EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Aug. 31, 2021	Aug. 31, 2020
Earnings Per Share [Abstract]
Net income		$ 2,457	$ 2,251
Weighted average common shares outstanding		2,769	3,041
Dilutive effect of employee stock plans		92	66
Dilutive weighted average common shares outstanding		2,861	3,107
Basic earnings per share		$ 0.89	$ 0.74
Diluted earnings per share		$ 0.86	$ 0.72
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	30	36

[1] Substantially all of these weighted shares are related to contingently issuable shares related to PSO arrangements that could be dilutive in the future.