Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Product revenue, net	$ 10,564	$ 2,194
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember
Operating expenses
Cost of sales	$ 1,762	$ 2,698
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 15,424	$ 11,551
Selling, general and administrative	32,222	26,899
Total operating expenses	49,408	41,148
Loss from operations	(38,844)	(38,954)
Other (expense) income
Interest income	1,011	1,161
Interest expense	(3,936)	(3,919)
Other income	231	143
Total other (expense) income	(2,694)	(2,615)
Net loss	$ (41,538)	$ (41,569)
Net loss per common share, basic and diluted	$ (1.09)	$ (1.10)
Weighted average common shares outstanding, basic and diluted	37,992	37,620
Other comprehensive income (loss):
Unrealized gains (losses) from available-for-sale securities, net of tax of $0	$ 182	$ (169)
Total other comprehensive income (loss)	182	(169)
Comprehensive loss	$ (41,356)	$ (41,738)