Loans and Related Allowance for Credit Losses (Financial Effect of Loan Modification) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Total commercial | Commercial and industrial
Financing Receivable [Line Items]
Weighted-Average Term Extension (in Months)	5 months
Weighted-Average Payment Delay (in Months)	2 months
Total commercial | Commercial and industrial | Principal Forgiveness
Financing Receivable [Line Items]
Total Principal Forgiveness	$ 2
Total commercial | Commercial real estate
Financing Receivable [Line Items]
Weighted-Average Term Extension (in Months)	13 months
Total consumer | Residential real estate
Financing Receivable [Line Items]
Weighted-Average Interest Rate Reduction	1.71%
Weighted-Average Term Extension (in Months)	145 months
Weighted-Average Payment Delay (in Months)	8 months
Total consumer | Home equity
Financing Receivable [Line Items]
Weighted-Average Interest Rate Reduction	0.77%
Weighted-Average Term Extension (in Months)	51 months
Weighted-Average Payment Delay (in Months)	6 months
Total consumer | Education
Financing Receivable [Line Items]
Weighted-Average Term Extension (in Months)	27 months