Employee Benefit Plans - Changes in Benefit Obligation and Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Change in plan assets:
Fair value of plan assets beginning balance	$ 227
Fair value of plan assets ending balance	241	$ 227
Defined Pension  Benefits
Change in benefit obligation:
Accumulated benefit beginning balance	128	163
Service cost	1	1
Interest cost	7	4
Benefits paid	(10)	(11)
Actuarial loss (gain)	1	(29)
Accumulated benefit ending balance	127	128
Change in plan assets:
Fair value of plan assets beginning balance	222	273
Actual return on plan assets	23	(41)
Employer contributions	1	1
Benefits paid	(10)	(11)
Fair value of plan assets ending balance	236	222
Over (under) funded status as of December 31,	109	94
Other Postretirement Benefits
Change in benefit obligation:
Accumulated benefit beginning balance	12	16
Service cost	0	0
Interest cost	0	0
Benefits paid	(2)	(1)
Actuarial loss (gain)	0	(3)
Accumulated benefit ending balance	10	12
Change in plan assets:
Fair value of plan assets beginning balance	5	6
Actual return on plan assets	1	(1)
Employer contributions	1	1
Benefits paid	(2)	(1)
Fair value of plan assets ending balance	5	5
Over (under) funded status as of December 31,	$ (5)	$ (7)