Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net sales	$ 197,892	$ 164,525	$ 137,831
Cost of products sold and services delivered	69,245	62,977	51,988
Gross margin	128,647	101,548	85,843
Operating expenses:
Sales, general and administrative	69,698	54,158	46,557
Research and development	23,614	14,885	9,888
Litigation judgments	0	0	1,450
Total operating expenses	93,312	69,043	57,895
Income from operations	35,335	32,505	27,948
Interest and other income (expense), net	26	(194)	86
Income before provision for income taxes	35,361	32,311	28,034
Provision for income taxes	15,428	12,393	9,790
Net income	$ 19,933	$ 19,918	$ 18,244
Net income per common and common equivalent shares:
Basic (in dollars per share)	$ 0.37	$ 0.38	$ 0.35
Diluted (in dollars per share)	$ 0.36	$ 0.37	$ 0.34
Weighted average number of common and common equivalent shares outstanding:
Basic (in shares)	53,548	52,948	51,880
Diluted (in shares)	54,638	54,500	54,152
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 19,933	$ 19,918	$ 18,244
Foreign currency translation adjustments	19	66	55
Comprehensive income	$ 19,952	$ 19,984	$ 18,299