v2.4.0.6
Estimated Useful Lives for Depreciation Computed Using Straight-line Method (Detail)
12 Months Ended
Dec. 31, 2011
Year
Computer Equipment
 
Property, Plant and Equipment, Estimated Useful Lives, Lease Terms [Line Items]  
Property, Plant and Equipment, Estimated Useful Lives 5
Leasehold Improvements
 
Property, Plant and Equipment, Estimated Useful Lives, Lease Terms [Line Items]  
Property, Plant and Equipment, Estimated Useful Lives Over the shorter of the lease term or the estimated useful lives of the assets
Furniture and Fixtures
 
Property, Plant and Equipment, Estimated Useful Lives, Lease Terms [Line Items]  
Property, Plant and Equipment, Estimated Useful Lives 5
Vehicles
 
Property, Plant and Equipment, Estimated Useful Lives, Lease Terms [Line Items]  
Property, Plant and Equipment, Estimated Useful Lives 5
Property
 
Property, Plant and Equipment, Estimated Useful Lives, Lease Terms [Line Items]  
Property, Plant and Equipment, Estimated Useful Lives 42