v2.3.0.11
Condensed Consolidated Balance Sheets (Parenthetical) (USD $)
In Millions, except Per Share data
Jun. 30, 2011
Dec. 31, 2010
Consolidated Balance Sheets    
Preferred stock, par value $ 0.01 $ 0.01
Preferred stock, shares authorized 100.0 100.0
Preferred stock, shares issued 0 0
Preferred stock, shares outstanding 0 0
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 500.0 500.0
Common stock, shares issued 185.9 184.9
Treasury stock, shares 17.5 16.8