Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Total revenue	$ 87,782	$ 80,962	$ 34,042
Cost of revenue:
Total cost of revenue	93,260	74,359	27,710
Gross margin	(5,478)	6,603	6,332
Operating expenses:
Research and development	23,794	16,520	14,709
Selling and marketing	25,806	15,062	8,412
General and administrative	65,717	50,113	31,375
Total operating expenses	115,317	81,695	54,496
Loss from operations	(120,795)	(75,092)	(48,164)
Interest income	1,721	8	5
Interest expense	(4,327)	(7,701)	(7,247)
Other income (expense), net	3,202	6,389	(16,770)
Loss before provision for income taxes	(120,199)	(76,396)	(72,176)
Provision for income taxes	0	0	0
Net loss and comprehensive loss	(120,199)	(76,396)	(72,176)
Amortization of beneficial conversion feature related to Series A convertible preferred stock	0	(2,728)	0
Net loss attributable to common stockholders, basic and diluted	$ (120,199)	$ (79,124)	$ (72,176)
Net loss per share, basic and diluted	$ (1.18)	$ (0.98)	$ (1.23)
Weighted-average common shares used to compute net loss per share attributable to common stockholders, basic and diluted	102,001,954	81,123,140	58,457,868
Product
Revenue:
Total revenue	$ 79,504	$ 76,626	$ 30,458
Cost of revenue:
Total cost of revenue	80,446	66,522	25,488
Service
Revenue:
Total revenue	7,803	3,861	3,109
Cost of revenue:
Total cost of revenue	12,814	7,837	2,222
Distribution Rights
Revenue:
Total revenue	$ 475	$ 475	$ 475