Certain Balance Sheet Accounts - Summary of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 74,626	$ 75,692
Less accumulated depreciation	42,452	35,824
Property and equipment, net	32,174	39,868
Computers and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	17,785	18,446
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	22,399	22,315
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	8,627	8,902
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 25,815	$ 26,029