Summary Of Significant Accounting Policies (Schedule Of Earnings Per Share Basic And Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Weighted average shares outstanding (basic)									4,337	4,297	4,244
Impact of common stock equivalents									22	5	6
Weighted average shares outstanding (diluted)									4,359	4,302	4,250
Anti-dilutive options excluded from calculation										9	27
Net income	$ (7,263)	$ 3,076	$ 3,342	$ 3,020	$ 1,723	$ 2,075	$ 1,561	$ 2,726	$ 2,176	$ 8,087	$ 10,204
Basic earnings per share	$ (1.67)	$ 0.71	$ 0.77	$ 0.70	$ 0.40	$ 0.48	$ 0.36	$ 0.64	$ 0.50	$ 1.88	$ 2.40
Diluted earnings per share	$ (1.67)	$ 0.70	$ 0.77	$ 0.70	$ 0.40	$ 0.48	$ 0.36	$ 0.64	$ 0.50	$ 1.88	$ 2.40