Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Sales:
Product	$ 24,529	$ 17,987	$ 62,653	$ 61,203
Service	14,293	7,634	34,916	19,400
Net sales	38,822	25,621	97,569	80,603
Costs and expenses:
Costs of product sales	13,297	9,745	37,026	33,756
Costs of service sales	10,035	5,464	22,659	15,360
Sales, marketing and support	6,360	5,614	17,239	16,790
Research and development	2,949	2,792	9,148	8,645
General and administrative	3,040	2,312	8,906	7,789
Total costs and expenses	35,681	25,927	94,978	82,340
Income (loss) from operations	3,141	(306)	2,591	(1,737)
Interest income	147	65	359	198
Interest expense	76	64	243	177
Other income, net	23	872	99	887
Income (loss) before income tax (expense) benefit	3,235	567	2,806	(829)
Income tax (expense) benefit	(1,490)	33	(1,983)	85
Net income (loss)	$ 1,745	$ 600	$ 823	$ (744)
Net Income (Loss) per Common Share [Abstract]
Basic	$ 0.12	$ 0.04	$ 0.06	$ (0.05)
Diluted	$ 0.12	$ 0.04	$ 0.05	$ (0.05)
Number of shares used in per share calculation:
Basic	14,846,249	14,877,481	14,742,855	14,842,746
Diluted	15,023,580	15,058,194	14,971,667	14,842,746