Derivative Instruments (Change In Fair Value Of Derivative Instruments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Not Designated as Hedging Instrument | Derivative assets | Other Income
Derivatives, Fair Value [Line Items]
Change in Fair Value	$ (3,379)	$ 3,904	$ 1,030
Not Designated as Hedging Instrument | Derivative liabilities | Other Income
Derivatives, Fair Value [Line Items]
Change in Fair Value	3,379	(3,904)	(1,030)
Not Designated as Hedging Instrument | Derivative liabilities | Other Expense
Derivatives, Fair Value [Line Items]
Change in Fair Value	86	(52)	0
Designated as Hedging Instrument | Derivative assets | Other Expense
Derivatives, Fair Value [Line Items]
Change in Fair Value	8	0	0
Designated as Hedging Instrument | Derivative liabilities | Other Expense
Derivatives, Fair Value [Line Items]
Change in Fair Value	0	13	(12)
Loans Receivable | Designated as Hedging Instrument | Derivative assets
Derivatives, Fair Value [Line Items]
Change in Fair Value	$ 38	$ (36)	$ 25