Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net revenue	$ 26,296	$ 1,077
Cost of goods sold	9,895	548
Gross profit	16,401	529
Operating Expenses
Research and development	6,884	4,219
General and administrative	7,653	4,015
Sales and marketing	16,569	5,914
Total operating expenses	31,106	14,148
Loss from operations	(14,705)	(13,619)
Other Income (Expense)
Interest income	642	1,034
Interest and other expense	(552)	(532)
Other income, net	90	502
Loss before income tax expense	(14,615)	(13,117)
Income tax expense	1	0
Net loss	(14,616)	(13,117)
Foreign currency translation adjustment	(177)	(10)
Comprehensive loss	$ (14,793)	$ (13,127)
Net loss per share, basic and diluted (USD per share)	$ (0.43)	$ (0.47)
Weighted-average shares used to compute basic and diluted net loss per share (shares)	33,637,646	27,828,201