Pension and Postretirement Benefit Plans - Components of Net Periodic Benefit Cost and Other Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Non-operating expense
Total net periodic benefit cost (benefit)	$ (65)	$ (80)	$ (199)	$ (239)
Postretirement Benefits
Operating expense
Service cost	10	12	31	35
Non-operating expense
Interest cost	13	11	39	33
Expected return on plan assets	(17)	(19)	(52)	(58)
Amortization of transition asset	0	0	0	0
Amortization of prior service benefit	(8)	(9)	(24)	(25)
Amortization of net actuarial loss	10	14	30	42
Settlements, curtailments, special termination benefits and other	0	0	2	2
Total non-operating expense (benefit)	(2)	(3)	(5)	(6)
Total net periodic benefit cost (benefit)	8	9	26	29
UNITED STATES | Qualified and Non-qualified Pension Benefits
Operating expense
Service cost	64	72	192	216
Non-operating expense
Interest cost	105	90	313	270
Expected return on plan assets	(241)	(264)	(723)	(792)
Amortization of transition asset	0	0	0	0
Amortization of prior service benefit	(6)	(6)	(18)	(18)
Amortization of net actuarial loss	106	132	318	396
Settlements, curtailments, special termination benefits and other	0	0	0	0
Total non-operating expense (benefit)	(36)	(48)	(110)	(144)
Total net periodic benefit cost (benefit)	28	24	82	72
International | Qualified and Non-qualified Pension Benefits
Operating expense
Service cost	32	41	100	125
Non-operating expense
Interest cost	32	25	96	75
Expected return on plan assets	(69)	(81)	(211)	(244)
Amortization of transition asset	0	1	1	2
Amortization of prior service benefit	0	0	0	(2)
Amortization of net actuarial loss	10	26	30	80
Settlements, curtailments, special termination benefits and other	0	0	0	0
Total non-operating expense (benefit)	(27)	(29)	(84)	(89)
Total net periodic benefit cost (benefit)	$ 5	$ 12	$ 16	$ 36