Derivative Instruments - Summary of Notional for VIE Derivatives Outstanding (Details) - Variable Interest Entity, Primary Beneficiary [Member] - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Interest Rate Swap [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative products, Notional Amount	$ 1,245	$ 1,233
Interest Rate Swaps-Pay-Fixed/Receive-Variable [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative products, Notional Amount	1,127	1,151
Currency Swaps [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative products, Notional Amount	$ 294	$ 308