Collaborative Arrangements and Licensing Agreements, Atlantic Pharmaceuticals Limited (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Mar. 31, 2007	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned		$ 172,299	$ 120,911	$ 104,152	$ 110,304	$ 160,349	$ 110,927	$ 38,470	$ 36,874	$ 507,666	$ 346,620	$ 283,703
Atlantic Pharmaceuticals Limited [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Ownership interest percentage		9.00%				9.00%				9.00%	9.00%
Atlantic Pharmaceuticals Limited [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront fee in the form of equity securities	$ 2,000
Maximum amount of payments receivable for regulatory milestones		$ 1,400								$ 1,400
Next prospective milestone		$ 600								600
Revenue earned										$ 0	$ 0	$ 0	[1]

[1] Revenue from this relationship was negligible for the year.