Earnings Per Share - Reconciliation from Basic Earnings Per Share to Diluted Earnings Per Share (Detail) - $ / shares shares in Millions	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Determination of shares:
Weighted average common shares outstanding	1,693.8	1,722.9	1,703.2	1,726.3
Assumed conversion of dilutive stock options and awards	43.5	44.8	45.3	44.7
DILUTED WEIGHTED AVERAGE COMMON SHARES OUTSTANDING	1,737.3	1,767.7	1,748.5	1,771.0
Earnings per common share:
Basic (in dollars per share)	$ 0.56	$ 0.46	$ 1.71	$ 1.39
Diluted (in dollars per share)	$ 0.55	$ 0.45	$ 1.67	$ 1.36