CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Product sales, net	$ 33,627	$ 26,678
Other revenue	941	0
Total revenue	34,568	26,678
Cost of product sales	11,583	9,922
Gross profit	22,985	16,756
Research and development	3,630	3,763
Selling, general and administrative	22,660	18,069
Total operating expenses	26,290	21,832
Loss from operations	(3,305)	(5,076)
Other income (expense):
Interest income	76	306
Other income	(1)	(2)
Interest expense	84	67
Total other income	159	371
Net loss before tax provision	(3,146)	(4,705)
Tax provision	(143)	0
Net loss	$ (3,289)	$ (4,705)
Net loss per share (basic) (in USD per share)	$ (0.07)	$ (0.10)
Net loss per share (diluted) (in USD per share)	$ (0.07)	$ (0.10)
Weighted average number of common shares outstanding (basic) (in shares)	45,984	44,924
Weighted average number of common shares outstanding (diluted) (in shares)	45,984	44,924
Revenue, Product and Service [Extensible List]	us-gaap:ProductMember
Cost, Product and Service [Extensible List]	us-gaap:ProductMember