Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statements of Operations:
Revenues	$ 88,105	$ 78,173	$ 250,312	$ 225,702
Cost of revenue	38,793	33,448	109,358	99,077
Gross profit	49,312	44,725	140,954	126,625
Operating expenses
Marketing and sales	13,846	11,787	41,463	34,182
Research and development	5,877	5,976	17,784	17,110
General and administrative	10,222	10,020	28,256	28,397
Total operating expenses	29,945	27,783	87,503	79,689
Income from operations	19,367	16,942	53,451	46,936
Other income, net	291	625	1,779	2,342
Income before income taxes	19,658	17,567	55,230	49,278
Provision for income taxes	6,438	5,585	17,724	15,943
Net income	$ 13,220	$ 11,982	$ 37,506	$ 33,335
Net income per share:
Basic (in dollars per share)	$ 0.50	$ 0.45	$ 1.41	$ 1.27
Diluted (in dollars per share)	$ 0.49	$ 0.45	$ 1.40	$ 1.26
Shares used to compute net income per share:
Basic - weighted-average shares outstanding: (in shares)	26,617,349	26,416,041	26,600,174	26,334,738
Diluted (in shares)	26,802,034	26,609,878	26,716,553	26,539,078
Comprehensive Income (net of tax)
Comprehensive income	$ 14,875	$ 11,828	$ 42,510	$ 31,781