Collaborative Arrangements - Development and Commercialization Agreement (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Feb. 28, 2015
Collaborative Arrangements
Revenue from collaborative arrangements	$ 15,174,000	$ 8,386,000		$ 30,385,000	$ 32,517,000
Mylan
Collaborative Arrangements
Revenue from collaborative arrangements	25,000	$ 25,000		15,076,000	$ 19,149,000
Amortization of previously deferred revenue	$ 25,000
Milestone payment(s) received				$ 15,000,000
Achievement in enrollment (as a percent)				50.00%
Mylan | Purchase Agreement
Collaborative Arrangements
Share Price						$ 18.918
Premium proceeds from sale of ordinary shares			$ 4,200,000
Mylan | Development and Commercialization Agreement
Collaborative Arrangements
Initial cash payment			15,000,000
Payments received			$ 19,200,000