Collaborative Arrangements and Licensing Agreements, Research, Development and Commercialization Partners - Janssen Biotech, Inc. (Details) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Jul. 31, 2016 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) Program	Jun. 30, 2015 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned			$ 38,470	$ 120,428	$ 75,345	$ 183,012
Agreement Entered Into in December 2014 [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of programs under which drugs are to be developed and commercialized | Program					3
Upfront payment recorded as deferred revenue		$ 35,000
Maximum amount of payments receivable for license fees and substantive milestones			800,000		$ 800,000
Maximum amount of payments receivable for development milestones			175,000		175,000
Maximum amount of payments receivable for regulatory milestones			420,000		420,000
Maximum amount of payments receivable for commercialization milestones			180,000		180,000
Cumulative payments received			37,000		37,000
Next prospective milestone			$ 5,000		$ 5,000
Agreement Entered Into in December 2014 [Member] | Subsequent Event [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned	$ 10,000