CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues	$ 78,648	$ 65,207	$ 37,774
Costs and expenses
Costs of revenues	58,534	43,127	25,969
Research and development	28,568	22,418	14,304
Selling, general and administrative	33,692	22,080	11,271
Total costs and expenses	120,794	87,625	51,544
Loss from operations	(42,146)	(22,418)	(13,770)
Interest income	949	1,620	293
Interest expense	(2)	(1,133)	(1,894)
Loss on debt extinguishment		(1,704)	(4,658)
Other income (expense), net	(24)	(1,440)	150
Loss before income taxes	(41,223)	(25,075)	(19,879)
Provision for income taxes	(57)	(9)	(7)
Net loss	$ (41,280)	$ (25,084)	$ (19,886)
Net loss per share, basic and diluted	$ (1.20)	$ (1.39)	$ (6.49)
Weighted-average shares outstanding, basic and diluted	34,374,903	18,011,470	3,063,157