Revenue from Contracts with Customers - Disaggregation of Revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Servicing fees	$ 1,228	$ 1,217
Management fees	510	457
Foreign exchange trading services	331	342
Securities finance	96	109
Software and processing fees	207	165
Other fee revenue	50	45
Total fee revenue	2,422	2,335
Net interest income	716	766
Total revenue	3,138	3,101
Operating Segments | Investment Servicing
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,525	1,490
All other revenue	1,062	1,106
Servicing fees	1,228	1,217
Management fees	0	0
Foreign exchange trading services	308	321
Securities finance	90	103
Software and processing fees	207	165
Other fee revenue	43	28
Total fee revenue	1,876	1,834
Net interest income	711	762
Total revenue	2,587	2,596
Operating Segments | Investment Servicing | Servicing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,228	1,217
All other revenue	0	0
Servicing fees	1,228	1,217
Operating Segments | Investment Servicing | Management fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Management fees	0	0
Operating Segments | Investment Servicing | Foreign exchange trading services
Disaggregation of Revenue [Line Items]
Topic 606 revenue	95	90
All other revenue	213	231
Foreign exchange trading services	308	321
Operating Segments | Investment Servicing | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	47	63
All other revenue	43	40
Securities finance	90	103
Operating Segments | Investment Servicing | Software and processing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	155	120
All other revenue	52	45
Software and processing fees	207	165
Operating Segments | Investment Servicing | Other fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	43	28
Other fee revenue	43	28
Operating Segments | Investment Servicing | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,525	1,490
All other revenue	351	344
Total fee revenue	1,876	1,834
Operating Segments | Investment Servicing | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	711	762
Net interest income	711	762
Operating Segments | Investment Management
Disaggregation of Revenue [Line Items]
Topic 606 revenue	533	478
All other revenue	18	27
Servicing fees	0	0
Management fees	510	457
Foreign exchange trading services	23	21
Securities finance	6	6
Software and processing fees	0	0
Other fee revenue	7	17
Total fee revenue	546	501
Net interest income	5	4
Total revenue	551	505
Operating Segments | Investment Management | Servicing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Servicing fees	0	0
Operating Segments | Investment Management | Management fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	510	457
All other revenue	0	0
Management fees	510	457
Operating Segments | Investment Management | Foreign exchange trading services
Disaggregation of Revenue [Line Items]
Topic 606 revenue	23	21
All other revenue	0	0
Foreign exchange trading services	23	21
Operating Segments | Investment Management | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	6	6
Securities finance	6	6
Operating Segments | Investment Management | Software and processing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Software and processing fees	0	0
Operating Segments | Investment Management | Other fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	7	17
Other fee revenue	7	17
Operating Segments | Investment Management | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	533	478
All other revenue	13	23
Total fee revenue	546	501
Operating Segments | Investment Management | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	5	4
Net interest income	5	4
Other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
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
Other | Servicing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Servicing fees	0	0
Other | Management fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Management fees	0	0
Other | Foreign exchange trading services
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Foreign exchange trading services	0	0
Other | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Securities finance	0	0
Other | Software and processing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Software and processing fees	0	0
Other | Other fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Other fee revenue	0	0
Other | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Total fee revenue	0	0
Other | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0
All other revenue	0	0
Net interest income	$ 0	$ 0