Variable Interest Entities (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Total standby bond purchase agreement committed to trusts	$ 0	$ 0
Assets	301,450,000,000	314,624,000,000
Liabilities	276,259,000,000	287,261,000,000
VIE - primary beneficiary
Variable Interest Entity [Line Items]
Assets	0
Liabilities	0
VIE - not primary beneficiary
Variable Interest Entity [Line Items]
Potential maximum loss exposure of unconsolidated funds	15,000,000	17,000,000
VIE - not primary beneficiary | Low Income Housing Production And Investment Tax Credit Entities
Variable Interest Entity [Line Items]
Potential maximum loss exposure of unconsolidated funds	$ 1,600,000,000	$ 1,690,000,000