Level 3 plan assets roll forward (Details) - Buy-in annuity insurance contract - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Defined Benefit Plan, Plan Assets, Level 3 Reconciliation [Line Items]
Balance at the beginning of the year	$ 565	$ 2
Purchase of insurance contract	0	590
Return on assets	23	(18)
Payment from the insurance policy	(27)	(9)
Balance at the end of the year	$ 561	$ 565