Credit Quality And Allowance For Credit Losses (Financial Effect of Loan Modifications) (Details)	3 Months Ended
	Mar. 31, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	(0.27%)
Weighted-Average Term Extension (in months)	17 years 10 months 24 days
Business loans:
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	(0.27%)
Weighted-Average Term Extension (in months)	18 years 2 months 12 days
Business loans: | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	(0.25%)
Weighted-Average Term Extension (in months)	17 years 10 months 24 days
Retail loans: | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	0.00%
Weighted-Average Term Extension (in months)	10 years
Commercial mortgage: | Business loans: | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	(0.27%)
Weighted-Average Term Extension (in months)	18 years 4 months 24 days
Commercial mortgage: | Business loans: | Commercial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	(0.27%)	[1]
Weighted-Average Term Extension (in months)	21 years 2 months 12 days	[1]
Commercial mortgage: | Business loans: | Commercial | Other business lines
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	0.00%	[2]
Weighted-Average Term Extension (in months)	7 years 4 months 24 days	[2]
Other consumer | Retail loans: | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Term Extension (in months)	10 years
Consumer: | Retail loans: | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	0.00%

[1] Primarily loans to real estate developers.

[2] Primarily loans secured by owner-occupied real estate.