Postretirement benefit plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
U.S. | Defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 2	$ 6	$ 6
Interest cost	7	7	19	21
Expected return on plan assets	(7)	(6)	(18)	(17)
Recognized net actuarial losses (gains)	1	2	3	5
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit costs (credits)	3	5	10	15
Settlement losses			0	1
Total, including other postretirement losses (gains)	3	5	10	16
U.S. | Retiree health care plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	4	4	10	11
Expected return on plan assets	(4)	(4)	(13)	(13)
Recognized net actuarial losses (gains)	(1)	(1)	(2)	(4)
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit costs (credits)	(1)	(1)	(4)	(5)
Settlement losses			0	0
Total, including other postretirement losses (gains)	(1)	(1)	(4)	(5)
Non-U.S. | Defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	12	12
Interest cost	15	14	42	43
Expected return on plan assets	(22)	(16)	(60)	(48)
Recognized net actuarial losses (gains)	3	3	9	9
Amortization of prior service cost (credit)	1	1	1	1
Net periodic benefit costs (credits)	1	6	4	17
Settlement losses			0	1
Total, including other postretirement losses (gains)	$ 1	$ 6	$ 4	$ 18