Line of Business Information - Summary of Line of Business (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Servicing fees	$ 1,228,000,000	$ 1,217,000,000
Management fees	510,000,000	457,000,000
Foreign exchange trading services	331,000,000	342,000,000
Securities finance	96,000,000	109,000,000
Software and processing fees	207,000,000	165,000,000
Other fee revenue	50,000,000	45,000,000
Total fee revenue	2,422,000,000	2,335,000,000
Net interest income	716,000,000	766,000,000
Total revenue	3,138,000,000	3,101,000,000
Provision for credit losses	27,000,000	44,000,000
Total expenses	2,513,000,000	2,369,000,000
Income before income tax expense	$ 598,000,000	$ 688,000,000
Pre-tax margin	19.00%	22.00%
Operating Segments | Investment Servicing
Segment Reporting Information [Line Items]
Servicing fees	$ 1,228,000,000	$ 1,217,000,000
Management fees	0	0
Foreign exchange trading services	308,000,000	321,000,000
Securities finance	90,000,000	103,000,000
Software and processing fees	207,000,000	165,000,000
Other fee revenue	43,000,000	28,000,000
Total fee revenue	1,876,000,000	1,834,000,000
Net interest income	711,000,000	762,000,000
Total revenue	2,587,000,000	2,596,000,000
Provision for credit losses	27,000,000	44,000,000
Total expenses	1,963,000,000	1,978,000,000
Income before income tax expense	$ 597,000,000	$ 574,000,000
Pre-tax margin	23.00%	22.00%
Operating Segments | Investment Management
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0
Management fees	510,000,000	457,000,000
Foreign exchange trading services	23,000,000	21,000,000
Securities finance	6,000,000	6,000,000
Software and processing fees	0	0
Other fee revenue	7,000,000	17,000,000
Total fee revenue	546,000,000	501,000,000
Net interest income	5,000,000	4,000,000
Total revenue	551,000,000	505,000,000
Provision for credit losses	0	0
Total expenses	420,000,000	386,000,000
Income before income tax expense	$ 131,000,000	$ 119,000,000
Pre-tax margin	24.00%	24.00%
Other
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0
Management fees	0	0
Foreign exchange trading services	0	0
Securities finance	0	0
Software and processing fees	0	0
Other fee revenue	0	0
Total fee revenue	0	0
Net interest income	0	0
Total revenue	0	0
Provision for credit losses	0	0
Total expenses	130,000,000	5,000,000
Income before income tax expense	$ (130,000,000)	$ (5,000,000)