Line of Business Information - Summary of Line of Business (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Servicing fees	$ 1,266	$ 1,234	$ 3,733	$ 3,710
Management fees	527	479	1,548	1,397
Foreign exchange trading services	374	313	1,041	958
Securities finance	116	103	320	329
Software and processing fees	208	188	629	574
Other fee revenue	125	44	223	147
Total fee revenue	2,616	2,361	7,494	7,115
Net interest income	723	624	2,174	2,081
Total other income (loss)	(80)	(294)	(80)	(294)
Total revenue	3,259	2,691	9,588	8,902
Provision for credit losses	26	0	63	26
Total expenses	2,308	2,180	7,090	6,761
Income before income tax expense	$ 925	$ 511	$ 2,435	$ 2,115
Pre-tax margin	28.00%	19.00%	25.00%	24.00%
Operating Segments | Investment Servicing
Segment Reporting Information [Line Items]
Servicing fees	$ 1,266	$ 1,234	$ 3,733	$ 3,710
Management fees	0	0	0	0
Foreign exchange trading services	312	278	924	875
Securities finance	111	98	302	310
Software and processing fees	208	188	629	574
Other fee revenue	48	41	127	124
Total fee revenue	1,945	1,839	5,715	5,593
Net interest income	716	620	2,157	2,069
Total other income (loss)	1	0	1	0
Total revenue	2,662	2,459	7,873	7,662
Provision for credit losses	26	0	63	26
Total expenses	1,891	1,798	5,734	5,626
Income before income tax expense	$ 745	$ 661	$ 2,076	$ 2,010
Pre-tax margin	28.00%	27.00%	26.00%	26.00%
Operating Segments | Investment Management
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	527	479	1,548	1,397
Foreign exchange trading services	47	35	102	83
Securities finance	5	5	18	19
Software and processing fees	0	0	0	0
Other fee revenue	11	3	30	23
Total fee revenue	590	522	1,698	1,522
Net interest income	7	4	17	12
Total other income (loss)	0	0	0	0
Total revenue	597	526	1,715	1,534
Provision for credit losses	0	0	0	0
Total expenses	417	379	1,225	1,126
Income before income tax expense	$ 180	$ 147	$ 490	$ 408
Pre-tax margin	30.00%	28.00%	29.00%	27.00%
Other
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	0	0	0	0
Foreign exchange trading services	15	0	15	0
Securities finance	0	0	0	0
Software and processing fees	0	0	0	0
Other fee revenue	66	0	66	0
Total fee revenue	81	0	81	0
Net interest income	0	0	0	0
Total other income (loss)	(81)	(294)	(81)	(294)
Total revenue	0	(294)	0	(294)
Provision for credit losses	0	0	0	0
Total expenses	0	3	131	9
Income before income tax expense	$ 0	$ (297)	$ (131)	$ (303)