Collaborative Arrangements and Acquisitions - Aggregate VIE Financial Information, Increase in the fair value of contingent payments (Details) - Variable Interest Entity, Primary Beneficiary - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Decrease (increase) in fair value of contingent payments	$ (24,000)	$ (3,730)
Parion Sciences, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Decrease (increase) in fair value of contingent payments	0	(2,830)
BioAxone Biosciences Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Decrease (increase) in fair value of contingent payments	$ (24,000)	$ (900)