Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Product sales	$ 34,986	$ 15,622	$ 11,698
Operating expenses:
Cost of goods sold	3,168
Research and development	49,223	35,147	42,589
Selling, general and administrative	47,838	29,431	24,909
Intangible impairment charge		23,200
Change in contingent consideration liability	916	(5,800)	2,600
Total operating expenses	101,145	81,978	70,098
Operating loss	(66,159)	(66,356)	(58,400)
Other (expense) income:
Interest (expense) income and other income, net	(2,376)	(2,933)	(4,285)
Total other (expense) income	(2,376)	(2,933)	(4,285)
Loss before income tax (expense) benefit	(68,535)	(69,289)	(62,685)
Income tax (expense) benefit	(17)	1,632	11,672
Net loss	$ (68,552)	$ (67,657)	$ (51,013)
Net loss per share - basic and diluted (in dollars per share)	$ (0.80)	$ (0.87)	$ (0.73)
Weighted-average shares - basic and diluted (in shares)	85,607	77,890	70,284
Product [Member]
Revenues:
Product sales	$ 1,559
Royalty [Member]
Revenues:
Product sales	16,970	14,908	10,965
License and Other [Member]
Revenues:
Product sales	$ 16,457	$ 714	$ 733