License, Collaboration and Other Significant Agreements - Revenues Recognized From License, Collaboration and Other Significant Agreements (Details) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					$ 207,742,000	$ 181,227,000	$ 1,535,000
License, Collaboration and Other Revenue
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue	$ 53,026,000	$ 53,169,000	$ 48,793,000	$ 45,930,000	200,918,000	181,227,000	1,535,000
License, Collaboration and Other Revenue | Mitsubishi Tanabe Pharma Corporation
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					9,281,000	42,918,000
License, Collaboration and Other Revenue | Otsuka Pharmaceutical Company. Ltd.
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue							1,500,000
License, Collaboration and Other Revenue | Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize United States Collaboration and License Agreement
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					103,870,000	85,971,000	1,535,000
License, Collaboration and Other Revenue | Otsuka Pharmaceutical Company. Ltd. | Development and Commercialize International Collaboration and License Agreement
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					87,320,000	52,307,000
License, Collaboration and Other Revenue | Mitsubishi Tanabe Pharma Corporation and Otsuka Pharmaceutical Company Limited
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					200,471,000	181,196,000	$ 1,535,000
License, Collaboration and Other Revenue | Japan Tobacco Incorporation and Torii Pharmaceutical Company Limited
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					112,000
License, Collaboration and Other Revenue | Clinical and Regulatory Activities
License, Collaboration and Other Revenue:
License, Collaboration and Other Revenue					$ 335,000	$ 31,000