CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 28,196	$ 40,762	$ 102,475	$ 112,015
Cost of revenue	14,824	20,981	54,749	57,945
Gross profit	13,372	19,781	47,726	54,070
Operating expenses:
Research and development	11,901	10,344	33,619	27,678
Sales and marketing	6,964	7,842	20,577	24,579
General and administrative	7,527	5,503	26,215	16,653
Total operating expenses	26,392	23,689	80,411	68,910
Loss from operations	(13,020)	(3,908)	(32,685)	(14,840)
Other income, net	49	317	584	947
Interest expense	(1,360)	(413)	(4,021)	(1,263)
Loss before income taxes	(14,331)	(4,004)	(36,122)	(15,156)
Income tax expense	(15)	(77)	(84)	(151)
Net loss	$ (14,346)	$ (4,081)	$ (36,206)	$ (15,307)
Net loss per share — basic and diluted	$ (0.63)	$ (0.19)	$ (1.60)	$ (0.70)
Weighted-average shares outstanding — basic and diluted	22,931	21,961	22,686	21,738