v2.4.0.6
Employee Benefit Plans (Details 9) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using $ 303.6 $ 363.9
Quoted Prices in Active Markets (Level 1) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 179.4 200.3
Significant Other Observable Inputs (Level 2) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 123.8 163.1
Significant Unobservable Inputs (Level 3) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0.4 0.5
Money Market Account [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 3.3 4.6
Money Market Account [Member] | Quoted Prices in Active Markets (Level 1) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 3.3 4.6
Money Market Account [Member] | Significant Other Observable Inputs (Level 2) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Money Market Account [Member] | Significant Unobservable Inputs (Level 3) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Common Stock [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 13.7 37.1
Common Stock [Member] | Quoted Prices in Active Markets (Level 1) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 13.7 37.1
Common Stock [Member] | Significant Other Observable Inputs (Level 2) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Common Stock [Member] | Significant Unobservable Inputs (Level 3) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Mutual funds and real estate investment trusts [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 206.1 231.2
Mutual funds and real estate investment trusts [Member] | Quoted Prices in Active Markets (Level 1) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 162.4 158.6
Mutual funds and real estate investment trusts [Member] | Significant Other Observable Inputs (Level 2) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 43.7 72.6
Mutual funds and real estate investment trusts [Member] | Significant Unobservable Inputs (Level 3) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Bonds [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 80.1 90.5
Bonds [Member] | Quoted Prices in Active Markets (Level 1) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 80.1 90.5
Bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Limited Partnerships [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0.4 0.5
Limited Partnerships [Member] | Quoted Prices in Active Markets (Level 1) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Limited Partnerships [Member] | Significant Other Observable Inputs (Level 2) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using 0 0
Limited Partnerships [Member] | Significant Unobservable Inputs (Level 3) [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Fair Value Measurements Using $ 0.4 $ 0.5