Postretirement Benefits - Schedule of net benefit costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension Benefits | U.S. Pension Benefits
Components of net periodic benefit cost:
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	164	100	492	301
Expected return on plan assets	(173)	(167)	(517)	(502)
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit cost (benefit)	(9)	(67)	(25)	(201)
Pension Benefits | Non-U.S. Pension Benefits
Components of net periodic benefit cost:
Service cost	10	15	30	40
Interest cost	30	17	91	53
Expected return on plan assets	(40)	(33)	(120)	(100)
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit cost (benefit)	0	(1)	1	(7)
Other Postretirement Benefits
Components of net periodic benefit cost:
Service cost	16	24	50	74
Interest cost	36	20	108	60
Expected return on plan assets	(2)	(3)	(8)	(9)
Amortization of prior service cost (credit)	(3)	(1)	(9)	(4)
Net periodic benefit cost (benefit)	$ 47	$ 40	$ 141	$ 121