Revenue from Contracts with Customers - Disaggregation of Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,784	$ 2,903	$ 8,786	$ 8,708
Servicing fees	1,301	1,272	3,860	3,775
Management fees	455	445	1,329	1,306
Foreign exchange trading services	294	284	1,097	837
Securities finance	84	116	268	360
Software and processing fees	172	142	529	501
Total fee revenue	2,306	2,259	7,083	6,779
Net interest income	478	644	1,701	1,930
Total fee revenue	0	0	2	(1)
Operating Segments | Investment Servicing
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,541	1,523	4,673	4,559
All other revenue	737	901	2,689	2,737
Total revenue	2,278	2,424	7,362	7,296
Servicing fees	1,301	1,272	3,860	3,775
Management fees	0	0	0	0
Foreign exchange trading services	252	249	998	735
Securities finance	81	114	258	353
Software and processing fees	162	140	528	483
Total fee revenue	1,796	1,775	5,644	5,346
Net interest income	482	649	1,716	1,951
Total fee revenue			2	(1)
Operating Segments | Investment Servicing | Servicing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,301	1,272	3,860	3,775
All other revenue	0	0	0	0
Servicing fees	1,301	1,272	3,860	3,775
Operating Segments | Investment Servicing | Management fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	0	0	0	0
Management fees	0	0	0	0
Operating Segments | Investment Servicing | Foreign exchange trading services
Disaggregation of Revenue [Line Items]
Topic 606 revenue	90	90	285	258
All other revenue	162	159	713	477
Foreign exchange trading services	252	249	998	735
Operating Segments | Investment Servicing | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	42	64	162	209
All other revenue	39	50	96	144
Securities finance	81	114	258	353
Operating Segments | Investment Servicing | Processing fees and other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	108	97	366	317
All other revenue	54	43	162	166
Software and processing fees	162	140	528	483
Operating Segments | Investment Servicing | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,541	1,523	4,673	4,559
All other revenue	255	252	971	787
Total fee revenue	1,796	1,775	5,644	5,346
Operating Segments | Investment Servicing | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	482	649	1,716	1,951
Net interest income	482	649	1,716	1,951
Operating Segments | Investment Servicing | Total other income
Disaggregation of Revenue [Line Items]
Topic 606 revenue			0	0
All other revenue			2	(1)
Total fee revenue			2	(1)
Operating Segments | Investment Management
Disaggregation of Revenue [Line Items]
Topic 606 revenue	497	480	1,428	1,408
All other revenue	9	(1)	(4)	4
Total revenue	506	479	1,424	1,412
Servicing fees	0	0	0	0
Management fees	455	445	1,329	1,306
Foreign exchange trading services	42	35	99	102
Securities finance	3	2	10	7
Software and processing fees	10	2	1	18
Total fee revenue	510	484	1,439	1,433
Net interest income	(4)	(5)	(15)	(21)
Total fee revenue			0	0
Operating Segments | Investment Management | Servicing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	0	0	0	0
Servicing fees	0	0	0	0
Operating Segments | Investment Management | Management fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	455	445	1,329	1,306
All other revenue	0	0	0	0
Management fees	455	445	1,329	1,306
Operating Segments | Investment Management | Foreign exchange trading services
Disaggregation of Revenue [Line Items]
Topic 606 revenue	42	35	99	102
All other revenue	0	0	0	0
Foreign exchange trading services	42	35	99	102
Operating Segments | Investment Management | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	3	2	10	7
Securities finance	3	2	10	7
Operating Segments | Investment Management | Processing fees and other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	10	2	1	18
Software and processing fees	10	2	1	18
Operating Segments | Investment Management | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	497	480	1,428	1,408
All other revenue	13	4	11	25
Total fee revenue	510	484	1,439	1,433
Operating Segments | Investment Management | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	(4)	(5)	(15)	(21)
Net interest income	$ (4)	$ (5)	(15)	(21)
Operating Segments | Investment Management | Total other income
Disaggregation of Revenue [Line Items]
Topic 606 revenue			0	0
All other revenue			0	0
Total fee revenue			$ 0	$ 0