6-K

Liabilities subject to compromise

Note 4 – Liabilities subject to compromise


(In $ millions)	June 30, 2018		December 31, 2017
Senior undersecured or impaired external debt		5,266		5,371
Unsecured bonds		2,334		2,334
Newbuild global settlement agreement		1,064		1,064
Derivatives previously recorded at fair value		249		249
Accounts payable and other liabilities		84		103
Accrued interest payable		49		50
Amount due to related party		4		20

Total liabilities subject to compromise		9,050		9,191

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Segment information

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Segment information

Note 5 – Segment information

Operating segments

We provide drilling and related services to the offshore oil and gas industry. We have been organized into three operating segments:

Other: Operations including management services to third parties and related parties. Income and expenses from these management services are classified under this segment.

Segment results are evaluated on the basis of operating income, and the information given below is based on information used for internal management reporting.

Total operating revenue


(In $ millions)	Six Months Ended June 30,
	2018		2017
Floaters		482		744
Jack-ups		193		360
Other		37		42

Total operating revenue		712		1,146

Depreciation and amortization


(In $ millions)	Six Months Ended June 30,
	2018		2017
Floaters		298		301
Jack-ups		93		105

Total		391		406

Operating loss - Net loss


(In $ millions)	Six Months Ended June 30,
	2018			2017
Floaters		(446	)		95
Jack-ups		(167	)		(115	)
Other		—			3

Operating loss		(613	)		(17	)

Unallocated items:
Total financial items and other		14			(96	)
Income taxes		(36	)		12

Net loss		(635	)		(101	)

Drilling units and Newbuildings - Total assets


(In $ millions)	June 30, 2018		December 31, 2017
Floaters		9,411		9,956
Jack-ups		3,369		3,508

Total drilling units and newbuildings		12,780		13,464

Unallocated items:
Assets held for sale		—		126
Investments in associated companies		1,615		1,473
Marketable securities		121		124
Cash and restricted cash		1,218		1,359
Other assets		1,311		1,436

Total assets		17,045		17,982

Drilling units and Newbuildings - Capital expenditures


(In $ millions)	Six Months Ended June 30,
	2018		2017
Floaters		93		54
Jack-ups		24		12

Total		117		66

Geographic segment data

Revenues


(In US$ millions)	Six Months Ended June 30,
	2018		2017
Brazil		188		197
Nigeria		105		110
Angola		100		249
Norway		82		115
Saudi Arabia		79		80
United States		30		187
Others ⁽¹⁾		128		208

Total		712		1,146

⁽¹⁾	Other countries represent countries in which we operate that individually had revenues representing less than 10% of total revenues earned for any of the periods presented.

Major Customers

We had the following customers with contract revenues greater than 10% in any of the periods presented:


(In US$ millions)	Six Months Ended June 30,
	2018			2017
Petroleo Brasileiro S.A (“Petrobras”)		27	%		17	%
Total S.A Group (“Total”)		20	%		22	%
Saudi Aramco		12	%		8	%
Exxon Mobil Corp (“Exxon”)		11	%		7	%
LLOG		5	%		18	%

Fixed assets – drilling units ⁽¹⁾


(In US$ millions)	As at June 30, 2018		As at December 31, 2017
Brazil		2,405		1,816
Norway		2,331		2,258
Malaysia		1,445		1,809
Spain		1,344		2,016
United States		1,239		1,266
Other ⁽²⁾		3,767		4,051

Total		12,531		13,216

⁽¹⁾

⁽²⁾	“Other countries” represent countries in which we operate that individually had fixed assets representing less than 10% of total fixed assets for any of the periods presented.

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Revenue from Contracts with Customers

6 Months Ended

Jun. 30, 2018

Revenue from Contract with Customer [Abstract]

Revenue from Contracts with Customers

Note 6 – Revenue from Contracts with Customers

Contract Balances

The following table provides information about receivables, contract assets and contract liabilities from our contracts with customers:


(In $ millions)	June 30, 2018			January 1, 2018
Accounts receivable, net		272			295
Current contract assets ⁽¹⁾		9			7
Current contract liabilities (deferred revenue) ⁽¹⁾		(25	)		(37	)
Non-current contract liabilities (deferred revenue) ⁽¹⁾		(7	)		(18	)

⁽¹⁾	Current contract asset and liability balances are included in “other current assets” and “other current liabilities,” respectively in our unaudited Consolidated Balance Sheet as of June 30, 2018.

Significant changes in the contract assets and the contract liabilities balances during the period are as follows:


(In $ millions)	Net Contract Balances
Contract assets at January 1, 2018		7
Contract liabilities at January 1, 2018		(55	)

Net contract liability at January 1, 2018		(48	)

Decrease due to amortization of revenue that was included in the beginning contract liability balance		25
Increase due to cash received, excluding amounts recognized as revenue		(9	)
Decrease due to recognized during the period but contingent on future performance		9

Net contract liability at June 30, 2018		(23	)

Contract assets at June 30, 2018		9
Contract liabilities at June 30, 2018		(32	)

Deferred Contract Costs

Transaction Price Allocated to Remaining Performance Obligations

The following table reflects revenue expected to be recognized in the future related to unsatisfied performance obligations as of June 30, 2018:


	For the Years Ending December 31,
(In $ millions)	2018⁽¹⁾			2019			Total
Deferred mobilization revenue		(11	)		(18	)		(29	)
Other deferred revenue		(2	)		(1	)		(3	)
Total		(13	)		(19	)		(32	)

⁽¹⁾

Represents the six-month period beginning July 1, 2018.

The revenue included above consists primarily of expected mobilization and upgrade revenue for both wholly and partially unsatisfied performance obligations as well as expected variable mobilization and upgrade revenue for partially unsatisfied performance obligations, which has been estimated for purposes of allocating across the entire corresponding 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 June 30, 2018. The actual timing of recognition of such amounts may vary due to factors outside of our control.

Impact of Topic 606 on Financial Statement Line Items

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Reorganization items

6 Months Ended

Jun. 30, 2018

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Reorganization items

Note 7 – Reorganization items


(In $ millions)	Six Months Ended June 30, 2018
Advisory and professional fees		(115	)
Interest income on surplus cash invested		6

Total reorganization items		(109	)

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Loss on disposals and contingent consideration

6 Months Ended

Jun. 30, 2018

Loss on disposals and contingent consideration

Note 8 - Loss on disposals and contingent consideration


(In $ millions)	Six Months Ended June 30,
	2018		2017
Loss on disposals
Loss on disposal of West Triton to Shelf Drilling		—		(34	)
Loss on disposal of West Resolute to Shelf Drilling		—		(61	)
Loss on disposal of West Mischief to Shelf Drilling		—		(71	)

Total loss on disposals		—		(166	)

Contingent Consideration realized
West Polaris earn out realized		—		4
West Vela earn out realized		7		7

Total contingent consideration recognized		7		11

Disposal of West Triton, West Resolute and West Mischief

West Polaris contingent consideration

West Vela contingent consideration

Our accounting policy is not to recognize contingent consideration before it is considered realizable and has therefore not recognized on disposal any amounts receivable relating to the elements of consideration which are contingent on future events. From the disposal date of the West Vela on November 4, 2014 to June 30, 2018, we have recognized $45 million in contingent consideration, as it became realized, within “Contingent consideration realized” on the Consolidated Statement of Operations.

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Taxation	6 Months Ended
Taxation	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Taxation	Note 9 – Taxation The income tax expense increased by $48 million for the six months ended June 30, 2018 with an expense of $36 million as compared to a benefit of $12 million for the six months ended June 30, 2017. The tax provision for the first six months of 2018 has been prepared based on the actual results for the period rather than using the estimated results for the entirety of 2018. This is on the basis that it is known that due to the emergence from bankruptcy protection in early July, the results for the rest of 2018 reflect a series of adjustments arising from fresh start accounting that are not reliably estimable. The income tax expense for the six months ended June 30, 2018 of $36 million includes an increase in uncertain tax positions of $8 million and an $18 million tax expense due to an adjustment in the income tax charge for a subsidiary related to prior years. The Company considers the effect of this prior period correction not to be material in the context of the overall results for the current or prior periods. In the first six months of 2017 there was a net benefit in the tax expense due to a reduction in uncertain tax positions which did not recur and also a benefit following the submission of a tax return in respect of a prior year. Companies in the group are subject to taxation in various jurisdictions. Tax authorities in certain jurisdictions examine the tax returns and some have issued assessments. Companies in the group are defending the tax positions in those jurisdictions. The Brazilian tax authorities have issued a series of assessments with respect to our returns for certain years up to 2012 for an aggregate amount equivalent to $161 million including interest and penalties. The relevant group companies are robustly contesting these assessments including filing relevant appeals. An adverse outcome on these proposed assessments could result in a material adverse impact on our consolidated statement of financial position, results of operations or cash flows. The Nigerian tax authorities have issued a series of claims and assessments both directly and lodged through the Chapter 11 process with respect to returns for subsidiaries for certain years up to 2016 for an aggregate amount equivalent to $171 million. The relevant group companies are robustly contesting these assessments including filing relevant appeals in Nigeria and it is also intended that one or more formal objections against these claims for distribution purposes will be filed in the US court. An adverse outcome on these proposed assessments could result in a material adverse impact on our consolidated statement of financial position, results of operations or cash flows.

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Earnings per share

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

Earnings per share

Note 10 – Earnings per share

The components of the numerator for the calculation of basic and diluted EPS are as follows:


(In $ millions)	Six Months Ended June 30,
	2018			2017
Net loss		(477	)		(78	)
Less: Allocation to participating securities		—			—

Net loss available to shareholders		(477	)		(78	)

Effect of dilution		—			—

Diluted net loss available to shareholders		(477	)		(78	)

The components of the denominator for the calculation of basic and diluted EPS are as follows:


(In millions)	Six Months Ended June 30,
	2018			2017
Basic earnings per share:
Weighted average number of common shares outstanding		504			504
Diluted earnings per share:
Weighted average number of common shares outstanding		504			504
Effect of dilutive share options ⁽¹⁾		—			—
Effect of dilutive convertible bonds		—			—

Weighted average number of common shares outstanding adjusted for the effects of dilution		504			504

Basic (loss)/income per share (US dollar)		(0.95	)		(0.16	)

Diluted (loss)/income per share (US dollar)		(0.95	)		(0.16	)

⁽¹⁾	Certain stock options have been excluded from the calculation of diluted EPS because their exercise price exceeded our average share price during the calculation period.

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Cash and cash equivalents

6 Months Ended

Jun. 30, 2018

Cash and Cash Equivalents [Abstract]

Cash and cash equivalents

Note 11 – Cash and cash equivalents


(In $ millions)	June 30, 2018		December 31, 2017
Cash and cash equivalents		809		1,255
Restricted cash⁽¹⁾		409		104

Total		1,218		1,359

⁽¹⁾

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Marketable securities

6 Months Ended

Jun. 30, 2018

Investments, Debt and Equity Securities [Abstract]

Marketable securities

Note 12 – Marketable securities


(In $ millions)	June 30, 2018		December 31, 2017
Seadrill Partners —Common units		91		96
Archer		30		28

Total marketable securities		121		124


(In $ millions)	Six Months Ended June 30,

	2018
Seadrill Partners—Common Units—unrealized loss on marketable securities		(5	)
Archer—unrealized gain on marketable securities		2

Total unrealized loss on marketable securities		(3	)


(In $ millions)	Six Months Ended June 30,
	2017
Seadrill Partners—Common Units—unrealized loss on marketable securities		(21	)
Archer—unrealized gain on marketable securities		27

Total unrealized gain on marketable securities		6

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Accounts receivable	6 Months Ended
Accounts receivable	Jun. 30, 2018
Receivables [Abstract]
Accounts receivable	Note 13 – Accounts receivable Accounts receivable are presented net of allowances for doubtful accounts. The allowance for doubtful accounts receivables at June 30, 2018 was $83 million (December 31, 2017: $35 million). We recognized $48 million of bad debt expense for the six months ended June 30, 2018 (nil in the six months ended June 30, 2017).

Investments, Debt and Equity Securities [Abstract]

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

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Investment in associated companies

6 Months Ended

Jun. 30, 2018

Investment in associated companies

Note 14 – Investment in associated companies

We have the following investments that are either recorded using the equity method or at cost less impairment for the periods presented in these Consolidated Financial Statements:


(In $ millions)	June 30, 2018		December 31, 2017
Seabras Sapura Participacoes		76		63
Seabras Sapura Holdco		334		290
Seadrill Partners—Total direct ownership interests		914		857
Seadrill Partners—Subordinated units		120		97
Seadrill Partners—Seadrill member interest and IDRs ⁽¹⁾		64		64
SeaMex Ltd		107		102

Total investment in associated companies		1,615		1,473

⁽¹⁾	The Seadrill Partners—Seadrill member interest and Incentive Distribution Rights (“IDRs”) are recorded at cost less impairment on the basis that they do not represent common stock interests and their fair value is not readily determinable.

Seadrill Partners

Equity method investments

For the six months ended June 30, 2018, no other than temporary impairment has been identified.

Investments recorded at cost less impairment

For the six months ended June 30, 2018, no impairment has been identified.

SeaMex Limited

For the six months ended June 30, 2018, no other than temporary impairment has been identified.

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Property plant and equipment

6 Months Ended

Jun. 30, 2018

Newbuildings [Member]

Note 15 – Newbuildings


(In $ millions)	As at June 30, 2018		As at December 31, 2017
Total Newbuildings		249		248

Drilling Unit [Member]

Note 16 – Drilling units


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Cost		17,452			17,335
Accumulated depreciation		(4,507	)		(4,119	)
Impairment		(414	)		—

Net book value		12,531			13,216

The depreciation expense on drilling units was $388 million for the six months ended June 30, 2018, and $392 million for the six months ended June 30, 2017.

In addition, the depreciation expense on equipment was $3 million for the six months ended June 30, 2018, and $14 million for the six months ended June 30, 2017.

Impairment of long-lived assets

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Debt

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Debt

Note 17 – Debt


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Credit facilities:
$2,000 facility (North Atlantic Drilling) ⁽¹⁾		880			897
$400 facility ⁽¹⁾		130			133
$440 facility ⁽¹⁾		60			62
$1,450 facility ⁽¹⁾		311			318
$360 facility (Asia Offshore Drilling)		210			210
$300 facility ⁽¹⁾		140			142
$1,750 facility (Sevan Drilling) ⁽¹⁾		835			856
$450 facility ⁽¹⁾		255			261
$1,500 facility ⁽¹⁾		1,095			1,112
$1,350 facility ⁽¹⁾		913			931
$950 facility ⁽¹⁾		549			558
$450 facility (2015) ⁽¹⁾		98			101

Total credit facilities		5,476			5,581

Loans contained within VIEs:
$375 facility		237			251
$390 facility		215			226
$475 facility		285			309

Total loans contained within VIEs		737			786

Unsecured bonds:
NOK1,800 bond ⁽²⁾		231			231
$1,000 bond ⁽²⁾		843			843
$500 bond ⁽²⁾		479			479
NOK1,500 bond (NADL) ⁽²⁾		182			182
$ 600 bond (NADL) ⁽²⁾		413			413
SEK 1,500 bond ⁽²⁾		186			186

Total unsecured bonds		2,334			2,334

Total debt principal		8,547			8,701
Less: Debt balance held as subject to compromise		(7,600	)		(7,705	)

Total debt not subject to compromise		947			996

Less: current portion of debt principal		(91	)		(511	)

Long-term portion of debt principal		856			485

⁽¹⁾	Denotes impaired secured credit facilities that were reclassified to “Liabilities subject to compromise” on September 12, 2017

⁽²⁾	Denotes unsecured bonds that were reclassified to “Liabilities subject to compromise” on September 12, 2017

Details of the debt issuance costs netted against the non-impaired current and long-term debt for each of the periods presented are shown below.


Outstanding debt as at June 30, 2018
(In $ millions)	Principal outstanding		Less: Debt Issuance Costs			Total Debt
Debt due within one year		91		(1	)		90
Long-term debt		856		—			856
Debt held as subject to compromise		7,600		—			7,600

Total		8,547		(1	)		8,546


Outstanding debt as at December 31, 2017
(In $ millions)	Principal outstanding		Less: Debt Issuance Costs			Total Debt
Debt due within one year		511		(2	)		509
Long-term debt		485		—			485
Debt held as subject to compromise		7,705		—			7,705

Total		8,701		(2	)		8,699

The outstanding debt as at June 30, 2018 is repayable as follows:


(In $ millions)	Year ended June 30,
2019		91
2020		57
2021		68
2022		70
2023		523
2024 and thereafter		138

Total debt principal		947

The significant developments relating to our debt in the six months ended June 30, 2018 are explained below.

New Secured Notes on emergence

$360 million senior secured credit facility

Ship Finance International Limited (“Ship Finance”) Loans

Covenants contained in our debt facilities

Credit facilities

•

for the twelve months ending 31 March 2022, be equal to or less than 4.5x;

for the twelve months ending 30 June 2022, be equal to or less than 4.2x;

for the twelve months ending 30 September 2022, be equal to or less than 3.9x; and

for the twelve months ending 31 December 2022, be equal to or less than 3.7x.

•

New Secured Notes

The covenants included in the New Secured Notes agreements entered into on July 2, 2018, limit our restricted subsidiaries and our ability to:

•

pay dividends or make certain other restricted payments or investments;

•

incur additional indebtedness and issue disqualified shares;

•

create liens on assets;

•

amalgamate, merge, consolidate or sell substantially all of our, NSNCo’s, IHCo’s, RigCo’s and their respective subsidiaries and the guarantors’ assets;

•

enter into certain transactions with affiliates;

•

create restrictions on dividends and other payments by our restricted subsidiaries; and

•

guarantee indebtedness by our restricted subsidiaries. The above covenants are subject to important exceptions and qualifications.

Total gain/loss on debt extinguishment

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Common shares

6 Months Ended

Jun. 30, 2018

Temporary Equity Disclosure [Abstract]

Common shares

Note 18 – Common shares


	As at June 30, 2018						As at December 31, 2017
	Shares			$ million			Shares			$ million
All shares are common shares of $2.00 par value each
Authorized share capital		800,000,000			1,600			800,000,000			1,600
Issued and fully paid share capital		508,763,020			1,017			508,763,020			1,017
Treasury shares held by the Company		(4,244,080	)		(9	)		(4,244,080	)		(9	)

Outstanding common shares in issue		504,518,940			1,008			504,518,940			1,008

As at June 30, 2018, our shares were listed on the Oslo Stock Exchange and the New York Stock Exchange.

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Non-controlling interest

6 Months Ended

Jun. 30, 2018

Noncontrolling Interest [Abstract]

Non-controlling interest

Note 19 – Non-controlling interest

Changes in non-controlling interest for the period ended June 30, 2018 is as follows:


(In $ millions)	Ship Finance International Ltd VIEs			North Atlantic Drilling Ltd			Asia Offshore Drilling Ltd			Sevan Drilling ASA			Seadrill Nigeria Operations Limited		Total
December 31, 2017		(59	)		76			149			226			7		399
Adoption of new accounting standard ASU 2016-16 - Income Taxes⁽¹⁾		—			(25	)		—			—			—		(25	)
Net income attributable to non-controlling interest in 2018		7			(160	)		1			(10	)		2		(160	)
Redeemable non-controlling interest⁽²⁾		—			—			(150	)		—			—		(150	)

Ending balance, June 30, 2018		(52	)		(109	)		—			216			9		64

⁽¹⁾	For further information see Note 2 “Recent accounting pronouncements”

⁽²⁾	For further information see Note 20 “Redeemable non-controlling interest”

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Redeemable non-controlling interest

6 Months Ended

Jun. 30, 2018

Redeemable non-controlling interest

Note 20 – Redeemable non-controlling interest

Changes in redeemable non-controlling interest for the period ended June 30, 2018 is as follows:


(In $ millions)	Asia Offshore Drilling Ltd
As at December 31, 2017		—
Reclassification from non-controlling interest		150
Fair value adjustment on initial recognition		(127	)
Net income attributable to redeemable non-controlling interest in 2018		2

As at June 30, 2018		25

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Accumulated other comprehensive income

6 Months Ended

Jun. 30, 2018

Accumulated other comprehensive income

Note 21 – Accumulated other comprehensive income

Accumulated other comprehensive income as at June 30, 2018 and December 31, 2017 was as follows:


(In $ millions)	Unrealized gain on marketable securities			Unrealized gain on foreign exchange		Actuarial (loss) / gain relating to pension			Share in unrealized gain from associated companies		Change in unrealized gain on interest rate swaps in VIEs		Change in conversion option on Archer debt facility		Total
Beginning balance, December 31, 2017		31			36		(26	)		15		2		—		58
Adoption of accounting standard update		(31	)		—		—			—		—		—		(31	)
Beginning balance, January 1, 2018		—			36		(26	)		15		2		—		27
Other comprehensive income before reclassifications		—			—		1			11		—		2		14

Ending balance, June 30, 2018		—			36		(25	)		26		2		2		41

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Risk management and financial instruments

6 Months Ended

Jun. 30, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Risk management and financial instruments

Note 22 – Risk management and financial instruments

Interest rate risk management

Our exposure to interest rate risk relates mainly to our floating interest rate debt and balances of surplus funds placed with financial institutions. The exposure related to our floating interest debt has reduced since filing for Chapter 11, as noted above. We have historically managed this risk through the use of interest rate swaps and other derivative arrangements and continue to do so for some of our facilities which are not subject to compromise. Our objective is to obtain the most favorable interest rate borrowings available without increasing our foreign currency exposure. The extent to which we utilized interest rate swaps and other derivatives to manage our interest rate risk has been determined by the net debt exposure.

Interest rate swap agreements not qualified for hedge accounting

Cross currency interest rate swaps not qualified as hedge accounting

Interest rate swaps agreements qualified for hedge accounting

Below is a summary of the notional amount, fixed interest rate payable and duration of the outstanding principal as at June 30, 2018.

Variable interest entity

Outstanding principal as at
June 30, 2018
(In $ millions)

Receive rate

Pay rates

Length of contracts

SFL Linus Limited

(West Linus)

141

1—3 month LIBOR

1.77—2.01

Dec 2013—Dec 2018

Interest Rate Cap

Foreign exchange risk management

Foreign currency forwards not qualified for hedge accounting

As at June 30, 2018 and 2017 we had no outstanding forward currency agreements.

Other derivative agreements

Archer convertible debt instrument

Realized and unrealized gains and losses


(In $ millions)	Six Months Ended June 30,
*(Losses)/Gains recognized in the consolidated statement of operations relating to derivative financial instruments*		2018		2017
Interest rate swap agreements not qualified as hedge accounting		(1	)	(18	)
Cross currency interest rate swaps not qualified as hedge accounting		—		29
Foreign currency spot trades not qualified as hedge accounting		—		1
Convertible loan agreement		4		(5	)
Interest rate cap		(7	)	—

(Loss)/Gain on derivative financial instruments		(4	)	7

Fair values of financial instruments

The carrying value and estimated fair value of our financial instruments as at June 30, 2018 and December 31, 2017 were as follows

Financial assets


	As at June 30, 2018				As at December 31, 2017
(In $ millions)	Fair value		Carrying value		Fair value		Carrying value
Cash and cash equivalents		809		809		1,255		1,255
Restricted cash		409		409		104		104
Derivative Asset—interest rate cap		61		61		—		—
Related party loans receivable—short term		18		18		25		25
Related party loans receivable—long term		547		535		522		515

Financial liabilities

Fair value considerations

The carrying value of cash and cash equivalents and restricted cash, which are liquid, is a reasonable estimate of fair value and categorized at level 1 on the fair value measurement hierarchy.

Financial assets that are measured at fair value on a recurring basis:


			Fair value measurements as at the reporting date using
(In $ millions)	Total fair value As at June 30, 2018		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Marketable securities - current asset		121		121		—		—
Interest rate cap – current asset		61		—		61		—
Convertible debt instruments - non-current asset		58		—		—		58

Total assets		240		121		61		58


			Fair value measurements as at the reporting date using
(In $ millions)	Total fair value As at December 31, 2017		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Marketable securities - current asset		124		124		—		—
Convertible debt instrument - non-current asset		52		—		—		52

Total assets		176		124		—		52

Quoted market prices are used to estimate the fair value of marketable securities, which are valued at fair value on a recurring basis.

The following table is a reconciliation of the convertible debt instrument classified within Level 3 of the valuation hierarchy for the periods indicated:


(In $ millions)	Total fair value (Level 3)
As at December 31, 2017		52
Change in fair valued recognized in the Statement of Operations		4
Change in fair value recognized in Other Comprehensive Income		2

As at June 30, 2018		58

Credit risk

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Variable Interest Entities (VIEs)

6 Months Ended

Jun. 30, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Variable Interest Entities (VIEs)

Note 23 – Variable Interest Entities (VIEs)

The following table gives a summary of the sale and leaseback arrangements, as at June 30, 2018:

Unit

Effective
from

Sale value
(In $ millions)

First
repurchase
option
(In $ millions)

Month of first
repurchase
option

Last
repurchase
option
(In $ millions)

Month of last
repurchase
Option*

West Taurus

Nov 2008

850

418

Feb 2015

149

⁽¹⁾

Nov 2023

West Hercules

Oct 2008

850

580

Aug 2011

135

⁽¹⁾

Aug 2023

West Linus

June 2013

600

370

June 2018

170

⁽²⁾

June 2028

⁽¹⁾	Purchase obligations at the end of the 15-year lease period

⁽²⁾	Ship Finance has a right to require us to purchase the West Linus rig on the 15^th anniversary for $100 million if we do not exercise the final repurchase option


	(In $ thousands)
Unit	2018		2019		2020		2021		2022		2023
West Taurus		112		103		101		97		96		181
West Hercules		118		101		100		96		96		184
West Linus		158		122		99		99		93		189

The assets and liabilities in the financial statements of the VIEs as at June 30, 2018 and as at December 31, 2017 are as follows:


	As at June 30, 2018						As at December 31, 2017
(In $ millions)	SFL Deepwater Limited		SFL Hercules Limited		SFL Linus Limited		SFL Deepwater Limited		SFL Hercules Limited		SFL Linus Limited
Name of unit	West Taurus		West Hercules		West Linus		West Taurus		West Hercules		West Linus
Investment in finance lease		326		316		414		335		326		431
Amount due from related parties		3		4		—		4		4		—
Other assets		6		6		7		6		6		8

Total assets of the VIEs		335		326		421		345		336		439

Short-term interest bearing debt		19		28		45		226		27		48
Long-term interest bearing debt		196		210		240		—		224		261
Other liabilities		10		10		—		3		2		—
Short-term amounts due to related parties		—		—		12		—		—		4
Long-term debt due to related parties		106		73		115		113		80		121

Total liabilities of the VIEs		331		321		412		342		333		434

Equity of the VIEs		4		5		9		3		3		5

Book value of units in the Company’s consolidated financial statements		373		525		504		385		508		515

In the period ended June 30, 2018 the VIEs declared no dividends (June 30, 2017: $14 million).

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Related party transactions

6 Months Ended

Jun. 30, 2018

Related party transactions

Note 24 – Related party transactions

Seadrill Partners

The net income/(expenses) with Seadrill Partners for the six months ended June 30, 2018 and 2017 were as follows:


(In US$ millions)	Six Months Ended June 30,
	2018			2017
Management fees charged to Seadrill Partners - Other revenues (a) and (b)		35			37
Rig operating expenses charged to Seadrill Partners - Other revenues (c)		1			13
Contingent consideration realized (d)		7			11
Interest recognized on deferred consideration receivable (d)		2			2
Insurance premiums charged to Seadrill Partners (e)		5			5
Rig operating costs charged by Seadrill Partners (f)		(1	)		(2	)
Bareboat charter arrangements (g)		—			3
Interest expenses charged to Seadrill Partners (h)		—			5
Related party inventory purchases		(3	)		(2	)
Derivatives recharged to Seadrill Partners (i)		—			1

Net related party income from Seadrill Partners		46			73

Receivables/(payables) with Seadrill Partners and its subsidiaries as at June 30, 2018 and December 31, 2017 consisted of the following:


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Rig financing and loan agreements (j)		—			25
Deferred consideration receivable (d)		41			52
Other receivables (k)		148			157
Other payables (k)		(7	)		(24	)

The following is a summary of the related party agreements with Seadrill Partners:

(a, b) Management, administrative, and technical service agreements

(c) Rig operating costs charged to Seadrill Partners

(d) Deferred consideration receivable

(e) Insurance premiums

(f) Rig operating costs charged by Seadrill Partners

(g) Bareboat charter arrangements

(h) Interest expenses

(i) Derivative interest rate swap agreements

(j) Rig financing agreements

(k) Receivables and Payables

Guarantees

Seadrill provides certain guarantees on behalf of Seadrill Partners:

•

Guarantees in favor of customers, which guarantee the performance of the Seadrill Partners drilling units, totaled $57 million as at June 30, 2018 (December 31, 2017: $165 million);

•

Guarantees in favor of banks provided on behalf of Seadrill Partners totaled nil as at December 31, 2017 after Seadrill Partners insulated itself from Seadrill in August 2017; and

•

Guarantees in favor of suppliers provided on behalf of Seadrill Partners, relating to customs guarantees totaled nil as at June 30, 2018 (December 31, 2017: $0.6 million).

West Vela facility

West Polaris facility

T-15 / T-16 facility

Archer transactions

Archer restructuring

Total interest income for the six months ended June 30, 2018 for the above loans was nil (six months ended June 30, 2017: $3 million).

Guarantees

Operating activities

SeaMex Limited transactions

Management and administrative service agreements

Loans

Interest income accrued for the six months ended June 30, 2018 in respect of the loans above was $12 million (six months ended June 30, 2017: $17 million).

Receivables and Payables

Receivables/(payables) with SeaMex joint venture as at June 30, 2018 consisted of the following:


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Seller’s credit		250			250
$45 million loan facility		45			45
Interest on long-term funding and seller’s credit		62			50
Other receivables		39			32
Other payables		(1	)		(3	)

Performance Guarantees

In addition, Seadrill has also provided performance guarantees for the SeaMex drilling units, up to a total of $30 million as at June 30, 2018 (December 31, 2017: $30 million).

Seabras Sapura transactions

Loans

Financial guarantees

PLSV II - In April 2015 certain subsidiaries of Seabras Sapura Holding GmbH entered into a $780 million senior secured credit facility agreement in order to part fund the acquisition of the Sapura Onix, Sapura Jade and Sapura Rubi pipe-laying support vessels. As a condition to the lenders making the loan available to each of the borrowers, the Company provides a sponsor guarantee, on a 50:50 basis with the joint venture partner, Sapura Energy Berhad, in respect of the obligations of the borrowers during certain defined time periods, the release of such guarantees being subject to the satisfaction of certain defined conditions. The guarantees cover obligations and liabilities of the borrowers under the facility agreement which arise during the period between the expiry of a contract and extension or renewal of that contract and following a guarantee extension relating to early termination of a contract. During these periods, the guarantees can only be called if the facility is in default. The amount guaranteed by Seadrill as at June 30, 2018 was $312 million (December 31, 2017: $328 million).

As at the Consolidated Balance Sheet date, we have not recognized a liability as we do not consider it is probable that the guarantees will be called.

Operating activities

Other trading balances with Seabras Sapura, including interest receivable, totaled a receivable of $4 million as at June 30, 2018 (December 31, 2017: $6 million).

Related parties to Hemen Holding Ltd (“Hemen”)

The Company transacts business with the following related parties, being companies in which our principal shareholder, Hemen, has a significant interest:

•

Ship Finance International Limited (“Ship Finance”);

•

Metrogas Holdings Inc. (“Metrogas”);

•

Archer;

•

Frontline Management (Bermuda) Limited (“Frontline”); and

•

Seatankers Management Norway AS (“Seatankers”).

Ship Finance transactions

During the six month periods ended June 30, 2018 and 2017, we incurred the following lease costs on units leased back from Ship Finance subsidiaries:


	Six Months Ended June 30,
	2018		2017
West Hercules		20		28
West Taurus		18		25
West Linus		30		41

Total		68		94

These lease costs are eliminated on consolidation.

Frontline transactions

Seatankers Management transactions

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Commitments and contingencies

6 Months Ended

Jun. 30, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and contingencies

Note 25 – Commitments and contingencies

Purchase Commitments

The table below shows the maturity schedule for the newbuilding contractual commitments as of June 30, 2018.


(In $ millions)	As at June 30, 2018
2018		1,683
2019		—
2020		—
2021		—

Total purchase commitments		1,683

Legal Proceedings

Class action

Sevan Drilling

Seabras Sapura joint venture

Patent infringement

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Supplementary cash flow information

6 Months Ended

Jun. 30, 2018

Supplemental Cash Flow Elements [Abstract]

Supplementary cash flow information

Note 26 – Supplementary cash flow information

The table below summarizes the non-cash investing and financing activities relating to the periods presented:


	Six Months Ended June 30,
(In $ millions)	2018		2017
*Non-cash investing activities*
Sale of rigs and equipment ⁽¹⁾		—		74
*Non-cash financing activities*
Repayment of debt following sale of rigs and equipment ⁽¹⁾		—		(74	)
Dividend to non-controlling interests in VIEs ⁽²⁾		—		(14	)

⁽¹⁾

⁽²⁾	During the period ended June 30, 2017 the Ship Finance VIEs that we consolidate declared dividends payable totaling $14 million to Ship Finance. Refer to Note 23 “Variable Interest Entities” for more details.

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Assets held for sale

6 Months Ended

Jun. 30, 2018

Discontinued Operations and Disposal Groups [Abstract]

Assets held for sale

Note 27 – Assets held for sale

West Rigel

On May 9, 2018 the West Rigel was sold by Jurong and we received a share of proceeds totaling $126 million.


(In $ millions)	Six months ended June 30, 2018			Year ended December 31, 2017
Opening balance at the beginning of the period		126			128
Sale of West Rigel		(126	)		—
Loss on disposal		—			(2	)

Non-current assets held for sale		—			126

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Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 28 – Subsequent Events Emergence from Chapter 11 On July 2, 2018, we successfully completed our reorganization pursuant to our Chapter 11 plan of reorganization and emerged from Chapter 11. All conditions precedent to the restructuring contemplated by the Plan have been satisfied or otherwise waived. The Plan has re-profiled our debt by extending near term maturities and provided substantial liquidity that puts us in a strong position to execute its business plan. The Plan equitized approximately $2.4 billion in unsecured bond obligations, more than $1 billion in contingent newbuild obligations, substantial unliquidated guaranty obligations, and c. $249 million in unsecured interest rate and currency swap claims. Additionally, the Plan reinstated c.$5.4 billion of senior secured credit facilities with extended maturities, provided us with over $1.0 billion in fresh capital and leaving employee, customer, and ordinary trade claims largely unimpaired. The Plan provides for New Seadrill to serve as the parent holding company for Seadrill’s subsidiaries after Seadrill’s and the other Debtors’ emerged from bankruptcy. New Seadrill was initially formed as a wholly-owned subsidiary of Seadrill and has not conducted any material operations prior to the Effective Date of the Plan. As part of the Debtors’ emergence from bankruptcy on July 2, 2018, the economic interests in the existing shares of Seadrill were extinguished, Seadrill will be dissolved under Bermuda law, and common shares of New Seadrill were issued to the parties entitled thereto under the Plan and under the Investment Agreement. The corporate reorganization also included the formation of two intermediate holding company subsidiaries of New Seadrill and the formation of NSNCo, which issued its New Secured Notes to the commitment parties and to participants in a rights offering to purchase New Secured Notes. New Secured Notes On July 2, 2018, we raised $880 million of aggregate principle amount of 12.0% senior secured notes due in 2025. The notes bear interest at the annual rate of 4.00% payable in cash plus at the annual rate of 8.00% payable in kind. Under certain circumstances, we may elect to pay the amount of payment in kind interest payable on any interest payment date in cash at an annual rate of 8.00%. Interest will be payable semi-annually in arrears. On August 8, 2018 these notes were admitted for listing on the Global Exchange Market of Euronext Dublin under the name Seadrill New Finance Limited. Fresh Start Reporting On the Effective Date, we expect to adopt fresh start reporting. Under fresh start reporting, the fair value of our assets and liabilities as of that date are expected to differ materially from the recorded values of our assets and liabilities as reflected in our historical Consolidated Financial Statements. In addition, we expect the adoption of fresh start accounting to materially affect the results of operations following the fresh start reporting date, as we will have a new basis in our assets and liabilities. Consequently, our historical financial statements would not be reliable indicators of our financial condition and results of operations for any period should we apply fresh start accounting New Board of Directors In accordance with the Plan, a newly constituted Board of Directors was appointed on July 2, 2018, consisting of John Fredriksen (chairman), Harald Thorstein, Kjell-Erik Østdahl, Scott D. Vogel, Peter J. Sharpe, Eugene I. Davis, and Birgitte Ringstad Vartdal.

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General information (Policies)	6 Months Ended
General information (Policies)	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The Consolidated Financial Statements are presented in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP). The amounts are presented in United States dollar (“U.S. dollar” or “US$”) rounded to the nearest million, unless otherwise stated. The accompanying Consolidated Financial Statements present the financial position of Seadrill Limited, the consolidated subsidiaries and our interests in associated entities. Investments in companies in which we control, or directly or indirectly hold more than 50% of the voting control are consolidated in the Consolidated Financial Statements, as well as certain variable interest entities of which we are deemed to be the primary beneficiary. The accompanying unaudited interim financial statements, in the opinion of management, include all material adjustments, consisting only of normal recurring adjustments that are considered necessary for a fair statement of the Company’s financial statements in accordance with generally accepted accounting principles in the United States of America. The accompanying unaudited interim financial statements do not include all of the disclosures required in complete annual financial statements. These financial statements should be read in conjunction with our annual financial statements filed with the SEC on Form 20-F for the year ended December 31, 2017.
Significant accounting policies	Significant accounting policies The accounting policies adopted in the preparation of the unaudited interim financial statements are consistent with those followed in the preparation of our annual audited consolidated financial statements for the year ended December 31, 2017 except as discussed below or unless otherwise included in these unaudited interim financial statements as separate disclosures.
Bankruptcy accounting	Bankruptcy accounting Seadrill Limited and certain of its direct and indirect consolidated subsidiaries (the “Debtors”) filed voluntary petitions on September 12, 2017 (the “Petition Date”) to commence prearranged reorganization proceedings under Chapter 11 of Title 11 of the United States Bankruptcy Code (“Bankruptcy Code”) in the Southern District of Texas (the “Bankruptcy Court”) [case number 17-60079]. The Debtors also commenced a provisional liquidation proceeding in Bermuda on behalf of the Bermudian entities. During the pendency of the Chapter 11 proceedings, the Debtors will operate its business as “debtor-in-possession” under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provision of the Bankruptcy Code. Refer to Note 3 “Chapter 11 Proceedings” for further information. The consolidated financial statements have been prepared as if we are a going concern and reflect the application of Accounting Standards Codification 852, Reorganizations (“ASC 852”). ASC 852 requires that the financial statements, for periods subsequent to filing bankruptcy petitions, distinguish transactions and events that are directly associated with the reorganization from the ongoing operations of the business. Accordingly, certain expenses, gains and losses that are realized or incurred in the bankruptcy proceedings are recorded in “Reorganization items” on our Consolidated Statements of Operations. In addition, ASC 852 provides for changes in the accounting and presentation of significant items on the Consolidated Balance Sheets, particularly liabilities. Pre-petition obligations that may be impacted by the Chapter 11 reorganization process have been classified on the Consolidated Balance Sheets within “Liabilities subject to compromise”. These liabilities are reported at the amounts expected to be allowed by the Bankruptcy Court, even if they may be settled for lesser amounts. Please see Note 28 – Subsequent Events for fresh start reporting considerations upon emergence.
Liquidity and ability to continue as a going concern	Liquidity and ability to continue as a going concern The Consolidated Financial Statements are prepared on a going concern basis and contemplate the realization of assets and satisfaction of liabilities in the normal course of business. We have historically relied on our cash generated from operations to meet our short-term liquidity needs. However, as a result of the downturn in the offshore industry, we were required to obtain additional liquidity to fully meet our short-term liquidity requirements. To obtain this additional liquidity and to implement the transactions contemplated as part of the RSA and Investment Agreement, we commenced Chapter 11 proceedings under the Bankruptcy Code on September 12, 2017. In our form 20-F covering our annual report for the fiscal year ended December 31, 2017, issued on April 12, 2018, we reported that these conditions gave rise to a substantial doubt over our ability to continue as a going concern for a period of at least twelve months after the date the financial statements were issued. On July 2, 2018, we emerged from the Chapter 11 Proceedings. The emergence from the Chapter 11 Proceedings and consummation of the Plan addressed our liquidity concerns as it provided for $1.08 billion of in new capital, equitized approximately $2.4 billion in unsecured bond obligations and approximately $250 million in unsecured interest rate and currency swaps, eliminated near-term amortization obligations and extended maturities on debt. We emerged from Chapter 11 with $2.1 billion of post emergence cash and $7.6 billion of outstanding debt principal. We believe that cash on hand, liquid investments, contract and other revenues will generate sufficient cash flow to fund our anticipated debt service and working capital requirements for the next twelve months. Therefore, there is no longer a substantial doubt over our ability to continue as a going concern for at least the twelve months after the date the financial statements are issued.

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Liabilities subject to compromise (Tables)

6 Months Ended

Jun. 30, 2018

Schedule of Liabilities Subject to Compromise


(In $ millions)	June 30, 2018		December 31, 2017
Senior undersecured or impaired external debt		5,266		5,371
Unsecured bonds		2,334		2,334
Newbuild global settlement agreement		1,064		1,064
Derivatives previously recorded at fair value		249		249
Accounts payable and other liabilities		84		103
Accrued interest payable		49		50
Amount due to related party		4		20

Total liabilities subject to compromise		9,050		9,191

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Segment information (Tables)

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Segment Results

Segment results are evaluated on the basis of operating income, and the information given below is based on information used for internal management reporting.

Total operating revenue


(In $ millions)	Six Months Ended June 30,
	2018		2017
Floaters		482		744
Jack-ups		193		360
Other		37		42

Total operating revenue		712		1,146

Depreciation and amortization


(In $ millions)	Six Months Ended June 30,
	2018		2017
Floaters		298		301
Jack-ups		93		105

Total		391		406

Operating loss - Net loss


(In $ millions)	Six Months Ended June 30,
	2018			2017
Floaters		(446	)		95
Jack-ups		(167	)		(115	)
Other		—			3

Operating loss		(613	)		(17	)

Unallocated items:
Total financial items and other		14			(96	)
Income taxes		(36	)		12

Net loss		(635	)		(101	)

Drilling units and Newbuildings - Total assets


(In $ millions)	June 30, 2018		December 31, 2017
Floaters		9,411		9,956
Jack-ups		3,369		3,508

Total drilling units and newbuildings		12,780		13,464

Unallocated items:
Assets held for sale		—		126
Investments in associated companies		1,615		1,473
Marketable securities		121		124
Cash and restricted cash		1,218		1,359
Other assets		1,311		1,436

Total assets		17,045		17,982

Drilling units and Newbuildings - Capital expenditures


(In $ millions)	Six Months Ended June 30,
	2018		2017
Floaters		93		54
Jack-ups		24		12

Total		117		66

Summary of Geographic Segment Data

The following information presents our revenues and fixed assets by geographic area:

Revenues


(In US$ millions)	Six Months Ended June 30,
	2018		2017
Brazil		188		197
Nigeria		105		110
Angola		100		249
Norway		82		115
Saudi Arabia		79		80
United States		30		187
Others ⁽¹⁾		128		208

Total		712		1,146

⁽¹⁾	Other countries represent countries in which we operate that individually had revenues representing less than 10% of total revenues earned for any of the periods presented.

Summary of Major Customers

We had the following customers with contract revenues greater than 10% in any of the periods presented:


(In US$ millions)	Six Months Ended June 30,
	2018			2017
Petroleo Brasileiro S.A (“Petrobras”)		27	%		17	%
Total S.A Group (“Total”)		20	%		22	%
Saudi Aramco		12	%		8	%
Exxon Mobil Corp (“Exxon”)		11	%		7	%
LLOG		5	%		18	%

Summary of Geographic Segment Data

Fixed assets – drilling units ⁽¹⁾


(In US$ millions)	As at June 30, 2018		As at December 31, 2017
Brazil		2,405		1,816
Norway		2,331		2,258
Malaysia		1,445		1,809
Spain		1,344		2,016
United States		1,239		1,266
Other ⁽²⁾		3,767		4,051

Total		12,531		13,216

⁽¹⁾

⁽²⁾	“Other countries” represent countries in which we operate that individually had fixed assets representing less than 10% of total fixed assets for any of the periods presented.

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Revenue from Contracts with Customers (Tables)

6 Months Ended

Jun. 30, 2018

Revenue from Contract with Customer [Abstract]

Schedule of Information about Receivables, Contract Assets and Contract Liabilities from Contracts with Customers

The following table provides information about receivables, contract assets and contract liabilities from our contracts with customers:


(In $ millions)	June 30, 2018			January 1, 2018
Accounts receivable, net		272			295
Current contract assets ⁽¹⁾		9			7
Current contract liabilities (deferred revenue) ⁽¹⁾		(25	)		(37	)
Non-current contract liabilities (deferred revenue) ⁽¹⁾		(7	)		(18	)

⁽¹⁾	Current contract asset and liability balances are included in “other current assets” and “other current liabilities,” respectively in our unaudited Consolidated Balance Sheet as of June 30, 2018.

Significant changes in the contract assets and the contract liabilities balances during the period are as follows:


(In $ millions)	Net Contract Balances
Contract assets at January 1, 2018		7
Contract liabilities at January 1, 2018		(55	)

Net contract liability at January 1, 2018		(48	)

Decrease due to amortization of revenue that was included in the beginning contract liability balance		25
Increase due to cash received, excluding amounts recognized as revenue		(9	)
Decrease due to recognized during the period but contingent on future performance		9

Net contract liability at June 30, 2018		(23	)

Contract assets at June 30, 2018		9
Contract liabilities at June 30, 2018		(32	)

Summary of Revenue Expected to be Recognized in Future Related to Performance Unsatisfied Obligations

The following table reflects revenue expected to be recognized in the future related to unsatisfied performance obligations as of June 30, 2018:


	For the Years Ending December 31,
(In $ millions)	2018⁽¹⁾			2019			Total
Deferred mobilization revenue		(11	)		(18	)		(29	)
Other deferred revenue		(2	)		(1	)		(3	)
Total		(13	)		(19	)		(32	)

⁽¹⁾

Represents the six-month period beginning July 1, 2018.

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Reorganization items (Tables)

6 Months Ended

Jun. 30, 2018

Schedule of Reorganization Items

The following table summarizes the components included within reorganization items:


(In $ millions)	Six Months Ended June 30, 2018
Advisory and professional fees		(115	)
Interest income on surplus cash invested		6

Total reorganization items		(109	)

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Loss on disposals and contingent consideration (Tables)

6 Months Ended

Jun. 30, 2018

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Summary of Loss on Disposals and Contingent Consideration


(In $ millions)	Six Months Ended June 30,
	2018		2017
Loss on disposals
Loss on disposal of West Triton to Shelf Drilling		—		(34	)
Loss on disposal of West Resolute to Shelf Drilling		—		(61	)
Loss on disposal of West Mischief to Shelf Drilling		—		(71	)

Total loss on disposals		—		(166	)

Contingent Consideration realized
West Polaris earn out realized		—		4
West Vela earn out realized		7		7

Total contingent consideration recognized		7		11

Summary of Earnings Per Share

Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65878427&loc=SL51721533-107759

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721665-107760

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1474-107760

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721683-107760

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=84176398&loc=SL51724579-110230

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5C
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721675-107760

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 4A
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 3
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Paragraph 3A
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Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5A
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Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
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-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721677-107760

+ Details

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Earnings per share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share [Abstract]

The components of the numerator for the calculation of basic and diluted EPS are as follows:


(In $ millions)	Six Months Ended June 30,
	2018			2017
Net loss		(477	)		(78	)
Less: Allocation to participating securities		—			—

Net loss available to shareholders		(477	)		(78	)

Effect of dilution		—			—

Diluted net loss available to shareholders		(477	)		(78	)

The components of the denominator for the calculation of basic and diluted EPS are as follows:


(In millions)	Six Months Ended June 30,
	2018			2017
Basic earnings per share:
Weighted average number of common shares outstanding		504			504
Diluted earnings per share:
Weighted average number of common shares outstanding		504			504
Effect of dilutive share options ⁽¹⁾		—			—
Effect of dilutive convertible bonds		—			—

Weighted average number of common shares outstanding adjusted for the effects of dilution		504			504

Basic (loss)/income per share (US dollar)		(0.95	)		(0.16	)

Diluted (loss)/income per share (US dollar)		(0.95	)		(0.16	)

⁽¹⁾	Certain stock options have been excluded from the calculation of diluted EPS because their exercise price exceeded our average share price during the calculation period.

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Cash and cash equivalents (Tables)

6 Months Ended

Jun. 30, 2018

Cash and Cash Equivalents [Abstract]

Cash and cash equivalents


(In $ millions)	June 30, 2018		December 31, 2017
Cash and cash equivalents		809		1,255
Restricted cash⁽¹⁾		409		104

Total		1,218		1,359

⁽¹⁾

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Marketable securities (Tables)

6 Months Ended

Jun. 30, 2018

Investments, Debt and Equity Securities [Abstract]

Marketable Securities Held


(In $ millions)	June 30, 2018		December 31, 2017
Seadrill Partners —Common units		91		96
Archer		30		28

Total marketable securities		121		124

Net Unrealized Gains and Losses Related to Marketable Securities


(In $ millions)	Six Months Ended June 30,

	2018
Seadrill Partners—Common Units—unrealized loss on marketable securities		(5	)
Archer—unrealized gain on marketable securities		2

Total unrealized loss on marketable securities		(3	)


(In $ millions)	Six Months Ended June 30,
	2017
Seadrill Partners—Common Units—unrealized loss on marketable securities		(21	)
Archer—unrealized gain on marketable securities		27

Total unrealized gain on marketable securities		6

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Investment in associated companies (Tables)

6 Months Ended

Jun. 30, 2018

Investments, Debt and Equity Securities [Abstract]

Equity Method Investments

We have the following investments that are either recorded using the equity method or at cost less impairment for the periods presented in these Consolidated Financial Statements:


(In $ millions)	June 30, 2018		December 31, 2017
Seabras Sapura Participacoes		76		63
Seabras Sapura Holdco		334		290
Seadrill Partners—Total direct ownership interests		914		857
Seadrill Partners—Subordinated units		120		97
Seadrill Partners—Seadrill member interest and IDRs ⁽¹⁾		64		64
SeaMex Ltd		107		102

Total investment in associated companies		1,615		1,473

⁽¹⁾	The Seadrill Partners—Seadrill member interest and Incentive Distribution Rights (“IDRs”) are recorded at cost less impairment on the basis that they do not represent common stock interests and their fair value is not readily determinable.

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Property plant and equipment (Tables)

6 Months Ended

Jun. 30, 2018

Drilling Unit [Member]


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Cost		17,452			17,335
Accumulated depreciation		(4,507	)		(4,119	)
Impairment		(414	)		—

Net book value		12,531			13,216

Newbuildings [Member]

Schedule of Debt Issuance Costs Against Current and Long-Term Debt


(In $ millions)	As at June 30, 2018		As at December 31, 2017
Total Newbuildings		249		248

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Debt (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Schedule of Debt


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Credit facilities:
$2,000 facility (North Atlantic Drilling) ⁽¹⁾		880			897
$400 facility ⁽¹⁾		130			133
$440 facility ⁽¹⁾		60			62
$1,450 facility ⁽¹⁾		311			318
$360 facility (Asia Offshore Drilling)		210			210
$300 facility ⁽¹⁾		140			142
$1,750 facility (Sevan Drilling) ⁽¹⁾		835			856
$450 facility ⁽¹⁾		255			261
$1,500 facility ⁽¹⁾		1,095			1,112
$1,350 facility ⁽¹⁾		913			931
$950 facility ⁽¹⁾		549			558
$450 facility (2015) ⁽¹⁾		98			101

Total credit facilities		5,476			5,581

Loans contained within VIEs:
$375 facility		237			251
$390 facility		215			226
$475 facility		285			309

Total loans contained within VIEs		737			786

Unsecured bonds:
NOK1,800 bond ⁽²⁾		231			231
$1,000 bond ⁽²⁾		843			843
$500 bond ⁽²⁾		479			479
NOK1,500 bond (NADL) ⁽²⁾		182			182
$ 600 bond (NADL) ⁽²⁾		413			413
SEK 1,500 bond ⁽²⁾		186			186

Total unsecured bonds		2,334			2,334

Total debt principal		8,547			8,701
Less: Debt balance held as subject to compromise		(7,600	)		(7,705	)

Total debt not subject to compromise		947			996

Less: current portion of debt principal		(91	)		(511	)

Long-term portion of debt principal		856			485

⁽¹⁾	Denotes impaired secured credit facilities that were reclassified to “Liabilities subject to compromise” on September 12, 2017

⁽²⁾	Denotes unsecured bonds that were reclassified to “Liabilities subject to compromise” on September 12, 2017


Outstanding debt as at June 30, 2018
(In $ millions)	Principal outstanding		Less: Debt Issuance Costs			Total Debt
Debt due within one year		91		(1	)		90
Long-term debt		856		—			856
Debt held as subject to compromise		7,600		—			7,600

Total		8,547		(1	)		8,546


Outstanding debt as at December 31, 2017
(In $ millions)	Principal outstanding		Less: Debt Issuance Costs			Total Debt
Debt due within one year		511		(2	)		509
Long-term debt		485		—			485
Debt held as subject to compromise		7,705		—			7,705

Total		8,701		(2	)		8,699

Outstanding Debt

The outstanding debt as at June 30, 2018 is repayable as follows:


(In $ millions)	Year ended June 30,
2019		91
2020		57
2021		68
2022		70
2023		523
2024 and thereafter		138

Total debt principal		947

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21521-112644

+ Details

XML 54 R47.htm IDEA: XBRL DOCUMENT

Common shares (Tables)

6 Months Ended

Jun. 30, 2018

Changes in Non-Controlling Interest

Share Capital


	As at June 30, 2018						As at December 31, 2017
	Shares			$ million			Shares			$ million
All shares are common shares of $2.00 par value each
Authorized share capital		800,000,000			1,600			800,000,000			1,600
Issued and fully paid share capital		508,763,020			1,017			508,763,020			1,017
Treasury shares held by the Company		(4,244,080	)		(9	)		(4,244,080	)		(9	)

Outstanding common shares in issue		504,518,940			1,008			504,518,940			1,008

XML 55 R48.htm IDEA: XBRL DOCUMENT

Non-controlling interest (Tables)

6 Months Ended

Jun. 30, 2018

Noncontrolling Interest [Abstract]

Changes in non-controlling interest for the period ended June 30, 2018 is as follows:


(In $ millions)	Ship Finance International Ltd VIEs			North Atlantic Drilling Ltd			Asia Offshore Drilling Ltd			Sevan Drilling ASA			Seadrill Nigeria Operations Limited		Total
December 31, 2017		(59	)		76			149			226			7		399
Adoption of new accounting standard ASU 2016-16 - Income Taxes⁽¹⁾		—			(25	)		—			—			—		(25	)
Net income attributable to non-controlling interest in 2018		7			(160	)		1			(10	)		2		(160	)
Redeemable non-controlling interest⁽²⁾		—			—			(150	)		—			—		(150	)

Ending balance, June 30, 2018		(52	)		(109	)		—			216			9		64

⁽¹⁾	For further information see Note 2 “Recent accounting pronouncements”

⁽²⁾	For further information see Note 20 “Redeemable non-controlling interest”

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Redeemable non-controlling interest (Tables)

6 Months Ended

Jun. 30, 2018

Temporary Equity Disclosure [Abstract]

Changes in Redeemable Non-Controlling Interest

Changes in redeemable non-controlling interest for the period ended June 30, 2018 is as follows:


(In $ millions)	Asia Offshore Drilling Ltd
As at December 31, 2017		—
Reclassification from non-controlling interest		150
Fair value adjustment on initial recognition		(127	)
Net income attributable to redeemable non-controlling interest in 2018		2

As at June 30, 2018		25

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Accumulated other comprehensive income (Tables)

6 Months Ended

Jun. 30, 2018

Schedule of Accumulated Other Comprehensive Income

Accumulated other comprehensive income as at June 30, 2018 and December 31, 2017 was as follows:


(In $ millions)	Unrealized gain on marketable securities			Unrealized gain on foreign exchange		Actuarial (loss) / gain relating to pension			Share in unrealized gain from associated companies		Change in unrealized gain on interest rate swaps in VIEs		Change in conversion option on Archer debt facility		Total
Beginning balance, December 31, 2017		31			36		(26	)		15		2		—		58
Adoption of accounting standard update		(31	)		—		—			—		—		—		(31	)
Beginning balance, January 1, 2018		—			36		(26	)		15		2		—		27
Other comprehensive income before reclassifications		—			—		1			11		—		2		14

Ending balance, June 30, 2018		—			36		(25	)		26		2		2		41

XML 58 R51.htm IDEA: XBRL DOCUMENT

Risk management and financial instruments (Tables)

6 Months Ended

Jun. 30, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Summary of Notional Amount, Fixed Interest Rate Payable

Below is a summary of the notional amount, fixed interest rate payable and duration of the outstanding principal as at June 30, 2018.

Variable interest entity

Outstanding principal as at
June 30, 2018
(In $ millions)

Receive rate

Pay rates

Length of contracts

SFL Linus Limited

(West Linus)

141

1—3 month LIBOR

1.77—2.01

Dec 2013—Dec 2018

Realized and Unrealized Gains and Losses


(In $ millions)	Six Months Ended June 30,
*(Losses)/Gains recognized in the consolidated statement of operations relating to derivative financial instruments*		2018		2017
Interest rate swap agreements not qualified as hedge accounting		(1	)	(18	)
Cross currency interest rate swaps not qualified as hedge accounting		—		29
Foreign currency spot trades not qualified as hedge accounting		—		1
Convertible loan agreement		4		(5	)
Interest rate cap		(7	)	—

(Loss)/Gain on derivative financial instruments		(4	)	7

Carrying Value and Estimated at Fair Value of Financial Instruments

The carrying value and estimated fair value of our financial instruments as at June 30, 2018 and December 31, 2017 were as follows

Financial assets


	As at June 30, 2018				As at December 31, 2017
(In $ millions)	Fair value		Carrying value		Fair value		Carrying value
Cash and cash equivalents		809		809		1,255		1,255
Restricted cash		409		409		104		104
Derivative Asset—interest rate cap		61		61		—		—
Related party loans receivable—short term		18		18		25		25
Related party loans receivable—long term		547		535		522		515

Financial Instruments Measured at Fair Value on a Recurring Basis

Financial assets that are measured at fair value on a recurring basis:


			Fair value measurements as at the reporting date using
(In $ millions)	Total fair value As at June 30, 2018		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Marketable securities - current asset		121		121		—		—
Interest rate cap – current asset		61		—		61		—
Convertible debt instruments - non-current asset		58		—		—		58

Total assets		240		121		61		58


			Fair value measurements as at the reporting date using
(In $ millions)	Total fair value As at December 31, 2017		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Marketable securities - current asset		124		124		—		—
Convertible debt instrument - non-current asset		52		—		—		52

Total assets		176		124		—		52

Reconciliation of Convertible Debt Instrument Classified Within Level 3

The following table is a reconciliation of the convertible debt instrument classified within Level 3 of the valuation hierarchy for the periods indicated:


(In $ millions)	Total fair value (Level 3)
As at December 31, 2017		52
Change in fair valued recognized in the Statement of Operations		4
Change in fair value recognized in Other Comprehensive Income		2

As at June 30, 2018		58

XML 59 R52.htm IDEA: XBRL DOCUMENT

Variable Interest Entities (VIEs) (Tables)

6 Months Ended

Jun. 30, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Sale and Leaseback Arrangements

The following table gives a summary of the sale and leaseback arrangements, as at June 30, 2018:

Unit

Effective
from

Sale value
(In $ millions)

First
repurchase
option
(In $ millions)

Month of first
repurchase
option

Last
repurchase
option
(In $ millions)

Month of last
repurchase
Option*

West Taurus

Nov 2008

850

418

Feb 2015

149

⁽¹⁾

Nov 2023

West Hercules

Oct 2008

850

580

Aug 2011

135

⁽¹⁾

Aug 2023

West Linus

June 2013

600

370

June 2018

170

⁽²⁾

June 2028

⁽¹⁾	Purchase obligations at the end of the 15-year lease period

⁽²⁾	Ship Finance has a right to require us to purchase the West Linus rig on the 15^th anniversary for $100 million if we do not exercise the final repurchase option

Summary of Bareboat Charter Rates per Day Based on Base LIBOR Interest Rate for Next Five Years

A summary of the bareboat charter rates per day for each unit is given below.


	(In $ thousands)
Unit	2018		2019		2020		2021		2022		2023
West Taurus		112		103		101		97		96		181
West Hercules		118		101		100		96		96		184
West Linus		158		122		99		99		93		189

Assets and Liabilities in Statutory Accounts of VIEs

The assets and liabilities in the financial statements of the VIEs as at June 30, 2018 and as at December 31, 2017 are as follows:


	As at June 30, 2018						As at December 31, 2017
(In $ millions)	SFL Deepwater Limited		SFL Hercules Limited		SFL Linus Limited		SFL Deepwater Limited		SFL Hercules Limited		SFL Linus Limited
Name of unit	West Taurus		West Hercules		West Linus		West Taurus		West Hercules		West Linus
Investment in finance lease		326		316		414		335		326		431
Amount due from related parties		3		4		—		4		4		—
Other assets		6		6		7		6		6		8

Total assets of the VIEs		335		326		421		345		336		439

Short-term interest bearing debt		19		28		45		226		27		48
Long-term interest bearing debt		196		210		240		—		224		261
Other liabilities		10		10		—		3		2		—
Short-term amounts due to related parties		—		—		12		—		—		4
Long-term debt due to related parties		106		73		115		113		80		121

Total liabilities of the VIEs		331		321		412		342		333		434

Equity of the VIEs		4		5		9		3		3		5

Book value of units in the Company’s consolidated financial statements		373		525		504		385		508		515

Schedule of Related Party Transactions

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

XML 60 R53.htm IDEA: XBRL DOCUMENT

Related party transactions (Tables)

6 Months Ended

Jun. 30, 2018

The net income/(expenses) with Seadrill Partners for the six months ended June 30, 2018 and 2017 were as follows:


(In US$ millions)	Six Months Ended June 30,
	2018			2017
Management fees charged to Seadrill Partners - Other revenues (a) and (b)		35			37
Rig operating expenses charged to Seadrill Partners - Other revenues (c)		1			13
Contingent consideration realized (d)		7			11
Interest recognized on deferred consideration receivable (d)		2			2
Insurance premiums charged to Seadrill Partners (e)		5			5
Rig operating costs charged by Seadrill Partners (f)		(1	)		(2	)
Bareboat charter arrangements (g)		—			3
Interest expenses charged to Seadrill Partners (h)		—			5
Related party inventory purchases		(3	)		(2	)
Derivatives recharged to Seadrill Partners (i)		—			1

Net related party income from Seadrill Partners		46			73

Receivables/(payables) with Seadrill Partners and its subsidiaries as at June 30, 2018 and December 31, 2017 consisted of the following:


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Rig financing and loan agreements (j)		—			25
Deferred consideration receivable (d)		41			52
Other receivables (k)		148			157
Other payables (k)		(7	)		(24	)

The following is a summary of the related party agreements with Seadrill Partners:

(a, b) Management, administrative, and technical service agreements

(c) Rig operating costs charged to Seadrill Partners

(d) Deferred consideration receivable

(e) Insurance premiums

(f) Rig operating costs charged by Seadrill Partners

(g) Bareboat charter arrangements

(h) Interest expenses

(i) Derivative interest rate swap agreements

(j) Rig financing agreements

(k) Receivables and Payables

SeaMex Limited [Member]

Schedule of Related Party Transactions

Receivables/(payables) with SeaMex joint venture as at June 30, 2018 consisted of the following:


(In $ millions)	As at June 30, 2018			As at December 31, 2017
Seller’s credit		250			250
$45 million loan facility		45			45
Interest on long-term funding and seller’s credit		62			50
Other receivables		39			32
Other payables		(1	)		(3	)

Ship Finance International Ltd VIEs [Member]

Schedule of Related Party Transactions

During the six month periods ended June 30, 2018 and 2017, we incurred the following lease costs on units leased back from Ship Finance subsidiaries:


	Six Months Ended June 30,
	2018		2017
West Hercules		20		28
West Taurus		18		25
West Linus		30		41

Total		68		94

XML 61 R54.htm IDEA: XBRL DOCUMENT

Commitments and contingencies (Tables)

6 Months Ended

Jun. 30, 2018

Commitments and Contingencies Disclosure [Abstract]

Maturity Schedule for Contractual Commitments

The table below shows the maturity schedule for the newbuilding contractual commitments as of June 30, 2018.


(In $ millions)	As at June 30, 2018
2018		1,683
2019		—
2020		—
2021		—

Total purchase commitments		1,683

XML 62 R55.htm IDEA: XBRL DOCUMENT

Supplementary cash flow information (Tables)

6 Months Ended

Jun. 30, 2018

Supplemental Cash Flow Elements [Abstract]

Non-cash Investing and Financing Activities

The table below summarizes the non-cash investing and financing activities relating to the periods presented:


	Six Months Ended June 30,
(In $ millions)	2018		2017
*Non-cash investing activities*
Sale of rigs and equipment ⁽¹⁾		—		74
*Non-cash financing activities*
Repayment of debt following sale of rigs and equipment ⁽¹⁾		—		(74	)
Dividend to non-controlling interests in VIEs ⁽²⁾		—		(14	)

XML 63 R56.htm IDEA: XBRL DOCUMENT

Assets held for sale (Tables)

6 Months Ended

Jun. 30, 2018

Discontinued Operations and Disposal Groups [Abstract]

Asset Held-for-sale

On May 9, 2018 the West Rigel was sold by Jurong and we received a share of proceeds totaling $126 million.


(In $ millions)	Six months ended June 30, 2018			Year ended December 31, 2017
Opening balance at the beginning of the period		126			128
Sale of West Rigel		(126	)		—
Loss on disposal		—			(2	)

Non-current assets held for sale		—			126

XML 64 R57.htm IDEA: XBRL DOCUMENT

General Information - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018 Option	Jul. 02, 2018 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of offshore drilling units owned by the Company	35
Number of offshore drilling units under construction	8
Number of options to acquire semi-submersible rig \| Option	1
New capital		$ 1,080
Unsecured bond obligation		2,400
Unsecured interest rate and currency swaps		250
Post emergence cash		2,100
Outstanding debt principal		$ 7,600

XML 65 R58.htm IDEA: XBRL DOCUMENT

Recent Accounting Pronouncements - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Jun. 30, 2018	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption		$ (31,000,000)
Accounting Standards Update 2016-02 [Member] \| Scenario, Forecast [Member] \| Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use asset	$ 30,000,000
Operating lease, liability	30,000,000
Accounting Standards Update 2016-02 [Member] \| Scenario, Forecast [Member] \| Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use asset	50,000,000
Operating lease, liability	$ 50,000,000
Accounting standards update 2014-09 \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption			$ 7,000,000
Accounting Standards Update 2016-01 [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption			31,000,000
Accounting standards update 2016-16 \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption			59,000,000
Accounting standards update 2016-16 \| Non-controlling Interest [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption			$ 25,000,000

XML 66 R59.htm IDEA: XBRL DOCUMENT

Chapter 11 Proceedings - Additional Information (Detail) $ in Millions				6 Months Ended	12 Months Ended
	Jun. 15, 2018 USD ($)	Feb. 28, 2018 USD ($)	Feb. 26, 2018 USD ($)	Jun. 30, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	Aug. 08, 2018 USD ($) shares	Sep. 12, 2017 shares
Fresh-Start Adjustment [Line Items]
Amount of new cash commitments in the form of new notes and equity			$ 1,080.0
Number of days after Confirmation Date the plan must effective by				90 days
Bankruptcy claims, unsecured claims, pro rata cash recovery pool			23.0
Plan of reorganization, equity securities issued or to be issued, ownership percentage				2.00%
Notes rights offering, maximum aggregate principal amount of new secured notes			119.4
Common shares outstanding \| shares				504,518,940	504,518,940		504,518,940
Protection payments				$ 104.0	$ 81.0
Contractual interest on liabilities subject to compromise				76.0
Bankruptcy claims, number claims filed	1,597
Bankruptcy claims, amount of claims filed	$ 19,200.0
Debtor reorganization items, claims settlement accrual					1,064.0
Loss on impairment of long lived assets				$ 414.0	$ 696.0
Employee Stock Option [Member] \| Employee Incentive Plan [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, share-based compensation arrangement, percentage of shares available for grant				10.00%
New Secured Notes [Member]
Fresh-Start Adjustment [Line Items]
Notes rights offering, pro rata equity securities issued or to be issued, ownership percentage						57.50%
Holders of General Unsecured Claims [Member]
Fresh-Start Adjustment [Line Items]
Payment for debt extinguishment			17.0
Shipyards [Member]
Fresh-Start Adjustment [Line Items]
Payment for debt extinguishment			$ 17.0
NSNCo [Member] \| New Secured Notes [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, debt securities issued or to be issued, value						$ 880.0
New Seadrill [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, percentage of equity securities issued or to be issued			15.00%	23.75%
Plan of reorganization, equity securities issued or to be issued, ownership percentage			2.00%
Notes rights offering, pro rata equity securities issued or to be issued, ownership percentage			57.50%
Notes rights offering, maximum value of common shares issued		$ 48.1
Common shares outstanding \| shares						100,000,000
Equity method investment				$ 200.0
New Seadrill [Member] \| New Secured Notes [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, percentage of equity securities issued or to be issued				54.625%
Plan of reorganization, debt securities issued or to be issued, value				$ 880.0
New Seadrill [Member] \| Structuring Fees [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, percentage of equity securities issued or to be issued				5.475%
New Seadrill [Member] \| Unsecured Claims And Debtor Affiliates [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, percentage of equity securities issued or to be issued				14.25%
New Seadrill [Member] \| Existing Common Equity Interest Holder [Member]
Fresh-Start Adjustment [Line Items]
Plan of reorganization, percentage of equity securities issued or to be issued				1.90%
Exchange ratio of common shares				0.0037345

XML 67 R60.htm IDEA: XBRL DOCUMENT

Liabilities Subject to Compromise - Schedule of Liabilities Subject to Compromise (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	$ 9,050	$ 9,191
Senior under secured or impaired external debt [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	5,266	5,371
Senior Unsecured Bonds [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	2,334	2,334
New build global settlement agreement [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	1,064	1,064
Derivative [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	249	249
Accounts Payable And Other Liabilities [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	84	103
Accrued Interest On Notes Payable [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	49	50
Related Party Debt [Member]
Fresh-Start Adjustment [Line Items]
Liabilities subject to compromise	$ 4	$ 20

XML 68 R61.htm IDEA: XBRL DOCUMENT

Segment Information - Additional Information (Detail)	6 Months Ended
Segment Information - Additional Information (Detail)	Jun. 30, 2018 Segment
Segment Reporting Information [Line Items]
Number of operating segments	3
Sales Revenue, Net [Member] \| Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration risk percentage	10.00%

XML 69 R62.htm IDEA: XBRL DOCUMENT

Segment Information - Segment Results (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Drilling units and new buildings	$ 12,780		$ 13,464
Operating Revenue	712	$ 1,146
Depreciation and amortization	391	406
Operating loss	(613)	(17)
Drilling unit and new buildings capital expenditure	117	66
Unallocated items:
Assets held for sale			126
Total financial items and other	14	(96)
Investments in associated companies	1,615		1,473
Income taxes	(36)	12
Marketable securities	121		124
Net loss	(635)	(101)
Cash and restricted cash	1,218	1,441	1,359	$ 1,443
Other assets	1,311		1,436
Total assets	17,045		17,982
Floaters [Member]
Segment Reporting Information [Line Items]
Drilling units and new buildings	9,411		9,956
Operating Revenue	482	744
Depreciation and amortization	298	301
Operating loss	(446)	95
Drilling unit and new buildings capital expenditure	93	54
Jack Ups [Member]
Segment Reporting Information [Line Items]
Drilling units and new buildings	3,369		$ 3,508
Operating Revenue	193	360
Depreciation and amortization	93	105
Operating loss	(167)	(115)
Drilling unit and new buildings capital expenditure	24	12
Other Drilling Units [Member]
Segment Reporting Information [Line Items]
Operating Revenue	$ 37	42
Operating loss		$ 3

XML 70 R63.htm IDEA: XBRL DOCUMENT

Segment Information - Summary of Geographic Segment Data (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 712	$ 1,146
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	188	197
NORWAY
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	82	115
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	30	187
Others [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	128	208
NIGERIA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	105	110
ANGOLA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	100	249
SAUDI ARABIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	79	$ 80
Drilling Unit [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	12,531		$ 13,216
Drilling Unit [Member] \| Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	2,405		1,816
Drilling Unit [Member] \| NORWAY
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	2,331		2,258
Drilling Unit [Member] \| MALAYSIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	1,445		1,809
Drilling Unit [Member] \| SPAIN
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	1,344		2,016
Drilling Unit [Member] \| UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	1,239		1,266
Drilling Unit [Member] \| Others [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Fixed assets	$ 3,767		$ 4,051

XML 71 R64.htm IDEA: XBRL DOCUMENT

Segment Information - Summary of Geographic Segment Data (Parenthetical) (Detail) - Geographic Concentration Risk [Member] - Maximum [Member]	6 Months Ended
	Jun. 30, 2018
Net Assets, Geographic Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage	10.00%
Sales Revenue, Net [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage	10.00%

XML 72 R65.htm IDEA: XBRL DOCUMENT

Segment Information - Summary of Major Customers (Detail) - Sales Revenue, Net [Member] - Customer Concentration Risk [Member]	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Revenue, Major Customer [Line Items]
Customers with contract revenue	10.00%
Petroleo Brasileiro Sa [Member]
Revenue, Major Customer [Line Items]
Customers with contract revenue	27.00%	17.00%
SA Group [Member]
Revenue, Major Customer [Line Items]
Customers with contract revenue	20.00%	22.00%
Saudi Aramco [Member]
Revenue, Major Customer [Line Items]
Customers with contract revenue	12.00%	8.00%
Exxon Mobil Corporation [Member]
Revenue, Major Customer [Line Items]
Customers with contract revenue	11.00%	7.00%
L L O G [Member]
Revenue, Major Customer [Line Items]
Customers with contract revenue	5.00%	18.00%

XML 73 R66.htm IDEA: XBRL DOCUMENT

Revenue from Contracts with Customers - Schedule of Information about Receivables, Contract Assets and Contract Liabilities from Contracts with Customers (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Change in Contract with Customer, Asset and Liability [Abstract]
Accounts receivable, net	$ 272	$ 295	$ 295
Current contract assets	9	7
Current contract liabilities (deferred revenue)	(25)	(37)
Non-current contract liabilities (deferred revenue)	(7)	$ (18)
Contract assets,beginning balance	7
Contract liabilities,beginning balance	(55)
Net contract liability,beginning balance	(48)
Decrease due to amortization of revenue that was included in the beginning contract liability balance	25
Increase due to cash received, excluding amounts recognized as revenue	(9)
Decrease due to recognized during the period but contingent on future performance	9
Net contract liability,ending balance	(23)
Contract assets,ending balance	9
Contract liabilities,ending balance	$ (32)

XML 74 R67.htm IDEA: XBRL DOCUMENT

Revenue from Contracts with Customers - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Revenue From Contract With Customers [Line Items]
Amortization of deferred contract costs	$ 15
Other Current Assets [Member]
Revenue From Contract With Customers [Line Items]
Deferred contract costs	9
Other Noncurrent Assets [Member]
Revenue From Contract With Customers [Line Items]
Deferred contract costs	$ 2

XML 75 R68.htm IDEA: XBRL DOCUMENT

Revenue from Contracts with Customers - Summary of Revenue Expected to be Recognized in Future Related to Performance Unsatisfied Obligations (Detail) $ in Millions	Jun. 30, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	$ (32)
July One Two Thousand Eighteen [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(13)
July One Two Thousand Nineteen [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(19)
Deferred Revenue [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(29)
Deferred Revenue [Member] \| July One Two Thousand Eighteen [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(11)
Deferred Revenue [Member] \| July One Two Thousand Nineteen [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(18)
Other Deferred Revenue [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(3)
Other Deferred Revenue [Member] \| July One Two Thousand Eighteen [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	(2)
Other Deferred Revenue [Member] \| July One Two Thousand Nineteen [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue remaining performance obligation	$ (1)

XML 76 R69.htm IDEA: XBRL DOCUMENT

Reorganization Items - Schedule of Reorganization Items (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Reorganizations [Abstract]
Advisory and professional fees	$ (115)
Interest income on surplus cash invested	6
Total reorganization items	$ (109)

XML 77 R70.htm IDEA: XBRL DOCUMENT

Loss on Disposals and Contingent Consideration - Summary of Loss on Disposals and Contingent Consideration (Detail) - USD ($) $ in Millions	6 Months Ended		36 Months Ended	44 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposals		$ (166)
Contingent consideration realized	$ 7	11
West Triton [Member] \| Drilling Unit [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposals		(34)
West Resolute [Member] \| Drilling Unit [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposals		(61)
West Mischief [Member] \| Drilling Unit [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposals		(71)
West Polaris [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration realized			$ 53
West Polaris [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration realized		4
West Vela [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration realized				$ 45
West Vela [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration realized	$ 7	$ 7

XML 78 R71.htm IDEA: XBRL DOCUMENT

Loss on Disposals and Contingent Consideration - Additional Information (Detail) - USD ($)		6 Months Ended		36 Months Ended	44 Months Ended
	Apr. 29, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2018	Jun. 19, 2015	Nov. 04, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposals			$ (166,000,000)
Contingent consideration realized		$ 7,000,000	$ 11,000,000
Seadrill Operating LP [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest (as percent)						42.00%
Contingent consideration arrangements, description		In relation to the sale, we may be entitled to receive a contingent consideration from Seadrill Partners, consisting of (a) any day rates earned by Seadrill Partners in excess of $450,000 per day, adjusted for daily utilization, tax and agency commission for the remainder of the ExxonMobil contract, which completed in December 2017 and (b) 50% of any day rate earned above $450,000 per day, adjusted for daily utilization, tax and agency commission fee after December 2017 until 2025.
Amount to be paid under contingent consideration arrangements, value, low		$ 450,000		$ 450,000	$ 450,000
West Triton West Mischief and West Resolute [Member] \| Drilling Unit [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Fair value of consideration received	$ 225,000,000
Loss on disposals	$ (166,000,000)
West Polaris [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent consideration realized				$ 53,000,000
West Vela [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest (as percent)							49.00%
Contingent consideration realized					$ 45,000,000
West Vela [Member] \| Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Fair value of consideration received							$ 40,000

XML 79 R72.htm IDEA: XBRL DOCUMENT

Taxation - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Transactions with Third Party [Line Items]
Increase in income tax expense	$ 48
Tax expense	18
Income tax expense (benefit)	36	$ (12)
Increase in uncertain tax position	8
Secretariat of the Federal Revenue Bureau of Brazil [Member]
Transactions with Third Party [Line Items]
Income tax examination, estimate of possible loss	161
Nigerian tax authorities [member]
Transactions with Third Party [Line Items]
Income tax examination, estimate of possible loss	$ 171

XML 80 R73.htm IDEA: XBRL DOCUMENT

Earnings Per Share - Summary of Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net loss	$ (477)	$ (78)
Less: Allocation to participating securities	0	0
Net loss available to shareholders	(477)	(78)
Effect of dilution	0	0
Diluted net loss available to shareholders	$ (477)	$ (78)
Basic earnings per share:
Weighted average number of common shares outstanding	504,000,000	504,000,000
Diluted earnings per share:
Weighted average number of common shares outstanding	504,000,000	504,000,000
Effect of dilutive share options	0	0
Effect of dilutive convertible bonds	0	0
Weighted average number of common shares outstanding adjusted for the effects of dilution	504,000,000	504,000,000
Basic (loss)/income per share (US dollar)	$ (0.95)	$ (0.16)
Diluted (loss)/income per share (US dollar)	$ (0.95)	$ (0.16)

XML 81 R74.htm IDEA: XBRL DOCUMENT

Earnings Per Share - Additional Information (Detail)	6 Months Ended
Earnings Per Share - Additional Information (Detail)	Jun. 30, 2018
Earnings Per Share [Abstract]
Plan of reorganization, equity securities issued or to be issued, ownership percentage	2.00%

XML 82 R75.htm IDEA: XBRL DOCUMENT

Cash and Cash Equivalents (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 809	$ 1,255
Restricted cash	409	104
Total	$ 1,218	$ 1,359	$ 1,441	$ 1,443

XML 83 R76.htm IDEA: XBRL DOCUMENT

Marketable Securities - Additional Information (Detail) $ in Millions	Jun. 30, 2018 USD ($)
Accounting Standards Update 2016-01 [Member]
Gain (Loss) on Investments [Line Items]
Reclassification of previously recognized fair value gains from accumulated other comprehensive income to retained earnings	$ 31

XML 84 R77.htm IDEA: XBRL DOCUMENT

Marketable Securities - Marketable Securities In The Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Marketable Securities [Line Items]
Total marketable securities	$ 121	$ 124
Seadrill Partners Common Units [Member]
Marketable Securities [Line Items]
Total marketable securities	91	96
Archer [Member]
Marketable Securities [Line Items]
Total marketable securities	$ 30	$ 28

XML 85 R78.htm IDEA: XBRL DOCUMENT

Marketable Securities - Net Unrealized Gains and Losses for Consolidated Statement of Operations (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Marketable Securities [Line Items]
Total unrealized (loss) / gain on marketable securities	$ (3)	$ 6
Seadrill Partners Common Units [Member]
Marketable Securities [Line Items]
Total unrealized (loss) / gain on marketable securities	(5)	(21)
Archer [Member]
Marketable Securities [Line Items]
Total unrealized (loss) / gain on marketable securities	$ 2	$ 27

XML 86 R79.htm IDEA: XBRL DOCUMENT

Accounts Receivable - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Accounts Receivable, Net, Current [Abstract]
Allowance for doubtful accounts receivables	$ 83,000,000		$ 35,000,000
Bad debt expense	$ 48,000,000	$ 0

XML 87 R80.htm IDEA: XBRL DOCUMENT

Investment in Associated Companies - Investments Either Recorded Using Equity Method or At Cost Less Impairment (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Total investment in associated companies	$ 1,615	$ 1,473
Seabras Sapura Participacoes Sa [Member]
Schedule of Investments [Line Items]
Equity method investments	76	63
Seabras Sapura Hold Co Ltd [Member]
Schedule of Investments [Line Items]
Equity method investments	334	290
SeaMex Limited [Member]
Schedule of Investments [Line Items]
Equity method investments	107	102
Direct Ownership Interest [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Equity method investments	914	857
Subordinated Units [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Equity method investments	120	97
Member Interest and Incentive Distribution Rights [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Cost method investments	$ 64	$ 64

XML 88 R81.htm IDEA: XBRL DOCUMENT

Investment In Associated Companies - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Equity method investment other than temporary impairment	$ 0
Remaining economic lives of underlying assets	30 years
Weighted average cost of capital	9.75%
Total Cost method investments other than temporary impairment	$ 0
SeaMex Limited [Member]
Schedule of Investments [Line Items]
Equity method investment other than temporary impairment	$ 0	$ 36,000,000
Remaining economic lives of underlying assets	30 years
Weighted average cost of capital	10.25%
Ownership interest	50.00%
Direct Ownership Interest [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Equity method investment other than temporary impairment		82,000,000
Subordinated Units [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Equity method investment other than temporary impairment		$ 723,000,000
Non Economic Interest [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Ownership interest	0.00%
Incentive Distribution Rights [Member] \| Seadrill Partners LLC [Member]
Schedule of Investments [Line Items]
Ownership interest	100.00%

XML 89 R82.htm IDEA: XBRL DOCUMENT

Newbuildings - Summary Of Newbuildings (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total Newbuildings	$ 249	$ 248
Newbuildings [Member]
Property, Plant and Equipment [Line Items]
Total Newbuildings	$ 249	$ 248

XML 90 R83.htm IDEA: XBRL DOCUMENT

Drilling Units - Summary Of Net Book Value (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Impairment	$ (414)	$ (696)
Net book value	12,780	13,464
Drilling Unit [Member]
Property, Plant and Equipment [Line Items]
Cost	17,452	17,335
Accumulated depreciation	(4,507)	(4,119)
Impairment	(414)
Net book value	$ 12,531	$ 13,216

XML 91 R84.htm IDEA: XBRL DOCUMENT

Drilling Units - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets	$ 414		$ 696
Drilling Unit [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	388	$ 392
Impairment of long-lived assets	$ 414
Weighted average cost of capital	11.40%
Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 3	$ 14

XML 92 R85.htm IDEA: XBRL DOCUMENT

Debt - Schedule of Debt (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Debt and Financial Instruments [Line Items]
Total debt principal	$ 8,547	$ 8,701
Less: Debt balance held as subject to compromise	(7,600)	(7,705)
Total debt not subject to compromise	947	996
Total debt not subject to compromise	947	996
Less: current portion of debt principal	(91)	(511)
Long-term portion of debt principal	856	485
Credit Facility Ship Finance International Loans 375 Facility [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	237	251
Credit Facility Ship Finance International Loans 390 Facility [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	215	226
Credit Facility Ship Finance International Loans 475 Facility [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	285	309
Credit Facility Ship Finance International Loans Total [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	737	786
Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	5,476	5,581
Secured Debt [Member] \| Credit Facility US 2000 North Atlantic Drilling [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	880	897
Secured Debt [Member] \| Credit Facility US 400 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	130	133
Secured Debt [Member] \| Credit Facility US 440 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	60	62
Secured Debt [Member] \| Credit Facility US 1450 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	311	318
Secured Debt [Member] \| Credit facility US 360 Asia Off shore Drilling [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	210	210
Secured Debt [Member] \| Credit Facility US300 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	140	142
Secured Debt [Member] \| Credit FacilityUS1750 Sevan Drilling [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	835	856
Secured Debt [Member] \| Credit Facility US450 Eminence [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	255	261
Secured Debt [Member] \| Credit Facility US 1500 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	1,095	1,112
Secured Debt [Member] \| Credit Facility US 1350 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	913	931
Secured Debt [Member] \| Credit Facility US 950 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	549	558
Secured Debt [Member] \| Credit Facility US 450 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	98	101
Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Less: Debt balance held as subject to compromise	(5,300)	(5,400)
Unsecured Debt [Member] \| Floating Interest Rate Bonds [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	231	231
Unsecured Debt [Member] \| Fixed Interest Rate Bonds1 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	843	843
Unsecured Debt [Member] \| US 500 Million Fixed Interest Bond [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	479	479
Unsecured Debt [Member] \| NOK 1500 Million Floating Interest Rate Bond [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	182	182
Unsecured Debt [Member] \| US600 Million Senior Unsecured Bond [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	413	413
Unsecured Debt [Member] \| SEK1 500 Million Senior Unsecured Bond [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	186	186
Unsecured Debt [Member] \| Total Bonds [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	$ 2,334	$ 2,334

XML 93 R86.htm IDEA: XBRL DOCUMENT

Debt - Schedule of Debt (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Apr. 30, 2013
Credit Facility US 2000 North Atlantic Drilling [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	$ 2,000	$ 2,000
Credit Facility US 400 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	400	400
Credit Facility US 440 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	440	440
Credit Facility US 1450 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	1,450	1,450
Credit facility US 360 Asia Off shore Drilling [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	360	360	$ 360
Credit Facility US300 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	300	300
Credit FacilityUS1750 Sevan Drilling [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	1,750	1,750
Credit Facility US450 Eminence [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	450	450
Credit Facility US 1500 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	1,500	1,500
Credit Facility US 1350 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	1,350	1,350
Credit Facility US 950 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	950	950
Credit Facility US 450 [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	450	450
Credit Facility Ship Finance International Loans 375 Facility [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	375	375
Credit Facility Ship Finance International Loans 390 Facility [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	390	390
Credit Facility Ship Finance International Loans 475 Facility [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	475	475
Floating Interest Rate Bonds [Member] \| Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	800	800
Fixed Interest Rate Bonds1 [Member] \| Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	1,000	1,000
US 500 Million Fixed Interest Bond [Member] \| Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	500	500
NOK 1500 Million Floating Interest Rate Bond [Member] \| Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	1,500	1,500
US600 Million Senior Unsecured Bond [Member] \| Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	600	600
SEK1 500 Million Senior Unsecured Bond [Member] \| Unsecured Debt [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount	$ 1,500	$ 1,500

XML 94 R87.htm IDEA: XBRL DOCUMENT

Debt - Additional Information (Detail) $ in Millions		1 Months Ended		6 Months Ended
Debt - Additional Information (Detail) $ in Millions	Jul. 02, 2018 USD ($)	May 31, 2013 USD ($) Facility	Apr. 30, 2013 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Oct. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Apr. 26, 2017 USD ($)
Debt and Financial Instruments [Line Items]
Protection payment				$ 185
Total debt principal				$ 8,547			$ 8,701
Debt service coverage ratio				1
Credit Facility Ship Finance International Loans 375 Facility [Member]
Debt and Financial Instruments [Line Items]
Total debt principal				$ 237			251
Debt, face amount				375			375
Credit Facility Ship Finance International Loans 390 Facility [Member]
Debt and Financial Instruments [Line Items]
Total debt principal				215			226
Debt, face amount				390			390
Credit Facility Ship Finance International Loans 475 Facility [Member]
Debt and Financial Instruments [Line Items]
Total debt principal				285			309
Debt, face amount				475			475
Credit Facility [Member]
Debt and Financial Instruments [Line Items]
Debt covenant, cash and cash equivalents				400
Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Total debt principal				5,476			5,581
Number of facilities \| Facility		3
Secured Debt [Member] \| Credit facility US 360 Asia Off shore Drilling [Member]
Debt and Financial Instruments [Line Items]
Total debt principal				210			210
Debt, face amount			$ 360	360			$ 360
Debt instrument term			5 years
Secured Debt [Member] \| SFL Hercules Limited [Member] \| Credit Facility Ship Finance International Loans 375 Facility [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount		$ 375
Secured Debt [Member] \| SFL Deepwater Limited [Member] \| Credit Facility Ship Finance International Loans 390 Facility [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount						$ 390
Secured Debt [Member] \| SFL Linus Limited [Member] \| Credit Facility Ship Finance International Loans 475 Facility [Member]
Debt and Financial Instruments [Line Items]
Debt, face amount						$ 475
Secured Debt [Member] \| Ship Finance International Limited [Member] \| Long-term Debt [Member]
Debt and Financial Instruments [Line Items]
Reclassification of long-term debt				200
Archer [Member]
Debt and Financial Instruments [Line Items]
Subordinated loan					$ 37			$ 37
Loans payable					45			45
Loans payable fair value					56			$ 56
Net gain on debt extinguishment				19	$ 19
Minimum [Member] \| Credit Facility [Member]
Debt and Financial Instruments [Line Items]
Debt covenant, cash and cash equivalents				$ 525
Maximum [Member] \| Secured Debt [Member]
Debt and Financial Instruments [Line Items]
Permitted leverage ratio for period one				4.5
Permitted leverage ratio for period two				4.2
Permitted leverage ratio for period three				3.9
Permitted leverage ratio for period four				3.7
LIBOR [Member] \| Secured Debt [Member] \| Credit facility US 360 Asia Off shore Drilling [Member]
Debt and Financial Instruments [Line Items]
Basis spread on variable rate			2.75%
Subsequent Event [Member] \| Senior Secured Notes Due in 2025 [Member]
Debt and Financial Instruments [Line Items]
Total debt principal	$ 880
Interest rate	12.00%
Cash interest	4.00%
Interest payable in kind	8.00%
Debt, face amount	$ 880

XML 95 R88.htm IDEA: XBRL DOCUMENT

Debt - Schedule of Debt Issuance Costs Against Current and Long-Term Debt (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Principal outstanding
Principal outstanding, current portion of long-term debt	$ 91	$ 511
Principal outstanding, noncurrent portion	856	485
Debt held as subject to compromise	7,600	7,705
Total	8,547	8,701
Debt issuance costs
Debt issuance costs, current portion of long-term debt	(1)	(2)
Debt issuance costs, noncurrent portion	0	0
Debt issuance costs, Debt held as subject to compromise	0	0
Debt issuance costs, gross	(1)	(2)
Total debt
Total debt, current portion	90	509
Total debt, noncurrent portion	856	485
Total debt, Debt held as subject to compromise	7,600	7,705
Total	$ 8,546	$ 8,699

XML 96 R89.htm IDEA: XBRL DOCUMENT

Debt - Outstanding Debt (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
2019	$ 91
2020	57
2021	68
2022	70
2023	523
2024 and thereafter	138
Total debt not subject to compromise	$ 947	$ 996

XML 97 R90.htm IDEA: XBRL DOCUMENT

Common Shares - Share Capital (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Sep. 12, 2017	May 10, 2005
Equity [Abstract]
Authorized share capital	800,000,000	800,000,000
Issued and fully paid share capital	508,763,020	508,763,020		6,000
Treasury shares held by the Company	(4,244,080)	(4,244,080)
Outstanding common shares in issue	504,518,940	504,518,940	504,518,940
Authorized share capital	$ 1,600	$ 1,600
Issued and fully paid share capital	1,017	1,017
Treasury shares held by the Company	(9)	(9)
Outstanding common shares in issue	$ 1,008	$ 1,008

XML 98 R91.htm IDEA: XBRL DOCUMENT

Common Shares - Share Capital (Parenthetical) (Detail) - $ / shares	Jun. 30, 2018	Dec. 31, 2017	May 10, 2005
Equity [Abstract]
Common shares, par value	$ 2.00	$ 2.00	$ 2.00

XML 99 R92.htm IDEA: XBRL DOCUMENT

Common Shares - Additional Information (Detail) - USD ($)	Jul. 02, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 12, 2017	May 10, 2005
Class of Stock [Line Items]
Common stock, shares issued		508,763,020	508,763,020		6,000
Common shares, par value		$ 2.00	$ 2.00		$ 2.00
Treasury shares held by Company		4,244,080	4,244,080
Outstanding shares in issue		504,518,940	504,518,940	504,518,940
Dividends payable				$ 0
Subsequent Event [Member]
Class of Stock [Line Items]
Common share issued	100,000,000

XML 100 R93.htm IDEA: XBRL DOCUMENT

Non-controlling Interest - Changes in Non-controlling Interest (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Noncontrolling Interest [Line Items]
Beginning balance	$ 399
Net income attributable to non-controlling interest in 2018	(160)	$ (23)
Ending balance	64
Ship Finance International Ltd VIEs [Member]
Noncontrolling Interest [Line Items]
Beginning balance	(59)
Net income attributable to non-controlling interest in 2018	7
Ending balance	(52)
North Atlantic Drilling Ltd [Member]
Noncontrolling Interest [Line Items]
Beginning balance	76
Net income attributable to non-controlling interest in 2018	(160)
Ending balance	(109)
Asia Offshore Drilling [Member]
Noncontrolling Interest [Line Items]
Beginning balance	149
Net income attributable to non-controlling interest in 2018	1
Redeemable non-controlling interest	(150)
Sevan Drilling Asa [Member]
Noncontrolling Interest [Line Items]
Beginning balance	226
Net income attributable to non-controlling interest in 2018	(10)
Ending balance	216
Seadrill Nigeria Operations Limited [Member]
Noncontrolling Interest [Line Items]
Beginning balance	7
Net income attributable to non-controlling interest in 2018	2
Ending balance	9
Accounting standards update 2016-16
Noncontrolling Interest [Line Items]
Adoption of new accounting standard ASU 2016-16 - Income Taxes	(84)
Accounting standards update 2016-16 \| North Atlantic Drilling Ltd [Member]
Noncontrolling Interest [Line Items]
Adoption of new accounting standard ASU 2016-16 - Income Taxes	(25)
Non-controlling Interest [Member]
Noncontrolling Interest [Line Items]
Beginning balance	399
Net income attributable to non-controlling interest in 2018	(160)
Redeemable non-controlling interest	(150)
Ending balance	64
Non-controlling Interest [Member] \| Accounting standards update 2016-16
Noncontrolling Interest [Line Items]
Adoption of new accounting standard ASU 2016-16 - Income Taxes	$ (25)

XML 101 R94.htm IDEA: XBRL DOCUMENT

Redeemable Non-controlling Interest - Changes in Redeemable Non-Controlling Interest (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Redeemable Non-controlling Interest [Line Items]
Reclassification from non-controlling interest	$ (150)
Fair value adjustment on initial recognition	127
Net income attributable to redeemable non-controlling interest in 2018	(2)
Ending balance	25
Asia Offshore Drilling [Member]
Redeemable Non-controlling Interest [Line Items]
Beginning balance	0
Reclassification from non-controlling interest	150
Fair value adjustment on initial recognition	(127)
Net income attributable to redeemable non-controlling interest in 2018	2
Ending balance	$ 25

XML 102 R95.htm IDEA: XBRL DOCUMENT

Redeemable Non-controlling Interest - Additional Information (Detail) - USD ($) $ in Millions		6 Months Ended
	Apr. 04, 2018	Jun. 30, 2018
Redeemable Non-controlling Interest [Line Items]
Reclassification from non-controlling interest		$ 150
Net income attributable to redeemable non-controlling interest		2
Fair value adjustment of redeemable non-controlling interest		127
Redeemable non-controlling interest		25
Non-controlling Interest [Member]
Redeemable Non-controlling Interest [Line Items]
Reclassification from non-controlling interest	$ 150	$ 150

XML 103 R96.htm IDEA: XBRL DOCUMENT

Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 58
Adoption of accounting standard update	(31)
Beginning balance, adjusted	27
Other comprehensive income before reclassifications	14
Ending balance	41
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	31
Adoption of accounting standard update	(31)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	36
Beginning balance, adjusted	36
Ending balance	36
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(26)
Beginning balance, adjusted	(26)
Other comprehensive income before reclassifications	1
Ending balance	(25)
Accumulated Other Comprehensive Income Loss Unrealized Gains Losses From Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	15
Beginning balance, adjusted	15
Other comprehensive income before reclassifications	11
Ending balance	26
Accumulated other comprehensive income loss change in unrealized gain on derivative in VIEs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	2
Beginning balance, adjusted	2
Ending balance	2
Accumulated Other Comprehensive Income Loss Change In Conversion Option On Debt Facility [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income before reclassifications	2
Ending balance	$ 2

XML 104 R97.htm IDEA: XBRL DOCUMENT

Accumulated Other Comprehensive Income - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income taxes	$ 0
Actuarial gain related to pension, tax effect	400,000	$ 600,000
Accounting Standards Update 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income	$ 31,000,000

XML 105 R98.htm IDEA: XBRL DOCUMENT

Risk Management and Financial Instruments - Additional Information (Detail) - USD ($)		6 Months Ended
	May 11, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Apr. 26, 2017	Mar. 31, 2016
Derivative [Line Items]
Derivatives previously recorded at fair value		$ 249,000,000			$ 249,000,000
Interest rate contracts not designated as instrument hedging		0	$ 18,000,000
Loss/gain on derivative financial instruments		(4,000,000)	7,000,000
Total debt principal		7,600,000,000			7,705,000,000
Archer [Member]
Derivative [Line Items]
Subordinated loan			37,000,000			$ 37,000,000
Loans payable			45,000,000			45,000,000
Loans payable fair value			56,000,000			$ 56,000,000
Net gain on extinguishment of subordinated debt		19,000,000	19,000,000
Fair value of the convertible debt instrument		58,000,000
Gain on the debt component		2,000,000
Gain on the embedded conversion option		4,000,000
Archer [Member] \| Debt [Member]
Derivative [Line Items]
Fair value of the convertible debt instrument		46,000,000
Unsecured Debt [Member]
Derivative [Line Items]
Total debt principal		5,300,000,000			5,400,000,000
Carrying Value [Member]
Derivative [Line Items]
Long-term floating rate debt (including the current portion)		6,200,000,000			6,400,000,000
Fixed interest bonds, fair value disclosures, noncurrent		1,700,000,000		$ 1,700,000,000
Floating interest bonds - long term		600,000,000		600,000,000
Related party fixed rate debt - long term		314,000,000		314,000,000
Fair Value [Member]
Derivative [Line Items]
Related party fixed rate debt - long term		$ 219,000,000		$ 218,000,000
Ship Finance Variable Interest Entities [Member]
Derivative [Line Items]
Weighted average cost of capital		11.00%
Interest Rate Swap [Member]
Derivative [Line Items]
Derivatives previously recorded at fair value		$ 39,000,000			39,000,000
Interest rate contracts not designated as instrument hedging		(1,000,000)	(18,000,000)
Interest Rate Swap [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Derivative [Line Items]
Gross liability					1,000,000
Other comprehensive income, unrealized gain (loss) on interest rate swaps in VIEs		300,000	1,000,000
Net gain (loss) on fair value hedge ineffectiveness		0	0
Interest rate swap cash settlement		100,000	600,000
Interest Rate Swap [Member] \| Other Noncurrent Assets [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Derivative [Line Items]
Derivative asset		$ 400,000
Interest Rate Swap [Member] \| Minimum [Member]
Derivative [Line Items]
Derivative maturity date		Nov. 02, 2017
Derivative, fixed interest rate		0.74%
Interest Rate Swap [Member] \| Maximum [Member]
Derivative [Line Items]
Derivative maturity date		Jan. 29, 2027
Derivative, fixed interest rate		3.34%
Interest Rate Swap 2 [Member]
Derivative [Line Items]
Derivative, fixed interest rate							2.12%
Cross Currency Interest Rate Swaps [Member]
Derivative [Line Items]
Derivatives previously recorded at fair value		$ 210,000,000			$ 210,000,000
Interest rate contracts not designated as instrument hedging		$ 0	29,000,000
Cross Currency Interest Rate Swaps [Member] \| Minimum [Member]
Derivative [Line Items]
Derivative maturity date		Mar. 01, 2018
Derivative, fixed interest rate		4.94%
Cross Currency Interest Rate Swaps [Member] \| Maximum [Member]
Derivative [Line Items]
Derivative maturity date		Mar. 01, 2019
Derivative, fixed interest rate		6.18%
Interest Rate Cap [Member]
Derivative [Line Items]
Derivative maturity date	Jun. 15, 2019
Derivative notional amount	$ 68,000,000	$ 4,500,000,000
Derivative inception date	Jun. 15, 2019
Fair value of derivative financial instrument		61,000,000
Loss/gain on derivative financial instruments		(7,000,000)
Interest Rate Cap [Member] \| LIBOR [Member]
Derivative [Line Items]
Derivative variable interest rate	2.87%
Interest Rate Cap [Member] \| Carrying Value [Member]
Derivative [Line Items]
Derivative asset		61,000,000
Interest Rate Cap [Member] \| Fair Value [Member]
Derivative [Line Items]
Derivative asset		61,000,000
Foreign Currency Forwards [Member]
Derivative [Line Items]
Interest rate contracts not designated as instrument hedging		0	$ 1,000,000
Embedded Derivative Option [Member] \| Archer [Member]
Derivative [Line Items]
Fair value of the convertible debt instrument		$ 12,000,000

XML 106 R99.htm IDEA: XBRL DOCUMENT

Risk Management And Financial Instruments - Variable Interest Entities (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Derivative [Line Items]
Outstanding principal	$ 141
Interest Rate Swap [Member] \| Minimum [Member]
Derivative [Line Items]
Pay rates	0.74%
Interest Rate Swap [Member] \| Maximum [Member]
Derivative [Line Items]
Pay rates	3.34%
Derivative Instrument Maturity Date [Member] \| Interest Rate Swap [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Minimum [Member]
Derivative [Line Items]
Pay rates	177.00%
Length of contracts	2013-12
Derivative Instrument Maturity Date [Member] \| Interest Rate Swap [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Maximum [Member]
Derivative [Line Items]
Pay rates	201.00%
Length of contracts	2018-12

XML 107 R100.htm IDEA: XBRL DOCUMENT

Risk Management And Financial Instruments - Realized and Unrealized Gains and Losses Recognized In Consolidated Statement of Operations (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate contracts not designated as instrument hedging	$ 0	$ 18,000,000
Gain / (loss) on derivative financial instruments	(4,000,000)	7,000,000
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate contracts not designated as instrument hedging	(1,000,000)	(18,000,000)
Cross Currency Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate contracts not designated as instrument hedging	0	29,000,000
Foreign Currency Forwards [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate contracts not designated as instrument hedging	0	1,000,000
Interest Rate Cap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain / (loss) on derivative financial instruments	(7,000,000)
Convertible Loan Agreement [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain / (loss) on derivative financial instruments	$ 4,000,000	$ (5,000,000)

XML 108 R101.htm IDEA: XBRL DOCUMENT

Risk Management and Financial Instruments - Carrying Value and Estimated at Fair Value of Financial Instruments (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 809	$ 1,255
Restricted cash	409	104
Related party loans receivable-short term	18	25
Related party loans receivable-long term	547	522
Fair Value [Member] \| Interest Rate Cap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset-interest rate cap	61
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	809	1,255
Restricted cash	409	104
Related party loans receivable-short term	18	25
Related party loans receivable-long term	535	$ 515
Carrying Value [Member] \| Interest Rate Cap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset-interest rate cap	$ 61

XML 109 R102.htm IDEA: XBRL DOCUMENT

Risk Management and Financial Instruments - Financial Instruments Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities-current asset	$ 121	$ 124
Interest rate cap - current asset	61
Convertible debt instrument-non-current asset	58	52
Total assets	240	176
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities-current asset	121	124
Total assets	121	124
Fair Value Measurements as at the Reporting Date Using Significant Other Observable Inputs (Level 2) [Member] \| Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate cap - current asset	61
Total assets	61
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible debt instrument-non-current asset	58	52
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible debt instrument-non-current asset	58	52
Total assets	$ 58	$ 52