Line of Business Information - Summary of Line of Business (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Servicing fees	$ 1,234,000,000	$ 1,219,000,000	$ 3,710,000,000	$ 3,884,000,000
Management fees	479,000,000	472,000,000	1,397,000,000	1,482,000,000
Foreign exchange trading services	313,000,000	319,000,000	958,000,000	1,009,000,000
Securities finance	103,000,000	110,000,000	329,000,000	313,000,000
Software and processing fees	188,000,000	184,000,000	574,000,000	573,000,000
Other fee revenue	44,000,000	(5,000,000)	147,000,000	(19,000,000)
Total fee revenue	2,361,000,000	2,299,000,000	7,115,000,000	7,242,000,000
Net interest income	624,000,000	660,000,000	2,081,000,000	1,753,000,000
Total other income	(294,000,000)	0	(294,000,000)	(2,000,000)
Total revenue	2,691,000,000	2,959,000,000	8,902,000,000	8,993,000,000
Provision for credit losses	0	0	26,000,000	10,000,000
Total expenses	2,180,000,000	2,110,000,000	6,761,000,000	6,545,000,000
Income before income tax expense	$ 511,000,000	$ 849,000,000	$ 2,115,000,000	$ 2,438,000,000
Pre-tax margin	19.00%	29.00%	24.00%	27.00%
Operating Segments | Investment Servicing
Segment Reporting Information [Line Items]
Servicing fees	$ 1,234,000,000	$ 1,219,000,000	$ 3,710,000,000	$ 3,884,000,000
Management fees	0	0	0	0
Foreign exchange trading services	278,000,000	293,000,000	875,000,000	948,000,000
Securities finance	98,000,000	105,000,000	310,000,000	300,000,000
Software and processing fees	188,000,000	184,000,000	574,000,000	573,000,000
Other fee revenue	41,000,000	12,000,000	124,000,000	46,000,000
Total fee revenue	1,839,000,000	1,813,000,000	5,593,000,000	5,751,000,000
Net interest income	620,000,000	663,000,000	2,069,000,000	1,760,000,000
Total other income	0	0	0	(2,000,000)
Total revenue	2,459,000,000	2,476,000,000	7,662,000,000	7,509,000,000
Provision for credit losses	0	0	26,000,000	10,000,000
Total expenses	1,798,000,000	1,760,000,000	5,626,000,000	5,452,000,000
Income before income tax expense	$ 661,000,000	$ 716,000,000	$ 2,010,000,000	$ 2,047,000,000
Pre-tax margin	27.00%	29.00%	26.00%	27.00%
Operating Segments | Investment Management
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	479,000,000	472,000,000	1,397,000,000	1,482,000,000
Foreign exchange trading services	35,000,000	26,000,000	83,000,000	61,000,000
Securities finance	5,000,000	5,000,000	19,000,000	13,000,000
Software and processing fees	0	0	0	0
Other fee revenue	3,000,000	(17,000,000)	23,000,000	(65,000,000)
Total fee revenue	522,000,000	486,000,000	1,522,000,000	1,491,000,000
Net interest income	4,000,000	(3,000,000)	12,000,000	(7,000,000)
Total other income	0	0	0	0
Total revenue	526,000,000	483,000,000	1,534,000,000	1,484,000,000
Provision for credit losses	0	0	0	0
Total expenses	379,000,000	335,000,000	1,126,000,000	1,051,000,000
Income before income tax expense	$ 147,000,000	$ 148,000,000	$ 408,000,000	$ 433,000,000
Pre-tax margin	28.00%	31.00%	27.00%	29.00%
Other
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	0	0	0	0
Foreign exchange trading services	0	0	0	0
Securities finance	0	0	0	0
Software and processing fees	0	0	0	0
Other fee revenue	0	0		0
Total fee revenue	0	0	0	0
Net interest income	0	0	0	0
Total other income	(294,000,000)	0	(294,000,000)	0
Total revenue	(294,000,000)	0	(294,000,000)	0
Provision for credit losses	0	0	0	0
Total expenses	3,000,000	15,000,000	9,000,000	42,000,000
Income before income tax expense	$ (297,000,000)	$ (15,000,000)	$ (303,000,000)	$ (42,000,000)