License, Collaboration and Other Significant Agreements - Revenues Recognized From License, Collaboration and Other Significant Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
License, Collaboration and Other Revenue:
Total revenues	$ 90,142	$ 100,803	$ 178,620	$ 173,469
License, collaboration and other revenue
License, Collaboration and Other Revenue:
Total revenues	59,446	71,714	118,715	121,269
License, collaboration and other revenue | Mitsubishi Tanabe Pharma Corporation
License, Collaboration and Other Revenue:
Total revenues	15,000	10,000	15,000	10,000
License, collaboration and other revenue | Otsuka Pharmaceutical Company. Ltd. | Otsuka U.S. Agreement
License, Collaboration and Other Revenue:
Total revenues	25,888	37,519	64,465	63,742
License, collaboration and other revenue | Otsuka Pharmaceutical Company. Ltd. | Otsuka International Agreement
License, Collaboration and Other Revenue:
Total revenues	12,832	22,467	32,202	44,423
License, collaboration and other revenue | Total Proportional Performance Revenue
License, Collaboration and Other Revenue:
Total revenues	53,720	69,986	111,667	118,165
License, collaboration and other revenue | JT and Torii
License, Collaboration and Other Revenue:
Total revenues	1,740	1,491	2,866	2,719
License, collaboration and other revenue | Other Revenue | Mitsubishi Tanabe Pharma Corporation
License, Collaboration and Other Revenue:
Total revenues	$ 3,986	$ 237	$ 4,182	$ 385