EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Aug. 31, 2016	Aug. 31, 2015
Earnings Per Share [Abstract]
Net income		$ 1,832	$ 1,747
Weighted average common shares outstanding		4,119	4,317
Dilutive effect of employee stock plans		102	95
Dilutive weighted average common shares outstanding		4,221	4,412
Basic earnings per share		$ 0.44	$ 0.40
Diluted earnings per share		$ 0.43	$ 0.40
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	72	57

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