CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Total revenue	$ 13,194,000	$ 18,257,000	$ 40,365,000	$ 53,127,000
Expenses:
Research and development (1)	43,739,000	67,371,000	162,431,000	195,788,000
Selling, general and administrative (1)	21,299,000	27,501,000	77,780,000	78,606,000
Restructuring and related expenses	1,771,000		1,771,000
Total expenses	66,809,000	94,872,000	241,982,000	274,394,000
Loss from operations	(53,615,000)	(76,615,000)	(201,617,000)	(221,267,000)
Income from investment in TRC, LLC	30,208,000	13,403,000	68,681,000	48,299,000
Interest expense	(11,742,000)	(11,573,000)	(35,227,000)	(32,905,000)
Loss on extinguishment of debt				(15,464,000)
Interest and other income (expense), net	(166,000)	1,235,000	771,000	2,033,000
Loss before income taxes	(35,315,000)	(73,550,000)	(167,392,000)	(219,304,000)
Provision for income tax benefit (expense)	7,000	(93,000)	0	(279,000)
Net loss	(35,308,000)	(73,643,000)	(167,392,000)	(219,583,000)
Net unrealized gain (loss) on available-for-sale investments	6,000	(158,000)	(33,000)	(23,000)
Total comprehensive loss	$ (35,302,000)	$ (73,801,000)	$ (167,425,000)	$ (219,606,000)
Net loss per share:
Basic net loss per share	$ (0.48)	$ (1.16)	$ (2.46)	$ (3.55)
Diluted net loss per share	$ (0.48)	$ (1.16)	$ (2.46)	$ (3.55)
Shares used to compute basic net loss per share	73,574	63,303	67,945	61,881
Shares used to compute diluted net loss per share	73,574	63,303	67,945	61,881
Total share-based compensation expense	$ 14,370,000	$ 15,564,000	$ 45,143,000	$ 47,425,000
Research and development
Expenses:
Restructuring and related expenses	1,000,000.0		1,000,000.0
Net loss per share:
Total share-based compensation expense	6,956,000	7,761,000	22,192,000	23,724,000
Selling, general and administrative
Expenses:
Restructuring and related expenses	800,000		800,000
Net loss per share:
Total share-based compensation expense	7,414,000	7,803,000	22,951,000	23,701,000
Collaborative revenue
Revenue:
Total revenue	2,797,000	7,261,000	8,649,000	19,381,000
Licensing revenue
Revenue:
Total revenue				1,500,000
Viatris collaboration agreement
Revenue:
Total revenue	$ 10,397,000	$ 10,996,000	$ 31,716,000	$ 32,246,000