Components of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Computer hardware	$ 132,331	$ 122,619
Computer software	269,917	249,843
Furniture and equipment	114,623	108,917
Leasehold improvements	122,060	113,972
Other	12,884	15,143
Property and equipment, cost	651,815	610,494
Accumulated depreciation	(544,135)	(502,522)
Property and equipment, net	$ 107,680	$ 107,972	$ 103,651