CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2016
Revenues:
Total revenues	$ 21,506	$ 53,446	$ 115,447	$ 60,002
Operating Expenses:
Research and development	66,566	174,456	139,739	148,077
General and administrative	17,995	36,746	33,911	36,916
Restructuring charge	4,431	3,693	779
Total operating expenses	88,992	214,895	174,429	184,993
Loss from operations	(67,486)	(161,449)	(58,982)	(124,991)
Investment income, net	259	4,227	1,146	325
Non-cash interest expense on liability related to the sale of future royalties and convertible senior notes	(8,665)	(10,631)	(13,682)	(20,130)
Interest expense on convertible senior notes	(2,249)	(95)	(3,040)	(138)
Non-cash debt conversion expense			(22,915)
Other (expense) income, net	(742)	(895)	1,461	117
Net loss	$ (78,883)	$ (168,843)	$ (96,012)	$ (144,817)
Basic and diluted net loss per common share (in dollar per share)	$ (0.91)	$ (1.21)	$ (0.98)	$ (1.67)
Basic and diluted weighted average common shares outstanding (in shares)	87,102	139,946	98,068	86,976
Total comprehensive loss	$ (78,883)	$ (168,843)	$ (96,012)	$ (144,817)
License and milestone fees
Revenues:
Total revenues	5,152	15,280	79,469	26,915
Royalty revenue
Revenues:
Total revenues				195
Non-cash royalty revenue related to the sale of future royalties
Revenues:
Total revenues	12,894	32,154	28,142	25,299
Research and development support
Revenues:
Total revenues	2,781	1,377	3,482	4,014
Clinical materials revenue
Revenues:
Total revenues	$ 679	$ 4,635	$ 4,354	$ 3,579