Collaborative Arrangements and Licensing Agreements, External Project Funding (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangement and Licensing Agreement [Abstract]
Research and development expense									$ 319,500,000	$ 238,900,000	$ 173,700,000
Revenue earned	$ 51,571,000	$ 49,121,000	$ 120,428,000	$ 62,583,000	$ 84,861,000	$ 44,063,000	$ 57,076,000	$ 28,161,000	283,703,000	214,161,000	147,285,000
Collaborations and Licensing Agreements [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Research and development expense									161,700,000	85,600,000	51,000,000
CHDI Foundation Inc [Member] | Collaborations and Licensing Agreements [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Research and development expense									5,000,000	3,000,000
Maximum amount of milestone payments payable	$ 4,000,000								4,000,000
Revenue earned									$ 0	$ 0	$ 400,000