Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net revenues	$ 30,334	$ 28,669	$ 89,722	$ 99,530
Cost of product sales	12,531	29,505	41,739	60,227
Operating expenses:
Selling, general and administrative	18,348	21,395	65,773	72,360
Research and development	9,031	17,112	31,157	37,236
Restructuring charges	2,151	56	2,151	2,541
Total operating expenses	29,530	38,563	99,081	112,137
Loss from operations	(11,727)	(39,399)	(51,098)	(72,834)
Interest expense, net	(12,022)	(9,897)	(34,501)	(28,722)
Other (expense) income, net	(926)	49	(1,961)	176
Loss before provision for income taxes	(24,675)	(49,247)	(87,560)	(101,380)
Provision for income taxes	(133)	(497)	(1,338)	(762)
Net loss	$ (24,808)	$ (49,744)	$ (88,898)	$ (102,142)
Net loss per common share—basic and diluted (in usd per share)	$ (1.32)	$ (2.67)	$ (4.74)	$ (5.49)
Weighted-average shares outstanding—basic and diluted (in shares)	18,854	18,648	18,772	18,599