v2.4.0.6
Total Stock Based Compensation Expense (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended
Nov. 30, 2012
Nov. 30, 2011
Nov. 30, 2012
Nov. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Stock-based compensation expense $ 46 $ 36 $ 83 $ 61
Stock options
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Stock-based compensation expense 32 [1] 26 [1] 58 [1] 44 [1]
ESPPs
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Stock-based compensation expense 6 5 10 8
Restricted stock
        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Stock-based compensation expense $ 8 $ 5 $ 15 $ 9
[1] Expense for stock options includes the expense associated with stock appreciation rights. Accelerated stock option expense is recorded for employees eligible for accelerated stock option vesting upon retirement. Accelerated stock option expense was $6 million and $4 million for the three month periods ended November 30, 2012 and 2011, respectively, and $10 million and $8 million for the six month periods ended November 30, 2012 and 2011, respectively.