v2.4.0.6
Employee Benefit Plans (Details 4) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Change in Plan Assets:    
Fair value of plan assets at beginning of year $ 363.9  
Employer contributions 10.0  
Benefits paid (67.0)  
Fair value of plan assets at end of year 303.6  
Amounts recognized in the statement of financial position consist of:    
Noncurrent liabilities 46.8 14.4
Defined Benefit Pension Plan [Member]
   
Change in Plan Assets:    
Fair value of plan assets at beginning of year 363.9 333.3
Actual return on plan assets 18.0 37.8
Employer contributions   10.0
Estimated expenses (3.0)  
Benefits paid (75.3) (17.2)
Fair value of plan assets at end of year 303.6 363.9
Unfunded status 39.9 7.7
Amounts recognized in the statement of financial position consist of:    
Noncurrent liabilities 39.9 7.7
Net amount recognized $ 39.9 $ 7.7
Weighted average assumptions used to determine benefit obligations:    
Discount rate 4.25% 5.25%
Rate of compensation increase 0.00% 0.00%