Guarantee Arrangements, Pledged Assets and Repurchase Agreements, Collateral Pledged and Remaining Contractual Maturity of Repurchase Agreements Accounted for as Secured Borrowings (Details) - U.S. Treasury, U.S. Government sponsored and U.S. Government agency securities - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	$ 3,675	$ 4,710
Overnight and Continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	1,633	2,729
Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	757	1,074
31 to 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	586	386
91 Days to One Year
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	699	521
Greater Than One Year
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral pledged and remaining contractual maturity of repurchase agreements accounted for as secured borrowings	$ 0	$ 0