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Variable Interest Entities and Securitizations - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Amortization method qualified affordable housing investments, amortization	$ 556	$ 554
Affordable housing tax credits	607	610
Amortization method qualified affordable housing investments	4,500	4,400
Qualified affordable housing investments, commitment	1,500	1,500
Carrying Amount of Assets	421,602	390,365
VIE, reporting entity involvement, maximum loss exposure	5,343	5,413
Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	5,093	5,127
Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	26,619	35,519
Affordable housing entities
Variable Interest Entity [Line Items]
VIE, reporting entity involvement, maximum loss exposure	4,602	4,559
Affordable housing entities | Unconsolidated
Variable Interest Entity [Line Items]
Total assets of the unconsolidated VIE investment funds	11,000	10,900
Carrying Amount of Assets	4,602	4,559
Affordable housing entities | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	242	236
Entities that provide capital to low-income and rural communities
Variable Interest Entity [Line Items]
VIE, reporting entity involvement, maximum loss exposure	0	0
Entities that provide capital to low-income and rural communities | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	0	0
Entities that provide capital to low-income and rural communities | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	1,951	1,889
Other
Variable Interest Entity [Line Items]
VIE, reporting entity involvement, maximum loss exposure	436	502
Other | Unconsolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	436	502
Other | Consolidated
Variable Interest Entity [Line Items]
Carrying Amount of Assets	$ 0	$ 0

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Amount of affordable housing tax credits and other tax benefits recognized.

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