Employee Benefits And Deferred Compensation Plans (Schedule Of Net Periodic Benefit Costs, SERP) (Details) - Supplemental Executive Retirement Plans [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 188	$ 194	$ 168
Interest cost	144	146	159
Net amortization and deferral	167	161	115
Net periodic benefit cost	$ 499	$ 501	$ 442