Condensed Consolidated Statements of Operations and Comprehensive Loss (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Collaborative arrangement revenue	$ 2,422	$ 1,977	$ 114,398	$ 4,408
Total revenues	19,273	8,910	240,026	34,677
Operating expenses:
Research and development	140,431	151,412	450,862	420,592
Selling, general and administrative	68,046	66,250	209,922	195,160
Cost of royalty and other revenue	1,318	862	3,897	1,905
Change in fair value of contingent consideration	(828)	802	(5,591)	1,312
Total operating expenses	208,967	219,326	659,090	618,969
Loss from operations	(189,694)	(210,416)	(419,064)	(584,292)
Interest income, net	1,964	8,417	10,258	27,906
Other expense, net	(6,686)	(4,298)	(9,582)	(10,623)
Loss before income taxes	(194,416)	(206,297)	(418,388)	(567,009)
Income tax (expense) benefit	(329)	264	(433)	748
Net loss	$ (194,745)	$ (206,033)	$ (418,821)	$ (566,261)
Net loss per share - basic and diluted: (in dollars per share)	$ (2.94)	$ (3.73)	$ (6.89)	$ (10.27)
Weighted-average number of common shares used in computing net loss per share - basic and diluted: (in shares)	66,251	55,292	60,762	55,139
Other comprehensive (loss) income:
Other comprehensive (loss) income, net of tax benefit (expense) of $0.1 million and $0.0 million for the three months ended September 30, 2020 and 2019, respectively, and $0.0 million and $(1.3) million for the nine months ended September 30, 2020 and 2019, respectively	$ (1,823)	$ (2,032)	$ (2,330)	$ 776
Comprehensive loss	(196,568)	(208,065)	(421,151)	(565,485)
Service revenue
Revenue:
Revenue	13,352	4,598	108,542	24,902
Royalty and other revenue
Revenue:
Revenue	$ 3,499	$ 2,335	$ 17,086	$ 5,367