Stock Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Common Stock and Share Based Compensation [Line Items]
Accelerated stock option expense	$ 4	$ 6	$ 8	$ 10
Stock Incentive Plan 1990 [Member] | Common Class B
Common Stock and Share Based Compensation [Line Items]
Shares available for grant (in shares)	326,000,000		326,000,000
Stock options vesting period (in years)			4 years
Stock options expiration from the date of grant (in years)			10 years
Unrecognized compensation costs from stock options, net of estimated forfeitures	$ 242		$ 242
Unrecognized compensation costs from stock options, net of estimated forfeitures, to be recognized as operating overhead expense over a weighted average period (in years)			2 years 7 months 6 days
Weighted average fair value per share of the options granted (in dollars per share)			$ 14.88	$ 12.71
Minimum term of market traded options for estimates of expected volatility (in years)			1 year
Employee Stock [Member] | Common Class B
Common Stock and Share Based Compensation [Line Items]
Employee stock purchase plans, payroll deductions (percent)	10.00%		10.00%
Employee stock purchase plan offering period (in months)			6 months
Shares purchased, price as percentage of lower of the fair market value (percent)	85.00%		85.00%