v2.4.0.6
Employee Benefit Plans (Details 1) (USD $)
In Millions, except Per Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Y
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
The following table summarizes the stock option activity        
Number of Shares, Outstanding, Beginning Balance 13.6 15.1 18.7  
Number of Shares, Granted 3.0 3.1 0.3  
Number of Shares, Exercised (1.7) (3.9) (2.1)  
Number of Share, Forfeited or expired (0.6) (0.7) (1.8)  
Number of Shares, Outstanding, Ending Balance 14.3 13.6 15.1  
Number of Shares, Exercisable 8.6      
Weighted Average Exercise Price per Share, Outstanding, Beginning Balance $ 24.97 $ 23.69 $ 23.57  
Weighted Average Exercise Price per Share, Granted $ 29.83 $ 27.48 $ 21.03  
Weighted Average Exercise Price per Share, Exercised $ 22.31 $ 21.73 $ 18.12  
Weighted Average Exercise Price per Share, Forfeited or expired $ 28.63 $ 27.38 $ 28.59  
Weighted Average Exercise Price per Share, Outstanding, Ending Balance $ 26.13 $ 24.97 $ 23.69  
Weighted Average Exercise Price per Share, Exercisable $ 24.92      
Weighted Average Remaining Contractual Term (years), Outstanding 4.2      
Weighted Average Remaining Contractual Term (years), Exercisable 3.4      
Aggregate Intrinsic Value, Exercised $ 14.4 $ 34.3 $ 17.8  
Aggregate Intrinsic Value, Outstanding 32.8      
Aggregate Intrinsic Value, Exercisable $ 28.3 $ 8.7 $ 4.0 $ 3.9