Goodwill And Other Intangible Assets (Schedule Of Intangible Assets With Estimable Useful Lives) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 38,631	$ 36,942
Accumulated Amortization	(31,227)	(30,211)
Valuation Allowance	(16)	(22)
Net Amount	7,388	6,709
Core Deposit Premium [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	31,270	31,270
Accumulated Amortization	(28,127)	(27,429)
Valuation Allowance	0	0
Net Amount	3,143	3,841
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,361	5,672
Accumulated Amortization	(3,100)	(2,782)
Valuation Allowance	(16)	(22)
Net Amount	$ 4,245	$ 2,868