Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 214,552	$ 147,277	$ 99,129
Cost of revenue	52,485	38,795	28,203
Gross profit	162,067	108,482	70,926
Operating expenses:
Research and development	37,299	20,860	13,265
Selling, general and administrative	179,523	133,313	85,252
Total operating expenses	216,822	154,173	98,517
Loss from operations	(54,755)	(45,691)	(27,591)
Interest expense	(1,643)	(3,115)	(3,386)
Other income, net	1,895	1,501	1,237
Loss on extinguishment of debt	0	(3,029)	0
Loss before income taxes	(54,503)	(50,334)	(29,740)
Income tax provision	65	44	0
Net loss	$ (54,568)	$ (50,378)	$ (29,740)
Net loss per common share, basic and diluted	$ (2.16)	$ (2.11)	$ (1.31)
Weighted-average shares, basic and diluted	25,265,918	23,885,858	22,627,327