Pension and Other Postretirement Benefits - Change in Plan Benefit Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension
Change in benefit obligation:
Beginning balance	$ 2,765	$ 2,939
Service cost	47	53	$ 55
Interest cost	50	39	60
Plan participants' contributions	1	2
Actuarial (gain) loss	(607)	(131)
Acquisitions	0	40
Benefits paid	(160)	(161)
Medicare subsidy received	0	0
Foreign currency translation	(103)	(16)
Ending balance	1,993	2,765	2,939
Accumulated benefit obligation as of December 31	1,911	2,642
Other Postretirement Benefits
Change in benefit obligation:
Beginning balance	580	591
Service cost	7	7	8
Interest cost	13	11	16
Plan participants' contributions	10	10
Actuarial (gain) loss	(101)	2
Acquisitions	0	0
Benefits paid	(43)	(42)
Medicare subsidy received	2	1
Foreign currency translation	0	0
Ending balance	$ 468	$ 580	$ 591