Derivative Instruments (Impact Of Derivatives On Balance Sheet) (Details) - Not Designated As Hedging Instruments [Member] - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Other Assets [Member]
Derivative [Line Items]
Fair value of derivative assets	$ 17,791	$ 20,623
Other Assets [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of derivative assets	15,548	17,157
Other Assets [Member] | Mortgage Derivatives [Member]
Derivative [Line Items]
Fair value of derivative assets	2,243	3,466
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	21,896	23,299
Other Liabilities [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of derivative liabilities	15,923	17,531
Other Liabilities [Member] | Mortgage Derivatives [Member]
Derivative [Line Items]
Fair value of derivative liabilities	561	0
Other Liabilities [Member] | Visa Derivative [Member]
Derivative [Line Items]
Fair value of derivative liabilities	$ 5,412	$ 5,768