Leases - Operating Subleases (Details) $ in Millions	Dec. 31, 2019 USD ($)
Leases [Abstract]
2020	$ 1
2021	1
2022	1
2023	0
2024	0
Total	$ 3

Lessor, Operating Sublease, Payment to be Received

No definition available.

Name:	sdrl_LessorOperatingSubleasePaymenttobeReceived
Namespace Prefix:	sdrl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Lessor, Operating Sublease, Payment to be Received, Year Five And Thereafter

No definition available.

Name:	sdrl_LessorOperatingSubleasePaymenttobeReceivedYearFiveAndThereafter
Namespace Prefix:	sdrl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Lessor, Operating Sublease, Payment to be Received, Year Four

No definition available.

Name:	sdrl_LessorOperatingSubleasePaymenttobeReceivedYearFour
Namespace Prefix:	sdrl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Lessor, Operating Sublease, Payment to be Received, Year One

No definition available.

Name:	sdrl_LessorOperatingSubleasePaymenttobeReceivedYearOne
Namespace Prefix:	sdrl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Lessor, Operating Sublease, Payment to be Received, Year Three

No definition available.

Name:	sdrl_LessorOperatingSubleasePaymenttobeReceivedYearThree
Namespace Prefix:	sdrl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Lessor, Operating Sublease, Payment to be Received, Year Two

No definition available.

Name:	sdrl_LessorOperatingSubleasePaymenttobeReceivedYearTwo
Namespace Prefix:	sdrl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.