Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Product revenue, net	$ 3,797		$ 5,991
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Operating expenses
Cost of sales	$ 946		$ 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	$ 13,094	$ 11,769	$ 24,645	$ 22,524
Selling, general and administrative	31,036	15,133	57,935	28,158
Total operating expenses	45,076	26,902	86,224	50,682
Loss from operations	(41,279)	(26,902)	(80,233)	(50,682)
Other income (expense)
Interest income	1,254	797	2,415	1,355
Interest expense	(3,926)	(2,887)	(7,845)	(3,520)
Other income	76	112	219	83
Total other income (expense)	(2,596)	(1,978)	(5,211)	(2,082)
Net loss	$ (43,875)	$ (28,880)	$ (85,444)	$ (52,764)
Net loss per common share, basic and diluted	$ (1.16)	$ (0.91)	$ (2.27)	$ (1.66)
Weighted average common shares outstanding, basic and diluted	37,697	31,826	37,659	31,765
Other comprehensive income (loss):
Unrealized gains (losses) from available-for-sale securities, net of tax of $0	$ 266	$ (17)	$ 97	$ (6)
Total other comprehensive income (loss)	266	(17)	97	(6)
Comprehensive loss	$ (43,609)	$ (28,897)	$ (85,347)	$ (52,770)