Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements Of Operations [Abstract]
Sales, net	$ 63,933	$ 56,058	$ 58,697
Cost of sales	48,957	43,392	43,684
Gross profit	14,976	12,666	15,013
Operating expenses:
Sales and marketing	3,324	3,185	3,133
General and administrative	5,958	5,797	5,801
Research and development	4,694	4,876	4,485
Total operating expenses	13,976	13,858	13,419
Operating income (loss)	1,000	(1,192)	1,594
Interest expense	(755)	(609)	(655)
Equity in income (loss) of partnerships	(116)	174	(135)
Gain on sale of investment in partnership	822
Other income (expense), net	(78)	42	(4)
Income (loss) from continuing operations before income taxes and discontinued operations	873	(1,585)	800
Income tax (expense) benefit	(164)	160	(145)
Income (loss) before discontinued operations	709	(1,425)	655
Loss from discontinued operations, net of income taxes			(329)
Gain on sale of discontinued operations, net of income taxes			35
Net income (loss)	$ 709	$ (1,425)	$ 361
Basic income (loss) per share:
Continuing operations	$ 0.13	$ (0.25)	$ 0.12
Discontinued operations			$ (0.05)
Net income (loss)	$ 0.13	$ (0.25)	$ 0.07
Diluted income (loss) per share:
Continuing operations	$ 0.12	$ (0.25)	$ 0.12
Discontinued operations			$ (0.05)
Net income (loss)	$ 0.12	$ (0.25)	$ 0.07