Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Sales:
Product	$ 21,041	$ 24,331	$ 38,124	$ 43,215
Service	10,978	6,241	20,623	11,766
Net sales	32,019	30,572	58,747	54,981
Costs and expenses:
Costs of product sales	12,746	13,482	23,729	24,010
Costs of service sales	6,822	5,095	12,624	9,897
Sales, marketing and support	5,547	5,976	10,879	11,175
Research and development	3,059	2,878	6,199	5,853
General and administrative	2,918	2,550	5,866	5,477
Total costs and expenses	31,092	29,981	59,297	56,412
Income (loss) from operations	927	591	(550)	(1,431)
Interest income	109	67	212	132
Interest expense	85	57	167	113
Other income, net	39	1	76	15
Income (loss) before income taxes	990	602	(429)	(1,397)
Income tax expense (benefit)	537	412	493	(53)
Net income (loss)	$ 453	$ 190	$ (922)	$ (1,344)
Net Income (Loss) per Common Share [Abstract]
Basic	$ 0.03	$ 0.01	$ (0.06)	$ (0.09)
Diluted	$ 0.03	$ 0.01	$ (0.06)	$ (0.09)
Number of shares used in per share calculation:
Basic	14,776,239	14,901,495	14,690,591	14,825,091
Diluted	14,886,548	15,199,900	14,690,591	14,825,091