Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statements of Operations:
Revenue	$ 115,430	$ 88,105	$ 332,827	$ 250,312
Cost of revenue	53,027	38,793	153,303	109,358
Gross profit	62,403	49,312	179,524	140,954
Operating expenses
Marketing and sales	16,818	13,846	50,947	41,463
Research and development	7,458	5,877	21,155	17,784
General and administrative	13,096	10,222	38,679	28,256
Total operating expenses	37,372	29,945	110,781	87,503
Income from operations	25,031	19,367	68,743	53,451
Other income, net	390	291	1,376	1,779
Income before income taxes	25,421	19,658	70,119	55,230
Provision for income taxes	4,484	6,438	12,817	17,724
Net income	$ 20,937	$ 13,220	$ 57,302	$ 37,506
Net income per share:
Basic (in dollars per share)	$ 0.77	$ 0.50	$ 2.13	$ 1.41
Diluted (in dollars per share)	$ 0.77	$ 0.49	$ 2.10	$ 1.40
Shares used to compute net income per share:
Basic (in shares)	27,038,585	26,617,349	26,963,205	26,600,174
Diluted (in shares)	27,337,886	26,802,034	27,268,311	26,716,553
Comprehensive Income (net of tax)
Comprehensive income	$ 20,058	$ 14,875	$ 55,298	$ 42,510