XML 105 R98.htm IDEA: XBRL DOCUMENT
v3.10.0.1

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 |  |  |  |  |

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Debt instrument fair value disclosure fixed interest rate related party long term. + References No definition available. + Details
Name: | sdrl_DebtInstrumentFairValueDisclosureFixedInterestRateRelatedPartyLongTerm
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt instrument floating rate fair value disclosure non-current. + References No definition available. + Details
Name: | sdrl_DebtInstrumentFloatingRateFairValueDisclosureNoncurrent
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fixed interest bonds fair value disclosures non-current. + References No definition available. + Details
Name: | sdrl_FixedInterestBondsFairValueDisclosuresNoncurrent
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Floating interest bonds fair value disclosures non-current. + References No definition available. + Details
Name: | sdrl_FloatingInterestBondsFairValueDisclosuresNoncurrent
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Interest rate swap settlement amount. + References No definition available. + Details
Name: | sdrl_InterestRateSwapSettlementAmount
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Liabilities subject to compromise derivative liability. + References No definition available. + Details
Name: | sdrl_LiabilitiesSubjectToCompromiseDerivativeLiability
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Other comprehensive income unrealized gain loss on interest rate swaps in vies. + References No definition available. + Details
Name: | sdrl_OtherComprehensiveIncomeUnrealizedGainLossOnInterestRateSwapsInVies
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock. + References No definition available. + Details
Name: | us-gaap_ConvertibleDebtFairValueDisclosures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=82924980&loc=SL51823488-111719 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226000-175313 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fixed interest rate related to the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Date the entity entered into the derivative contract, in CCYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DerivativeInceptionDates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the derivative contract matures, in CCYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DerivativeMaturityDates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Variable interest rate in effect as of the balance sheet date related to the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeVariableInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Increase in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
Name: | us-gaap_EmbeddedDerivativeGainOnEmbeddedDerivative
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
Name: | us-gaap_GainLossOnFairValueHedgesRecognizedInEarnings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of gain (loss) included in earnings for the period from the increase (decrease) in fair value of interest rate derivatives not designated as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
Name: | us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net gain (loss) recognized in earnings during the period due to the ineffectiveness on interest rate fair value hedges. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986 + Details
Name: | us-gaap_GainLossOnInterestRateFairValueHedgeIneffectiveness
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629 + Details
Name: | us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of debt and related accrued interest included in liabilities subject to compromise. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=64805424&loc=d3e55717-112764 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6918054&loc=d3e56015-112765 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 55 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766 + Details
Name: | us-gaap_LiabilitiesSubjectToCompromiseDebtAndAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Including the current and noncurrent portions, aggregate carrying value as of the balance sheet date of loans payable (with maturities initially due after one year or beyond the operating cycle if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: 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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)(a)(2)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_LoansPayable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of contractual obligation to pay money on demand or on fixed or determinable dates. + References No definition available. + Details
Name: | us-gaap_LoansPayableFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: 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 3: 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(19)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_SubordinatedDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LineOfCreditFacilityAxis=sdrl_ArcherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=sdrl_ShipFinanceVariableInterestEntitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=sdrl_InterestRateSwapTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CrossCurrencyInterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateCapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EmbeddedDerivativeFinancialInstrumentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |