XML 170 R158.htm IDEA: XBRL DOCUMENT
v3.20.4

Redeemable non-controlling interest - Schedule of Changes in Redeemable Non-controlling Interest (Details) - USD ($) $ in Millions |  | 12 Months Ended
--- | --- | ---
Sep. 11, 2020 | Dec. 31, 2020 | Dec. 31, 2019
Increase (Decrease) in Temporary Equity [Roll Forward] |  |  |
Acquisition of NCI |  | $ (31) |
Asia Offshore Drilling Ltd |  |  |
Increase (Decrease) in Temporary Equity [Roll Forward] |  |  |
Acquisition of NCI | $ 31 |  |
Redeemable non-controlling interest |  |  |
Increase (Decrease) in Temporary Equity [Roll Forward] |  |  |
Beginning balance |  | 57 |
Ending balance |  | 0 | $ 57
Redeemable non-controlling interest | Asia Offshore Drilling Ltd |  |  |
Increase (Decrease) in Temporary Equity [Roll Forward] |  |  |
Beginning balance |  |  | 38
Net loss attributable to redeemable non-controlling interest |  | (1) | (2)
Fair value adjustment |  | $ (25) | $ 21

X
- Definition Temporary Equity, Decrease From Acquisition Of Interest + References No definition available. + Details
Name: | sdrl_TemporaryEquityDecreaseFromAcquisitionOfInterest
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Temporary Equity, Fair Value Adjustment + References No definition available. + Details
Name: | sdrl_TemporaryEquityFairValueAdjustment
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_IncreaseDecreaseInTemporaryEquityRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount, attributable to parent and noncontrolling interests, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.27(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_TemporaryEquityCarryingAmountIncludingPortionAttributableToNoncontrollingInterests
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The portion of net income or loss attributable to temporary equity interest. + References No definition available. + Details
Name: | us-gaap_TemporaryEquityNetIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_OwnershipAxis=sdrl_AsiaOffshoreDrillingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_NoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |