v2.4.0.6
Segment Reporting (Details Textual) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Segment
Dec. 31, 2010
Dec. 31, 2009
Segment Information (Textual)      
Number of reportable segments 4    
Net decrease/increase in amortization expense related to changes in estimates and assumptions concerning the cost and timing of future final capping, closure and post - closure activities $ 9.6 $ 10.2 $ 5.1
Loss from disposition of assets included in operating income 43.0 11.2 147.1
Asset impairments 49.1 15.1 7.1
Impairment loss of long lived assets 20.4 15.1 7.1
Eastern [Member]
      
Segment Information (Textual)      
Loss from disposition of assets included in operating income 0.6 15.0 4.0
Assets impairment expense related to assets held for sale 12.8    
Insurance proceeds to remediation costs 12.0    
Midwestern [Member]
      
Segment Information (Textual)      
Loss from disposition of assets included in operating income   9.3 27.1
Southern [Member]
      
Segment Information (Textual)      
Loss from disposition of assets included in operating income 17.2   29.8
Asset impairments 28.7    
Western [Member]
      
Segment Information (Textual)      
Loss from disposition of assets included in operating income 1.8   88.1
Asset impairments 7.0    
Operating income for environmental conditions at closed disposal facility 5.2    
Corporate entities [Member]
      
Segment Information (Textual)      
Loss from disposition of assets included in operating income     8.2
Asset impairments     3.7
Impairment loss of long lived assets   $ 14.4