Pension and Postretirement Benefit Plans - Components of Net Periodic Benefit Cost and Other Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Non-operating expense
Total net periodic benefit cost (benefit)	$ (31)	$ (67)
Postretirement Benefits
Operating expense
Service cost	6	11
Non-operating expense
Interest cost	22	13
Expected return on plan assets	(19)	(18)
Amortization of transition asset	0	0
Amortization of prior service benefit	(8)	(7)
Amortization of net actuarial loss	2	10
Settlements, curtailments, special termination benefits and other	0	1
Total non-operating expense (benefit)	(3)	(1)
Total net periodic benefit cost (benefit)	3	10
United States | Qualified and Non-qualified Pension Benefits
Operating expense
Service cost	43	64
Non-operating expense
Interest cost	166	104
Expected return on plan assets	(244)	(241)
Amortization of transition asset	0	0
Amortization of prior service benefit	(6)	(6)
Amortization of net actuarial loss	73	106
Settlements, curtailments, special termination benefits and other	0	0
Total non-operating expense (benefit)	(11)	(37)
Total net periodic benefit cost (benefit)	32	27
International | Qualified and Non-qualified Pension Benefits
Operating expense
Service cost	19	35
Non-operating expense
Interest cost	55	32
Expected return on plan assets	(75)	(72)
Amortization of transition asset	0	0
Amortization of prior service benefit	1	0
Amortization of net actuarial loss	2	11
Settlements, curtailments, special termination benefits and other	0	0
Total non-operating expense (benefit)	(17)	(29)
Total net periodic benefit cost (benefit)	$ 2	$ 6