Variable Interest Entities and Securitizations - Carrying Amount of Consolidated and Unconsolidated VIEs (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	$ 5,788	$ 5,281
Carrying Amount of Assets	467,800	455,249
Carrying Amount of Liabilities	413,241	402,667
Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	32,580	31,045
Carrying Amount of Liabilities	18,815	17,908
Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	5,788	5,281
Carrying Amount of Liabilities	1,891	1,596
Affordable housing entities
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	5,332	4,944
VIE, nonconsolidated, carrying amount of assets included in certain investment structures	2,400	2,300
VIE, nonconsolidated, carrying amount of liabilities included in certain investment structures	780	616
Affordable housing entities | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	266	261
Carrying Amount of Liabilities	14	19
Affordable housing entities | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	5,332	4,944
Carrying Amount of Liabilities	1,891	1,596
Entities that provide capital to low-income and rural communities
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	0	0
Entities that provide capital to low-income and rural communities | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	2,562	2,301
Carrying Amount of Liabilities	10	10
Entities that provide capital to low-income and rural communities | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Carrying Amount of Liabilities	0	0
Other
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	456	337
Other | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Carrying Amount of Liabilities	0	0
Other | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	456	337
Carrying Amount of Liabilities	0	0
Total other VIEs
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	5,788	5,281
Total other VIEs | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	2,828	2,562
Carrying Amount of Liabilities	24	29
Total other VIEs | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	5,788	5,281
Carrying Amount of Liabilities	1,891	1,596
Credit card loan securitizations
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	0	0
Credit card loan securitizations | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	24,763	23,620
Carrying Amount of Liabilities	14,689	13,877
Credit card loan securitizations | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Carrying Amount of Liabilities	0	0
Auto loan securitizations
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	0	0
Auto loan securitizations | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	4,989	4,863
Carrying Amount of Liabilities	4,102	4,002
Auto loan securitizations | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Carrying Amount of Liabilities	0	0
Total securitization-related VIEs
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	0	0
Total securitization-related VIEs | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	29,752	28,483
Carrying Amount of Liabilities	18,791	17,879
Total securitization-related VIEs | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Carrying Amount of Liabilities	$ 0	$ 0