CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue:
Revenue	$ 15,008,000	$ 26,150,000	$ 34,870,000	$ 31,488,000
Costs and expenses:
Research and development (1)	62,404,000	46,399,000	128,417,000	100,217,000
Selling, general and administrative (1)	24,780,000	22,227,000	51,105,000	47,413,000
Total costs and expenses	87,184,000	68,626,000	179,522,000	147,630,000
Loss from operations	(72,176,000)	(42,476,000)	(144,652,000)	(116,142,000)
Income from investment in TRC, LLC	21,381,000	8,366,000	34,896,000	14,595,000
Interest expense	(11,391,000)	(7,901,000)	(21,332,000)	(15,759,000)
Loss on extinguishment of debt			(15,464,000)
Interest and other income (expense), net	(662,000)	2,374,000	798,000	5,169,000
Loss before income taxes	(62,848,000)	(39,637,000)	(145,754,000)	(112,137,000)
Provision for income tax expense	(39,000)	(201,000)	(186,000)	(281,000)
Net loss	(62,887,000)	(39,838,000)	(145,940,000)	(112,418,000)
Net unrealized gain (loss) on available-for-sale investments	(232,000)	165,000	135,000	295,000
Total comprehensive loss	$ (63,119,000)	$ (39,673,000)	$ (145,805,000)	$ (112,123,000)
Net loss per share:
Basic and diluted net loss per share (in dollars per share)	$ (1.00)	$ (0.72)	$ (2.39)	$ (2.04)
Shares used to compute basic and diluted net loss per share (in shares)	62,861	55,529	61,162	55,235
Share-based compensation expense	$ 16,585,000	$ 11,298,000	$ 31,861,000	$ 23,519,000
Research and development
Net loss per share:
Share-based compensation expense	8,098,000	5,720,000	15,963,000	11,880,000
Selling, general and administrative
Net loss per share:
Share-based compensation expense	8,487,000	5,578,000	15,898,000	11,639,000
Collaborative revenue
Revenue:
Revenue	5,488,000	7,493,000	12,120,000	12,831,000
Licensing revenue
Revenue:
Revenue		18,500,000	1,500,000	18,500,000
Mylan collaboration agreement
Revenue:
Revenue	$ 9,520,000	$ 157,000	$ 21,250,000	$ 157,000