Goodwill And Other Intangible Assets (Schedule Of Intangible Assets With Estimable Useful Lives) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 40,971	$ 39,176
Accumulated Amortization	(32,501)	(31,549)
Valuation Allowance	0	(9)
Net Amount	8,470	7,618
Core Deposit Premium [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	31,270	31,270
Accumulated Amortization	(28,808)	(28,305)
Valuation Allowance	0	0
Net Amount	2,462	2,965
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9,701	7,906
Accumulated Amortization	(3,693)	(3,244)
Valuation Allowance	0	(9)
Net Amount	$ 6,008	$ 4,653