CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Net product sales	$ 17,540	$ 12,503	$ 47,817	$ 34,595
Net product sales	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of goods sold	$ 6,447	$ 6,957	$ 17,942	$ 19,165
Cost of goods sold	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit	$ 11,093	$ 5,546	$ 29,875	$ 15,430
Research and development expenses	1,551	2,037	6,757	6,109
Selling and marketing expenses	7,125	10,446	21,463	34,993
General and administrative expenses	2,850	3,537	10,355	10,588
Loss from operations	(433)	(10,474)	(8,700)	(36,260)
Interest expense	(1,869)	(2,260)	(5,971)	(6,712)
Other income, net	251	39	1,257	634
Net loss	$ (2,051)	$ (12,695)	$ (13,414)	$ (42,338)
Weighted average common shares outstanding used to compute net loss per share, basic and diluted	49,730,755	29,625,792	49,720,780	29,212,856
Net loss per share of common stock, basic and diluted	$ (0.04)	$ (0.43)	$ (0.27)	$ (1.45)