Derivative Instruments (Fair Value Of Derivative Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Customer Counterparties Loan Interest Rate Swap Assets | Not Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Notional Amount	$ 225,480	$ 234,806
Fair Value	4,877	7,352
Customer Counterparties Loan Interest Rate Swap Liabilities | Not Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Notional Amount	314,450	207,201
Fair Value	9,513	8,111
Financial Institution Counterparties Loan Interest Rate Swap Asset | Not Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Notional Amount	320,949	207,201
Fair Value	9,591	8,111
Financial Institution Counterparties Loan Interest Rate Swap Asset | Designated as Hedging Instrument | Other Assets
Derivatives, Fair Value [Line Items]
Notional Amount	4,326	0
Fair Value	34	0
Financial Institution Counterparties Loan Interest Rate Swap Liabilities | Not Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Notional Amount	218,924	241,995
Fair Value	4,877	7,360
Financial Institution Counterparties Loan Interest Rate Swap Liabilities | Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value [Line Items]
Notional Amount	0	4,626
Fair Value	$ 0	$ 12