Loans And Allowance For Credit Losses (Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding by FICO Score ) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Loans And Allowance For Loan Losses [Line Items]
Credit Quality Personal Real Estate Loans Excluded	$ 168.8	$ 168.9
Consumer Healthcare Loans Excluded	$ 210.4	$ 211.3
Credit quality personal banking loan table percentage loans excluded	7.00%
Real estate - personal
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Real estate - personal | Under 600
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.00%	2.00%
Real estate - personal | 600 - 659
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.50%	2.30%
Real estate - personal | 660 - 719
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	8.50%	8.50%
Real estate - personal | 720 - 779
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	21.60%	21.90%
Real estate - personal | 780 and over
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	65.40%	65.30%
Consumer
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer | Under 600
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.80%	2.50%
Consumer | 600 - 659
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	4.10%	4.30%
Consumer | 660 - 719
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	13.00%	12.90%
Consumer | 720 - 779
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	24.20%	28.20%
Consumer | 780 and over
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	55.90%	52.10%
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Revolving Home Equity [Member] | Under 600
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.00%	1.90%
Revolving Home Equity [Member] | 600 - 659
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	3.30%	3.30%
Revolving Home Equity [Member] | 660 - 719
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	11.70%	10.90%
Revolving Home Equity [Member] | 720 - 779
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	22.20%	22.40%
Revolving Home Equity [Member] | 780 and over
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	60.80%	61.50%
Consumer credit card
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer credit card | Under 600
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	5.00%	4.70%
Consumer credit card | 600 - 659
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	12.20%	12.10%
Consumer credit card | 660 - 719
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	30.40%	29.20%
Consumer credit card | 720 - 779
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	27.00%	27.00%
Consumer credit card | 780 and over
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	25.40%	27.00%