Variable Interest Entities and Securitizations - Carrying Amount of Consolidated and Unconsolidated VIEs (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Carrying Amount of Assets	$ 478,464	$ 455,249
Carrying Amount of Liabilities	420,375	402,667
Maximum Exposure to Loss	6,175	5,281
Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	33,288	31,045
Carrying Amount of Liabilities	18,746	17,908
Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	6,175	5,281
Carrying Amount of Liabilities	2,085	1,596
Affordable housing entities
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	5,726	4,944
VIE, nonconsolidated, carrying amount of assets included in certain investment structures	2,600	2,300
VIE, nonconsolidated, carrying amount of liabilities included in certain investment structures	989	616
Affordable housing entities | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	297	261
Carrying Amount of Liabilities	23	19
Affordable housing entities | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	5,726	4,944
Carrying Amount of Liabilities	2,085	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	2,498	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	449	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	449	337
Carrying Amount of Liabilities	0	0
Total other VIEs
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	6,175	5,281
Total other VIEs | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	2,795	2,562
Carrying Amount of Liabilities	33	29
Total other VIEs | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	6,175	5,281
Carrying Amount of Liabilities	2,085	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	25,474	23,620
Carrying Amount of Liabilities	14,692	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	5,019	4,863
Carrying Amount of Liabilities	4,021	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	30,493	28,483
Carrying Amount of Liabilities	18,713	17,879
Total securitization-related VIEs | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Carrying Amount of Liabilities	$ 0	$ 0