Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Product revenue, net	$ 16,953	$ 3,797	$ 27,517	$ 5,991
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Operating expenses
Cost of sales	$ 1,398	$ 946	$ 3,160	$ 3,644
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 16,125	$ 13,094	$ 31,550	$ 24,645
Selling, general and administrative	33,103	31,036	65,325	57,935
Total operating expenses	50,626	45,076	100,035	86,224
Loss from operations	(33,673)	(41,279)	(72,518)	(80,233)
Other (expense) income
Interest income	831	1,254	1,842	2,415
Interest expense	(3,949)	(3,926)	(7,885)	(7,845)
Other income	304	76	536	219
Total other (expense) income	(2,814)	(2,596)	(5,507)	(5,211)
Net loss	$ (36,487)	$ (43,875)	$ (78,025)	$ (85,444)
Net loss per common share, basic and diluted	$ (0.96)	$ (1.16)	$ (2.05)	$ (2.27)
Weighted average common shares outstanding, basic and diluted	38,010	37,697	38,001	37,659
Other comprehensive income:
Unrealized gains from available-for-sale securities, net of tax of $0	$ 125	$ 266	$ 307	$ 97
Total other comprehensive income	125	266	307	97
Comprehensive loss	$ (36,362)	$ (43,609)	$ (77,718)	$ (85,347)