Summary of Total Revenues from External Customers and Collaborative Partners by Geographic Region (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue from External Customer [Line Items]
Total revenues	$ 889,895	$ 749,284	$ 548,485
United States
Revenue from External Customer [Line Items]
Total revenues	444,075	378,288	284,303
Europe
Revenue from External Customer [Line Items]
Total revenues	178,746	139,940	115,729
Latin America
Revenue from External Customer [Line Items]
Total revenues	142,305	118,562	67,339
Rest of World
Revenue from External Customer [Line Items]
Total revenues	$ 124,769	$ 112,494	$ 81,114