EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020
Earnings Per Share [Abstract]
Net income		$ 5,021	$ 2,571	$ 9,714	$ 7,019
Weighted average common shares outstanding		2,913	3,190	2,977	3,251
Dilutive effect of employee stock plans		81	81	72	86
Dilutive weighted average common shares outstanding		2,994	3,271	3,049	3,337
Basic earnings per share		$ 1.72	$ 0.81	$ 3.26	$ 2.16
Diluted earnings per share		$ 1.68	$ 0.79	$ 3.19	$ 2.10
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	36	55	36	55

[1] These weighted shares relate to anti-dilutive restricted stock-based awards and stock options, both of which were service-based, as calculated using the treasury stock method and contingently issuable shares, substantially all of which were related to performance based stock option (PSO) arrangements. Such shares could be dilutive in the future.