Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenue	$ 30,519	$ 22,844
Cost of revenue	9,660	7,654
Gross profit	20,859	15,190
Operating expenses:
Sales and marketing	15,776	10,906
Research and development	8,171	5,277
General and administrative	7,844	5,200
Total operating expenses	31,791	21,383
Operating loss	(10,932)	(6,193)
Other income (expense), net:
Interest and investment income	456	51
Interest expense	(1,572)	(1)
Other expense, net	(198)	(32)
Total other income (expense), net	(1,314)	18
Loss before income taxes	(12,246)	(6,175)
Provision for income taxes	(96)	(27)
Net loss	$ (12,342)	$ (6,202)
Net loss per share attributable to common stockholders:
Basic	$ (0.43)	$ (0.23)
Diluted	$ (0.43)	$ (0.23)
Weighted-average common shares outstanding:
Basic	28,434,678	27,170,827
Diluted	28,434,678	27,170,827