v2.4.0.6
Income Taxes (Details Textual) (USD $)
In Millions, unless otherwise specified
 1 Months Ended 12 Months Ended
Sep. 30, 2010
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
Income Tax Contingency [Line Items]            
Gross reduction in unrecognized tax benefits         $ 299.6  
Valuation Allowance [Line Items]            
Valuation allowance on deferred tax assets relating to state net operating loss carryforwards     118.1 120.1 126.5 156.4
Income Taxes (Textual)            
Effective tax rate     35.00% 42.10% 42.60%  
Tax charge related to non-deductible goodwill expense as a result of various divestitures     7.1 13.1 13.5  
Net operating loss carryforwards, state taxes     126.3 127.5    
Income taxes paid, net of refunds received     173 418 444  
Bonus depreciation for property 100.00% 50.00%        
Unrecognized Tax Benefits related to tax position taken by Allied     50.6   54.3  
Unrecognized tax benefits if recognized that would impact effective tax rate     42.9 209.1    
Interest on income taxes accrued     12.0 19.2 24.5 5.2
Accrued liability for penalties       1.2 1.5 88.1
Accrued liability for interest related to uncertain tax positions and penalties       99.9 92.3 180.0
Potential cash taxes related to an exchange of partnership interests that the IRS issued a formal disallowance     156.2      
Accrued interest related to an exchange of partnership interests that the IRS issued a formal disallowance     80.7      
IRS asserted penalty, percentage of the additional income tax due     20.00%      
Income tax examination penalties and interest asserted by taxing authority     50.6      
Unrecognized Tax Benefits Settlements With Taxing Authorities Minimum     15      
Unrecognized Tax Benefits Settlements With Taxing Authorities maximum     30      
Valuation Allowance, Operating Loss Carryforwards [Member]
            
Valuation Allowance [Line Items]            
Valuation allowance on deferred tax assets relating to state net operating loss carryforwards     10.6      
Internal Revenue Service (IRS) [Member]
            
Income Tax Contingency [Line Items]            
Gross reduction in unrecognized tax benefits     166.2 1.9 62.6  
State and Local Jurisdiction [Member]
            
Income Tax Contingency [Line Items]            
Gross reduction in unrecognized tax benefits     2.9 10.0 5.8  
State and Local Jurisdiction [Member] | Valuation Allowance, Operating Loss Carryforwards [Member]
            
Valuation Allowance [Line Items]            
Valuation allowance on deferred tax assets relating to state net operating loss carryforwards     $ 107.5