Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Revenue	$ 193,534	$ 159,258	$ 147,176
Cost of revenue	118,241	94,206	90,106
Gross profit	75,293	65,052	57,070
Operating expenses:
Selling, general and administrative	44,195	33,656	35,218
Research and development	22,542	21,700	22,356
Total operating expenses	66,737	55,356	57,574
Income (loss) from operations	8,556	9,696	(504)
Interest expense, net	(4)	(116)	(109)
Amortization of debt discount and prepaid debt costs	(60)	(57)	(55)
Gain on embedded derivatives	0	0	1,086
Income from operations before income taxes	8,492	9,523	418
Income tax provision	2,152	2,349	1,856
Net income (loss)	$ 6,340	$ 7,174	$ (1,438)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.22	$ 0.25	$ (0.05)
Diluted (in dollars per share)	$ 0.22	$ 0.25	$ (0.05)
Weighted average common shares outstanding:
Basic (in shares)	28,869	28,568	27,637
Diluted (in shares)	28,903	28,709	27,637