Condensed Consolidated Statements of Operations (Unaudited) - 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
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Total revenues	$ 94,586	$ 58,305	$ 240,750	$ 164,236
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Cost of product sales	$ 2,416	$ 3,839	$ 8,324	$ 9,554
License fees and royalties	2,273	1,536	5,940	4,384
Research and development	62,622	53,112	182,865	138,980
Selling, general and administrative	72,696	61,089	233,767	191,487
Total operating expenses	140,007	119,576	430,896	344,405
Loss from operations	(45,421)	(61,271)	(190,146)	(180,169)
Interest income, net	2,432	1,229	7,893	3,678
Other income (expense)	747	(1,720)	506	(1,967)
Loss before income taxes	(42,242)	(61,762)	(181,747)	(178,458)
Income tax (benefit) expense	(264)	376	476	1,242
Net loss	$ (41,978)	$ (62,138)	$ (182,223)	$ (179,700)
Net loss per common share, basic and diluted	$ (0.29)	$ (0.50)	$ (1.26)	$ (1.44)
Weighted average common shares outstanding, basic and diluted	145,906	125,009	144,741	124,883