Goodwill and intangible assets - Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Goodwill [Roll Forward]
Beginning balance	$ 17,386	$ 17,350
Foreign currency translation	(29)	(102)
Other	0
Ending balance	17,357	17,248
Investment Services
Goodwill [Roll Forward]
Beginning balance	8,332	8,333
Foreign currency translation	21	(45)
Other	47
Ending balance	8,400	8,288
Investment and Wealth Management
Goodwill [Roll Forward]
Beginning balance	9,007	8,970
Foreign currency translation	(50)	(57)
Other	0
Ending balance	8,957	8,913
Other
Goodwill [Roll Forward]
Beginning balance	47	47
Foreign currency translation	0	0
Other	(47)
Ending balance	$ 0	$ 47