Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net revenues	$ 27,484,000	$ 29,984,000
Cost of product sales	13,505,000	16,445,000
Operating expenses:
Selling, general and administrative	23,689,000	24,451,000
Research and development	11,766,000	9,300,000
Restructuring charges	0	1,451,000
Total operating expenses	35,455,000	35,202,000
Loss from operations	(21,476,000)	(21,663,000)
Interest expense, net	(10,886,000)	(9,212,000)
Other (expense) income, net	(307,000)	52,000
Loss before provision for income taxes	(32,669,000)	(30,823,000)
Provision for income taxes	(159,000)	(139,000)
Net loss	$ (32,828,000)	$ (30,962,000)
Net loss per common share—basic and diluted (in usd per share)	$ (1.76)	$ (1.67)
Weighted-average shares outstanding—basic and diluted (in shares)	18,703	18,540