Common Stock and Stock Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012
Class A Convertible Common Stock
Common Stock and Share Based Compensation [Line Items]
Common Stock, number of shares authorized (in shares)	200,000,000
Common stock conversion	Each share of Class A Common Stock is convertible into one share of Class B Common Stock.
Common stock, Class A conversion ratio to Class B (in shares)	1
Class B Common Stock
Common Stock and Share Based Compensation [Line Items]
Common Stock, number of shares authorized (in shares)	1,200,000,000
Stock Incentive Plan 1990 [Member] | Class B Common Stock
Common Stock and Share Based Compensation [Line Items]
Shares available for grant (in shares)	326,000,000
Stock options vesting period (in years)	4 years
Stock options expiration from the date of grant (in years)	10 years
Weighted average fair value per share of the options granted (in dollars per share)	$ 14.89	$ 12.71	$ 11.08
Minimum term of market traded options for estimates of expected volatility (in years)	1 year
Weighted average remaining contractual life for options outstanding (in years)	6 years
Weighted average remaining contractual life for options exercisable (in years)	4 years 7 months 6 days
Aggregate intrinsic value for options outstanding	$ 2,391
Aggregate intrinsic value for options exercisable	1,682
Total intrinsic value of options exercised	474	293	453
Stock Options | Stock Incentive Plan 1990 [Member]
Common Stock and Share Based Compensation [Line Items]
Unrecognized compensation costs from stock options, net of estimated forfeitures	179
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 1 month 6 days
Restricted Stock | Stock Incentive Plan 1990 [Member]
Common Stock and Share Based Compensation [Line Items]
Unrecognized compensation costs from stock options, net of estimated forfeitures	61
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 8 months 12 days
Restricted Stock | Stock Incentive Plan 1990 [Member] | Class B Common Stock
Common Stock and Share Based Compensation [Line Items]
Restricted and unrestricted stock granted to key employees under 1990 Plan, number of shares (in shares)	300,000	1,600,000	700,000
Restricted stock granted to key employees under 1990 Plan, weighted average values per share (in dollars per shares)	$ 63.89	$ 46.86	$ 49.49
Restricted stock vested, fair value	$ 28	$ 25	$ 22
Employee Stock | Class B Common Stock
Common Stock and Share Based Compensation [Line Items]
Employee stock purchase plans, payroll deductions	10.00%
Employee stock purchase plan offering period	6 months
Shares purchased, price as percentage of lower of the fair market value	85.00%
Purchase of shares by employee (in shares)	1,400,000	1,600,000	1,700,000