Property and Equipment, Net - Components of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Computer hardware	$ 149,644	$ 148,541
Computer software	305,823	288,532
Furniture and equipment	105,504	111,426
Leasehold improvements	113,732	118,868
Other	8,990	11,488
Property and equipment, cost	683,693	678,855
Accumulated depreciation	(573,985)	(566,211)
Property and equipment, net	$ 109,708	$ 112,644