Collaborative Arrangements - Reimbursement of R&D Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total reduction to R&D expense	$ 90,737	$ 55,156	$ 1,884
Mylan
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total reduction to R&D expense	83,490	52,551	0
Alfa Wassermann
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total reduction to R&D expense	7,113	2,122	1,764
Other
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total reduction to R&D expense	$ 134	$ 483	$ 120