at cost — — 10,956,412 — 10,956,412 Accumulated depreciation — — (2,475,694 ) — (2,475,694 ) Property and equipment, net — — 8,480,718 — 8,480,718 Notes receivable from affiliates 5,145 — — (5,145 ) — Investments in affiliates 7,716,068 12,300,840 — (20,016,908 ) — Other assets 609 — 124,540 — 125,149 Total assets $ 7,997,548 $ 12,379,704 $ 17,244,516 $ (28,358,389 ) $ 9,263,379 LIABILITIES AND EQUITY Current liabilities Short-term notes payables to affiliates $ — $ 3,175,662 $ — $ (3,175,662 ) $ — Accounts payable 45 — 125,192 — 125,237 Accrued payroll and related costs — — 50,284 — 50,284 Accounts payable to affiliates 3,725,506 1,098,395 336,773 (5,160,674 ) — Taxes payable — — 29,386 — 29,386 Interest payable 3 99,997 100 — 100,100 Other current liabilities — — 60,012 — 60,012 Total current liabilities 3,725,554 4,374,054 601,747 (8,336,336 ) 365,019 Long-term debt — 3,817,153 60,249 — 3,877,402 Notes payable to affiliates — — 5,145 (5,145 ) — Deferred income taxes — — 91,695 — 91,695 Other liabilities 19,929 — 255,866 — 275,795 Total liabilities 3,745,483 8,191,207 1,014,702 (8,341,481 ) 4,609,911 Commitments and contingencies Total shareholder equity 4,252,065 4,188,497 15,828,411 (20,016,908 ) 4,252,065 Noncontrolling interests — — 401,403 — 401,403 Total equity 4,252,065 4,188,497 16,229,814 (20,016,908 ) 4,653,468 Total liabilities and equity $ 7,997,548 $ 12,379,704 $ 17,244,516 $ (28,358,389 ) $ 9,263,379 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2017 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total ASSETS Current assets Cash and cash equivalents $ 11 $ — $ 23,160 $ 29,324 $ — $ 609,516 $ — $ 662,011 Accounts receivable — — 24,722 — — 179,974 — 204,696 Taxes receivable — 93,302 3 — — 12,040 — 105,345 Short-term notes receivable from affiliates — — 119,476 — 2,373,452 — (2,492,928 ) — Accounts receivable from affiliates 594,456 1,454 144,367 60,945 465,749 5,813,846 (7,080,817 ) — Prepaid expenses and other current assets — — 1,477 — 1 63,963 — 65,441 Total current assets 594,467 94,756 313,205 90,269 2,839,202 6,679,339 (9,573,745 ) 1,037,493 Property and equipment, at cost — — 857,784 — — 11,176,547 — 12,034,331 Accumulated depreciation — — (110,005 ) — — (2,435,086 ) — (2,545,091 ) Property and equipment, net — — 747,779 — — 8,741,461 — 9,489,240 Notes receivable from affiliates 3,177,248 — 1,199,815 — 3,943,299 1,175,300 (9,495,662 ) — Investments in affiliates 4,933,978 4,550,358 5,252,135 12,560,598 7,237,474 — (34,534,543 ) — Other assets 2,663 16,775 8,372 — — 238,718 — 266,528 Total assets $ 8,708,356 $ 4,661,889 $ 7,521,306 $ 12,650,867 $ 14,019,975 $ 16,834,818 $ (53,603,950 ) $ 10,793,261 LIABILITIES AND EQUITY Current liabilities Short-term notes payables to affiliates $ — $ 1,605,243 $ — $ — $ — $ 887,685 $ (2,492,928 ) $ — Current maturities of long-term debt — — — 249,843 — — — 249,843 Accounts payable — — 1,467 — — 82,406 — 83,873 Accrued payroll and related costs — — 4,780 — — 50,124 — 54,904 Accounts payable to affiliates 3,410,669 393,073 1,770,066 661,375 — 845,634 (7,080,817 ) — Taxes payable — — — — — 33,965 — 33,965 Interest payable 2,211 — — 83,960 12,018 — — 98,189 Other current liabilities — — 5,169 — — 66,297 — 71,466 Total current liabilities 3,412,880 1,998,316 1,781,482 995,178 12,018 1,966,111 (9,573,745 ) 592,240 Long-term debt — — — 3,594,332 201,535 — — 3,795,867 Notes payable to affiliates — 700,000 474,637 3,175,663 — 5,145,362 (9,495,662 ) — Deferred income taxes — — 5 — — 164,957 — 164,962 Other liabilities 19,929 — 30,330 — — 239,919 — 290,178 Total liabilities 3,432,809 2,698,316 2,286,454 7,765,173 213,553 7,516,349 (19,069,407 ) 4,843,247 Commitments and contingencies Total shareholder equity 5,275,547 1,963,573 5,234,852 4,885,694 13,806,422 8,644,002 (34,534,543 ) 5,275,547 Noncontrolling interests — — — — — 674,467 — 674,467 Total equity 5,275,547 1,963,573 5,234,852 4,885,694 13,806,422 9,318,469 (34,534,543 ) 5,950,014 Total liabilities and equity $ 8,708,356 $ 4,661,889 $ 7,521,306 $ 12,650,867 $ 14,019,975 $ 16,834,818 $ (53,603,950 ) $ 10,793,261
Condensed Consolidating Statement of Income	NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS and COMPREHENSIVE INCOME (LOSS) Year Ended December 31, 2018 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHIL Other Consolidating Total Operating revenues Contract drilling services $ — $ — $ 1,036,082 $ — $ 1,036,082 Reimbursables and other — — 46,744 — 46,744 Total operating revenues — — 1,082,826 — 1,082,826 Operating costs and expenses Contract drilling services 2 (22 ) 628,148 — 628,128 Reimbursables — — 37,084 — 37,084 Depreciation and amortization — — 482,660 — 482,660 General and administrative 57 214 37,932 — 38,203 Loss on impairment — — 802,133 — 802,133 Total operating costs and expenses 59 192 1,987,957 — 1,988,208 Operating loss (59 ) (192 ) (905,131 ) — (905,382 ) Other income (expense) Income (loss) of unconsolidated affiliates - continuing operations (2,738,475 ) (258,687 ) — 2,997,162 — Interest expense, net of amounts capitalized (1,324 ) (449,824 ) (1,911,822 ) 2,065,359 (297,611 ) Gain (loss) on extinguishment of debt, net (2,336 ) 12,651 (12,108 ) — (1,793 ) Interest income and other, net 1,897,709 (74 ) 176,006 (2,065,359 ) 8,282 Income (loss) before income taxes (844,485 ) (696,126 ) (2,653,055 ) 2,997,162 (1,196,504 ) Income tax benefit (provision) — — 106,534 — 106,534 Net income (loss) (844,485 ) (696,126 ) (2,546,521 ) 2,997,162 (1,089,970 ) Net income attributable to noncontrolling interests — — 245,485 — 245,485 Net income (loss) attributable to Noble Corporation (844,485 ) (696,126 ) (2,301,036 ) 2,997,162 (844,485 ) Other comprehensive income (loss), net (8,644 ) — (8,644 ) 8,644 (8,644 ) Comprehensive income (loss) attributable to Noble Corporation $ (853,129 ) $ (696,126 ) $ (2,309,680 ) $ 3,005,806 $ (853,129 ) NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS and COMPREHENSIVE INCOME (LOSS) Year Ended December 31, 2017 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Operating revenues Contract drilling services $ — $ — $ 168,592 $ — $ — $ 1,086,320 $ (47,886 ) $ 1,207,026 Reimbursables and other — — 3,443 — — 26,446 — 29,889 Total operating revenues — — 172,035 — — 1,112,766 (47,886 ) 1,236,915 Operating costs and expenses Contract drilling services 304 12,090 43,161 3,115 — 629,699 (47,886 ) 640,483 Reimbursables — — 1,992 — — 16,443 — 18,435 Depreciation and amortization — — 58,236 — — 484,883 — 543,119 General and administrative 129 5,761 — 1,588 9 33,600 — 41,087 Loss on impairment — — 45,012 — — 76,627 — 121,639 Total operating costs and expenses 433 17,851 148,401 4,703 9 1,241,252 (47,886 ) 1,364,763 Operating income (loss) (433 ) (17,851 ) 23,634 (4,703 ) (9 ) (128,486 ) — (127,848 ) Other income (expense) Income (loss) of unconsolidated affiliates - continuing operations (476,382 ) (528,702 ) 82,596 188,809 17,874 — 715,805 — Income (loss) of unconsolidated affiliates - discontinued operations, net of tax 2,967 4,566 — — — — (7,533 ) — Interest expense, net of amounts capitalized (10,951 ) (32,838 ) (13,493 ) (430,580 ) (15,288 ) (130,442 ) 341,603 (291,989 ) Interest income and other, net 10,483 (141 ) 87,287 4,771 224,772 22,164 (341,603 ) 7,733 Income (loss) before income taxes (474,316 ) (574,966 ) 180,024 (241,703 ) 227,349 (236,764 ) 708,272 (412,104 ) Income tax benefit (provision) — 241,960 (440 ) — — (284,115 ) — (42,595 ) Net income (loss) from continuing operations (474,316 ) (333,006 ) 179,584 (241,703 ) 227,349 (520,879 ) 708,272 (454,699 ) Net income (loss) from discontinuing operations, net of tax — (1,598 ) — — — 4,565 — 2,967 Net income (loss) (474,316 ) (334,604 ) 179,584 (241,703 ) 227,349 (516,314 ) 708,272 (451,732 ) Net income attributable to noncontrolling interests — — — — — (20,589 ) (1,995 ) (22,584 ) Net income (loss) attributable to Noble Corporation (474,316 ) (334,604 ) 179,584 (241,703 ) 227,349 (536,903 ) 706,277 (474,316 ) Other comprehensive income (loss), net 9,252 — — — — 9,252 (9,252 ) 9,252 Comprehensive income (loss) attributable to Noble Corporation $ (465,064 ) $ (334,604 ) $ 179,584 $ (241,703 ) $ 227,349 $ (527,651 ) $ 697,025 $ (465,064 ) NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF INCOME and COMPREHENSIVE INCOME (LOSS) Year Ended December 31, 2016 (Unless otherwise indicated, dollar amounts in tables are in thousands, except per share data) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Operating revenues Contract drilling services $ — $ — $ 250,049 $ — $ — $ 2,086,848 $ (94,697 ) $ 2,242,200 Reimbursables and other — — 9,190 — — 51,375 — 60,565 Total operating revenues — — 259,239 — — 2,138,223 (94,697 ) 2,302,765 Operating costs and expenses Contract drilling services 4,532 18,902 70,801 84,309 — 788,065 (94,697 ) 871,912 Reimbursables — — 8,231 — — 37,268 — 45,499 Depreciation and amortization — — 91,802 — — 519,211 — 611,013 General and administrative 1,264 8,716 — 40,082 1 (4,018 ) — 46,045 Loss on impairment — — — — — 1,458,749 — 1,458,749 Total operating costs and expenses 5,796 27,618 170,834 124,391 1 2,799,275 (94,697 ) 3,033,218 Operating income (loss) (5,796 ) (27,618 ) 88,405 (124,391 ) (1 ) (661,052 ) — (730,453 ) Other income (expense) Income (loss) of unconsolidated affiliates (962,662 ) (257,142 ) (980,099 ) (333,446 ) 515,518 — 2,017,831 — Interest expense, net of amounts capitalized (27,891 ) (70,494 ) (11,461 ) (228,423 ) (15,117 ) (122,345 ) 252,816 (222,915 ) Gain on extinguishment of debt, net — — — 17,814 — — — 17,814 Interest income and other, net 96,635 120 12,616 20,412 15,058 106,359 (252,816 ) (1,616 ) Income (loss) before income taxes (899,714 ) (355,134 ) (890,539 ) (648,034 ) 515,458 (677,038 ) 2,017,831 (937,170 ) Income tax benefit (provision) — (42,522 ) 163 — — 151,522 — 109,163 Net income (loss) (899,714 ) (397,656 ) (890,376 ) (648,034 ) 515,458 (525,516 ) 2,017,831 (828,007 ) Net (income) loss attributable to noncontrolling interests — — — — — (39,294 ) (32,413 ) (71,707 ) Net income (loss) attributable to Noble Corporation (899,714 ) (397,656 ) (890,376 ) (648,034 ) 515,458 (564,810 ) 1,985,418 (899,714 ) Other comprehensive income (loss), net 11,035 — — — — 11,035 (11,035 ) 11,035 Comprehensive income (loss) attributable to Noble Corporation $ (888,679 ) $ (397,656 ) $ (890,376 ) $ (648,034 ) $ 515,458 $ (553,775 ) $ 1,974,383 $ (888,679 )
Condensed Consolidating Statement of Cash Flows	CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2018 (Unless otherwise indicated, dollar amounts in tables are in thousands) Noble- NHIL Other Consolidating Total Cash flows from operating activities Net cash provided by (used in) operating activities $ 1,920,724 $ (426,298 ) $ (1,281,667 ) $ — $ 212,759 Cash flows from investing activities Capital expenditures — — (194,779 ) — (194,779 ) Proceeds from disposal of assets — — 5,402 — 5,402 Net cash used in investing activities — — (189,377 ) — (189,377 ) Cash flows from financing activities Issuance of senior notes — 750,000 — — 750,000 Repayment of long-term debt — (759,053 ) (213,655 ) — (972,708 ) Debt issuance costs (845 ) (13,027 ) (1,767 ) — (15,639 ) Dividends paid to noncontrolling interests — — (27,579 ) — (27,579 ) Distribution to parent company, net (44,417 ) — — — (44,417 ) Advances (to) from affiliates (1,875,473 ) 436,872 1,438,601 — — Net cash provided by (used in) financing activities (1,920,735 ) 414,792 1,195,600 — (310,343 ) Net change in cash, cash equivalents and restricted cash (11 ) (11,506 ) (275,444 ) — (286,961 ) Cash, cash equivalents and restricted cash, beginning of period 11 29,324 632,676 — 662,011 Cash, cash equivalents and restricted cash, end of period $ — $ 17,818 $ 357,232 $ — $ 375,050 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2017 (Unless otherwise indicated, dollar amounts in tables are in thousands) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Cash flows from operating activities Net cash provided by (used in) operating activities $ 32,195 $ 100,883 $ 209,898 $ (403,391 ) $ 217,080 $ 298,409 $ — $ 455,074 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (117,085 ) — (120,707 ) Proceeds from disposal of assets — — 46 — — 2,336 — 2,382 Net cash used in investing activities — — (3,576 ) — — (114,749 ) — (118,325 ) Cash flows from financing activities Repayment of long-term debt — — — (300,000 ) — — — (300,000 ) Debt issuance costs on senior notes and credit facilities — — — (42 ) — — — (42 ) Dividends paid to noncontrolling interests — — — — — (56,881 ) — (56,881 ) Contributions from parent company, net 28,352 — — — — — — 28,352 Advances (to) from affiliates (63,073 ) (100,883 ) (194,017 ) 732,757 (217,080 ) (157,704 ) — — Net cash provided by (used in) financing activities (34,721 ) (100,883 ) (194,017 ) 432,715 (217,080 ) (214,585 ) — (328,571 ) Net change in cash, cash equivalents and restricted cash (2,526 ) — 12,305 29,324 — (30,925 ) — 8,178 Cash, cash equivalents and restricted cash, beginning of period 2,537 — 10,855 — — 640,441 — 653,833 Cash, cash equivalents and restricted cash, end of period $ 11 $ — $ 23,160 $ 29,324 $ — $ 609,516 $ — $ 662,011 NOBLE CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2016 (Unless otherwise indicated, dollar amounts in tables are in thousands) Noble- NHUS NDH NHIL NDS6 Other Consolidating Total Cash flows from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,421,023 $ — $ 1,172,935 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (218,418 ) — (711,403 ) Proceeds from disposal of assets — — — — — 24,808 — 24,808 Net cash provided by (used in) investing activities — — (492,985 ) — — (193,610 ) — (686,595 ) Cash flows from financing activities Repayment of long-term debt — — — (1,049,338 ) — — — (1,049,338 ) Issuance of senior notes — — — 980,100 — — — 980,100 Tender offer premium — — — (24,649 ) — — — (24,649 ) Debt issuance costs on senior notes and credit facilities — — — (12,111 ) — — — (12,111 ) Dividends paid to noncontrolling interests — — — — — (85,944 ) — (85,944 ) Distributions to parent company, net (152,360 ) — — — — — — (152,360 ) Advances (to) from affiliates 55,882 150,735 352,308 450,110 60 (1,009,095 ) — — Net cash provided by (used in) financing activities (96,478 ) 150,735 352,308 344,112 60 (1,095,039 ) — (344,302 ) Net change in cash, cash equivalents and restricted cash 910 — 8,754 — — 132,374 — 142,038 Cash, cash equivalents and restricted cash, beginning of period 1,627 — 2,101 — — 508,067 — 511,795 Cash, cash equivalents and restricted cash, end of period $ 2,537 $ — $ 10,855 $ — $ — $ 640,441 $ — $ 653,833
Schedule of Prior Period Adjustments	The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 16,038 $ (37,263 ) $ (21,225 ) $ 73,645 $ 16,664 $ 90,309 Net cash provided by operating activities 453,938 (37,263 ) 416,675 1,126,076 16,664 1,142,740 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Cash flows from operating activities Net change in other assets and liabilities $ 17,183 $ (37,263 ) $ (20,080 ) $ 76,049 $ 16,664 $ 92,713 Net cash provided by operating activities 492,337 (37,263 ) 455,074 1,156,271 16,664 1,172,935 Cash flows from investing activities Capital expenditures $ (157,970 ) $ 37,263 $ (120,707 ) $ (694,739 ) $ (16,664 ) $ (711,403 ) Net cash used in investing activities (155,588 ) 37,263 (118,325 ) (669,931 ) (16,664 ) (686,595 ) The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Consolidated Statements of Cash Flows - Noble Corporation plc Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,638 $ (37,263 ) $ (14,625 ) $ (84,873 ) $ 16,664 $ (68,209 ) Net effect of changes in other assets and liabilities 16,038 (37,263 ) (21,225 ) 73,645 16,664 90,309 Consolidated Statements of Cash Flows - Noble Corporation (Cayman) Year Ended December 31, 2017 Year Ended December 31, 2016 As Reported Adjustment As Revised As Reported Adjustment As Revised Accounts payable $ 22,834 $ (37,263 ) $ (14,429 ) $ (83,085 ) $ 16,664 $ (66,421 ) Net effect of changes in other assets and liabilities 17,183 (37,263 ) (20,080 ) 76,049 16,664 92,713 The impacts on the Consolidated Statements of Cash Flows and related notes to the financial statements are presented below: Year Ended December 31, 2017 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 32,195 $ 100,883 $ 209,898 $ (403,391 ) $ 217,080 $ 335,672 $ — $ 492,337 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (154,348 ) — (157,970 ) Net cash used in investing activities — — (3,576 ) — — (152,012 ) — (155,588 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities — — — — — (37,263 ) — (37,263 ) Cash flows from investing activities Capital expenditures — — — — — 37,263 — 37,263 Net cash used in investing activities — — — — — 37,263 — 37,263 As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities 32,195 100,883 209,898 (403,391 ) 217,080 298,409 — 455,074 Cash flows from investing activities Capital expenditures — — (3,622 ) — — (117,085 ) — (120,707 ) Net cash used in investing activities — — (3,576 ) — — (114,749 ) — (118,325 ) Year Ended December 31, 2016 As Reported - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,404,359 $ — $ 1,156,271 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (201,754 ) — (694,739 ) Net cash used in investing activities — — (492,985 ) — — (176,946 ) — (669,931 ) Adjustments - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ — $ — $ — $ — $ — $ 16,664 $ — $ 16,664 Cash flows from investing activities Capital expenditures — — — — — (16,664 ) — (16,664 ) Net cash used in investing activities — — — — — (16,664 ) — (16,664 ) As Revised - Noble Corporation (Cayman) Noble- Cayman NHUS NDH NHIL NDS6 Other Non-guarantor Subsidiaries of Noble Consolidating Adjustments Total Cash flow from operating activities Net cash provided by (used in) operating activities $ 97,388 $ (150,735 ) $ 149,431 $ (344,112 ) $ (60 ) $ 1,421,023 $ — $ 1,172,935 Cash flows from investing activities Capital expenditures — — (492,985 ) — — (218,418 ) — (711,403 ) Net cash used in investing activities — — (492,985 ) — — (193,610 ) — (686,595 )

Unaudited Interim Financial D_2

Unaudited Interim Financial Data (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Unaudited Interim Financial Information	Unaudited interim consolidated financial information from continuing operations for Noble-UK is as follows: Quarters Ended March 31 June 30 September 30 December 31 2018 Operating revenues $ 235,157 $ 258,369 $ 279,408 $ 309,892 Operating loss (56,880 ) (845,606 ) (21,843 ) (21,745 ) Net loss from continuing operations (142,334 ) (628,063 ) (81,591 ) (33,062 ) Net loss per share from continuing operations attributable to Noble-UK (1) Basic Loss from continuing operations (0.58 ) (2.55 ) (0.33 ) (0.13 ) Diluted Loss from continuing operations (0.58 ) (2.55 ) (0.33 ) (0.13 ) Quarter Ended March 31 June 30 September 30 December 31 2017 Operating revenues $ 362,976 $ 278,142 $ 266,212 $ 329,585 Operating loss (45,463 ) (44,285 ) (56,604 ) (110,294 ) Net loss from continuing operations (301,694 ) (91,864 ) (96,792 ) (24,675 ) Net loss from discontinued operations, net of tax — (1,486 ) — — Net loss per share from continuing operations attributable to Noble-UK (1) Basic Loss from continuing operations (1.24 ) (0.37 ) (0.40 ) (0.10 ) Loss from discontinued operations — (0.01 ) — — Diluted Loss from continuing operations (1.24 ) (0.37 ) (0.40 ) (0.10 ) Loss from discontinued operations — (0.01 ) — — (1) Net loss per share is computed independently for each of the quarters presented. Therefore, the sum of the quarters’ net loss per share may not equal the total computed for the year.

Consolidated Joint Ventures (De

Consolidated Joint Ventures (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)RigJointVenture	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Schedule Of Equity Method Investments [Line Items]
Percent of interest in joint ventures	50.00%
Number of joint ventures | JointVenture	2
Number of bully class drillships | Rig	2
Percentage of dividends paid to joint venture partner	50.00%
Loss on impairment	$ 802,133	$ 121,639	$ 1,458,749
Cash and cash equivalents	375,232	662,829
Bully Joint Venture
Schedule Of Equity Method Investments [Line Items]
Dividends approved and paid	55,200	113,800	$ 171,900
Carrying amount of the drillships	700,000	1,300,000
Loss on impairment	250,300
Cash and cash equivalents	45,200	$ 41,600
Drillships | Bully Joint Venture
Schedule Of Equity Method Investments [Line Items]
Loss on impairment	$ 550,300

Organization and Significant _4

Organization and Significant Accounting Policies - Additional Information (Details)	Jan. 01, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)VesselRigJointVentureSegment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of rigs | Rig							24
Number of drillships | Vessel							8
Number of semisubmersibles | Vessel							4
Number of jackups | Vessel							12
Number of reportable segments | Segment							1
Number of joint ventures | JointVenture							2
Percent of interest in joint ventures							50.00%
Cash and cash equivalents		$ 662,829,000	$ 662,829,000				$ 375,232,000	$ 662,829,000
Restricted cash		0	0				700,000	0	$ 0
Allowance for doubtful accounts on receivables		20,800,000	20,800,000				2,200,000	20,800,000
Capital accruals							$ 52,100,000	25,500,000
Period for incurring maintenance costs, minimum							3 years
Period for incurring maintenance costs, maximum							5 years
Deferred revenues	$ 108,861,000	114,300,000	114,300,000				$ 80,753,000	114,300,000
Deferred expenses under drilling contracts		55,700,000	55,700,000				47,700,000	55,700,000
Tax Cuts and Jobs Act of 2018, provisional tax benefit recognized							24,900,000	109,000,000
Tax Cuts and Jobs Act of 2018, additional tax benefit recognized							24,900,000
Loss reserves for personal injury and protection claims		22,000,000	22,000,000				22,400,000	22,000,000
Net loss from discontinued operations, net of tax			0	$ 0	$ (1,486,000)	$ 0	$ 0	(1,486,000)	$ 0
Stranded tax effect resulting from the Act	(5,540,000)	0
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to new accounting standard		148,393,000	148,393,000					148,393,000
Drilling Equipment | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum useful life of property plant and equipment							3 years
Drilling Equipment | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum useful life of property plant and equipment							30 years
Other | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum useful life of property plant and equipment							2 years
Other | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Maximum useful life of property plant and equipment							40 years
Retained Earnings | Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to new accounting standard	148,400,000
Other assets | Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to new accounting standard	$ 148,400,000
Bully Joint Venture
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Carrying amount of the drillships		1,300,000,000	1,300,000,000				$ 700,000,000	1,300,000,000
Cash and cash equivalents		41,600,000	41,600,000				45,200,000	41,600,000
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stranded tax effect resulting from the Act		5,540,000					$ 5,500,000
Retained Earnings | Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to new accounting standard		$ 148,393,000	$ 148,393,000					$ 148,393,000
Subsequent Event | Forecast | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liability										$ 28,000,000
Right-of-use asset										$ 28,000,000

Organization and Significant _5

Organization and Significant Accounting Policies - Schedule of Prior Period Adjustments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net changes in other operating assets and liabilities	$ (34,940)	$ (21,225)	$ 90,309
Net cash provided by operating activities	171,851	416,675	1,142,740
Capital expenditures	(194,779)	(120,707)	(711,403)
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net changes in other operating assets and liabilities		16,038	73,645
Net cash provided by operating activities		453,938	1,126,076
Capital expenditures		(157,970)	(694,739)
Net cash used in investing activities		(155,588)	(669,931)
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net changes in other operating assets and liabilities		(37,263)	16,664
Net cash provided by operating activities		(37,263)	16,664
Capital expenditures		37,263	(16,664)
Net cash used in investing activities		37,263	(16,664)
Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net changes in other operating assets and liabilities	(30,679)	(20,080)	92,713
Net cash provided by operating activities	212,759	455,074	1,172,935
Capital expenditures	(194,779)	(120,707)	(711,403)
Net cash used in investing activities	$ (189,377)	(118,325)	(686,595)
Noble Corp | As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net changes in other operating assets and liabilities		17,183	76,049
Net cash provided by operating activities		492,337	1,156,271
Capital expenditures		(157,970)	(694,739)
Net cash used in investing activities		(155,588)	(669,931)
Noble Corp | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net changes in other operating assets and liabilities		(37,263)	16,664
Net cash provided by operating activities		(37,263)	16,664
Capital expenditures		37,263	(16,664)
Net cash used in investing activities		$ 37,263	$ (16,664)

Loss Per Share - Computation of

Loss Per Share - Computation of Basic and Diluted Earnings Per Share for Noble-UK (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic
Net loss from continuing operations									$ (885,050)	$ (515,025)	$ (929,580)
Net loss from discontinued operations, net of tax									0	(1,486)	0
Net loss attributable to Noble Corporation plc									(885,050)	(516,511)	(929,580)
Diluted
Net loss attributable to Noble Corporation plc									$ (885,050)	$ (516,511)	$ (929,580)
Denominator:
Weighted average shares outstanding - basic (in shares)									246,614,000	244,743,000	243,127,000
Weighted average shares outstanding - diluted (in shares)									246,614,000	244,743,000	243,127,000
Basic:
Loss from continuing operations (usd per share)	$ (0.13)	$ (0.33)	$ (2.55)	$ (0.58)	$ (0.10)	$ (0.40)	$ (0.37)	$ (1.24)	$ (3.59)	$ (2.10)	$ (3.82)
Loss from discontinued operations (usd per share)					0	0	(0.01)	0	0	(0.01)	0
Net income (loss) (usd per share)									(3.59)	(2.11)	(3.82)
Diluted:
Loss from continuing operations (usd per share)	$ (0.13)	$ (0.33)	$ (2.55)	$ (0.58)	(0.10)	(0.40)	(0.37)	(1.24)	(3.59)	(2.10)	(3.82)
Loss from discontinued operations (usd per share)					$ 0	$ 0	$ (0.01)	$ 0	0	(0.01)	0
Net income (loss) (usd per share)									(3.59)	(2.11)	(3.82)
Dividends per share (usd per share)									$ 0	$ 0	$ 0.20

Loss Per Share - Additional Inf

Loss Per Share - Additional Information (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the diluted net income per share (in shares)	12.5	12	9.9

Receivables from Customers (Det

Receivables from Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]
Receivables disputed by customer and written off	$ 0	$ 29,032	$ 0
Petroleos Mexicanos | Contract drilling services | Uncollectible receivables
Accounts Notes And Loans Receivable [Line Items]
Receivables disputed by customer and written off	$ 14,400
Petroleos Mexicanos | Other assets
Accounts Notes And Loans Receivable [Line Items]
Approximate receivable			$ 14,400

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 21, 2018	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, at cost			$ 10,956,412	$ 12,034,331
Capital expenditures			281,300	111,100	$ 659,900
Capitalized interest on construction-in-progress			2,900	0	22,400
Loss on impairment			802,133	121,639	$ 1,458,749
Hurricane
Property, Plant and Equipment [Line Items]
Contract drilling services costs				14,300
Drilling equipment and facilities
Property, Plant and Equipment [Line Items]
Property and equipment, at cost			10,546,376	11,746,629
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, at cost			209,091	83,509
Other
Property, Plant and Equipment [Line Items]
Property and equipment, at cost			$ 200,945	$ 204,193
Rig
Property, Plant and Equipment [Line Items]
Purchase price of asset acquired	$ 93,800
Seller-financed secured loan due September 2022
Property, Plant and Equipment [Line Items]
Financed value		$ 60,000
Seller Financing | Seller-financed secured loan due September 2022
Property, Plant and Equipment [Line Items]
Cash paid to acquire asset	$ 33,800

Loss on Impairment (Details)

Loss on Impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Loss on impairment	$ 802,133	$ 121,639	$ 1,458,749
Proceeds from disposal of assets	5,402	2,382	24,808
Noble Amos Runner, Noble Clyde Boudreaux And Noble Dave Beard
Loss Contingencies [Line Items]
Impairment related charges			1,000,000
Noble Homer Ferrington
Loss Contingencies [Line Items]
Impairment related charges			120,100
Capital Spare Equipment
Loss Contingencies [Line Items]
Impairment related charges			$ 170,500
Noble Max Smith
Loss Contingencies [Line Items]
Impairment related charges		164,800
Proceeds from disposal of assets		$ 1,200
Bully Joint Venture
Loss Contingencies [Line Items]
Loss on impairment	250,300
Bully Joint Venture | Drillships
Loss Contingencies [Line Items]
Loss on impairment	$ 550,300

Debt - Additional Information (

Debt - Additional Information (Details)

Feb. 14, 2019USD ($)

Sep. 21, 2018USD ($)

Jan. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Oct. 31, 2018USD ($)

Sep. 30, 2018USD ($)

Aug. 31, 2018USD ($)

Mar. 31, 2018USD ($)

Feb. 28, 2018USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Apr. 30, 2018

Jan. 03, 2018USD ($)

Debt Instrument [Line Items]

Gain (loss) on extinguishment of debt, net

$ (1,793,000)

$ 0

$ 17,814,000

Seller-financed secured loan due September 2022

Debt Instrument [Line Items]

Financed value

$ 60,000,000

Principal payment due

5.00%

8.70% Senior Notes due April 2045

Debt Instrument [Line Items]

Interest rate on senior notes

8.70%

7.50% Senior Notes due March 2019

Debt Instrument [Line Items]

Interest rate on senior notes

7.50%

5.75% Senior Notes due March 2018

Debt Instrument [Line Items]

Interest rate on senior notes

5.75%

Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Line of credit facility, term

5 years

Maximum borrowing capacity under credit facilities

$ 2,400,000,000

$ 2,400,000,000

Line of Credit | 2015 Credit Facility

Debt Instrument [Line Items]

Net loss recognized

$ (2,300,000)

Outstanding borrowings

0

Line of Credit | 2017 Credit Facility

Debt Instrument [Line Items]

Maximum borrowing capacity under credit facilities

$ 1,501,500,000

Outstanding borrowings

$ 0

Line of Credit | Revolving Credit Facility | 2015 Credit Facility

Debt Instrument [Line Items]

Maximum borrowing capacity under credit facilities

300,000,000

Maximum debt to tangible capitalization covenant

60.00%

Line of Credit | Revolving Credit Facility | 2017 Credit Facility

Debt Instrument [Line Items]

Amount credit facility can be increased

500,000,000

Maximum debt to tangible capitalization covenant

55.00%

48.00%

55.00%

Debt covenant, rig value of marketed rigs to indebtedness, required minimum ratio

3

Debt covenants, rig value of closing date rigs, required minimum ratio

0.8

Debt restrictive covenants, maximum available cash after borrowings

$ 200,000,000

Line of Credit | Letter of Credit | 2017 Credit Facility

Debt Instrument [Line Items]

Maximum borrowing capacity under credit facilities

$ 15,000,000

Outstanding borrowings

$ 3,400,000

Senior notes

Debt Instrument [Line Items]

Purchase of senior notes

$ 27,400,000

$ 400,000

$ 9,500,000

$ 754,200,000

Repurchase amount

20,200,000

300,000

8,700,000

750,000,000

Gain (loss) on extinguishment of debt, net

$ 6,900,000

$ 100,000

500,000

(3,500,000)

Extinguishment of debt

$ 126,600,000

Senior notes | Senior Notes due 2026

Debt Instrument [Line Items]

Face value of senior notes

$ 750,000,000

Senior notes | Senior Notes due 2026 | NHIL

Debt Instrument [Line Items]

Proceeds from issuance of debt

$ 737,400,000

Required percentage of book value of material drilling equipment for subsidiary guarantors

85.00%

85.00%

Senior notes | 7.70% Senior Notes due April 2025 | Standard And Poor Global Ratings

Debt Instrument [Line Items]

Interest rate on senior notes

7.95%

Senior notes | 8.70% Senior Notes due April 2045 | Standard And Poor Global Ratings

Debt Instrument [Line Items]

Interest rate on senior notes

8.95%

Senior notes | 7.50% Senior Notes due March 2019

Debt Instrument [Line Items]

Interest rate on senior notes

7.50%

Purchase of senior notes

61,900,000

Repurchase amount

65,300,000

Gain (loss) on extinguishment of debt, net

$ (3,500,000)

Senior notes | 5.75% Senior Notes due March 2018

Debt Instrument [Line Items]

Interest rate on senior notes

5.75%

Other: | Seller-financed secured loan due September 2022

Debt Instrument [Line Items]

Interest rate, paid in cash

4.25%

Paid-in-kind interest rate

1.25%

1.25%

Senior unsecured revolving credit facility maturity period

4 years

Paid in cash and paid-in-kind interest rate

8.91%

Rig

Debt Instrument [Line Items]

Purchase price of asset acquired

$ 93,800,000

Rig | Subsequent Event

Debt Instrument [Line Items]

Purchase price of asset acquired

$ 83,800,000

Debt - Aggregate Principal Repa

Debt - Aggregate Principal Repayments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2,019	$ 0
2,020	65,890
2,021	96,142
2,022	99,481
2,023	0
Thereafter	3,673,040
Total	$ 3,934,553

Debt - Estimated Fair Value of

Debt - Estimated Fair Value of Our Long-Term Debt, not Including Effect of Unamortized Debt Issuance Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 0	$ 249,843
5.75% Senior Notes due March 2018
Debt Instrument [Line Items]
Interest rate on senior notes	5.75%
7.50% Senior Notes due March 2019
Debt Instrument [Line Items]
Interest rate on senior notes	7.50%
4.90% Senior Notes due August 2020
Debt Instrument [Line Items]
Interest rate on senior notes	4.90%
4.625% Senior Notes due March 2021
Debt Instrument [Line Items]
Interest rate on senior notes	4.625%
3.95% Senior Notes due March 2022
Debt Instrument [Line Items]
Interest rate on senior notes	3.95%
7.75% Senior Notes due January 2024
Debt Instrument [Line Items]
Interest rate on senior notes	7.75%
7.95% Senior Notes due April 2025
Debt Instrument [Line Items]
Interest rate on senior notes	7.95%
7.875% Senior Notes due February 2026
Debt Instrument [Line Items]
Interest rate on senior notes	7.875%
6.20% Senior Notes due August 2040
Debt Instrument [Line Items]
Interest rate on senior notes	6.20%
6.05% Senior Notes due March 2041
Debt Instrument [Line Items]
Interest rate on senior notes	6.05%
5.25% Senior Notes due March 2042
Debt Instrument [Line Items]
Interest rate on senior notes	5.25%
Senior notes | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 3,877,402	4,045,710
Current maturities of long-term debt	0	249,843
Long-term debt	3,877,402	3,795,867
Senior notes | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	2,920,806	3,350,723
Current maturities of long-term debt	0	250,830
Long-term debt	$ 2,920,806	3,099,893
Senior notes | 5.75% Senior Notes due March 2018
Debt Instrument [Line Items]
Interest rate on senior notes	5.75%
Senior notes | 5.75% Senior Notes due March 2018 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 0	249,843
Senior notes | 5.75% Senior Notes due March 2018 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 0	250,830
Senior notes | 7.50% Senior Notes due March 2019
Debt Instrument [Line Items]
Interest rate on senior notes	7.50%
Senior notes | 7.50% Senior Notes due March 2019 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 0	201,535
Senior notes | 7.50% Senior Notes due March 2019 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 0	206,881
Senior notes | 4.90% Senior Notes due August 2020
Debt Instrument [Line Items]
Interest rate on senior notes	4.90%
Senior notes | 4.90% Senior Notes due August 2020 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 65,810	167,422
Senior notes | 4.90% Senior Notes due August 2020 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 60,177	163,283
Senior notes | 4.625% Senior Notes due March 2021
Debt Instrument [Line Items]
Interest rate on senior notes	4.625%
Senior notes | 4.625% Senior Notes due March 2021 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 92,967	208,095
Senior notes | 4.625% Senior Notes due March 2021 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 84,931	195,687
Senior notes | 3.95% Senior Notes due March 2022
Debt Instrument [Line Items]
Interest rate on senior notes	3.95%
Senior notes | 3.95% Senior Notes due March 2022 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 41,617	125,307
Senior notes | 3.95% Senior Notes due March 2022 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 37,096	107,348
Senior notes | 7.75% Senior Notes due January 2024
Debt Instrument [Line Items]
Interest rate on senior notes	7.75%
Senior notes | 7.75% Senior Notes due January 2024 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 783,350	971,498
Senior notes | 7.75% Senior Notes due January 2024 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 613,719	861,160
Senior notes | 7.95% Senior Notes due April 2025
Debt Instrument [Line Items]
Interest rate on senior notes	7.95%
Senior notes | 7.95% Senior Notes due April 2025 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 446,517	446,106
Senior notes | 7.95% Senior Notes due April 2025 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 339,035	380,732
Senior notes | 7.875% Senior Notes due February 2026
Debt Instrument [Line Items]
Interest rate on senior notes	7.875%
Senior notes | 7.875% Senior Notes due February 2026 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 738,075	0
Senior notes | 7.875% Senior Notes due February 2026 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 647,085	0
Senior notes | 6.20% Senior Notes due August 2040
Debt Instrument [Line Items]
Interest rate on senior notes	6.20%
Senior notes | 6.20% Senior Notes due August 2040 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 390,454	396,738
Senior notes | 6.20% Senior Notes due August 2040 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 245,242	274,988
Senior notes | 6.05% Senior Notes due March 2041
Debt Instrument [Line Items]
Interest rate on senior notes	6.05%
Senior notes | 6.05% Senior Notes due March 2041 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 389,693	394,514
Senior notes | 6.05% Senior Notes due March 2041 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 247,171	273,988
Senior notes | 5.25% Senior Notes due March 2042
Debt Instrument [Line Items]
Interest rate on senior notes	5.25%
Senior notes | 5.25% Senior Notes due March 2042 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 477,996	494,063
Senior notes | 5.25% Senior Notes due March 2042 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 277,056	315,430
Senior notes | 8.95% Senior Notes due April 2045
Debt Instrument [Line Items]
Interest rate on senior notes	8.95%
Senior notes | 8.95% Senior Notes due April 2045 | Carrying Value
Debt Instrument [Line Items]
Total debt	$ 390,672	390,589
Senior notes | 8.95% Senior Notes due April 2045 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	311,392	320,396
Other: | Seller-financed secured loan due September 2022 | Carrying Value
Debt Instrument [Line Items]
Total debt	60,251	0
Other: | Seller-financed secured loan due September 2022 | Estimated Fair Value
Debt Instrument [Line Items]
Total debt	$ 57,902	$ 0

Equity - Narrative (Details)

Equity - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 28, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding and trading (in shares)		246,794,000	244,971,000
Additional conditionally authorized shares without additional shareholder approval (in shares)		82,200,000
Current nominal value per share		$ 0.01
Shares allotted (in shares)		0
Repurchases of shares (in shares)		0	0
Stock options granted (in shares)		0	0	0
Compensation cost recognized			$ 0
2015 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized under plan (in shares)		5,000,000	3,700,000	9,500,000
Total number of shares issuable under stock option plan (in shares)		25,500,000
Remaining number of shares available for grants (in shares)		11,500,000
Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercisable term		10 years
Compensation cost recognized		$ 0		$ 0
TVRSUs Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average vesting period (years)		3 years
Total unrecognized compensation cost		$ 15,800,000
Period for recognizing unrecognized compensation cost		1 year 7 months 12 days
Incremental fair value awarded as a result of the issuance of awards		$ 20,300,000
Performance shares forfeited in period		1,054,808
PVRSUs Outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average vesting period (years)		3 years
Period for recognizing unrecognized compensation cost		1 year 1 month 15 days
Total unrecognized compensation cost		$ 6,700,000
Performance shares forfeited in period		1,784,740
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost recognized		$ 24,000,000	$ 29,100,000	34,700,000
Compensation cost recognized net of tax		21,900,000	26,300,000	31,000,000
Capitalized compensation costs		$ 0	$ 0	$ 200,000
Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrestricted shares awarded (in shares)		267,204	197,316	227,937
Subsequent Event | Performance Vested Shares for 2012-2014 Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares forfeited in period	1,450,802

Equity - Summary of Stock Optio

Equity - Summary of Stock Options Granted (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares Underlying Options
Outstanding at beginning of year (in shares)	1,313,155	1,420,175	1,677,154
Expired (in shares)	(209,913)	(107,020)	(256,979)
Outstanding at end of year (in shares)	1,103,242	1,313,155	1,420,175
Exercisable at end of year (in shares)	1,103,242	1,313,155	1,420,175
Weighted Average Exercise Price
Outstanding at beginning of year (usd per share)	$ 29.51	$ 29.52	$ 29.48
Expired (usd per share)	33.56	29.74	29.22
Outstanding at end of year (usd per share)	28.74	29.51	29.52
Exercisable at end of year (usd per share)	$ 28.74	$ 29.51	$ 29.52
Aggregate intrinsic value of options outstanding and exercisable	$ 0

Equity - Additional Information

Equity - Additional Information About Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable, Number of Shares Underlying Options (in shares) | shares	1,103,242
Options Outstanding and Exercisable, Weighted Average Remaining Life (Years)	1 year 9 months 39 days
Options Outstanding and Exercisable, Weighted Average Exercise Price (usd per share)	$ 28.74
$20.49 to $25.41
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	20.49
Exercise price range, upper range limit	$ 25.41
Options Outstanding and Exercisable, Number of Shares Underlying Options (in shares) | shares	290,962
Options Outstanding and Exercisable, Weighted Average Remaining Life (Years)	8 months 8 days
Options Outstanding and Exercisable, Weighted Average Exercise Price (usd per share)	$ 21.40
$25.42 to $30.59
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	25.42
Exercise price range, upper range limit	$ 30.59
Options Outstanding and Exercisable, Number of Shares Underlying Options (in shares) | shares	334,958
Options Outstanding and Exercisable, Weighted Average Remaining Life (Years)	3 years 1 month 6 days
Options Outstanding and Exercisable, Weighted Average Exercise Price (usd per share)	$ 30.59
$30.60 to $32.78
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	30.60
Exercise price range, upper range limit	$ 32.78
Options Outstanding and Exercisable, Number of Shares Underlying Options (in shares) | shares	477,322
Options Outstanding and Exercisable, Weighted Average Remaining Life (Years)	1 year 8 months 13 days
Options Outstanding and Exercisable, Weighted Average Exercise Price (usd per share)	$ 31.91

Equity - Assumptions used to Va

Equity - Assumptions used to Value the Performance-Vested Restricted Stock Awards (Details) - Restricted Stock Awards	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation assumptions:
Expected volatility	61.80%	56.40%	40.70%
Expected dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate	2.31%	1.49%	0.97%

Equity - Summary of Restricted

Equity - Summary of Restricted Share Awards (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
TVRSU
Schedule Of Share Based Compensation Arrangements By Restricted Stock Award [Abstract]
Units awarded (in shares)	3,578,212	3,231,225	3,624,182
Weighted-average share price at award date (usd per share)	$ 4.71	$ 6.96	$ 7.78
Weighted-average vesting period (years)	3 years	3 years	3 years
PVRSU
Schedule Of Share Based Compensation Arrangements By Restricted Stock Award [Abstract]
Units awarded (in shares)	2,733,906	2,474,978	2,914,044
Weighted-average share price at award date (usd per share)	$ 4.55	$ 7.28	$ 7.79
Three-year performance period ended December 31	2,020	2,019	2,018
Awarded, Weighted-average award-date fair value (usd per share)	$ 2.96	$ 4.37	$ 3.81

Equity - Summary of Status of N

Equity - Summary of Status of Non-Vested Restricted Shares (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
TVRSUs Outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested RSUs, Beginning balance (in shares)	5,043,502
Awarded (in shares)	3,578,212
Vested (in shares)	(2,342,503)
Forfeited (in shares)	(1,054,808)
Non-vested RSUs, Ending balance (in shares)	5,224,403
Weighted Average Award-Date Fair Value
Non-vested RSUs, Beginning balance (usd per share) | $ / shares	$ 7.95
Awarded (usd per share) | $ / shares	4.71
Vested (usd per share) | $ / shares	8.67
Forfeited (usd per share) | $ / shares	6.43
Non-vested RSUs, Ending balance (usd per share) | $ / shares	$ 5.71
PVRSUs Outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested RSUs, Beginning balance (in shares)	5,645,454
Awarded (in shares)	2,733,906
Vested (in shares)	(403,553)
Forfeited (in shares)	(1,784,740)
Non-vested RSUs, Ending balance (in shares)	6,191,067
Weighted Average Award-Date Fair Value
Non-vested RSUs, Beginning balance (usd per share) | $ / shares	$ 4.98
Awarded (usd per share) | $ / shares	4.87
Vested (usd per share) | $ / shares	9.12
Forfeited (usd per share) | $ / shares	5.97
Non-vested RSUs, Ending balance (usd per share) | $ / shares	$ 4.38
Minimum number of performance vested shares	0
Target level of performance, percent	50.00%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 5,950,628		$ 5,950,628	$ 6,467,445	$ 7,422,230
Stranded tax effect resulting from the Act	(5,540)	$ 0
Stockholders' equity, adjusted balance		5,800,747		5,800,747
Other comprehensive income before reclassifications			(2,729)	8,859
Amounts reclassified from AOCI			(5,915)	393
Other comprehensive income (loss), net			(8,644)	9,252	11,035
Ending Balance		5,950,628	4,654,574	5,950,628	6,467,445
Unrealized Gains /(Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	0		0	0
Stranded tax effect resulting from the Act	0
Stockholders' equity, adjusted balance	0
Other comprehensive income before reclassifications			0	1,239
Amounts reclassified from AOCI			0	(1,239)
Other comprehensive income (loss), net			0	0
Ending Balance		0	0	0	0
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(27,603)		(27,603)	(35,865)
Stranded tax effect resulting from the Act	(5,540)
Stockholders' equity, adjusted balance	(33,143)
Other comprehensive income before reclassifications			0	6,630
Amounts reclassified from AOCI			(5,915)	1,632
Other comprehensive income (loss), net			(5,915)	8,262
Ending Balance		(27,603)	(39,058)	(27,603)	(35,865)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(15,285)		(15,285)	(16,275)
Stranded tax effect resulting from the Act	0
Stockholders' equity, adjusted balance	(15,285)
Other comprehensive income before reclassifications			(2,729)	990
Amounts reclassified from AOCI			0	0
Other comprehensive income (loss), net			(2,729)	990
Ending Balance		(15,285)	(18,014)	(15,285)	(16,275)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(42,888)		(42,888)	(52,140)	(63,175)
Stranded tax effect resulting from the Act		(5,540)
Stockholders' equity, adjusted balance	$ (48,428)	(48,428)		(48,428)
Other comprehensive income (loss), net			(8,644)	9,252	11,035
Ending Balance		$ (42,888)	$ (57,072)	$ (42,888)	$ (52,140)

Revenue and Customers - Additio

Revenue and Customers - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Payment term	30

Revenue and Customers - Receiva

Revenue and Customers - Receivables, Contract Assets, and Contract Liabilities with Customers (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Current contract assets	$ 25,298	$ 21,229
Noncurrent contract assets	22,366	34,520
Total contract assets	47,664	55,749
Current contract liabilities (deferred revenue)	(32,906)	(35,422)
Noncurrent contract liabilities (deferred revenue)	(47,847)	(73,439)
Total contract liabilities	$ (80,753)	$ (108,861)	$ (114,300)

Revenue and Customers - Signifi

Revenue and Customers - Significant Changes in Contract Assets and Contract Liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract liabilities, beginning balance	$ (114,300)
Amortization of deferred costs	(32,420)
Additions to deferred costs	24,335
Amortization of deferred revenue	47,798
Additions to deferred revenue	(19,690)
Total	(8,085)
Total	28,108
Contract assets, ending balance	47,664
Contract liabilities, ending balance	$ (80,753)

Revenue and Customers - Remaini

Revenue and Customers - Remaining Performance Obligations (Details) $ in Thousands	Dec. 31, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue from Contract with Customer [Abstract]
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 32,889
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue from Contract with Customer [Abstract]
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 19,349
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 15,677
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 9,266
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 3,572
Performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 80,753
Drillships | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	20,658
Drillships | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	15,677
Drillships | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	15,677
Drillships | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	9,266
Drillships | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	3,572
Drillships | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	64,850
Semisubmersibles | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	363
Semisubmersibles | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Semisubmersibles | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Semisubmersibles | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Semisubmersibles | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Semisubmersibles | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	363
Jackups | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	11,868
Jackups | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	3,672
Jackups | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Jackups | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Jackups | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	0
Jackups | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations	$ 15,540

Revenue and Customers - Disaggr

Revenue and Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Operating revenues	$ 309,892	$ 279,408	$ 258,369	$ 235,157	$ 329,585	$ 266,212	$ 278,142	$ 362,976	$ 1,082,826	$ 1,236,915	$ 2,302,065
Drillships
Disaggregation of Revenue [Line Items]
Operating revenues	155,305								532,833
Semisubmersibles
Disaggregation of Revenue [Line Items]
Operating revenues	10,344								28,992
Jackups
Disaggregation of Revenue [Line Items]
Operating revenues	126,400								474,257
Contract drilling services
Disaggregation of Revenue [Line Items]
Operating revenues	$ 292,049								$ 1,036,082	$ 1,207,026	$ 2,242,200

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Income Tax Disclosure [Abstract]
Tax Cuts and Jobs Act of 2018, provisional tax benefit recognized	$ (24,900)	$ (109,000)
Reserves for uncertain tax positions	183,786	191,860
Related tax benefits	1,008	1,008	$ 1,008
Amount provision for income taxes reduced if reserves not realized	$ 183,800
Operational period	12 months
Interest and penalties resulted in an income tax expense	$ 5,100	4,700	$ 2,700
Provision for non-cash items related to impairment of three rigs	35,600
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax Cuts and Jobs Act of 2018, additional tax benefit recognized	$ 24,900
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to new accounting standard		$ 148,393
Other assets | Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to new accounting standard				$ 148,400

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Deferred tax assets	$ 203,876	$ 38,712
Less: valuation allowance	(12,306)	0
Net deferred tax assets	191,570	38,712
Deferred tax liabilities
Deferred tax liabilities	(263,813)	(189,455)
Net deferred tax liabilities	(72,243)	(150,743)
United States
Deferred tax assets
Net operating loss carry forwards	95,577	0
Disallowed interest deduction carryforwards	51,423	0
Deferred pension plan amounts	11,887	10,758
Accrued expenses not currently deductible	9,688	11,585
Other	1,936	2,150
Deferred tax liabilities
Excess of net book basis over remaining tax basis	(254,669)	(182,401)
Other	(6,482)	(6,652)
Non-U.S.
Deferred tax assets
Net operating loss carry forwards	26,441	0
Disallowed interest deduction carryforwards	6,254	0
Deferred pension plan amounts	670	134
Accrued expenses not currently deductible	0	14,085
Deferred tax liabilities
Excess of net book basis over remaining tax basis	(1,066)	0
Other	$ (1,596)	$ (402)

Income Taxes - Income (Loss) fr

Income Taxes - Income (Loss) from Continuing Operations Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
United States	$ (136,083)	$ (81,329)	$ (428,087)
Non-U.S.	(1,101,093)	(368,485)	(538,942)
Total	$ (1,237,176)	$ (449,814)	$ (967,029)

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision for Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Current- United States	$ (56,574)	$ (227,707)	$ 61,928
Current- Non-U.S.	18,348	29,010	18,813
Deferred- United States	(67,371)	257,432	(189,880)
Deferred- Non-U.S.	(1,044)	(16,106)	(17)
Total	$ (106,641)	$ 42,629	$ (109,156)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Reserve for Uncertain Tax Positions, Excluding Interest and Penalties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross balance at January 1,	$ 174,437	$ 159,826	$ 169,687
Additions based on tax positions related to current year	97	14,187	15,665
Additions for tax positions of prior years	25	1,284	18,662
Reductions for tax positions of prior years	(12,806)	(860)	(43,701)
Expiration of statutes	(497)	0	(487)
Tax settlements	0	0	0
Gross balance at December 31,	161,256	174,437	159,826
Related tax benefits	(1,008)	(1,008)	(1,008)
Net reserve at December 31,	$ 160,248	173,429	158,818
Non-U.S. | Libya | In 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross balance at January 1,		$ 40,000
Gross balance at December 31,			40,000
Related tax benefits			$ (13,000)

Income Taxes - Summary of Liabi

Income Taxes - Summary of Liabilities Related to Reserve for Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net reserve at December 31,	$ 160,248	$ 173,429	$ 158,818
Interest and penalties included in “Other liabilities”	23,538	18,431
Reserve for uncertain tax positions, including interest and penalties	$ 183,786	$ 191,860

Income Taxes - Effective Tax Re

Income Taxes - Effective Tax Reconciliation (Details) - UK income tax	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Tax rates which are different than the UK and Cayman Island rates	4.00%	23.40%	8.40%
Tax impact of asset impairment	2.90%	11.70%	3.90%
Tax impact of tax restructuring	0.00%	(76.10%)	0.00%
Tax impact of the Act	2.10%	33.40%	0.00%
Reserve for (resolution of) tax authority audits	(0.40%)	(1.90%)	(1.00%)
Total	8.60%	(9.50%)	11.30%

Employee Benefit Plans - Reconc

Employee Benefit Plans - Reconciliation of Changes in Projected Benefit Obligations for our Non - U.S. and U.S. Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-U.S.
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 61,952	$ 72,347
Service cost	0	0	$ 2,914
Interest cost	1,747	2,151	2,412
Actuarial loss (gain)	(2,683)	(11,265)
Plan amendments	285	0
Benefits paid	(3,282)	(2,836)
Settlements and curtailments	0	(4,825)
Foreign exchange rate changes	(3,121)	6,380
Benefit obligation at end of year	54,898	61,952	72,347
U.S.
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	235,175	216,577
Service cost	0	0	6,647
Interest cost	8,179	8,593	9,557
Actuarial loss (gain)	(20,673)	19,113
Plan amendments	0	0
Benefits paid	(7,218)	(6,795)
Settlements and curtailments	(4,519)	(2,313)
Foreign exchange rate changes	0	0
Benefit obligation at end of year	$ 210,944	$ 235,175	$ 216,577

Employee Benefit Plans - Reco_2

Employee Benefit Plans - Reconciliation of Changes in Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-U.S.
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 77,141	$ 71,286
Actual return on plan assets	(1,366)	5,594
Employer contributions	0	651	$ 2,800
Benefits paid	(3,282)	(2,836)
Settlement and curtailment	0	(4,597)
Foreign exchange rate changes	(3,896)	7,043
Fair value of plan assets at end of year	68,597	77,141	71,286
U.S.
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	189,240	171,240
Actual return on plan assets	(16,326)	24,760
Employer contributions	4,553	2,348	400
Benefits paid	(7,218)	(6,795)
Settlement and curtailment	(4,519)	(2,313)
Foreign exchange rate changes	0	0
Fair value of plan assets at end of year	$ 165,730	$ 189,240	$ 171,240

Employee Benefit Plans - Funded

Employee Benefit Plans - Funded Status of Plans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Funded status	$ 13,699	$ 15,189
U.S.
Defined Benefit Plan Disclosure [Line Items]
Funded status	$ (45,214)	$ (45,935)

Employee Benefit Plans - Amount

Employee Benefit Plans - Amounts Recognized in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Other assets (noncurrent)	$ 13,699	$ 15,189
Other liabilities (current)	0	0
Other liabilities (noncurrent)	0	0
Net amount recognized	13,699	15,189
U.S.
Defined Benefit Plan Disclosure [Line Items]
Other assets (noncurrent)	0	0
Other liabilities (current)	(1,062)	(2,312)
Other liabilities (noncurrent)	(44,152)	(43,623)
Net amount recognized	$ (45,214)	$ (45,935)

Employee Benefit Plans - Amou_2

Employee Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 3,622	$ 2,258
Prior service cost	273	0
Deferred income tax asset	(670)	(375)
Accumulated other comprehensive loss	3,225	1,883
U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	45,358	39,569
Prior service cost	0	0
Deferred income tax asset	(9,524)	(13,849)
Accumulated other comprehensive loss	$ 35,834	$ 25,720

Employee Benefit Plans - Pensio

Employee Benefit Plans - Pension Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 2,914
Interest cost	1,747	2,151	2,412
Return on plan assets	(2,762)	(2,879)	(3,393)
Amortization of prior service cost	0	0	104
Recognized net actuarial loss	0	743	142
Settlement and curtailment gains	0	(838)	600
Net pension benefit cost (gain)	(1,015)	(823)	2,779
U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	6,647
Interest cost	8,179	8,593	9,557
Return on plan assets	(11,914)	(11,764)	(12,389)
Amortization of prior service cost	0	0	118
Recognized net actuarial loss	1,642	1,464	4,398
Settlement and curtailment gains	135	82	200
Net pension benefit cost (gain)	$ (1,958)	$ (1,625)	$ 8,531

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Market cycle minimum period in which objective should be met over	3 years
Market cycle maximum period in which objective should be met over	5 years
Investment equity securities	$ 0	$ 0
Costs for maintaining contribution plans	25,000,000	27,600,000	$ 37,200,000
Restoration Plan
Defined Benefit Plan Disclosure [Line Items]
Liability under the restoration plan	$ 8,200,000	8,800,000
Noble Drilling Corporation Profit Sharing Plan
Defined Benefit Plan Disclosure [Line Items]
Number of years of service for the participants in the plan to become fully vested	3 years
Plan participants’ contributions	$ 2,300,000	3,100,000	6,000,000
Cash holdings
Defined Benefit Plan Disclosure [Line Items]
Percentage of company's overall investments	1.20%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of company's overall investments	31.50%
Debt security
Defined Benefit Plan Disclosure [Line Items]
Percentage of company's overall investments	67.30%
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial losses and prior service costs	$ 100,000
Projected benefit obligation	0	0
Accumulated benefit obligation	$ 0	0
Defined benefit plan, investment within plan asset category, de-risking basis of gilts, percentage	(0.45%)
Defined benefit plan, investment within plan asset category, minimum outperformance versus cash, percentage	4.00%
Employer contributions	$ 0	651,000	2,800,000
Expected contribution to non-U.S. and U.S pension plans	$ 0
Non-U.S. | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of company's overall investments	48.00%
Non-U.S. | Debt security
Defined Benefit Plan Disclosure [Line Items]
Percentage of company's overall investments	52.00%
U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial losses and prior service costs	$ 2,800,000
Decrease in pension liability	600,000	1,600,000	2,900,000
Projected benefit obligation	210,944,000	235,175,000
Accumulated benefit obligation	210,944,000	235,175,000
Employer contributions	4,553,000	2,348,000	$ 400,000
Expected contribution to non-U.S. and U.S pension plans	1,100,000
U.S. | Unfunded excess benefit plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	10,500,000	16,400,000
Accumulated benefit obligation	$ 10,500,000	$ 16,400,000

Employee Benefit Plans - Disagg

Employee Benefit Plans - Disaggregated Plan Information (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 54,898	$ 61,952	$ 72,347
Accumulated benefit obligation	54,898	61,952
Fair value of plan assets	68,597	77,141	71,286
U.S.
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	210,944	235,175	216,577
Accumulated benefit obligation	210,944	235,175
Fair value of plan assets	$ 165,730	$ 189,240	$ 171,240

Employee Benefit Plans - Plans

Employee Benefit Plans - Plans in which PBO Exceeded Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 0	$ 0
Fair value of plan assets	0	0
U.S.
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	210,944	235,175
Fair value of plan assets	$ 165,730	$ 189,240

Employee Benefit Plans - Plan_2

Employee Benefit Plans - Plans in which Accumulated Benefit Obligation Exceeded Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 0	$ 0
Fair value of plan assets	0	0
U.S.
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	210,944	235,175
Fair value of plan assets	$ 165,730	$ 189,240

Employee Benefit Plans - Define

Employee Benefit Plans - Defined Benefit Plans Key Assumptions (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-U.S.
Weighted-average assumptions used to determine benefit obligations:
Discount Rate	2.90%	2.60%
Weighted-average assumptions used to determine periodic benefit cost:
Discount Rate	2.60%
Expected long-term return on assets	3.70%	4.10%
Non-U.S. | Minimum
Weighted-average assumptions used to determine periodic benefit cost:
Discount Rate		2.48%	2.15%
Expected long-term return on assets			1.60%
Rate of compensation increase			3.60%
Non-U.S. | Maximum
Weighted-average assumptions used to determine periodic benefit cost:
Discount Rate		2.70%	3.90%
Expected long-term return on assets			5.00%
Rate of compensation increase			4.20%
U.S.
Weighted-average assumptions used to determine periodic benefit cost:
Expected long-term return on assets			7.00%
U.S. | Minimum
Weighted-average assumptions used to determine benefit obligations:
Discount Rate	3.65%	2.84%
Weighted-average assumptions used to determine periodic benefit cost:
Discount Rate	2.84%	3.00%	3.09%
Expected long-term return on assets	5.75%	6.00%
U.S. | Maximum
Weighted-average assumptions used to determine benefit obligations:
Discount Rate	4.29%	3.66%
Weighted-average assumptions used to determine periodic benefit cost:
Discount Rate	3.66%	4.24%	4.48%
Expected long-term return on assets	6.50%	6.50%

Employee Benefit Plans - Actual

Employee Benefit Plans - Actual Fair Values of Pension Plans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	$ 68,597	$ 77,141
Estimated Fair Value Measurements	68,597	77,141	$ 71,286
Non-U.S. | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	68,597	77,141
Non-U.S. | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	151	280
Non-U.S. | Cash and cash equivalents | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	151	280
Non-U.S. | Cash and cash equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	25,585	54,145
Non-U.S. | Equity securities | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	25,585	54,145
Non-U.S. | Equity securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Equity securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	42,861	22,716
Non-U.S. | Corporate bonds | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	42,861	22,716
Non-U.S. | Corporate bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Corporate bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
Non-U.S. | Other
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount		0
Non-U.S. | Other | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements		0
Non-U.S. | Other | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements		0
Non-U.S. | Other | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements		0
U.S.
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	165,730	189,240
Estimated Fair Value Measurements	165,730	189,240	$ 171,240
U.S. | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	129,401	162,135
U.S. | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	36,329	27,105
U.S. | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	4,801	3,275
U.S. | Cash and cash equivalents | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	4,801	3,275
U.S. | Cash and cash equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Equity securities | U.S.
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	47,950	43,535
U.S. | Equity securities | International
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	17,838	17,712
U.S. | Equity securities | Quoted Prices in Active Markets (Level 1) | U.S.
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	16,775	16,430
U.S. | Equity securities | Quoted Prices in Active Markets (Level 1) | International
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	17,838	17,712
U.S. | Equity securities | Significant Other Observable Inputs (Level 2) | U.S.
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	31,175	27,105
U.S. | Equity securities | Significant Other Observable Inputs (Level 2) | International
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Equity securities | Significant Unobservable Inputs (Level 3) | U.S.
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Equity securities | Significant Unobservable Inputs (Level 3) | International
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	64,802	40,793
U.S. | Corporate bonds | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	59,648	40,793
U.S. | Corporate bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	5,154	0
U.S. | Corporate bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Treasury bonds
Defined Benefit Plan Disclosure [Line Items]
Carrying Amount	30,339	83,925
U.S. | Treasury bonds | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	30,339	83,925
U.S. | Treasury bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	0	0
U.S. | Treasury bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Fair Value Measurements	$ 0	$ 0

Employee Benefit Plans - Estima

Employee Benefit Plans - Estimated Benefit Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
Total	$ 147,609
2,019	12,128
2,020	12,692
2,021	17,054
2,022	13,371
2,023	14,098
Thereafter	78,266
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Total	38,334
2,019	3,255
2,020	3,372
2,021	3,492
2,022	3,617
2,023	3,747
Thereafter	20,851
U.S.
Defined Benefit Plan Disclosure [Line Items]
Total	109,275
2,019	8,873
2,020	9,320
2,021	13,562
2,022	9,754
2,023	10,351
Thereafter	$ 57,415

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018paymentcontract	Jun. 30, 2017USD ($)$ / bbl
Derivative [Line Items]
Number of contingent payments | payment	2
FCX Settlement
Derivative [Line Items]
Derivative contingent settlement period		12 months
FCX Settlement | Noble Corp
Derivative [Line Items]
Estimated fair value of contingent payments		$ 0
FCX Settlement | WTI Crude Oil Averages Price More than $50 Per Barrel
Derivative [Line Items]
Crude oil average price | $ / bbl		50
Non designated derivatives contingent payment		$ 25
FCX Settlement | WTI Crude Oil Averages Price More than $65 Per Barrel
Derivative [Line Items]
Crude oil average price | $ / bbl		65
Non designated derivatives contingent payment		$ 50
Foreign currency forward contracts
Derivative [Line Items]
Number of contracts outstanding | contract	0

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Summarization of Recognized Gains and Losses of Cash Flow Hedges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Non-designated derivatives | FCX Settlement
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain/(loss) recognized through AOCL	$ 0	$ 0
Non-designated derivatives | Contract drilling services | FCX Settlement
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) reclassified from AOCL to Contract drilling services costs	0	0
Gain/(loss) recognized through Contract drilling services revenue	0	(14,400)
Foreign currency forward contracts | Designated as hedging | Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain/(loss) recognized through AOCL	0	(1,239)
Foreign currency forward contracts | Designated as hedging | Contract drilling services | Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) reclassified from AOCL to Contract drilling services costs	0	0
Gain/(loss) recognized through Contract drilling services revenue	$ 0	$ 1,239

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Carrying Amount and Estimated Fair Value of Financial Instruments (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Quoted Prices in Active Markets (Level 1)
Assets -
Marketable securities	$ 8,659	$ 7,321
Significant Other Observable Inputs (Level 2)
Assets -
Marketable securities	0	0
Significant Unobservable Inputs (Level 3)
Assets -
Marketable securities	0	0
Carrying Value
Assets -
Marketable securities	$ 8,659	$ 7,321

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	Dec. 15, 2017USD ($)	Jan. 31, 2017Rig	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	May 02, 2017USD ($)
Other Commitments [Line Items]
Number of newbuild rigs allegedly infringing patent | Rig		5
Net loss from discontinued operations, net of tax			$ 0	$ 0	$ (1,486)	$ 0	$ 0	$ (1,486)	$ 0
Years of effectiveness of employment agreements after the termination of employment							3 years
Rent expense							$ 7,500	8,300	$ 7,800
Minimum
Other Commitments [Line Items]
Percentage of uncertain tax positions likelihood of being sustained							50.00%
Paragon Offshore
Other Commitments [Line Items]
Litigation trust fund										$ 10,000
Damages sought	$ 1,700,000
Coverage limit							$ 150,000
Net charges recognized relating to Paragon Offshore emergence from bankruptcy								15,900
Net loss from discontinued operations, net of tax								$ 1,500
Customs And Other Business Taxes | Mexico | Non-U.S.
Other Commitments [Line Items]
Approximate audit claims assessed							$ 50,700

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Operating Lease Payments (Details) - USD ($) $ in Thousands	1 Months Ended
	Feb. 28, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
2,019		$ 15,213
2,020		7,913
2,021		5,522
2,022		1,821
2,023		695
Thereafter		5,724
Total (1)		$ 36,888
Subsequent Event
Subsequent Event [Line Items]
Extended lease	10 years

Segment and Related Informati_3

Segment and Related Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	$ 1,082,826	$ 1,236,915	$ 2,302,065
Identifiable Assets	9,264,923	10,794,659
Argentina
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	51,627
Identifiable Assets	0	0
Australia
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	12,262	89,847
Identifiable Assets	243,388	257,415
Brazil
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	27,640
Identifiable Assets	13,299	25,645
Brunei
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	3,080	45,450	42,710
Identifiable Assets	0	119
Bulgaria
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	84,757	55,145	78,985
Identifiable Assets	645,689	657,806
Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	47,085	1,639	0
Identifiable Assets	219,421	238,902
Curacao
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	0
Identifiable Assets	82,521	647,554
Denmark
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	35,855	44,671	46,342
Identifiable Assets	242,831	250,851
East Timor
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	33,733	0	0
Identifiable Assets	0	0
Egypt
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	112,473	0	0
Identifiable Assets	689,965	0
Gabon
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	23,385
Identifiable Assets	8,065	8,378
Guyana
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	50,839	0	0
Identifiable Assets	1,250,390	0
Malaysia
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	91,052	131,696	168,826
Identifiable Assets	665,822	293,297
Mexico
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	0
Identifiable Assets	27,542	27,391
Myanmar
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	16,572	0	0
Identifiable Assets	152,629	0
Qatar
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	35,180	16,488	608
Identifiable Assets	478,708	0
Saudi Arabia
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	156,989	140,453	120,132
Identifiable Assets	380,421	455,296
Singapore
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	1,769	0	0
Identifiable Assets	125,574	911,515
South Africa
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	48,228	1,803
Identifiable Assets	0	0
Suriname
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	(3)	13,034	0
Identifiable Assets	0	0
Tanzania
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	381	1,526	48,394
Identifiable Assets	0	0
The Netherlands
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	42
Identifiable Assets	0	0
Turkey
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	(3)	0
Identifiable Assets	0	0
United Arab Emirates
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	(17)	99,825	86,446
Identifiable Assets	45,205	590,863
United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	194,602	209,338	95,621
Identifiable Assets	1,152,596	894,902
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	218,479	417,163	1,404,365
Identifiable Assets	2,840,857	5,534,725
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	0	0	$ 15,292
Identifiable Assets	$ 0	$ 0

Supplemental Financial Inform_3

Supplemental Financial Information - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Supplemental Financial Information [Line Items]
Deferred revenues		$ 80,753	$ 108,861	$ 114,300
Deferred expenses under drilling contracts		47,700		55,700
Aramco | Prepaid expenses and other current assets
Schedule Of Supplemental Financial Information [Line Items]
Additions to property and equipment		52,100		25,500	$ 35,100
Contract drilling services
Schedule Of Supplemental Financial Information [Line Items]
Deferred revenues		$ 80,800		$ 114,300
Seller-financed secured loan due September 2022
Schedule Of Supplemental Financial Information [Line Items]
Financed value	$ 60,000

Supplemental Financial Inform_4

Supplemental Financial Information - Effect of Changes in Other Assets and Liabilities on Cash Flows from Operating Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Accounts payable		$ (14,625)	$ (68,209)
Net change in other assets and liabilities	$ (34,940)	(21,225)	90,309
Noble-UK
Supplemental Cash Flow Elements [Abstract]
Accounts receivable	3,974	114,456	179,779
Other current assets	(2,722)	26,155	81,657
Other assets	(10,378)	(89,021)	138,210
Accounts payable	14,955	(14,625)	(68,209)
Other current liabilities	(13,940)	33,906	(209,739)
Other liabilities	(26,829)	(92,096)	(31,389)
Net change in other assets and liabilities	(34,940)	(21,225)	90,309
Noble - Cayman
Supplemental Cash Flow Elements [Abstract]
Accounts receivable	3,974	114,456	179,779
Other current assets	(2,700)	23,309	79,720
Other assets	(6,424)	(91,236)	136,130
Accounts payable	14,795	(14,429)	(66,421)
Other current liabilities	(13,495)	35,033	(203,763)
Other liabilities	(26,829)	(87,213)	(32,732)
Net change in other assets and liabilities	$ (30,679)	$ (20,080)	$ 92,713

Supplemental Financial Inform_5

Supplemental Financial Information - Additional Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Noble-UK
Supplemental Cash Flow Elements [Abstract]
Interest, net of amounts capitalized	$ 286,506	$ 246,960	$ 232,907
Income taxes (net of refunds)	(107,554)	30,590	100,544
Noble - Cayman
Supplemental Cash Flow Elements [Abstract]
Interest, net of amounts capitalized	286,506	246,960	232,907
Income taxes (net of refunds)	$ (107,554)	$ 30,590	$ 100,717

Supplemental Financial Inform_6

Supplemental Financial Information - Schedule of Prior Period Adjustments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts payable		$ (14,625)	$ (68,209)
Net changes in other operating assets and liabilities	$ (34,940)	(21,225)	90,309
Noble - Cayman
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts payable	14,795	(14,429)	(66,421)
Net changes in other operating assets and liabilities	$ (30,679)	(20,080)	92,713
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts payable		(37,263)	16,664
Net changes in other operating assets and liabilities		(37,263)	16,664
Adjustment | Noble - Cayman
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts payable		(37,263)	16,664
Net changes in other operating assets and liabilities		(37,263)	16,664
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts payable		22,638	(84,873)
Net changes in other operating assets and liabilities		16,038	73,645
As Reported | Noble - Cayman
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts payable		22,834	(83,085)
Net changes in other operating assets and liabilities		$ 17,183	$ 76,049

Condensed Consolidating Finan_3

Condensed Consolidating Financial Information - Guarantor Obligations (Details)	Dec. 31, 2018
5.75% Senior Notes due March 2018
Guarantor Obligations [Line Items]
Interest rate on senior notes	5.75%
7.50% Senior Notes due March 2019
Guarantor Obligations [Line Items]
Interest rate on senior notes	7.50%
4.90% Senior Notes due August 2020
Guarantor Obligations [Line Items]
Interest rate on senior notes	4.90%
4.625% Senior Notes due March 2021
Guarantor Obligations [Line Items]
Interest rate on senior notes	4.625%
3.95% Senior Notes due March 2022
Guarantor Obligations [Line Items]
Interest rate on senior notes	3.95%
7.75% Senior Notes due January 2024
Guarantor Obligations [Line Items]
Interest rate on senior notes	7.75%
7.95% Senior Notes due April 2025
Guarantor Obligations [Line Items]
Interest rate on senior notes	7.95%
7.875% Senior Notes due February 2026
Guarantor Obligations [Line Items]
Interest rate on senior notes	7.875%
6.20% Senior Notes due August 2040
Guarantor Obligations [Line Items]
Interest rate on senior notes	6.20%
6.05% Senior Notes due March 2041
Guarantor Obligations [Line Items]
Interest rate on senior notes	6.05%
5.25% Senior Notes due March 2042
Guarantor Obligations [Line Items]
Interest rate on senior notes	5.25%
8.70% Senior Notes due April 2045
Guarantor Obligations [Line Items]
Interest rate on senior notes	8.70%

Condensed Consolidating Finan_4

Condensed Consolidating Financial Information - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 375,232	$ 662,829
Accounts receivable	200,722	204,696
Taxes receivable	20,498	105,345
Prepaid expenses and other current assets	62,604	66,105
Total current assets	659,056	1,038,975
Property and equipment, at cost	10,956,412	12,034,331
Accumulated depreciation	(2,475,694)	(2,545,091)
Property and equipment, net	8,480,718	9,489,240
Other assets	125,149	266,444
Total assets	9,264,923	10,794,659
Current liabilities
Current maturities of long-term debt	0	249,843
Accounts payable	125,557	84,032
Accrued payroll and related costs	50,284	54,904
Taxes payable	29,386	34,391
Interest payable	100,100	98,189
Other current liabilities	60,130	71,665
Total current liabilities	365,457	593,024
Long-term debt	3,877,402	3,795,867
Deferred income taxes	91,695	164,962
Other liabilities	275,795	290,178
Total liabilities	4,610,349	4,844,031
Commitments and contingencies
Total shareholders' equity	4,253,171	5,276,161
Noncontrolling interests	401,403	674,467
Total equity	4,654,574	5,950,628	$ 6,467,445	$ 7,422,230
Total liabilities and equity	9,264,923	10,794,659
Noble Corp
Current assets
Cash and cash equivalents	374,375	662,011
Accounts receivable	200,722	204,696
Taxes receivable	20,498	105,345
Short-term notes receivable from affiliates	0	0
Accounts receivable from affiliates	0	0
Prepaid expenses and other current assets	61,917	65,441
Total current assets	657,512	1,037,493
Property and equipment, at cost	10,956,412	12,034,331
Accumulated depreciation	(2,475,694)	(2,545,091)
Property and equipment, net	8,480,718	9,489,240
Notes receivable from affiliates	0	0
Investments in affiliates	0	0
Other assets	125,149	266,528
Total assets	9,263,379	10,793,261
Current liabilities
Short-term notes payables to affiliates	0	0
Current maturities of long-term debt	0	249,843
Accounts payable	125,237	83,873
Accrued payroll and related costs	50,284	54,904
Accounts payable to affiliates	0	0
Taxes payable	29,386	33,965
Interest payable	100,100	98,189
Other current liabilities	60,012	71,466
Total current liabilities	365,019	592,240
Long-term debt	3,877,402	3,795,867
Notes payable to affiliates	0	0
Deferred income taxes	91,695	164,962
Other liabilities	275,795	290,178
Total liabilities	4,609,911	4,843,247
Commitments and contingencies
Total shareholders' equity	4,252,065	5,275,547
Noncontrolling interests	401,403	674,467
Total equity	4,653,468	5,950,014	$ 6,391,977	$ 7,414,471
Total liabilities and equity	9,263,379	10,793,261
Noble Corp | Consolidating Adjustments
Current assets
Cash and cash equivalents	0	0
Accounts receivable	0	0
Taxes receivable	0	0
Short-term notes receivable from affiliates	(3,175,662)	(2,492,928)
Accounts receivable from affiliates	(5,160,674)	(7,080,817)
Prepaid expenses and other current assets	0	0
Total current assets	(8,336,336)	(9,573,745)
Property and equipment, at cost	0	0
Accumulated depreciation	0	0
Property and equipment, net	0	0
Notes receivable from affiliates	(5,145)	(9,495,662)
Investments in affiliates	(20,016,908)	(34,534,543)
Other assets	0	0
Total assets	(28,358,389)	(53,603,950)
Current liabilities
Short-term notes payables to affiliates	(3,175,662)	(2,492,928)
Current maturities of long-term debt		0
Accounts payable	0	0
Accrued payroll and related costs	0	0
Accounts payable to affiliates	(5,160,674)	(7,080,817)
Taxes payable	0	0
Interest payable	0	0
Other current liabilities	0	0
Total current liabilities	(8,336,336)	(9,573,745)
Long-term debt	0	0
Notes payable to affiliates	(5,145)	(9,495,662)
Deferred income taxes	0	0
Other liabilities	0	0
Total liabilities	(8,341,481)	(19,069,407)
Commitments and contingencies
Total shareholders' equity	(20,016,908)	(34,534,543)
Noncontrolling interests	0	0
Total equity	(20,016,908)	(34,534,543)
Total liabilities and equity	(28,358,389)	(53,603,950)
Noble Corp | Noble - Cayman | Reportable Legal Entities
Current assets
Cash and cash equivalents	0	11
Accounts receivable	0	0
Taxes receivable	0	0
Short-term notes receivable from affiliates	0	0
Accounts receivable from affiliates	275,726	594,456
Prepaid expenses and other current assets	0	0
Total current assets	275,726	594,467
Property and equipment, at cost	0	0
Accumulated depreciation	0	0
Property and equipment, net	0	0
Notes receivable from affiliates	5,145	3,177,248
Investments in affiliates	7,716,068	4,933,978
Other assets	609	2,663
Total assets	7,997,548	8,708,356
Current liabilities
Short-term notes payables to affiliates	0	0
Current maturities of long-term debt		0
Accounts payable	45	0
Accrued payroll and related costs	0	0
Accounts payable to affiliates	3,725,506	3,410,669
Taxes payable	0	0
Interest payable	3	2,211
Other current liabilities	0	0
Total current liabilities	3,725,554	3,412,880
Long-term debt	0	0
Notes payable to affiliates	0	0
Deferred income taxes	0	0
Other liabilities	19,929	19,929
Total liabilities	3,745,483	3,432,809
Commitments and contingencies
Total shareholders' equity	4,252,065	5,275,547
Noncontrolling interests	0	0
Total equity	4,252,065	5,275,547
Total liabilities and equity	7,997,548	8,708,356
Noble Corp | NHUS | Reportable Legal Entities
Current assets
Cash and cash equivalents		0
Accounts receivable		0
Taxes receivable		93,302
Short-term notes receivable from affiliates		0
Accounts receivable from affiliates		1,454
Prepaid expenses and other current assets		0
Total current assets		94,756
Property and equipment, at cost		0
Accumulated depreciation		0
Property and equipment, net		0
Notes receivable from affiliates		0
Investments in affiliates		4,550,358
Other assets		16,775
Total assets		4,661,889
Current liabilities
Short-term notes payables to affiliates		1,605,243
Current maturities of long-term debt		0
Accounts payable		0
Accrued payroll and related costs		0
Accounts payable to affiliates		393,073
Taxes payable		0
Interest payable		0
Other current liabilities		0
Total current liabilities		1,998,316
Long-term debt		0
Notes payable to affiliates		700,000
Deferred income taxes		0
Other liabilities		0
Total liabilities		2,698,316
Commitments and contingencies
Total shareholders' equity		1,963,573
Noncontrolling interests		0
Total equity		1,963,573
Total liabilities and equity		4,661,889
Noble Corp | NDH | Reportable Legal Entities
Current assets
Cash and cash equivalents		23,160
Accounts receivable		24,722
Taxes receivable		3
Short-term notes receivable from affiliates		119,476
Accounts receivable from affiliates		144,367
Prepaid expenses and other current assets		1,477
Total current assets		313,205
Property and equipment, at cost		857,784
Accumulated depreciation		(110,005)
Property and equipment, net		747,779
Notes receivable from affiliates		1,199,815
Investments in affiliates		5,252,135
Other assets		8,372
Total assets		7,521,306
Current liabilities
Short-term notes payables to affiliates		0
Current maturities of long-term debt		0
Accounts payable		1,467
Accrued payroll and related costs		4,780
Accounts payable to affiliates		1,770,066
Taxes payable		0
Interest payable		0
Other current liabilities		5,169
Total current liabilities		1,781,482
Long-term debt		0
Notes payable to affiliates		474,637
Deferred income taxes		5
Other liabilities		30,330
Total liabilities		2,286,454
Commitments and contingencies
Total shareholders' equity		5,234,852
Noncontrolling interests		0
Total equity		5,234,852
Total liabilities and equity		7,521,306
Noble Corp | NHIL | Reportable Legal Entities
Current assets
Cash and cash equivalents	17,818	29,324
Accounts receivable	0	0
Taxes receivable	0	0
Short-term notes receivable from affiliates	0	0
Accounts receivable from affiliates	61,046	60,945
Prepaid expenses and other current assets	0	0
Total current assets	78,864	90,269
Property and equipment, at cost	0	0
Accumulated depreciation	0	0
Property and equipment, net	0	0
Notes receivable from affiliates	0	0
Investments in affiliates	12,300,840	12,560,598
Other assets	0	0
Total assets	12,379,704	12,650,867
Current liabilities
Short-term notes payables to affiliates	3,175,662	0
Current maturities of long-term debt		249,843
Accounts payable	0	0
Accrued payroll and related costs	0	0
Accounts payable to affiliates	1,098,395	661,375
Taxes payable	0	0
Interest payable	99,997	83,960
Other current liabilities	0	0
Total current liabilities	4,374,054	995,178
Long-term debt	3,817,153	3,594,332
Notes payable to affiliates	0	3,175,663
Deferred income taxes	0	0
Other liabilities	0	0
Total liabilities	8,191,207	7,765,173
Commitments and contingencies
Total shareholders' equity	4,188,497	4,885,694
Noncontrolling interests	0	0
Total equity	4,188,497	4,885,694
Total liabilities and equity	12,379,704	12,650,867
Noble Corp | NDS6 | Reportable Legal Entities
Current assets
Cash and cash equivalents		0
Accounts receivable		0
Taxes receivable		0
Short-term notes receivable from affiliates		2,373,452
Accounts receivable from affiliates		465,749
Prepaid expenses and other current assets		1
Total current assets		2,839,202
Property and equipment, at cost		0
Accumulated depreciation		0
Property and equipment, net		0
Notes receivable from affiliates		3,943,299
Investments in affiliates		7,237,474
Other assets		0
Total assets		14,019,975
Current liabilities
Short-term notes payables to affiliates		0
Current maturities of long-term debt		0
Accounts payable		0
Accrued payroll and related costs		0
Accounts payable to affiliates		0
Taxes payable		0
Interest payable		12,018
Other current liabilities		0
Total current liabilities		12,018
Long-term debt		201,535
Notes payable to affiliates		0
Deferred income taxes		0
Other liabilities		0
Total liabilities		213,553
Commitments and contingencies
Total shareholders' equity		13,806,422
Noncontrolling interests		0
Total equity		13,806,422
Total liabilities and equity		14,019,975
Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Current assets
Cash and cash equivalents		609,516
Accounts receivable		179,974
Taxes receivable		12,040
Short-term notes receivable from affiliates		0
Accounts receivable from affiliates		5,813,846
Prepaid expenses and other current assets		63,963
Total current assets		6,679,339
Property and equipment, at cost		11,176,547
Accumulated depreciation		(2,435,086)
Property and equipment, net		8,741,461
Notes receivable from affiliates		1,175,300
Investments in affiliates		0
Other assets		238,718
Total assets		16,834,818
Current liabilities
Short-term notes payables to affiliates		887,685
Current maturities of long-term debt		0
Accounts payable		82,406
Accrued payroll and related costs		50,124
Accounts payable to affiliates		845,634
Taxes payable		33,965
Interest payable		0
Other current liabilities		66,297
Total current liabilities		1,966,111
Long-term debt		0
Notes payable to affiliates		5,145,362
Deferred income taxes		164,957
Other liabilities		239,919
Total liabilities		7,516,349
Commitments and contingencies
Total shareholders' equity		8,644,002
Noncontrolling interests		674,467
Total equity		9,318,469
Total liabilities and equity		$ 16,834,818
Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Current assets
Cash and cash equivalents	356,557
Accounts receivable	200,722
Taxes receivable	20,498
Short-term notes receivable from affiliates	3,175,662
Accounts receivable from affiliates	4,823,902
Prepaid expenses and other current assets	61,917
Total current assets	8,639,258
Property and equipment, at cost	10,956,412
Accumulated depreciation	(2,475,694)
Property and equipment, net	8,480,718
Notes receivable from affiliates	0
Investments in affiliates	0
Other assets	124,540
Total assets	17,244,516
Current liabilities
Short-term notes payables to affiliates	0
Accounts payable	125,192
Accrued payroll and related costs	50,284
Accounts payable to affiliates	336,773
Taxes payable	29,386
Interest payable	100
Other current liabilities	60,012
Total current liabilities	601,747
Long-term debt	60,249
Notes payable to affiliates	5,145
Deferred income taxes	91,695
Other liabilities	255,866
Total liabilities	1,014,702
Commitments and contingencies
Total shareholders' equity	15,828,411
Noncontrolling interests	401,403
Total equity	16,229,814
Total liabilities and equity	$ 17,244,516

Condensed Consolidating Finan_5

Condensed Consolidating Financial Information - Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements Captions [Line Items]
Operating revenues	$ 309,892	$ 279,408	$ 258,369	$ 235,157	$ 329,585	$ 266,212	$ 278,142	$ 362,976	$ 1,082,826	$ 1,236,915	$ 2,302,065
Depreciation and amortization									486,530	547,990	611,067
Operating costs and expenses
General and administrative									73,216	71,634	69,258
Loss on impairment									802,133	121,639	1,458,749
Total operating costs and expenses									2,028,900	1,402,635	3,062,262
Operating loss	(21,745)	(21,843)	(845,606)	(56,880)	(110,294)	(56,604)	(44,285)	(45,463)	(946,074)	(165,720)	(760,197)
Other income (expense)
Interest expense, net of amounts capitalized									(297,611)	(291,989)	(222,915)
Gain (loss) on extinguishment of debt, net									(1,793)	0	17,814
Interest income and other, net									8,302	7,897	(1,731)
Loss from continuing operations before income taxes									(1,237,176)	(449,812)	(967,029)
Income tax benefit (provision)									106,641	(42,629)	109,156
Net loss from continuing operations									(1,130,535)	(492,441)	(857,873)
Net loss from discontinued operations, net of tax									0	(1,486)	0
Net loss									(1,130,535)	(493,927)	(857,873)
Net income attributable to noncontrolling interests									245,485	(22,584)	(71,707)
Net income (loss) attributable to the company	(33,062)	$ (81,591)	$ (628,063)	$ (142,334)	$ (24,675)	$ (96,792)	$ (91,864)	$ (301,694)	(885,050)	(516,511)	(929,580)
Other comprehensive income, net									(8,644)	9,252	11,035
Comprehensive income (loss) attributable to the company									(893,694)	(507,259)	(918,545)
Noble Corp
Condensed Financial Statements Captions [Line Items]
Operating revenues									1,082,826	1,236,915	2,302,765
Depreciation and amortization									482,660	543,119	611,013
Operating costs and expenses
General and administrative									38,203	41,087	46,045
Loss on impairment									802,133	121,639	1,458,749
Total operating costs and expenses									1,988,208	1,364,763	3,033,218
Operating loss									(905,382)	(127,848)	(730,453)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations									0	0	0
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										0
Interest expense, net of amounts capitalized									(297,611)	(291,989)	(222,915)
Gain (loss) on extinguishment of debt, net									(1,793)	0	17,814
Interest income and other, net									8,282	7,733	(1,616)
Loss from continuing operations before income taxes									(1,196,504)	(412,104)	(937,170)
Income tax benefit (provision)									106,534	(42,595)	109,163
Net loss from continuing operations									(1,089,970)	(454,699)	(828,007)
Net loss from discontinued operations, net of tax									0	2,967	0
Net loss									(1,089,970)	(451,732)	(828,007)
Net income attributable to noncontrolling interests									245,485	(22,584)	(71,707)
Net income (loss) attributable to the company									(844,485)	(474,316)	(899,714)
Other comprehensive income, net									(8,644)	9,252	11,035
Comprehensive income (loss) attributable to the company									(853,129)	(465,064)	(888,679)
Noble Corp | Consolidating Adjustments
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	(47,886)	(94,697)
Depreciation and amortization									0	0	0
Operating costs and expenses
General and administrative									0	0	0
Loss on impairment									0	0	0
Total operating costs and expenses									0	(47,886)	(94,697)
Operating loss									0	0	0
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations									2,997,162	715,805	2,017,831
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										(7,533)
Interest expense, net of amounts capitalized									2,065,359	341,603	252,816
Gain (loss) on extinguishment of debt, net									0		0
Interest income and other, net									(2,065,359)	(341,603)	(252,816)
Loss from continuing operations before income taxes									2,997,162	708,272	2,017,831
Income tax benefit (provision)									0	0	0
Net loss from continuing operations										708,272
Net loss from discontinued operations, net of tax										0
Net loss									2,997,162	708,272	2,017,831
Net income attributable to noncontrolling interests									0	(1,995)	(32,413)
Net income (loss) attributable to the company									2,997,162	706,277	1,985,418
Other comprehensive income, net									8,644	(9,252)	(11,035)
Comprehensive income (loss) attributable to the company									3,005,806	697,025	1,974,383
Noble Corp | Noble - Cayman | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Depreciation and amortization									0	0	0
Operating costs and expenses
General and administrative									57	129	1,264
Loss on impairment									0	0	0
Total operating costs and expenses									59	433	5,796
Operating loss									(59)	(433)	(5,796)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations									(2,738,475)	(476,382)	(962,662)
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										2,967
Interest expense, net of amounts capitalized									(1,324)	(10,951)	(27,891)
Gain (loss) on extinguishment of debt, net									(2,336)		0
Interest income and other, net									1,897,709	10,483	96,635
Loss from continuing operations before income taxes									(844,485)	(474,316)	(899,714)
Income tax benefit (provision)									0	0	0
Net loss from continuing operations										(474,316)
Net loss from discontinued operations, net of tax										0
Net loss									(844,485)	(474,316)	(899,714)
Net income attributable to noncontrolling interests									0	0	0
Net income (loss) attributable to the company									(844,485)	(474,316)	(899,714)
Other comprehensive income, net									(8,644)	9,252	11,035
Comprehensive income (loss) attributable to the company									(853,129)	(465,064)	(888,679)
Noble Corp | NHUS | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										0	0
Depreciation and amortization										0	0
Operating costs and expenses
General and administrative										5,761	8,716
Loss on impairment										0	0
Total operating costs and expenses										17,851	27,618
Operating loss										(17,851)	(27,618)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations										(528,702)	(257,142)
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										4,566
Interest expense, net of amounts capitalized										(32,838)	(70,494)
Gain (loss) on extinguishment of debt, net											0
Interest income and other, net										(141)	120
Loss from continuing operations before income taxes										(574,966)	(355,134)
Income tax benefit (provision)										241,960	(42,522)
Net loss from continuing operations										(333,006)
Net loss from discontinued operations, net of tax										(1,598)
Net loss										(334,604)	(397,656)
Net income attributable to noncontrolling interests										0	0
Net income (loss) attributable to the company										(334,604)	(397,656)
Other comprehensive income, net										0	0
Comprehensive income (loss) attributable to the company										(334,604)	(397,656)
Noble Corp | NDH | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										172,035	259,239
Depreciation and amortization										58,236	91,802
Operating costs and expenses
General and administrative										0	0
Loss on impairment										45,012	0
Total operating costs and expenses										148,401	170,834
Operating loss										23,634	88,405
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations										82,596	(980,099)
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										0
Interest expense, net of amounts capitalized										(13,493)	(11,461)
Gain (loss) on extinguishment of debt, net											0
Interest income and other, net										87,287	12,616
Loss from continuing operations before income taxes										180,024	(890,539)
Income tax benefit (provision)										(440)	163
Net loss from continuing operations										179,584
Net loss from discontinued operations, net of tax										0
Net loss										179,584	(890,376)
Net income attributable to noncontrolling interests										0	0
Net income (loss) attributable to the company										179,584	(890,376)
Other comprehensive income, net										0	0
Comprehensive income (loss) attributable to the company										179,584	(890,376)
Noble Corp | NHIL | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Depreciation and amortization									0	0	0
Operating costs and expenses
General and administrative									214	1,588	40,082
Loss on impairment									0	0	0
Total operating costs and expenses									192	4,703	124,391
Operating loss									(192)	(4,703)	(124,391)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations									(258,687)	188,809	(333,446)
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										0
Interest expense, net of amounts capitalized									(449,824)	(430,580)	(228,423)
Gain (loss) on extinguishment of debt, net									12,651		17,814
Interest income and other, net									(74)	4,771	20,412
Loss from continuing operations before income taxes									(696,126)	(241,703)	(648,034)
Income tax benefit (provision)									0	0	0
Net loss from continuing operations										(241,703)
Net loss from discontinued operations, net of tax										0
Net loss									(696,126)	(241,703)	(648,034)
Net income attributable to noncontrolling interests									0	0	0
Net income (loss) attributable to the company									(696,126)	(241,703)	(648,034)
Other comprehensive income, net									0	0	0
Comprehensive income (loss) attributable to the company									(696,126)	(241,703)	(648,034)
Noble Corp | NDS6 | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										0	0
Depreciation and amortization										0	0
Operating costs and expenses
General and administrative										9	1
Loss on impairment										0	0
Total operating costs and expenses										9	1
Operating loss										(9)	(1)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations										17,874	515,518
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										0
Interest expense, net of amounts capitalized										(15,288)	(15,117)
Gain (loss) on extinguishment of debt, net											0
Interest income and other, net										224,772	15,058
Loss from continuing operations before income taxes										227,349	515,458
Income tax benefit (provision)										0	0
Net loss from continuing operations										227,349
Net loss from discontinued operations, net of tax										0
Net loss										227,349	515,458
Net income attributable to noncontrolling interests										0	0
Net income (loss) attributable to the company										227,349	515,458
Other comprehensive income, net										0	0
Comprehensive income (loss) attributable to the company										227,349	515,458
Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										1,112,766	2,138,223
Depreciation and amortization										484,883	519,211
Operating costs and expenses
General and administrative										33,600	(4,018)
Loss on impairment										76,627	1,458,749
Total operating costs and expenses										1,241,252	2,799,275
Operating loss										(128,486)	(661,052)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations										0	0
Income (loss) of unconsolidated affiliates - discontinued operations, net of tax										0
Interest expense, net of amounts capitalized										(130,442)	(122,345)
Gain (loss) on extinguishment of debt, net											0
Interest income and other, net										22,164	106,359
Loss from continuing operations before income taxes										(236,764)	(677,038)
Income tax benefit (provision)										(284,115)	151,522
Net loss from continuing operations										(520,879)
Net loss from discontinued operations, net of tax										4,565
Net loss										(516,314)	(525,516)
Net income attributable to noncontrolling interests										(20,589)	(39,294)
Net income (loss) attributable to the company										(536,903)	(564,810)
Other comprehensive income, net										9,252	11,035
Comprehensive income (loss) attributable to the company										(527,651)	(553,775)
Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									1,082,826
Depreciation and amortization									482,660
Operating costs and expenses
General and administrative									37,932
Loss on impairment									802,133
Total operating costs and expenses									1,987,957
Operating loss									(905,131)
Other income (expense)
Income (loss) of unconsolidated affiliates - continuing operations									0
Interest expense, net of amounts capitalized									(1,911,822)
Gain (loss) on extinguishment of debt, net									(12,108)
Interest income and other, net									176,006
Loss from continuing operations before income taxes									(2,653,055)
Income tax benefit (provision)									106,534
Net loss									(2,546,521)
Net income attributable to noncontrolling interests									245,485
Net income (loss) attributable to the company									(2,301,036)
Other comprehensive income, net									(8,644)
Comprehensive income (loss) attributable to the company									(2,309,680)
Contract drilling services
Condensed Financial Statements Captions [Line Items]
Operating revenues	$ 292,049								1,036,082	1,207,026	2,242,200
Cost of services									629,937	642,937	877,689
Contract drilling services | Noble Corp
Condensed Financial Statements Captions [Line Items]
Operating revenues									1,036,082	1,207,026	2,242,200
Cost of services									628,128	640,483	871,912
Contract drilling services | Noble Corp | Consolidating Adjustments
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	(47,886)	(94,697)
Cost of services									0	(47,886)	(94,697)
Contract drilling services | Noble Corp | Noble - Cayman | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Cost of services									2	304	4,532
Contract drilling services | Noble Corp | NHUS | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										0	0
Cost of services										12,090	18,902
Contract drilling services | Noble Corp | NDH | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										168,592	250,049
Cost of services										43,161	70,801
Contract drilling services | Noble Corp | NHIL | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Cost of services									(22)	3,115	84,309
Contract drilling services | Noble Corp | NDS6 | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										0	0
Cost of services										0	0
Contract drilling services | Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										1,086,320	2,086,848
Cost of services										629,699	788,065
Contract drilling services | Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									1,036,082
Cost of services									628,148
Reimbursables and other
Condensed Financial Statements Captions [Line Items]
Operating revenues									46,744	29,889	59,865
Cost of services									37,084	18,435	45,499
Reimbursables and other | Noble Corp
Condensed Financial Statements Captions [Line Items]
Operating revenues									46,744	29,889	60,565
Cost of services									37,084	18,435	45,499
Reimbursables and other | Noble Corp | Consolidating Adjustments
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Cost of services									0	0	0
Reimbursables and other | Noble Corp | Noble - Cayman | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Cost of services									0	0	0
Reimbursables and other | Noble Corp | NHUS | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										0	0
Cost of services										0	0
Reimbursables and other | Noble Corp | NDH | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										3,443	9,190
Cost of services										1,992	8,231
Reimbursables and other | Noble Corp | NHIL | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									0	0	0
Cost of services									0	0	0
Reimbursables and other | Noble Corp | NDS6 | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										0	0
Cost of services										0	0
Reimbursables and other | Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues										26,446	51,375
Cost of services										$ 16,443	$ 37,268
Reimbursables and other | Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Condensed Financial Statements Captions [Line Items]
Operating revenues									46,744
Cost of services									$ 37,084

Condensed Consolidating Finan_6

Condensed Consolidating Financial Information - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net cash provided by operating activities	$ 171,851	$ 416,675	$ 1,142,740
Cash flows from investing activities
Proceeds from disposal of assets	5,402	2,382	24,808
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
Cash flows from financing activities
Issuance of senior notes	750,000	0	980,100
Repayment of long-term debt	(972,708)	(300,000)	(1,049,338)
Tender offer premium	0	0	(24,649)
Debt issuance costs on senior notes and credit facilities	(15,639)	(42)	(12,111)
Dividends paid to noncontrolling interests	(27,579)	(56,881)	(85,944)
Net cash used in financing activities	(269,396)	(361,243)	(242,668)
Net increase (decrease) in cash, cash equivalents and restricted cash	(286,922)	(62,893)	213,477
Cash, cash equivalents and restricted cash, beginning of period	662,829	725,722	512,245
Cash, cash equivalents and restricted cash, end of period	375,907	662,829	725,722
Noble Corp
Cash flows from operating activities
Net cash provided by operating activities	212,759	455,074	1,172,935
Cash flows from investing activities
Capital expenditures	(194,779)	(120,707)	(711,403)
Proceeds from disposal of assets	5,402	2,382	24,808
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
Cash flows from financing activities
Issuance of senior notes	750,000	0	980,100
Repayment of long-term debt	(972,708)	(300,000)	(1,049,338)
Tender offer premium	0	0	(24,649)
Debt issuance costs on senior notes and credit facilities	(15,639)	(42)	(12,111)
Dividends paid to noncontrolling interests	(27,579)	(56,881)	(85,944)
Contributions (distributions) from (to) parent company, net	(44,417)	28,352	(152,360)
Advances (to) from affiliates	0	0	0
Net cash used in financing activities	(310,343)	(328,571)	(344,302)
Net increase (decrease) in cash, cash equivalents and restricted cash	(286,961)	8,178	142,038
Cash, cash equivalents and restricted cash, beginning of period	662,011	653,833	511,795
Cash, cash equivalents and restricted cash, end of period	375,050	662,011	653,833
Noble Corp | Consolidating Adjustments
Cash flows from operating activities
Net cash provided by operating activities	0	0	0
Cash flows from investing activities
Capital expenditures	0	0	0
Proceeds from disposal of assets	0	0	0
Net cash used in investing activities	0	0	0
Cash flows from financing activities
Issuance of senior notes	0		0
Repayment of long-term debt	0	0	0
Tender offer premium			0
Debt issuance costs on senior notes and credit facilities	0	0	0
Dividends paid to noncontrolling interests	0	0	0
Contributions (distributions) from (to) parent company, net	0	0	0
Advances (to) from affiliates	0	0	0
Net cash used in financing activities	0	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0	0
Cash, cash equivalents and restricted cash, beginning of period	0	0	0
Cash, cash equivalents and restricted cash, end of period	0	0	0
Noble Corp | Noble - Cayman | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities	1,920,724	32,195	97,388
Cash flows from investing activities
Capital expenditures	0	0	0
Proceeds from disposal of assets	0	0	0
Net cash used in investing activities	0	0	0
Cash flows from financing activities
Issuance of senior notes	0		0
Repayment of long-term debt	0	0	0
Tender offer premium			0
Debt issuance costs on senior notes and credit facilities	(845)	0	0
Dividends paid to noncontrolling interests	0	0	0
Contributions (distributions) from (to) parent company, net	(44,417)	28,352	(152,360)
Advances (to) from affiliates	(1,875,473)	(63,073)	55,882
Net cash used in financing activities	(1,920,735)	(34,721)	(96,478)
Net increase (decrease) in cash, cash equivalents and restricted cash	(11)	(2,526)	910
Cash, cash equivalents and restricted cash, beginning of period	11	2,537	1,627
Cash, cash equivalents and restricted cash, end of period	0	11	2,537
Noble Corp | NHUS | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities		100,883	(150,735)
Cash flows from investing activities
Capital expenditures		0	0
Proceeds from disposal of assets		0	0
Net cash used in investing activities		0	0
Cash flows from financing activities
Issuance of senior notes			0
Repayment of long-term debt		0	0
Tender offer premium			0
Debt issuance costs on senior notes and credit facilities		0	0
Dividends paid to noncontrolling interests		0	0
Contributions (distributions) from (to) parent company, net		0	0
Advances (to) from affiliates		(100,883)	150,735
Net cash used in financing activities		(100,883)	150,735
Net increase (decrease) in cash, cash equivalents and restricted cash		0	0
Cash, cash equivalents and restricted cash, beginning of period	0	0	0
Cash, cash equivalents and restricted cash, end of period		0	0
Noble Corp | NDH | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities		209,898	149,431
Cash flows from investing activities
Capital expenditures		(3,622)	(492,985)
Proceeds from disposal of assets		46	0
Net cash used in investing activities		(3,576)	(492,985)
Cash flows from financing activities
Issuance of senior notes			0
Repayment of long-term debt		0	0
Tender offer premium			0
Debt issuance costs on senior notes and credit facilities		0	0
Dividends paid to noncontrolling interests		0	0
Contributions (distributions) from (to) parent company, net		0	0
Advances (to) from affiliates		(194,017)	352,308
Net cash used in financing activities		(194,017)	352,308
Net increase (decrease) in cash, cash equivalents and restricted cash		12,305	8,754
Cash, cash equivalents and restricted cash, beginning of period	23,160	10,855	2,101
Cash, cash equivalents and restricted cash, end of period		23,160	10,855
Noble Corp | NHIL | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities	(426,298)	(403,391)	(344,112)
Cash flows from investing activities
Capital expenditures	0	0	0
Proceeds from disposal of assets	0	0	0
Net cash used in investing activities	0	0	0
Cash flows from financing activities
Issuance of senior notes	750,000		980,100
Repayment of long-term debt	(759,053)	(300,000)	(1,049,338)
Tender offer premium			(24,649)
Debt issuance costs on senior notes and credit facilities	(13,027)	(42)	(12,111)
Dividends paid to noncontrolling interests	0	0	0
Contributions (distributions) from (to) parent company, net	0	0	0
Advances (to) from affiliates	436,872	732,757	450,110
Net cash used in financing activities	414,792	432,715	344,112
Net increase (decrease) in cash, cash equivalents and restricted cash	(11,506)	29,324	0
Cash, cash equivalents and restricted cash, beginning of period	29,324	0	0
Cash, cash equivalents and restricted cash, end of period	17,818	29,324	0
Noble Corp | NDS6 | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities		217,080	(60)
Cash flows from investing activities
Capital expenditures		0	0
Proceeds from disposal of assets		0	0
Net cash used in investing activities		0	0
Cash flows from financing activities
Issuance of senior notes			0
Repayment of long-term debt		0	0
Tender offer premium			0
Debt issuance costs on senior notes and credit facilities		0	0
Dividends paid to noncontrolling interests		0	0
Contributions (distributions) from (to) parent company, net		0	0
Advances (to) from affiliates		(217,080)	60
Net cash used in financing activities		(217,080)	60
Net increase (decrease) in cash, cash equivalents and restricted cash		0	0
Cash, cash equivalents and restricted cash, beginning of period	0	0	0
Cash, cash equivalents and restricted cash, end of period		0	0
Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities		298,409	1,421,023
Cash flows from investing activities
Capital expenditures		(117,085)	(218,418)
Proceeds from disposal of assets		2,336	24,808
Net cash used in investing activities		(114,749)	(193,610)
Cash flows from financing activities
Issuance of senior notes			0
Repayment of long-term debt		0	0
Tender offer premium			0
Debt issuance costs on senior notes and credit facilities		0	0
Dividends paid to noncontrolling interests		(56,881)	(85,944)
Contributions (distributions) from (to) parent company, net		0	0
Advances (to) from affiliates		(157,704)	(1,009,095)
Net cash used in financing activities		(214,585)	(1,095,039)
Net increase (decrease) in cash, cash equivalents and restricted cash		(30,925)	132,374
Cash, cash equivalents and restricted cash, beginning of period	609,516	640,441	508,067
Cash, cash equivalents and restricted cash, end of period		609,516	$ 640,441
Noble Corp | Other Non-guarantor Subsidiaries of Noble | Reportable Legal Entities
Cash flows from operating activities
Net cash provided by operating activities	(1,281,667)
Cash flows from investing activities
Capital expenditures	(194,779)
Proceeds from disposal of assets	5,402
Net cash used in investing activities	(189,377)
Cash flows from financing activities
Issuance of senior notes	0
Repayment of long-term debt	(213,655)
Debt issuance costs on senior notes and credit facilities	(1,767)
Dividends paid to noncontrolling interests	(27,579)
Contributions (distributions) from (to) parent company, net	0
Advances (to) from affiliates	1,438,601
Net cash used in financing activities	1,195,600
Net increase (decrease) in cash, cash equivalents and restricted cash	(275,444)
Cash, cash equivalents and restricted cash, beginning of period	632,676
Cash, cash equivalents and restricted cash, end of period	$ 357,232	$ 632,676

Condensed Consolidating Finan_7

Condensed Consolidating Financial Information - Prior Period Adjustments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	$ 171,851	$ 416,675	$ 1,142,740
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	212,759	455,074	1,172,935
Capital expenditures	(194,779)	(120,707)	(711,403)
Net cash used in investing activities	(189,377)	(118,325)	(686,595)
Reportable Legal Entities | Noble - Cayman | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	1,920,724	32,195	97,388
Capital expenditures	0	0	0
Net cash used in investing activities	0	0	0
Reportable Legal Entities | NHUS | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		100,883	(150,735)
Capital expenditures		0	0
Net cash used in investing activities		0	0
Reportable Legal Entities | NDH | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		209,898	149,431
Capital expenditures		(3,622)	(492,985)
Net cash used in investing activities		(3,576)	(492,985)
Reportable Legal Entities | NHIL | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	(426,298)	(403,391)	(344,112)
Capital expenditures	0	0	0
Net cash used in investing activities	0	0	0
Reportable Legal Entities | NDS6 | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		217,080	(60)
Capital expenditures		0	0
Net cash used in investing activities		0	0
Reportable Legal Entities | Other Non-guarantor Subsidiaries of Noble | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		298,409	1,421,023
Capital expenditures		(117,085)	(218,418)
Net cash used in investing activities		(114,749)	(193,610)
Consolidating Adjustments | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	0	0	0
Capital expenditures	0	0	0
Net cash used in investing activities	$ 0	0	0
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		453,938	1,126,076
Net cash used in investing activities		(155,588)	(669,931)
As Reported | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		492,337	1,156,271
Capital expenditures		(157,970)	(694,739)
Net cash used in investing activities		(155,588)	(669,931)
As Reported | Reportable Legal Entities | Noble - Cayman | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		32,195	97,388
Capital expenditures		0	0
Net cash used in investing activities		0	0
As Reported | Reportable Legal Entities | NHUS | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		100,883	(150,735)
Capital expenditures		0	0
Net cash used in investing activities		0	0
As Reported | Reportable Legal Entities | NDH | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		209,898	149,431
Capital expenditures		(3,622)	(492,985)
Net cash used in investing activities		(3,576)	(492,985)
As Reported | Reportable Legal Entities | NHIL | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		(403,391)	(344,112)
Capital expenditures		0	0
Net cash used in investing activities		0	0
As Reported | Reportable Legal Entities | NDS6 | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		217,080	(60)
Capital expenditures		0	0
Net cash used in investing activities		0	0
As Reported | Reportable Legal Entities | Other Non-guarantor Subsidiaries of Noble | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		335,672	1,404,359
Capital expenditures		(154,348)	(201,754)
Net cash used in investing activities		(152,012)	(176,946)
As Reported | Consolidating Adjustments | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		0	0
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		(37,263)	16,664
Net cash used in investing activities		37,263	(16,664)
Adjustment | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		(37,263)	16,664
Capital expenditures		37,263	(16,664)
Net cash used in investing activities		37,263	(16,664)
Adjustment | Reportable Legal Entities | Noble - Cayman | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		0	0
Adjustment | Reportable Legal Entities | NHUS | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		0	0
Adjustment | Reportable Legal Entities | NDH | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		0	0
Adjustment | Reportable Legal Entities | NHIL | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		0	0
Adjustment | Reportable Legal Entities | NDS6 | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		0	0
Adjustment | Reportable Legal Entities | Other Non-guarantor Subsidiaries of Noble | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		(37,263)	16,664
Capital expenditures		37,263	(16,664)
Net cash used in investing activities		37,263	(16,664)
Adjustment | Consolidating Adjustments | Noble Corp
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		0	0
Capital expenditures		0	0
Net cash used in investing activities		$ 0	$ 0

Unaudited Interim Financial D_3

Unaudited Interim Financial Data - Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Operating revenues	$ 309,892	$ 279,408	$ 258,369	$ 235,157	$ 329,585	$ 266,212	$ 278,142	$ 362,976	$ 1,082,826	$ 1,236,915	$ 2,302,065
Operating loss	(21,745)	(21,843)	(845,606)	(56,880)	(110,294)	(56,604)	(44,285)	(45,463)	(946,074)	(165,720)	(760,197)
Net loss from continuing operations	$ (33,062)	$ (81,591)	$ (628,063)	$ (142,334)	(24,675)	(96,792)	(91,864)	(301,694)	(885,050)	(516,511)	(929,580)
Net loss from discontinued operations, net of tax					$ 0	$ 0	$ (1,486)	$ 0	$ 0	$ (1,486)	$ 0
Basic:
Loss from continuing operations (usd per share)	$ (0.13)	$ (0.33)	$ (2.55)	$ (0.58)	$ (0.10)	$ (0.40)	$ (0.37)	$ (1.24)	$ (3.59)	$ (2.10)	$ (3.82)
Loss from discontinued operations (usd per share)					0	0	(0.01)	0	0	(0.01)	0
Diluted:
Loss from continuing operations (usd per share)	$ (0.13)	$ (0.33)	$ (2.55)	$ (0.58)	(0.10)	(0.40)	(0.37)	(1.24)	(3.59)	(2.10)	(3.82)
Loss from discontinued operations (usd per share)					$ 0	$ 0	$ (0.01)	$ 0	$ 0	$ (0.01)	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	Feb. 14, 2019	Sep. 21, 2018
Subsequent Event | Seller financed loan due February 2023
Subsequent Event [Line Items]
Financed value	$ 53.8
Subsequent Event | Seller Financing | Seller financed loan due February 2023
Subsequent Event [Line Items]
Cash paid to acquire asset	30.1
Rig
Subsequent Event [Line Items]
Purchase price of asset acquired		$ 93.8
Rig | Subsequent Event
Subsequent Event [Line Items]
Purchase price of asset acquired	$ 83.8

Uncategorized Items - ne-201812

Label	Element	Value
Noble Corporation [Member]
Tax Cuts And Jobs Act Of 2017, Reclassification From Aoci To Retained Earnings, Tax Effect	ne_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	$ 0
AOCI Attributable to Parent [Member] | Noble Corporation [Member]
Tax Cuts And Jobs Act Of 2017, Reclassification From Aoci To Retained Earnings, Tax Effect	ne_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	(5,540,000)
Retained Earnings [Member] | Noble Corporation [Member]
Tax Cuts And Jobs Act Of 2017, Reclassification From Aoci To Retained Earnings, Tax Effect	ne_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	$ 5,540,000