Collaborative Arrangements and Licensing Agreements, External Project Funding (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Aug. 31, 2016	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
CHDI Foundation, Inc. [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments made		19,300								19,300
Revenue earned										0	0	$ 0	[1]
Cystic Fibrosis Foundation [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront payment recorded as deferred revenue	$ 1,000
Maximum amount of payments receivable		2,000								2,000
Maximum costs specific to collaboration to be shared evenly with partner		3,000								3,000
Maximum amount of payments payable for regulatory and commercialization milestones		18,000								18,000
Next prospective milestone		800								800
Cumulative payments received		$ 2,700								2,700
Milestone payments received										1,000
Revenue earned										$ 1,900	$ 600

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