Pension - Projected Benefit Obligations and Assets (Details) - Pension Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in benefit obligation
Benefit obligation, January 1	$ 3,948	$ 5,223
Service cost	1	2	$ 2
Interest cost	204	140	132
Actuarial (gains), net	93	(1,094)
Benefits paid from plan assets	(294)	(296)
Other	(18)	(27)
Benefit obligation, December 31	3,934	3,948	5,223
Change in plan assets
Fair value of plan assets, January 1	4,186	4,846
Actual return on plan assets	246	(366)
Benefits paid	(294)	(296)
Contributions	0	2
Fair value of plan assets, December 31	4,138	4,186	$ 4,846
Funded status	204	238
Amounts presented in Consolidated Balance Sheets
Other assets	$ 204	$ 238