Loans And Allowance For Loan Losses (Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding ) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Credit Quality Personal Real Estate Loans Excluded	$ 220.7	$ 237.2
Credit quality personal banking loan table percentage loans excluded	4.20%
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Real Estate - Personal [Member] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	1.40%	1.30%
Real Estate - Personal [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.20%	2.60%
Real Estate - Personal [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	10.10%	10.40%
Real Estate - Personal [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	24.80%	25.40%
Real Estate - Personal [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	61.50%	60.30%
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer [Member] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	3.30%	3.40%
Consumer [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	5.70%	6.40%
Consumer [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	17.10%	19.70%
Consumer [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	26.10%	26.30%
Consumer [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	47.80%	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] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	0.90%	1.00%
Revolving Home Equity [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.10%	1.80%
Revolving Home Equity [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	9.00%	9.70%
Revolving Home Equity [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	21.20%	21.10%
Revolving Home Equity [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	66.80%	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] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	5.00%	4.90%
Consumer Credit Card [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	15.10%	15.50%
Consumer Credit Card [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	34.90%	34.90%
Consumer Credit Card [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	25.90%	25.10%
Consumer Credit Card [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	19.10%	19.60%