Goodwill and intangible assets - Goodwill (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Goodwill [Roll Forward]
Beginning balance				$ 17,512,000,000	$ 17,496,000,000
Impairment losses	$ (680,000,000)	$ 0	$ 0	(680,000,000)	0
Dispositions				(13,000,000)	(5,000,000)
Foreign currency translation				(407,000,000)	(71,000,000)
Goodwill	17,092,000,000			17,092,000,000
Accumulated impairment losses	(680,000,000)			(680,000,000)
Ending balance	16,412,000,000		17,420,000,000	16,412,000,000	17,420,000,000
Securities Services
Goodwill [Roll Forward]
Beginning balance				7,062,000,000	7,033,000,000
Impairment losses				0
Dispositions				(13,000,000)	0
Foreign currency translation				(142,000,000)	(47,000,000)
Goodwill	6,907,000,000			6,907,000,000
Accumulated impairment losses	0			0
Ending balance	6,907,000,000		6,986,000,000	6,907,000,000	6,986,000,000
Market and Wealth Services
Goodwill [Roll Forward]
Beginning balance				1,435,000,000	1,423,000,000
Impairment losses				0
Dispositions				0	0
Foreign currency translation				(18,000,000)	(1,000,000)
Goodwill	1,417,000,000			1,417,000,000
Accumulated impairment losses	0			0
Ending balance	1,417,000,000		1,422,000,000	1,417,000,000	1,422,000,000
Investment and Wealth Management
Goodwill [Roll Forward]
Beginning balance				9,015,000,000	9,040,000,000
Impairment losses				(680,000,000)
Dispositions				0	(5,000,000)
Foreign currency translation				(247,000,000)	(23,000,000)
Goodwill	8,768,000,000			8,768,000,000
Accumulated impairment losses	(680,000,000)			(680,000,000)
Ending balance	$ 8,088,000,000		$ 9,012,000,000	$ 8,088,000,000	$ 9,012,000,000