Components of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Computer hardware	$ 125,951	$ 122,619
Computer software	259,773	249,843
Furniture and equipment	115,850	108,917
Leasehold improvements	116,842	113,972
Other	12,997	15,143
Property and equipment, cost	631,413	610,494
Accumulated depreciation	(525,909)	(502,522)
Property and equipment, net	$ 105,504	$ 107,972