Employee Benefits - Change in Plan Assets Measured at Fair Value (Details) - Combined Pension Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Change in plan assets
Fair value of plan assets at beginning of year	$ 4,476	$ 4,715
Fair value of plan assets at end of year	4,201	4,476
Level 3
Change in plan assets
Fair value of plan assets at beginning of year	5	5
Dispositions		(2)
Acquisition	1
Actual return on plan assets	0	2
Fair value of plan assets at end of year	6	5
Level 3 | High Yield Bonds
Change in plan assets
Fair value of plan assets at beginning of year	4	4
Dispositions		(2)
Acquisition	0
Actual return on plan assets	0	2
Fair value of plan assets at end of year	4	4
Level 3 | U.S. Stocks
Change in plan assets
Fair value of plan assets at beginning of year	1	1
Dispositions		0
Acquisition	0
Actual return on plan assets	0	0
Fair value of plan assets at end of year	1	1
Level 3 | Non-U.S. Stocks
Change in plan assets
Fair value of plan assets at beginning of year	0	0
Dispositions		0
Acquisition	1
Actual return on plan assets	0	0
Fair value of plan assets at end of year	$ 1	$ 0