Employee Benefits - Change in Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Change in plan assets
Return on plan assets	$ 107	$ 255
Combined Pension Plan
Change in plan assets
Fair value of plan assets at beginning of year	4,476	4,715	$ 8,531
Plan spin-off	0	0	(2,239)
Return on plan assets	107	255	(987)
Benefits paid from plan assets	(552)	(494)	(590)
Contributions	170	0	0
Fair value of plan assets at end of year	$ 4,201	$ 4,476	$ 4,715