Collaboration Revenue - Summary of Deferred Revenue (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Deferred Revenue Arrangement [Line Items]
Current portion of deferred revenue	$ 13,950	$ 7,793
Long-term portion of deferred revenue	95,902	65,778
Deferred revenue	109,852	73,571
Upfront and Milestone Payments
Deferred Revenue Arrangement [Line Items]
Deferred revenue	105,943	72,207
Prepaid Research and Development Services
Deferred Revenue Arrangement [Line Items]
Deferred revenue	1,423	1,319
Prepaid Product and Service Revenues
Deferred Revenue Arrangement [Line Items]
Deferred revenue	1,914	0
Other
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 572	$ 45