Loans and Related Allowance for Credit Losses (Financial Impact and TDRs by Concession Type) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($) customer	Jun. 30, 2022 USD ($) customer
Financing Receivable [Line Items]
Number of Loans | customer	3,040	5,947
Pre-TDR Amortized Cost Basis	$ 85	$ 174
Post-TDR Amortized Cost Basis	76	155
Principal Forgiveness
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	9	9
Interest Rate Reduction
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	40	66
Other TDR Concession Type [Member]
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	$ 27	$ 80
Total commercial
Financing Receivable [Line Items]
Number of Loans | customer	15	27
Pre-TDR Amortized Cost Basis	$ 35	$ 88
Post-TDR Amortized Cost Basis	31	77
Total commercial | Principal Forgiveness
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	9	9
Total commercial | Interest Rate Reduction
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis
Total commercial | Other TDR Concession Type [Member]
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	$ 22	$ 68
Total consumer
Financing Receivable [Line Items]
Number of Loans | customer	3,025	5,920
Pre-TDR Amortized Cost Basis	$ 50	$ 86
Post-TDR Amortized Cost Basis	45	78
Total consumer | Principal Forgiveness
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis
Total consumer | Interest Rate Reduction
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	40	66
Total consumer | Other TDR Concession Type [Member]
Financing Receivable [Line Items]
Post-TDR Amortized Cost Basis	$ 5	$ 12