Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue:
Total revenue	$ 20,862	$ 17,666	$ 71,313	$ 60,299
Cost of revenue:
Total cost of revenue	20,288	17,302	72,857	54,296
Gross margin	574	364	(1,544)	6,003
Operating expenses:
Research and development	5,641	4,347	17,135	12,506
Selling and marketing	7,297	3,384	19,845	10,024
General and administrative	19,381	16,721	49,888	37,070
Total operating expenses	32,319	24,452	86,868	59,600
Loss from operations	(31,745)	(24,088)	(88,412)	(53,597)
Interest income	484	2	1,391	6
Interest expense	(1,069)	(1,974)	(2,902)	(5,758)
Other income (expense), net	11,499	(6,792)	4,933	(307)
Loss before provision for income taxes	(20,831)	(32,852)	(84,990)	(59,656)
Provision for income taxes	0	0	0	0
Net loss and comprehensive loss	(20,831)	(32,852)	(84,990)	(59,656)
Amortization of beneficial conversion feature related to Series A convertible preferred stock	0	0	0	(2,728)
Net loss attributable to common stockholders, basic and diluted	$ (20,831)	$ (32,852)	$ (84,990)	$ (62,384)
Net loss per share, basic and diluted	$ (0.21)	$ (0.39)	$ (0.87)	$ (0.82)
Weighted-average common shares used to compute net loss per share attributable to common stockholders, basic and diluted	99,039,789	84,920,996	97,763,964	76,185,346
Product
Revenue:
Total revenue	$ 18,696	$ 16,492	$ 65,475	$ 57,237
Cost of revenue:
Total cost of revenue	18,521	15,199	63,368	49,564
Service
Revenue:
Total revenue	2,048	1,056	5,482	2,706
Cost of revenue:
Total cost of revenue	1,767	2,103	9,489	4,732
Distribution Rights
Revenue:
Total revenue	$ 118	$ 118	$ 356	$ 356