CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Net product sales	$ 64,649	$ 49,988	$ 27,132
Net product sales	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of goods sold	$ 25,123	$ 26,928	$ 14,030
Cost of goods sold	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Gross profit	$ 39,526	$ 23,060	$ 13,102
Research and development expenses	8,582	8,508	8,957
Selling and marketing expenses	28,122	44,133	46,881
General and administrative expenses	13,237	13,915	13,805
Loss from operations	(10,415)	(43,496)	(56,541)
Interest expense	(8,009)	(8,974)	(10,085)
Other income, net	1,533	795	854
Loss before income taxes	(16,891)	(51,675)	(65,772)
Income tax expense (benefit)	11
Net loss	$ (16,902)	$ (51,675)	$ (65,772)
Weighted average common shares outstanding used to compute net loss per share, basic and diluted	49,723,772	32,288,555	24,751,091
Net loss per share of common stock, basic and diluted	$ (0.34)	$ (1.60)	$ (2.66)