EARNINGS (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018
Earnings Per Share [Abstract]
Net income (loss)		$ 2,745	$ (4,047)	$ 7,343	$ 311
Weighted average common shares outstanding		3,526	4,122	3,716	4,146
Dilutive effect of employee stock plans		91	0	95	122
Dilutive weighted average common shares outstanding		3,617	4,122	3,811	4,268
Basic earnings (loss) per share		$ 0.78	$ (0.98)	$ 1.98	$ 0.07
Diluted earnings (loss) per share		$ 0.76	$ (0.98)	$ 1.93	$ 0.07
Shares subject to anti-dilutive restricted stock-based awards and stock options excluded from calculation	[1]	67	190	73	60

[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.