Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Revenues	$ 197,925	$ 164,284	$ 133,579
Cost of revenues	42,473	33,885	28,963
Gross profit	155,452	130,399	104,616
Operating expenses:
Research and development	35,267	29,451	26,320
Sales and marketing	57,970	49,569	48,049
General and administrative	32,108	26,573	21,000
Total operating expenses	125,345	105,593	95,369
Income from operations	30,107	24,806	9,247
Other income (expense), net:
Interest expense	(26)	(6)	(9)
Interest income	1,320	570	452
Other expense, net	(972)	(850)	(1,077)
Total other income (expense), net	322	(286)	(634)
Income before income taxes	30,429	24,520	8,613
Provision for (benefit from) income taxes	11,205	8,655	(21,631)
Net income	19,224	15,865	30,244
Net income attributable to common stockholders	$ 19,224	$ 15,865	$ 30,244
Net income per share:
Basic (usd per share)	$ 0.55	$ 0.47	$ 0.92
Diluted (usd per share)	$ 0.50	$ 0.42	$ 0.81
Weighted average shares used in computing net income per share:
Basic (in shares)	35,247	34,050	32,979
Diluted (in shares)	38,369	38,184	37,170