Property and Equipment by Geographic Area (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment	$ 61,924	$ 64,643
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment	47,971	49,957
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment	6,808	7,840
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment	3,286	3,123
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment	$ 3,859	$ 3,723