Variable Interest Entities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Aggregate assets	$ 680,950	$ 667,270
Aggregate liabilities	632,852	611,009
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Aggregate assets	1,095	1,076
Aggregate liabilities	516	530
Maximum exposure to loss	1,121	1,126
Variable Interest Entity, Not Primary Beneficiary [Member] | LIHTC Investments [Member]
Variable Interest Entity [Line Items]
Aggregate assets	914	915
Aggregate liabilities	516	530
Maximum exposure to loss	914	915
Variable Interest Entity, Not Primary Beneficiary [Member] | Other CRA Investments [Member]
Variable Interest Entity [Line Items]
Aggregate assets	181	161
Aggregate liabilities	0	0
Maximum exposure to loss	$ 207	$ 211