Share based compensation - Restricted Stock Unit Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Awards subject to service or external market conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of share awards vested during the period (in $ millions)	$ 12	$ 4	$ 2
Shares
Non-vested restricted share units, beginning balance (in shares)	857,350
Granted during the year (in shares)	647,413
Vested during the year (in shares)	(324,003)		(43,988)
Forfeited during the year (in shares)	(22,476)
Change in units based on performance (in shares)	(243,932)
Non-vested restricted share units, ending balance (in shares)	914,352	857,350
Weighted average grant date fair value (in $)
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 44.86
Weighted average grant date fair value, granted during the year (in dollars per share)	18.67	$ 55.15	$ 38.74
Weighted average grant date fair value, vested during the year (in dollars per share)	39.57
Weighted average grant date fair value, forfeited during the year (in dollars per share)	34.02
Change in units based on performance (in dollars per share)	44.07
Weighted average grant date fair value, ending balance (in dollars per share)	$ 28.68	$ 44.86
Weighted average remaining contractual term (in years)	1 year 8 months 19 days	1 year 3 months 21 days
Awards subject to internal performance conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of share awards vested during the period (in $ millions)	$ 4	$ 0	$ 0
Shares
Non-vested restricted share units, beginning balance (in shares)	224,840
Granted during the year (in shares)	172,683
Vested during the year (in shares)	(105,067)
Forfeited during the year (in shares)	(3,766)
Change in units based on performance (in shares)	(115,430)
Non-vested restricted share units, ending balance (in shares)	173,260	224,840
Weighted average grant date fair value (in $)
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 44.96
Weighted average grant date fair value, granted during the year (in dollars per share)	20.62	$ 49.81	$ 41.83
Weighted average grant date fair value, vested during the year (in dollars per share)	41.83
Weighted average grant date fair value, forfeited during the year (in dollars per share)	35.20
Change in units based on performance (in dollars per share)	33.25
Weighted average grant date fair value, ending balance (in dollars per share)	$ 30.66	$ 44.96
Weighted average remaining contractual term (in years)	1 year 7 months 28 days	1 year 6 months 3 days

Seadrill Ltd 10-K