XML 171 R159.htm IDEA: XBRL DOCUMENT
v3.20.4

Redeemable non-controlling interest - Additional Information (Details) - USD ($) |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | ---
Sep. 11, 2020 | Apr. 04, 2018 | Dec. 31, 2020 | Sep. 10, 2020 | Jul. 31, 2020
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Acquisition of NCI |  |  | $ (31,000,000) |  |
Asia Offshore Drilling Ltd |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Noncontrolling interest, ownership percentage by parent | 100.00% |  |  | 66.24% | 66.24%
Acquisition of NCI | $ 31,000,000 |  |  |  |
Mermaid | Asia Offshore Drilling Ltd |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Noncontrolling interest, ownership percentage by noncontrolling owners |  |  |  | 33.76% |
Noncontrolling interest owners option to redeem, price ceiling |  | $ 125,000,000 |  |  |
Noncontrolling interest parent option to redeem, price floor |  | $ 75,000,000 |  |  |

X
- Definition Noncontrolling Interest, Noncontrolling Owners Option To Redeem, Repurchase Price Ceiling + References No definition available. + Details
Name: | sdrl_NoncontrollingInterestNoncontrollingOwnersOptionToRedeemRepurchasePriceCeiling
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Noncontrolling Interest, Parent Option To Redeem, Repurchase Price Floor + References No definition available. + Details
Name: | sdrl_NoncontrollingInterestParentOptionToRedeemRepurchasePriceFloor
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_RedeemableNoncontrollingInterestLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | srt_CounterpartyNameAxis=sdrl_MermaidMaritimePublicCompanyLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |