Common Stock And Stock Options (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Common Stock And Stock Options [Abstract]
Number of Shares, Outstanding	1,324	1,313	1,407
Number of Shares, Options forfeited or cancelled	(70)		(63)
Number of Shares, Options granted	192	170	174
Number of Shares, Options exercised	(61)	(159)	(205)
Number of Shares, Outstanding	1,385	1,324	1,313
Weighted-average Exercise Price, Outstanding	$ 6.36	$ 5.86	$ 5.75
Weighted-average Exercise Price, Options forfeited or cancelled	5.75		7.87
Weighted-average Exercise Price, Options granted	7.11	7.14	4.99
Weighted-average Exercise Price, Options exercised	5.22	3.12	3.74
Weighted-average Exercise Price, Outstanding	$ 6.54	$ 6.36	$ 5.86
Aggregate Intrinsic Value, Outstanding	$ 1,774
Number of Shares, Exercisable	1,025	989
Weighted-average Exercise Price, Exercisable	$ 6.45	$ 6.50
Aggregate Intrinsic Value, Exercisable	$ 1,615	$ 2,076
Number of Shares, Available for future grant	404