Goodwill And Other Intangible Assets (Schedule Of Changes In Carrying Amount Of Goodwill And Net Other Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Amortization	$ (1,300)	$ (1,500)	$ (1,800)
Goodwill [Member]
Goodwill [Roll Forward]
Balance, beginning	138,921	138,921
Originations	0	0
Amortization	0	0
Impairment reversal	0	0
Balance, ending	138,921	138,921	138,921
Core Deposit Premium [Member]
Goodwill [Roll Forward]
Balance, beginning	3,841	5,031
Originations	0	0
Amortization	(876)	(1,190)
Impairment reversal	0	0
Balance, ending	2,965	3,841	5,031
Mortgage Servicing Rights [Member]
Goodwill [Roll Forward]
Balance, beginning	2,868	1,638
Originations	2,234	1,539
Amortization	(462)	(316)
Impairment reversal	13	7
Balance, ending	$ 4,653	$ 2,868	$ 1,638