Property and Equipment by Geographic Area (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 55,628	$ 61,924
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	43,854	47,971
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	5,058	6,808
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	3,253	3,286
Other international
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 3,463	$ 3,859