v2.4.0.6
Financial Instruments (Details 5) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Money market mutual funds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure $ 100.8 $ 135.7
Bonds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 34.6 27.2
Fair Value, Measurements, Recurring [Member]
   
Assets:    
Total assets 138.4 171.6
Liabilities:    
Liabilities 5.4 8.4
Quoted Prices in Active Markets (Level 1) [Member] | Money market mutual funds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 100.8 135.7
Quoted Prices in Active Markets (Level 1) [Member] | Bonds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 0 0
Quoted Prices in Active Markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Total assets 100.8 135.7
Liabilities:    
Liabilities 0 0
Significant Other Observable Inputs (Level 2) [Member] | Money market mutual funds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 0 0
Significant Other Observable Inputs (Level 2) [Member] | Bonds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 34.6 27.2
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Total assets 37.6 35.9
Liabilities:    
Liabilities 5.4 8.4
Significant Unobservable Inputs (Level 3) [Member] | Money market mutual funds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 0 0
Significant Unobservable Inputs (Level 3) [Member] | Bonds [Member]
   
Assets:    
Available-for-sale Securities, Fair Value Disclosure 0 0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Total assets 0 0
Liabilities:    
Liabilities 0 0
Recycling Commodity Hedges [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 1.4 1.9
Liabilities:    
Hedges 0.7 6.5
Recycling Commodity Hedges [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 0 0
Liabilities:    
Hedges 0 0
Recycling Commodity Hedges [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 1.4 1.9
Liabilities:    
Hedges 0.7 6.5
Recycling Commodity Hedges [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 0 0
Liabilities:    
Hedges 0 0
Interest rate swaps - other non-trade receivables [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis   5.2
Interest rate swaps - other non-trade receivables [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis   0
Interest rate swaps - other non-trade receivables [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis   5.2
Interest rate swaps - other non-trade receivables [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis   0
Fuel hedges [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 1.6 1.6
Liabilities:    
Hedges 4.7 1.9
Fuel hedges [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 0 0
Liabilities:    
Hedges 0 0
Fuel hedges [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 1.6 1.6
Liabilities:    
Hedges 4.7 1.9
Fuel hedges [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
   
Assets:    
Assets, at fair value on a recurring basis 0 0
Liabilities:    
Hedges $ 0 $ 0