Collaboration and Licensing Revenue - Summary of Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Current portion of deferred revenue	$ 42,870	$ 53,364
Long-term portion of deferred revenue	193,527	256,778
Deferred revenue	236,397	310,142
Upfront and milestone payments
Deferred Revenue Arrangement [Line Items]
Deferred revenue	230,531	297,867
Prepaid research and development services
Deferred Revenue Arrangement [Line Items]
Deferred revenue	1,052	6,015
Prepaid product and service revenues
Deferred Revenue Arrangement [Line Items]
Deferred revenue	4,681	5,554
Other
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 133	$ 706