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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Decrease (increase) in fair value of contingent payments	$ 1,100	$ (3,260)	$ (22,900)	$ (6,990)
Parion Sciences, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Decrease (increase) in fair value of contingent payments	0	(3,260)	0	(6,090)
BioAxone Biosciences Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Decrease (increase) in fair value of contingent payments	$ 1,100	$ 0	$ (22,900)	$ (900)