Loans And Allowance For Loan Losses (Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding ) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Abstract]
Credit Quality Personal Real Estate Loans Excluded	$ 219.2	$ 237.2
Consumer Healthcare Loans Excluded	$ 145.0	$ 75.4
Credit quality personal banking loan table percentage loans excluded	7.00%
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Real Estate - Personal [Member] | Under 600 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	1.30%	1.30%
Real Estate - Personal [Member] | 600 - 659 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.10%	2.60%
Real Estate - Personal [Member] | 660 - 719 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	10.50%	10.40%
Real Estate - Personal [Member] | 720 - 779 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	25.60%	25.40%
Real Estate - Personal [Member] | 780 and over [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	60.50%	60.30%
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer [Member] | Under 600 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	3.30%	3.40%
Consumer [Member] | 600 - 659 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	5.50%	6.40%
Consumer [Member] | 660 - 719 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	17.30%	19.70%
Consumer [Member] | 720 - 779 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	26.80%	26.30%
Consumer [Member] | 780 and over [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	47.10%	44.20%
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 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	1.10%	1.00%
Revolving Home Equity [Member] | 600 - 659 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	1.70%	1.80%
Revolving Home Equity [Member] | 660 - 719 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	9.50%	9.70%
Revolving Home Equity [Member] | 720 - 779 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	21.40%	21.10%
Revolving Home Equity [Member] | 780 and over [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	66.30%	66.40%
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer Credit Card [Member] | Under 600 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	4.70%	4.90%
Consumer Credit Card [Member] | 600 - 659 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	14.40%	15.50%
Consumer Credit Card [Member] | 660 - 719 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	34.40%	34.90%
Consumer Credit Card [Member] | 720 - 779 [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	26.00%	25.10%
Consumer Credit Card [Member] | 780 and over [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	20.50%	19.60%