Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net sales	$ 50,376	$ 44,349	$ 141,851	$ 117,709
Cost of products sold and services delivered	19,308	15,636	50,192	43,574
Gross margin	31,068	28,713	91,659	74,135
Operating expenses:
Sales, general and administrative	17,834	12,441	47,842	39,734
Research and development	6,528	3,759	16,992	10,820
Total operating expenses	24,362	16,200	64,834	50,554
Income from operations	6,706	12,513	26,825	23,581
Interest income and other (expense) income, net	(22)	(160)	12	(88)
Income before provision for income taxes	6,684	12,353	26,837	23,493
Provision for income taxes	5,163	4,795	12,008	8,661
Net income	$ 1,521	$ 7,558	$ 14,829	$ 14,832
Net income per common and common equivalent shares:
Basic (in dollars per share)	$ 0.03	$ 0.14	$ 0.28	$ 0.28
Diluted (in dollars per share)	$ 0.03	$ 0.14	$ 0.27	$ 0.27
Weighted average number of common and common equivalent shares outstanding:
Basic (in shares)	53,709	52,475	53,509	53,013
Diluted (in shares)	54,691	53,821	54,671	54,550
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 1,521	$ 7,558	$ 14,829	$ 14,832
Foreign currency translation adjustments	(115)	(15)	(18)	0
Comprehensive income	$ 1,406	$ 7,543	$ 14,811	$ 14,832