Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements Of Operations [Abstract]
Sales, net	$ 68,303	$ 52,961	$ 59,955
Cost of sales	49,819	40,792	44,656
Gross profit	18,484	12,169	15,299
Operating expenses:
Sales and marketing	3,699	3,308	3,324
General and administrative	6,462	5,789	5,426
Research and development	4,832	4,181	4,481
Restructuring charges (Note 3)	83	229
Total operating expenses	15,076	13,507	13,231
Operating income (loss)	3,408	(1,338)	2,068
Interest expense	(461)	(600)	(755)
Equity in income (loss) of partnerships	(228)	(262)	(116)
Gain on sale of investment in partnership			822
Other income (expense), net	227	127	(96)
Income (loss) from continuing operations before income taxes and discontinued operations	2,946	(2,073)	1,923
Income tax expense	428	217	164
Income (loss) before discontinued operations	2,518	(2,290)	1,759
Loss on sale of discontinued operations (Note 2)	(120)
Loss from discontinued operations, net of income taxes (Note 2)	(150)	(3,872)	(1,050)
Net income (loss)	$ 2,248	$ (6,162)	$ 709
Basic income (loss) per share:
Continuing operations	$ 0.43	$ (0.40)	$ 0.31
Discontinued operations	$ (0.05)	$ (0.68)	$ (0.19)
Net income (loss) per share:	$ 0.39	$ (1.08)	$ 0.13
Diluted income (loss) per share:
Continuing operations	$ 0.42	$ (0.40)	$ 0.30
Discontinued operations	$ (0.04)	$ (0.68)	$ (0.18)
Net income (loss) per share:	$ 0.37	$ (1.08)	$ 0.12
Average shares outstanding:
Basic	5,791	5,699	5,669
Diluted	6,038	5,699	5,888