Revenue from Contracts with Customers - Disaggregation of Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Servicing fees	$ 1,395	$ 1,301	$ 4,165	$ 3,860
Management fees	526	479	1,523	1,387
Foreign exchange trading services	279	270	911	1,039
Securities finance	106	84	314	268
Software and processing fees	198	172	588	529
Total fee revenue	2,504	2,306	7,501	7,083
Net interest income	487	478	1,421	1,701
Total other income (loss)	(1)	0	52	2
Total revenue	2,990	2,784	8,974	8,786
Operating Segments | Investment Servicing
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,663	1,541	4,996	4,673
All other revenue	795	737	2,358	2,689
Servicing fees	1,395	1,301	4,165	3,860
Management fees	0	0	0	0
Foreign exchange trading services	266	252	869	998
Securities finance	103	81	304	258
Software and processing fees	204	162	585	528
Total fee revenue	1,968	1,796	5,923	5,644
Net interest income	491	482	1,432	1,716
Total other income (loss)	(1)	0	(1)	2
Total revenue	2,458	2,278	7,354	7,362
Operating Segments | Investment Servicing | Servicing fees
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,395	1,301	4,165	3,860
All other revenue	0	0	0	0
Servicing fees	1,395	1,301	4,165	3,860
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	82	90	260	285
All other revenue	184	162	609	713
Foreign exchange trading services	266	252	869	998
Operating Segments | Investment Servicing | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	60	42	181	162
All other revenue	43	39	123	96
Securities finance	103	81	304	258
Operating Segments | Investment Servicing | Processing fees and other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	126	108	390	366
All other revenue	78	54	195	162
Software and processing fees	204	162	585	528
Operating Segments | Investment Servicing | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	1,663	1,541	4,996	4,673
All other revenue	305	255	927	971
Total fee revenue	1,968	1,796	5,923	5,644
Operating Segments | Investment Servicing | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	491	482	1,432	1,716
Net interest income	491	482	1,432	1,716
Operating Segments | Investment Servicing | Total other income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0		0	0
All other revenue	(1)		(1)	2
Total other income (loss)	(1)		(1)	2
Operating Segments | Investment Management
Disaggregation of Revenue [Line Items]
Topic 606 revenue	539	497	1,565	1,428
All other revenue	(7)	9	2	(4)
Servicing fees	0	0	0	0
Management fees	526	479	1,523	1,387
Foreign exchange trading services	13	18	42	41
Securities finance	3	3	10	10
Software and processing fees	(6)	10	3	1
Total fee revenue	536	510	1,578	1,439
Net interest income	(4)	(4)	(11)	(15)
Total other income (loss)	0	0	0	0
Total revenue	532	506	1,567	1,424
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	526	479	1,523	1,387
All other revenue	0	0	0	0
Management fees	526	479	1,523	1,387
Operating Segments | Investment Management | Foreign exchange trading services
Disaggregation of Revenue [Line Items]
Topic 606 revenue	13	18	42	41
All other revenue	0	0	0	0
Foreign exchange trading services	13	18	42	41
Operating Segments | Investment Management | Securities finance
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	3	3	10	10
Securities finance	3	3	10	10
Operating Segments | Investment Management | Processing fees and other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	(6)	10	3	1
Software and processing fees	(6)	10	3	1
Operating Segments | Investment Management | Total fee revenue
Disaggregation of Revenue [Line Items]
Topic 606 revenue	539	497	1,565	1,428
All other revenue	(3)	13	13	11
Total fee revenue	536	510	1,578	1,439
Operating Segments | Investment Management | Net interest income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0	0	0	0
All other revenue	(4)	(4)	(11)	(15)
Net interest income	(4)	(4)	(11)	(15)
Operating Segments | Investment Management | Total other income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0		0	0
All other revenue	0		0	0
Total other income (loss)	0		0	0
Other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0		0
All other revenue	0		53
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
Total fee revenue	0	0	0	0
Net interest income	0	0	0	0
Total other income (loss)	0	0	53	0
Total revenue	0	$ 0	53	$ 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 | Processing fees and other
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0		0
All other revenue	0		0
Software and processing fees	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
Other | Total other income
Disaggregation of Revenue [Line Items]
Topic 606 revenue	0		0
All other revenue	0		53
Total other income (loss)	$ 0		$ 53