|
Total Stock Based Compensation Expense (Parenthetical) (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] | ||||
| Accelerated stock option expense | $ 6 | $ 4 | $ 10 | $ 8 |