Derivative Instruments (Impact Of Derivatives On Balance Sheet) (Details) - Not Designated As Hedging Instruments [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Other Assets [Member]
Derivative [Line Items]
Fair Value of Derivative Assets	$ 20,623	$ 27,139
Other Assets [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair Value of Derivative Assets	17,157	25,580
Other Assets [Member] | Mortgage Derivatives [Member]
Derivative [Line Items]
Fair Value of Derivative Assets	3,466	1,559
Other Assets [Member] | Visa Derivative [Member]
Derivative [Line Items]
Fair Value of Derivative Assets	0	0
Other Liabilities [Member]
Derivative [Line Items]
Fair Value of Derivative Liabilities	23,299	27,445
Other Liabilities [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair Value of Derivative Liabilities	17,531	26,030
Other Liabilities [Member] | Mortgage Derivatives [Member]
Derivative [Line Items]
Fair Value of Derivative Liabilities	0	0
Other Liabilities [Member] | Visa Derivative [Member]
Derivative [Line Items]
Fair Value of Derivative Liabilities	$ 5,768	$ 1,415