Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 30	$ 32	$ 48
Interest cost	56	63	46
Expected return on plan assets	(80)	(64)	(86)
Amortization of unrecognized prior service (credit) cost	(43)	(49)	(57)
Net loss (gain) amortization	(51)	(42)	(43)
Termination benefits	4	0	0
Curtailments	0	(1)	(1)
Settlements	0	0	0
Net periodic benefit cost (credit)	(84)	(61)	(93)
United States | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	373	326	372
Interest cost	537	526	457
Expected return on plan assets	(826)	(735)	(753)
Amortization of unrecognized prior service (credit) cost	0	(1)	(32)
Net loss (gain) amortization	43	0	128
Termination benefits	5	3	2
Curtailments	0	8	12
Settlements	0	28	239
Net periodic benefit cost (credit)	132	155	425
International | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	243	196	283
Interest cost	294	299	145
Expected return on plan assets	(554)	(517)	(383)
Amortization of unrecognized prior service (credit) cost	(13)	2	(14)
Net loss (gain) amortization	5	(3)	96
Termination benefits	1	0	1
Curtailments	0	(1)	0
Settlements	(1)	(5)	1
Net periodic benefit cost (credit)	$ (25)	$ (29)	$ 129