Line of Business Information - Summary of Line of Business (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Servicing fees	$ 1,239	$ 1,259	$ 2,467	$ 2,476
Management fees	511	461	1,021	918
Foreign exchange trading services	336	303	667	645
Securities finance	108	117	204	226
Software and processing fees	214	221	421	386
Other fee revenue	48	58	98	103
Total fee revenue	2,456	2,419	4,878	4,754
Net interest income	735	691	1,451	1,457
Total other income			0	0
Total revenue	3,191	3,110	6,329	6,211
Provision for credit losses	10	(18)	37	26
Total expenses	2,269	2,212	4,782	4,581
Income before income tax expense	$ 912	$ 916	$ 1,510	$ 1,604
Pre-tax margin	29.00%	29.00%	24.00%	26.00%
Operating Segments | Investment Servicing
Segment Reporting Information [Line Items]
Servicing fees	$ 1,239	$ 1,259	$ 2,467	$ 2,476
Management fees	0	0	0	0
Foreign exchange trading services	304	276	612	597
Securities finance	101	109	191	212
Software and processing fees	214	221	421	386
Other fee revenue	36	55	79	83
Total fee revenue	1,894	1,920	3,770	3,754
Net interest income	730	687	1,441	1,449
Total other income			0	0
Total revenue	2,624	2,607	5,211	5,203
Provision for credit losses	10	(18)	37	26
Total expenses	1,880	1,850	3,843	3,828
Income before income tax expense	$ 734	$ 775	$ 1,331	$ 1,349
Pre-tax margin	28.00%	30.00%	26.00%	26.00%
Operating Segments | Investment Management
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	511	461	1,021	918
Foreign exchange trading services	32	27	55	48
Securities finance	7	8	13	14
Software and processing fees	0	0	0	0
Other fee revenue	12	3	19	20
Total fee revenue	562	499	1,108	1,000
Net interest income	5	4	10	8
Total other income			0	0
Total revenue	567	503	1,118	1,008
Provision for credit losses	0	0	0	0
Total expenses	388	361	808	747
Income before income tax expense	$ 179	$ 142	$ 310	$ 261
Pre-tax margin	32.00%	28.00%	28.00%	26.00%
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	0
Total fee revenue	0	0	0	0
Net interest income	0	0	0	0
Total other income			0	0
Total revenue	0	0	0	0
Provision for credit losses	0	0	0	0
Total expenses	1	1	131	6
Income before income tax expense	$ (1)	$ (1)	$ (131)	$ (6)