Condensed Consolidated Statements of Operations (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue:
Product revenue	$ 31,196	$ 27,051	$ 93,411	$ 81,555
Service revenue	11,974	11,334	35,201	33,910
Total revenue	43,170	38,385	128,612	115,465
Cost of sales	28,454	23,411	85,863	74,092
Gross profit	14,716	14,974	42,749	41,373
Operating expenses:
Product development and engineering	5,060	4,627	16,030	13,729
Selling, general and administrative	10,080	10,308	32,118	32,153
Total operating expenses	15,140	14,935	48,148	45,882
Operating (loss) income	(424)	39	(5,399)	(4,509)
Interest expense	(116)	(41)	(306)	(414)
Other expense, net	227	(132)	(160)	(217)
Loss before provision for income taxes	(313)	(134)	(5,865)	(5,140)
Provision for income taxes	727	12	1,659	433
Net Loss	$ (1,040)	$ (146)	$ (7,524)	$ (5,573)
Net loss per share — basic (in usd per share)	$ (0.14)	$ (0.02)	$ (1.03)	$ (0.74)
Net loss per share — diluted (in usd per share)	$ (0.14)	$ (0.02)	$ (1.03)	$ (0.74)
Weighted average number of shares:
Basic (in shares)	7,362	7,522	7,335	7,539
Diluted (in shares)	7,362	7,522	7,335	7,539