Income taxes - Income before income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
U.S.	$ 7,998	$ 5,210	$ 4,915
Non-U.S.	921	807	813
Income before income taxes	$ 8,919	$ 6,017	$ 5,728