Loans And Allowance For Loan Losses (Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding ) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Credit Quality Personal Real Estate Loans Excluded	$ 233.0	$ 237.2
Credit quality personal banking loan table percentage loans excluded	4.50%
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	1.30%	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	2.70%	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	10.50%	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	25.30%	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	60.20%	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	3.60%	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	6.10%	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	19.50%	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	27.20%	26.30%
Consumer [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	43.60%	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	1.00%	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	1.90%	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	8.60%	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	22.90%	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	65.60%	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	5.30%	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	16.00%	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	35.60%	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	25.00%	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	18.10%	19.60%