v2.4.0.6
Employee Benefit Plans (Details 3) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Change in Projected Benefit Obligation:      
Actuarial loss $ (3.6)    
Benefits paid (67.0)    
Defined Benefit Pension Plan [Member]
     
Defined Benefit Plan Disclosure [Line Items]      
Accumulated Benefit Obligation 343.5 371.6  
Change in Projected Benefit Obligation:      
Projected benefit obligation at beginning of year 371.6 364.7  
Service cost 3.0 0.2 0.2
Interest cost 17.0 20.5 20.2
Amendments   1.2  
Actuarial loss 30.2 2.2  
Benefits paid (75.3) (17.2)  
Projected benefit obligation at end of year $ 343.5 $ 371.6 $ 364.7