Variable Interest Entities - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Assets	$ 186,346,000,000	$ 170,336,000,000
Liabilities	168,923,000,000	152,355,000,000
Fair Value, Recurring
Variable Interest Entity [Line Items]
Other investments	105,000,000	81,000,000
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	2,827,000,000	351,000,000
Liabilities	1,000,000	1,000,000
Variable Interest Entity, Not Primary Beneficiary | Qualified affordable housing projects investment
Variable Interest Entity [Line Items]
Liabilities	675,000,000	484,000,000
Variable Interest Entity, Not Primary Beneficiary | Other Unconsolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Other investments	2,500,000,000
Variable Interest Entity, Not Primary Beneficiary | Accrued Income And Other Assets
Variable Interest Entity [Line Items]
Assets	1,600,000,000	1,400,000,000
Variable Interest Entity, Not Primary Beneficiary | Investments
Variable Interest Entity [Line Items]
Amortization of investment	192,000,000	195,000,000
Tax credit of investment	184,000,000	177,000,000
Variable Interest Entity, Primary Beneficiary | Investments
Variable Interest Entity [Line Items]
Liabilities	0	0
Measured at NAV | Variable Interest Entity, Not Primary Beneficiary | Fair Value, Recurring | Principal investments: Indirect
Variable Interest Entity [Line Items]
Other investments	$ 45,000,000	$ 53,000,000