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, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Non-operating expense
Total net periodic benefit cost (benefit)	$ 7	$ (26)	$ 792	$ (77)
Postretirement Benefits
Operating expense
Service cost	5	6	17	18
Non-operating expense
Interest cost	20	21	63	66
Expected return on plan assets	(15)	(20)	(49)	(58)
Amortization of transition asset	0	0	0	0
Amortization of prior service benefit	(6)	(7)	(18)	(23)
Amortization of net actuarial loss	5	2	15	6
Settlements, curtailments, special termination benefits and other	0	0	0	0
Total non-operating expense (benefit)	4	(4)	11	(9)
Total net periodic benefit cost (benefit)	9	2	28	9
Postretirement Benefits | Continuing Operations
Operating expense
Service cost	5	5	16	15
Non-operating expense
Total non-operating expense (benefit)	4	(3)	11	(7)
Total net periodic benefit cost (benefit)	9	2	27	8
Postretirement Benefits | Discontinued Operations
Operating expense
Service cost	0	1	1	3
Non-operating expense
Total non-operating expense (benefit)	0	(1)	0	(2)
Total net periodic benefit cost (benefit)	0	0	1	1
United States | U.S. Pension Plans
Operating expense
Service cost	28	42	94	128
Non-operating expense
Interest cost	110	166	411	497
Expected return on plan assets	(140)	(243)	(573)	(731)
Amortization of transition asset	0	0	0	0
Amortization of prior service benefit	(3)	(6)	(11)	(18)
Amortization of net actuarial loss	64	73	242	220
Settlements, curtailments, special termination benefits and other	0	0	795	0
Total non-operating expense (benefit)	31	(10)	864	(32)
Total net periodic benefit cost (benefit)	59	32	958	96
United States | U.S. Pension Plans | Continuing Operations
Operating expense
Service cost	28	34	87	104
Non-operating expense
Total non-operating expense (benefit)	31	(6)	864	(20)
Total net periodic benefit cost (benefit)	59	28	951	84
United States | U.S. Pension Plans | Discontinued Operations
Operating expense
Service cost	0	8	7	24
Non-operating expense
Total non-operating expense (benefit)	0	(4)	0	(12)
Total net periodic benefit cost (benefit)	0	4	7	12
International | U.S. Pension Plans
Operating expense
Service cost	15	21	50	60
Non-operating expense
Interest cost	50	56	153	165
Expected return on plan assets	(81)	(76)	(248)	(226)
Amortization of transition asset	0	1	2	2
Amortization of prior service benefit	0	0	1	1
Amortization of net actuarial loss	3	2	9	6
Settlements, curtailments, special termination benefits and other	0	0	0	0
Total non-operating expense (benefit)	(28)	(17)	(83)	(52)
Total net periodic benefit cost (benefit)	(13)	4	(33)	8
International | U.S. Pension Plans | Continuing Operations
Operating expense
Service cost	15	17	45	48
Non-operating expense
Total non-operating expense (benefit)	(28)	(17)	(83)	(50)
Total net periodic benefit cost (benefit)	(13)	0	(38)	(2)
International | U.S. Pension Plans | Discontinued Operations
Operating expense
Service cost	0	4	5	12
Non-operating expense
Total non-operating expense (benefit)	0	0	0	(2)
Total net periodic benefit cost (benefit)	$ 0	$ 4	$ 5	$ 10