v2.4.0.6
Income from Continuing Operations Per Unrestricted Share (Details) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Schedule of Basic and Diluted Earnings Per Share [Line Items]    
Income from Continuing Operations $ 36.3 $ 45.0
Dilutive Effect on Income of Equity-based Compensation Equivalent Shares 0 0
Diluted Income from Continuning Operations Attributed to Unrestricted Shares 36.1 44.8
Weighted-Average Unrestricted Shares Outstanding 59,865,700 60,677,500
Equity-based Compensation Equivalent Shares 130,400 104,400
Weighted-Average Unrestricted Shares and Equivalent Shares Outstanding Assuming Dilution 59,996,100 60,781,900
Basic Income from Continuing Operations Per Unrestricted Share $ 0.61 $ 0.74
Diluted Income from Continuing Operations Per Untrestriced Share $ 0.60 $ 0.73
Restricted Shares [Member]
   
Schedule of Basic and Diluted Earnings Per Share [Line Items]    
Income from Continuing Operations 0.2 0.2
Unrestricted Shares [Member]
   
Schedule of Basic and Diluted Earnings Per Share [Line Items]    
Income from Continuing Operations $ 36.1 $ 44.8