Goodwill and intangible assets - Intangible Assets by Business Segment (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
Intangible Assets [Roll Forward]
Beginning Balance		$ 2,991		$ 2,991	$ 3,012
Disposition					(6)
Amortization	$ (17)	(17)	$ (20)	(34)	(44)
Foreign currency translation				(23)	2
Ending Balance	2,934		2,964	2,934	2,964
Securities Services
Intangible Assets [Roll Forward]
Beginning Balance		230		230	194
Disposition					0
Amortization				(17)	(15)
Foreign currency translation				(6)	0
Ending Balance	207		179	207	179
Market and Wealth Services
Intangible Assets [Roll Forward]
Beginning Balance		392		392	414
Disposition					0
Amortization				(4)	(14)
Foreign currency translation				0	0
Ending Balance	388		400	388	400
Investment and Wealth Management
Intangible Assets [Roll Forward]
Beginning Balance		1,520		1,520	1,555
Disposition					(6)
Amortization				(13)	(15)
Foreign currency translation				(17)	2
Ending Balance	1,490		1,536	1,490	1,536
Other
Intangible Assets [Roll Forward]
Beginning Balance		$ 849		849	849
Disposition					0
Amortization				0	0
Foreign currency translation				0	0
Ending Balance	$ 849		$ 849	$ 849	$ 849