Employee Benefit Plans (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options Outstanding, beginning balance (in shares)	95,015	167,554
Options, Granted (in shares)	24,348	12,961
Options, Exercised (in shares)	(21,000)	(71,750)
Options, Forfeited (in shares)	0	(4,000)
Options Outstanding, ending balance (in shares)	98,363	104,765
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-Average Exercise Price, Outstanding, beginning balance (in dollars per share)	$ 38.38	$ 36.74
Weighted-Average Exercise Price, Granted (in dollars per share)	43.73	46.41
Weighted-Average Exercise Price, Exercised (in dollars per share)	33.57	37.01
Weighted-Average Exercise Price, Forfeited (in dollars per share)	0.00	31.66
Weighted-Average Exercise Price, Outstanding, ending balance (in dollars per share)	$ 40.76	$ 37.95
Exercisable (shares)	14,750	29,500
Exercisable, Weighted average exercise price (US$ per share)	$ 36.53	$ 34.30
Proceeds from Stock Options Exercised	$ 705	$ 2,649
Intrinsic value of stock options exercised	317	724
Allocated Share-based Compensation Expense	180	$ 160
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 440
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 7 months 6 days