Schedule of Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2012
Building
Property, Plant and Equipment [Line Items]
Estimated useful lives	39 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives	Lesser of life or lease or expected useful life
Equipment and Furniture | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Equipment and Furniture | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Computer Software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Computer Software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years