Postretirement benefit plans - Expense Related to Defined Benefit and Retiree Health Care Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
U.S. | Defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5	$ 12	$ 16
Interest cost	8	8	20	23
Expected return on plan assets	(6)	(8)	(22)	(25)
Recognized net actuarial loss	1	3	2	11
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit costs	7	8	12	25
Settlement losses	16	4	29	12
Total, including other postretirement losses	23	12	41	37
U.S. | Retiree health care plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	2	2
Interest cost	3	3	8	8
Expected return on plan assets	(3)	(2)	(9)	(8)
Recognized net actuarial loss	0	0	0	0
Amortization of prior service cost (credit)	(1)	(1)	(1)	(1)
Net periodic benefit costs	0	0	0	1
Settlement losses	0	0	0	0
Total, including other postretirement losses	0	0	0	1
Non-U.S. | Defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	9	19	27
Interest cost	7	9	26	28
Expected return on plan assets	(15)	(20)	(50)	(61)
Recognized net actuarial loss	1	2	1	6
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit costs	(1)	0	(4)	0
Settlement losses	1	1	10	2
Total, including other postretirement losses	$ 0	$ 1	$ 6	$ 2