Summary of Estimated Useful Lives Of Assets (Detail)	12 Months Ended
	Dec. 31, 2012
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment leasehold improvements usefullife	Lease term
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Maximum | Building and building improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	35 years
Maximum | Equipment and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Minimum | Building and building improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years
Minimum | Equipment and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years