Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Products, net		$ 455,865	$ 380,833	$ 301,034
Type of Revenue [Extensible List]			us-gaap:ProductMember	us-gaap:ProductMember
Collaboration		84,234
Total revenues		540,099	$ 380,833	$ 301,034
Cost and expenses:
Cost of sales (excluding amortization of in-licensed rights)		63,382	56,586	34,193
Research and development		722,343	560,909	401,843
Selling, general and administrative		317,875	284,812	207,761
Acquired in-process research and development			173,240
Settlement and license charges			10,000
Amortization of in-licensed rights		662	849	865
Total cost and expenses		1,104,262	1,086,396	644,662
Operating loss		(564,163)	(705,563)	(343,628)
Other income (loss):
Gain from sale of Priority Review Voucher		108,069
Loss on contingent consideration	[1]	(45,000)
Other expense, net		(51,971)	(8,317)	(18,982)
Total other income (loss)		11,098	(8,317)	(18,982)
Loss before income tax expense (benefit)		(553,065)	(713,880)	(362,610)
Income tax expense (benefit)		1,063	1,195	(692)
Net loss		(554,128)	(715,075)	(361,918)
Other comprehensive loss:
Unrealized (losses) gains on investments		(47)	149	280
Total other comprehensive (loss) income		(47)	149	280
Comprehensive loss		$ (554,175)	$ (714,926)	$ (361,638)
Net loss per share — basic and diluted		$ (7.11)	$ (9.71)	$ (5.46)
Weighted average number of shares of common stock used in computing basic and diluted net loss per share		77,956,000	73,615,000	66,250,000

[1] The loss on contingent consideration is related to the fair value adjustment of the regulatory-related contingent payments that are accounted for as derivatives. Please see Note 5. Fair Value Measurements for further details.