Employee benefit plans (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Health care benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0	$ 0
Interest cost	1	1	1	2	2
Expected return on assets	(1)	(2)	(1)	(3)	(3)
Other	(1)	(1)	0	(2)	0
Net periodic benefit (credit) cost	(1)	(2)	0	(3)	(1)
Domestic | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0	0
Interest cost	35	35	34	70	68
Expected return on assets	(78)	(78)	(75)	(156)	(150)
Other	17	17	24	34	49
Net periodic benefit (credit) cost	(26)	(26)	(17)	(52)	(33)
Foreign | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	3	6	7
Interest cost	7	8	7	15	13
Expected return on assets	(9)	(10)	(8)	(19)	(17)
Other	1	1	3	2	7
Net periodic benefit (credit) cost	$ 2	$ 2	$ 5	$ 4	$ 10