Other assets - Non-Readily Marketable Equity Securities (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	Dec. 31, 2021
Other Assets [Abstract]
Equity securities without readily determinable fair value, amount	$ 424			$ 424		$ 264
Equity securities without readily determinable fair value, upward price adjustment, annual amount	76	$ 46	$ 6	122	$ 6
Equity securities without readily determinable fair value, downward price adjustment, annual amount	(7)	0	0	(7)	0
Equity securities without readily determinable fair value, net adjustment, annual amount	69	$ 46	$ 6	115	$ 6
Equity securities without readily determinable fair value, upward price adjustment, cumulative amount amount	280			280
Equity securities without readily determinable fair value, downward price adjustment, cumulative amount	(11)			(11)
Equity securities without readily determinable fair value, net price adjustment, cumulative amount	$ 269			$ 269