EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Earnings Per Share [Abstract]
Net income		$ 2,319	$ 5,021	$ 3,528	$ 9,714
Weighted average common shares outstanding		2,670	2,913	2,711	2,977
Dilutive effect of employee stock plans		84	81	89	72
Dilutive weighted average common shares outstanding		2,754	2,994	2,800	3,049
Basic earnings per share		$ 0.87	$ 1.72	$ 1.30	$ 3.26
Diluted earnings per share		$ 0.84	$ 1.68	$ 1.26	$ 3.19
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	33	36	32	36

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