Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenue	$ 25,021	$ 18,565	$ 47,865	$ 35,634
Cost of revenue	7,239	5,676	14,893	11,151
Gross profit	17,782	12,889	32,972	24,483
Operating expenses:
Sales and marketing	11,057	8,849	21,963	17,054
Research and development	5,179	3,463	10,456	6,643
General and administrative	5,065	3,128	10,265	6,586
Total operating expenses	21,301	15,440	42,684	30,283
Operating loss	(3,519)	(2,551)	(9,712)	(5,800)
Other income (expense), net:
Interest and investment income	77		128
Interest expense	(2)	(174)	(3)	(311)
Other income (expense), net	(6)	(34)	(38)	(28)
Total other income (expense), net	69	(208)	87	(339)
Loss before income taxes	(3,450)	(2,759)	(9,625)	(6,139)
(Provision for) benefit from income taxes	13	(45)	(14)	110
Net loss	$ (3,437)	$ (2,804)	$ (9,639)	$ (6,029)
Net loss per share attributable to common stockholders:
Basic	$ (0.12)	$ (0.23)	$ (0.35)	$ (0.49)
Diluted	$ (0.12)	$ (0.23)	$ (0.35)	$ (0.49)
Weighted-average common shares outstanding:
Basic	27,877,346	12,300,951	27,526,038	12,287,064
Diluted	27,877,346	12,300,951	27,526,038	12,287,064