Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Product, net	$ 99,041	$ 78,486	$ 280,720	$ 216,619
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Total revenues	$ 99,041	$ 78,486	$ 280,720	$ 216,619
Cost and expenses:
Cost of sales (excluding amortization of in-licensed rights)	13,037	8,741	41,019	21,058
Research and development	133,949	86,584	337,768	255,636
Selling, general and administrative	75,429	53,044	203,388	143,541
Acquired in-process research and development			173,240
Amortization of in-licensed rights	216	216	649	649
Total cost and expenses	222,631	148,585	756,064	420,884
Operating loss	(123,590)	(70,099)	(475,344)	(204,265)
Other loss:
Other expense, net	(2,510)	(6,968)	(3,544)	(16,671)
Other loss	(2,510)	(6,968)	(3,544)	(16,671)
Loss before income tax expense	(126,100)	(77,067)	(478,888)	(220,936)
Income tax expense (benefit)	226	(674)	484	87
Net loss	(126,326)	(76,393)	(479,372)	(221,023)
Other comprehensive income (loss):
Unrealized (losses) gains on investments	(7)	369	174	387
Total other comprehensive income (loss)	(7)	369	174	387
Comprehensive loss	$ (126,333)	$ (76,024)	$ (479,198)	$ (220,636)
Net loss per share - basic and diluted	$ (1.70)	$ (1.15)	$ (6.54)	$ (3.38)
Weighted average number of shares of common stock used in computing basic and diluted net loss per share	74,177	66,209	73,298	65,454