Post-Employment Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined benefit plans
Defined benefit and other post-employment plans
Service cost	$ 68	$ 113	$ 203	$ 342
Interest cost	108	74	324	223
Expected return on plan assets	(181)	(177)	(543)	(536)
Amortization of prior service cost (credit)	0	1	1	2
Amortization of actuarial loss	4	57	12	173
Net periodic benefit cost (credit)	(1)	68	(3)	204
Other post-employment plans
Defined benefit and other post-employment plans
Service cost	9	13	27	38
Interest cost	9	6	28	18
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(9)	(10)	(27)	(29)
Amortization of actuarial loss	3	7	9	20
Net periodic benefit cost (credit)	$ 12	$ 16	$ 37	$ 47