Goodwill and intangible assets - Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Goodwill [Roll Forward]
Beginning balance	$ 17,496	$ 17,386
Dispositions	(5)
Foreign currency translation	(71)	(29)
Other		0
Ending balance	17,420	17,357
Investment Services
Goodwill [Roll Forward]
Beginning balance	8,456	8,332
Dispositions	0
Foreign currency translation	(48)	21
Other		47
Ending balance	8,408	8,400
Investment and Wealth Management
Goodwill [Roll Forward]
Beginning balance	9,040	9,007
Dispositions	(5)
Foreign currency translation	(23)	(50)
Other		0
Ending balance	9,012	8,957
Other
Goodwill [Roll Forward]
Beginning balance	0	47
Dispositions	0
Foreign currency translation	0	0
Other		(47)
Ending balance	$ 0	$ 0