Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues
Product revenue, net	$ 21,786	$ 6,990	$ 49,303	$ 12,981
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Operating expenses
Cost of sales	$ 2,872	$ 1,619	$ 6,032	$ 5,264
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 20,938	$ 13,578	$ 52,488	$ 38,223
Selling, general and administrative	32,136	32,804	97,461	90,739
Total operating expenses	55,946	48,001	155,981	134,226
Loss from operations	(34,160)	(41,011)	(106,678)	(121,245)
Other (expense) income
Interest income	721	1,157	2,563	3,572
Interest expense	(4,652)	(3,930)	(12,537)	(11,775)
Other (expense) income	(141)	144	395	364
Total other (expense) income	(4,072)	(2,629)	(9,579)	(7,839)
Net loss	$ (38,232)	$ (43,640)	$ (116,257)	$ (129,084)
Net loss per common share, basic and diluted	$ (1.00)	$ (1.15)	$ (3.06)	$ (3.42)
Weighted average common shares outstanding, basic and diluted	38,125	37,818	38,043	37,712
Other comprehensive (loss) income:
Unrealized (losses) gains from available-for-sale securities, net of tax of $0	$ (99)	$ 153	$ 208	$ 250
Total other comprehensive (loss) income	(99)	153	208	250
Comprehensive loss	$ (38,331)	$ (43,487)	$ (116,049)	$ (128,834)