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, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Non-operating expense
Total net periodic benefit cost (benefit)	$ 20	$ 7	$ 71	$ 792
Postretirement benefits
Operating expense
Service cost	5	5	14	17
Non-operating expense
Interest cost	18	20	56	63
Expected return on plan assets	(14)	(15)	(42)	(49)
Amortization of transition asset	0	0	0	0
Amortization of prior service benefit	(4)	(6)	(8)	(18)
Amortization of net actuarial loss	4	5	12	15
Settlements, curtailments, special termination benefits and other	0	0	0	0
Total non-operating expense (benefit)	4	4	18	11
Total net periodic benefit cost (benefit)	9	9	32	28
Service cost - continuing operations			14	16
Service cost - discontinued operations			0	1
Postretirement benefits | Continuing Operations
Non-operating expense
Total non-operating expense (benefit) - continuing operations			18	11
Total net periodic benefit cost (benefit) - continuing operations			32	27
Postretirement benefits | Discontinued Operations
Non-operating expense
Total non-operating expense (benefit) - discontinued operations			0	0
Total net periodic benefit cost (benefit) - discontinued operations			0	1
United States | U.S. Pension Plans
Operating expense
Service cost	26	28	77	94
Non-operating expense
Interest cost	108	110	325	411
Expected return on plan assets	(142)	(140)	(426)	(573)
Amortization of transition asset	0	0	0	0
Amortization of prior service benefit	0	(3)	0	(11)
Amortization of net actuarial loss	69	64	207	242
Settlements, curtailments, special termination benefits and other	0	0	0	795
Total non-operating expense (benefit)	35	31	106	864
Total net periodic benefit cost (benefit)	61	59	183	958
Service cost - continuing operations			77	87
Service cost - discontinued operations			0	7
United States | U.S. Pension Plans | Continuing Operations
Non-operating expense
Total non-operating expense (benefit) - continuing operations			106	864
Total net periodic benefit cost (benefit) - continuing operations			183	951
United States | U.S. Pension Plans | Discontinued Operations
Non-operating expense
Total non-operating expense (benefit) - discontinued operations			0	0
Total net periodic benefit cost (benefit) - discontinued operations			0	7
International | U.S. Pension Plans
Operating expense
Service cost	12	15	36	50
Non-operating expense
Interest cost	46	50	138	153
Expected return on plan assets	(67)	(81)	(198)	(248)
Amortization of transition asset	0	0	0	2
Amortization of prior service benefit	0	0	1	1
Amortization of net actuarial loss	2	3	6	9
Settlements, curtailments, special termination benefits and other	0	0	0	0
Total non-operating expense (benefit)	(19)	(28)	(53)	(83)
Total net periodic benefit cost (benefit)	$ (7)	$ (13)	(17)	(33)
Service cost - continuing operations			36	45
Service cost - discontinued operations			0	5
International | U.S. Pension Plans | Continuing Operations
Non-operating expense
Total non-operating expense (benefit) - continuing operations			(53)	(83)
Total net periodic benefit cost (benefit) - continuing operations			(17)	(38)
International | U.S. Pension Plans | Discontinued Operations
Non-operating expense
Total non-operating expense (benefit) - discontinued operations			0	0
Total net periodic benefit cost (benefit) - discontinued operations			$ 0	$ 5