EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Computation of Basic and Diluted Earnings Per Share [Abstract]
Net income		$ 2,142	$ 2,495	$ 6,087	$ 7,181
Weighted average common shares outstanding		4,182	4,389	4,246	4,419
Dilutive effect of employee stock plans		74	105	82	97
Dilutive weighted average common shares outstanding		4,256	4,494	4,328	4,516
Basic earnings per share		$ 0.51	$ 0.57	$ 1.43	$ 1.63
Diluted earnings per share		$ 0.50	$ 0.56	$ 1.41	$ 1.59
Shares subject to anti-dilutive stock options and restricted stock-based awards excluded from calculation	[1]	67	39	62	36

[1] These weighted shares relate to anti-dilutive stock options and restricted stock-based awards as calculated using the treasury stock method and could be dilutive in the future.