(LOSS) EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Nov. 30, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020
Earnings Per Share [Abstract]
Net (loss) income		$ (1,247)	$ 2,442	$ 1,209	$ 4,693
Weighted average common shares outstanding		2,694	2,977	2,731	3,009
Dilutive effect of employee stock plans		0	69	92	67
Dilutive weighted average common shares outstanding		2,694	3,046	2,823	3,076
Basic (loss) earnings per share		$ (0.46)	$ 0.82	$ 0.44	$ 1.56
Diluted (loss) earnings per share		$ (0.46)	$ 0.80	$ 0.43	$ 1.53
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	121	36	31	36

[1] For the three months ended November 30, 2021, these weighted shares related to anti-dilutive restricted stock-based awards and stock options that are service-based (as calculated using the treasury stock method) and contingently issuable shares related to PSO arrangements, all of which could be dilutive in the future. For all other periods presented, substantially all of these weighted shares related to contingently issuable shares related to PSO arrangements that could be dilutive in the future.