EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Aug. 31, 2018	Aug. 31, 2017
Earnings Per Share [Abstract]
Net income		$ 2,265	$ 2,144
Weighted average common shares outstanding		3,904	4,156
Dilutive effect of employee stock plans		95	128
Dilutive weighted average common shares outstanding		3,999	4,284
Basic earnings per share		$ 0.58	$ 0.52
Diluted earnings per share		$ 0.57	$ 0.50
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	81	31

[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.