Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Product, net	$ 94,668	$ 73,529	$ 181,679	$ 138,133
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Total revenues	$ 94,668	$ 73,529	$ 181,679	$ 138,133
Cost and expenses:
Cost of sales (excluding amortization of in-licensed rights)	15,919	6,735	27,982	12,317
Research and development	113,266	122,848	203,819	169,052
Selling, general and administrative	67,393	47,156	127,959	90,497
Acquired in-process research and development	173,240		173,240
Amortization of in-licensed rights	217	217	433	433
Total cost and expenses	370,035	176,956	533,433	272,299
Operating loss	(275,367)	(103,427)	(351,754)	(134,166)
Other loss:
Other expense, net	(862)	(5,218)	(1,034)	(9,703)
Other loss	(862)	(5,218)	(1,034)	(9,703)
Loss before income tax expense	(276,229)	(108,645)	(352,788)	(143,869)
Income tax expense	174	622	258	761
Net loss	(276,403)	(109,267)	(353,046)	(144,630)
Other comprehensive income:
Unrealized gains on investments	63	282	181	18
Total other comprehensive income	63	282	181	18
Comprehensive loss	$ (276,340)	$ (108,985)	$ (352,865)	$ (144,612)
Net loss per share - basic and diluted	$ (3.74)	$ (1.67)	$ (4.85)	$ (2.22)
Weighted average number of shares of common stock used in computing basic and diluted net loss per share	73,958	65,484	72,850	65,060