v2.4.0.6
Consolidated Balance Sheets (Parenthetical) (USD $)
In Millions, except Per Share data, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Consolidated Balance Sheets [Abstract]    
Allowance for doubtful accounts $ 48.1 $ 50.9
Preferred stock, par value $ 0.01 $ 0.01
Preferred stock, shares authorized 50 50
Preferred stock, shares issued      
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 750 750
Common stock, shares issued 402.1 400.2
Treasury stock, shares 32.2 16.5