EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Aug. 31, 2015	Aug. 31, 2014
Computation of Basic and Diluted Earnings Per Share [Abstract]
Net income		$ 1,747	$ 2,184
Weighted average common shares outstanding		4,317	4,451
Dilutive effect of employee stock plans		95	97
Dilutive weighted average common shares outstanding		4,412	4,548
Basic earnings per share		$ 0.40	$ 0.49
Diluted earnings per share		$ 0.40	$ 0.48
Shares subject to anti-dilutive stock options and restricted stock-based awards excluded from calculation	[1]	57	26

[1] These weighted shares relate to anti-dilutive stock options and restricted stock-based awards as calculated using the treasury stock method and could be dilutive in the future.