EARNINGS PER SHARE (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Aug. 31, 2012		Aug. 31, 2011
Computation of Basic and Diluted Earnings Per Share [Abstract]
Net income	$ 2,034		$ 1,840
Weighted average common shares outstanding	4,867		5,062
Dilutive effect of employee stock plans	72		88
Diluted weighted average common shares outstanding	4,939		5,150
Basic earnings per share	$ 0.42		$ 0.36
Diluted earnings per share	$ 0.41		$ 0.36
Shares subject to anti-dilutive stock options and restricted stock-based awards excluded from calculation	188	[1]	85	[1]

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