CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Net product sales	$ 15,643	$ 11,363	$ 30,277	$ 22,092
Net product sales	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of goods sold	$ 5,099	$ 6,987	$ 11,495	$ 12,208
Cost of goods sold	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit	$ 10,544	$ 4,376	$ 18,782	$ 9,884
Research and development expenses	2,009	2,381	5,206	4,072
Selling and marketing expenses	7,269	11,557	14,338	24,547
General and administrative expenses	3,712	3,705	7,505	7,051
Loss from operations	(2,446)	(13,267)	(8,267)	(25,786)
Interest expense	(1,987)	(2,232)	(4,102)	(4,452)
Other income, net	670	292	1,006	595
Net loss	$ (3,763)	$ (15,207)	$ (11,363)	$ (29,643)
Weighted average common shares outstanding used to compute net loss per share, basic and diluted	49,727,718	29,008,909	49,715,707	29,002,966
Net loss per share of common stock, basic and diluted	$ (0.08)	$ (0.52)	$ (0.23)	$ (1.02)