Property and Equipment, Net (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Capitalized software costs	$ 196,479	$ 186,538
Furniture and equipment	22,932	24,359
Leasehold improvements	41,210	45,184
Computer and communications equipment	187,582	191,377
Property, Plant and Equipment, Gross, Total	448,203	447,458
Less: accumulated depreciation	319,794	299,845
Property and equipment, net	$ 128,409	$ 147,613