XML 154 R142.htm IDEA: XBRL DOCUMENT
v3.20.4

Debt - Additional Information (Details) - USD ($) $ in Millions | 4 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2018 | Jul. 01, 2018 | Dec. 31, 2020 | Dec. 31, 2019
Debt Disclosure [Abstract] |  |  |  |  |
Write off of unamortized debt discount | $ 87 | $ 0 | $ 0 | $ 87 | $ 0

X
- Definition Write-Off Of Debt Discount + References No definition available. + Details
Name: | sdrl_WriteOffOfDebtDiscount
Namespace Prefix: | sdrl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_DebtDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration