Earnings Per Share - Reconciliation from Basic to Diluted Earnings Per Share (Detail) - $ / shares shares in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Determination of shares:
Weighted average common shares outstanding	1,659.1	1,706.5	1,665.6	1,707.8
Assumed conversion of dilutive stock options and awards	34.1	44.9	35.7	45.6
DILUTED WEIGHTED AVERAGE COMMON SHARES OUTSTANDING	1,693.2	1,751.4	1,701.3	1,753.4
Earnings per common share:
Basic (in dollars per share)	$ 0.51	$ 0.46	$ 1.26	$ 1.15
Diluted (in dollars per share)	$ 0.50	$ 0.45	$ 1.23	$ 1.12