Summary of Total Revenues from External Customers and Collaborative Partners by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue from External Customer [Line Items]
Total revenues	$ 317,448	$ 300,131	$ 621,193	$ 536,867
United States
Revenue from External Customer [Line Items]
Total revenues	141,612	126,172	274,097	235,318
Europe
Revenue from External Customer [Line Items]
Total revenues	64,931	64,798	130,950	124,508
Latin America
Revenue from External Customer [Line Items]
Total revenues	58,205	49,635	95,468	68,015
Rest of World
Revenue from External Customer [Line Items]
Total revenues	$ 52,700	$ 59,526	$ 120,678	$ 109,026