Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues
Product revenue, net	$ 15,451	$ 16,953	$ 35,578	$ 27,517
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Operating expenses
Cost of sales	$ 5,481	$ 1,398	$ 7,757	$ 3,160
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 12,507	$ 16,125	$ 33,641	$ 31,550
Selling, general and administrative	24,730	33,103	54,029	65,325
Total operating expenses	42,718	50,626	95,427	100,035
Loss from operations	(27,267)	(33,673)	(59,849)	(72,518)
Other (expense) income
Interest income	95	831	522	1,842
Interest expense	(5,002)	(3,949)	(9,723)	(7,885)
Other (expense) income	(197)	304	(123)	536
Total other (expense) income	(5,104)	(2,814)	(9,324)	(5,507)
Loss before income taxes	(32,371)	(36,487)	(69,173)	(78,025)
Income tax expense	248		248
Net loss	$ (32,619)	$ (36,487)	$ (69,421)	$ (78,025)
Net loss per common share, basic and diluted	$ (0.76)	$ (0.96)	$ (1.71)	$ (2.05)
Weighted average common shares outstanding, basic and diluted	42,776	38,010	40,664	38,001
Other comprehensive (loss) income:
Unrealized (losses) gains from available-for-sale securities, net of tax of $0	$ (3)	$ 125	$ (59)	$ 307
Total other comprehensive (loss) income	(3)	125	(59)	307
Comprehensive loss	$ (32,622)	$ (36,362)	$ (69,480)	$ (77,718)