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Landfill Accounting - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
9 Months Ended 12 Months Ended
Sep. 30, 2013
Landfill
Sep. 30, 2012
Dec. 31, 2012
Dec. 31, 2013
Scenario, Forecast
Debt Instrument [Line Items]        
Number of municipal solid waste landfills owned and operated by company 42      
Number of owned landfills that only accept exploration and production waste 5      
Number of owned landfills that only accept construction and demolition, industrial and other non-putrescible waste 7      
Number of landfills owned and operated by company 43      
Number of landfills operated, not owned, under life of site operating agreements 6      
Number of landfills operated under limited-term operating agreements 5      
Net Book Value Landfill Site Costs $ 1,626,169      
Number of life-of-site landfills for which the Company is responsible for final capping, closure and post-closure maintenance obligations 5      
Average remaining landfill life based on permitted capacity and projected annual disposal volumes 34 years      
Number of owned landfills the company is seeking to expand 8      
Number of landfills operated under life-of-site operating agreements that the company is seeking to expand 2      
Average remaining landfill life based on permitted capacity, projected annual disposal volumes and probable expansion capacity 43 years      
Life of Company's owned landfills and landfills operated under life of site operating agreements min range 6 years      
Life of Company's owned landfills and landfills operated under life of site operating agreements max range 201 years      
Landfill depletion expense 60,142 35,219    
Average rate per ton consumed related to landfill depletion at owned landfills and landfills operated under life of site agreements 4.21 3.15    
Discount rate for purposes of computing layers for final capping, closure and post-closure obligations     5.75% 5.75%
Inflation rate for purposes of computing layers for final capping, closure and post-closure obligations     2.50% 2.50%
Accretion expense associated with landfill obligations 2,077 1,870    
Average rate per ton consumed related to final capping, closure and post-closure landfill accretion expense 0.15 0.17    
Restricted asset balance for purposes of securing our performance of future final capping, closure and post-closure obligations $ 32,816