v2.4.0.6
Share-Based Compensation (Narrative) (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Number of stock options granted     21.8  
Number of restricted share units granted     5.7  
Weighted average fair value of stock options granted     $ 7.38  
Fair value of restricted share units granted     $ 27.43  
Employee Payroll Deductions For Share Purchases Through Employee Stock Purchase Plan $ 18 $ 13 $ 36 $ 28
Stock Options [Member]
       
Unrecognized pretax compensation expense on nonvested awards 385   385  
Restricted Share Units [Member]
       
Unrecognized pretax compensation expense on nonvested awards $ 411   $ 411