Earnings Per Share - Reconciliation from Basic Earnings Per Share to Diluted Earnings Per Share (Detail) - $ / shares shares in Millions	3 Months Ended	6 Months Ended
Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2015	Nov. 30, 2014
Determination of shares:
Weighted average common shares outstanding	1,706.5	1,726.2	1,707.8	1,728.0
Assumed conversion of dilutive stock options and awards	44.9	43.4	45.6	43.6
DILUTED WEIGHTED AVERAGE COMMON SHARES OUTSTANDING	1,751.4	1,769.6	1,753.4	1,771.6
Earnings per common share:
Basic (in dollars per share)	$ 0.46	$ 0.38	$ 1.15	$ 0.94
Diluted (in dollars per share)	$ 0.45	$ 0.37	$ 1.12	$ 0.91

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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