CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Product sales, net	$ 26,678	$ 21,810
Cost of product sales	9,922	8,640
Gross profit	16,756	13,170
Research and development	3,763	3,008
Selling, general and administrative	18,069	13,520
Total operating expenses	21,832	16,528
Loss from operations	(5,076)	(3,358)
Other income (expense):
Interest income	306	480
Other income	(2)	(2)
Interest expense	67	36
Total other income (expense)	371	514
Net loss	$ (4,705)	$ (2,844)
Net loss per share attributable to common shareholders (Basic and Diluted) (in dollars per share)	$ (0.10)	$ (0.07)
Weighted average number of common shares outstanding (Basic and Diluted) (in shares)	44,924	43,725