EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Aug. 31, 2017	Aug. 31, 2016
Earnings Per Share [Abstract]
Net income		$ 2,210	$ 1,832
Weighted average common shares outstanding		4,156	4,119
Dilutive effect of employee stock plans		128	102
Dilutive weighted average common shares outstanding		4,284	4,221
Basic earnings per share		$ 0.53	$ 0.44
Diluted earnings per share		$ 0.52	$ 0.43
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	31	72

[1] These weighted shares relate to anti-dilutive restricted service based stock-based awards and stock options (as calculated using the treasury stock method) and contingently issuable shares under PSO and PSU arrangements. Such shares could be dilutive in the future.