Derivative Instruments (Impact Of Derivatives On Balance Sheet) (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other assets
Derivative [Line Items]
Fair value of derivative assets	$ 9,407	$ 11,722
Other assets | Interest rate contracts
Derivative [Line Items]
Fair value of derivative assets	7,672	10,786
Other assets | Mortgage derivatives
Derivative [Line Items]
Fair value of derivative assets	1,735	936
Other assets | Visa derivative
Derivative [Line Items]
Fair value of derivative assets	0	0
Other liabilities
Derivative [Line Items]
Fair value of derivative liabilities	20,096	17,097
Other liabilities | Interest rate contracts
Derivative [Line Items]
Fair value of derivative liabilities	16,122	12,638
Other liabilities | Mortgage derivatives
Derivative [Line Items]
Fair value of derivative liabilities	0	129
Other liabilities | Visa derivative
Derivative [Line Items]
Fair value of derivative liabilities	$ 3,974	$ 4,330