Income taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Taxes calculated using the estimated annual effective tax rate	$ 391	$ 337	$ 1,147	$ 934
Discrete tax items	(28)	(9)	(69)	(109)
Provision for income taxes	$ 363	$ 328	$ 1,078	$ 825
Effective tax rate	14.00%	14.00%	14.00%	13.00%