CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenue	$ 33,063	$ 25,068
Cost of revenue	17,190	13,306
Gross profit	15,873	11,762
Operating expenses:
Research and development	8,561	8,003
Sales and marketing	8,549	8,859
General and administrative	5,695	5,225
Restructuring costs		3,927
Total operating expenses	22,805	26,014
Loss from operations	(6,932)	(14,252)
Other income, net	321	90
Interest expense	(429)	(229)
Loss before income taxes	(7,040)	(14,391)
Income tax expense	(28)	(51)
Net loss	$ (7,068)	$ (14,442)
Net loss per share — basic and diluted	$ (0.33)	$ (0.68)
Weighted-average shares outstanding — basic and diluted	21,544	21,125