FAIR VALUE MEASUREMENTS (Details) (USD $) In Millions, unless otherwise specified	May 31, 2012	May 31, 2011
Assets [Abstract]
Money market funds	$ 25	$ 3,362
U.S. Treasury, U.S. government and U.S. government agency debt securities	100	1,150
Commercial paper debt securities	13,954	11,884
Corporate debt securities and other	2,212	1,991
Derivative financial instruments	69	69
Total assets	16,360	18,456
Liabilities [Abstract]
Contingent consideration payable	387
Total debt	16,500	15,900
Fair Value Measurements Using Input Types Level 1 [Member]
Assets [Abstract]
Money market funds	25	3,362
U.S. Treasury, U.S. government and U.S. government agency debt securities	100	1,150
Corporate debt securities and other	229	106
Total assets	354	4,618
Fair Value Measurements Using Input Types Level 2 [Member]
Assets [Abstract]
Commercial paper debt securities	13,954	11,884
Corporate debt securities and other	1,983	1,885
Derivative financial instruments	69	69
Total assets	16,006	13,838
Liabilities [Abstract]
Total debt fair value	19,300	17,400
Fair Value Measurements Using Input Types Level 3 [Member]
Liabilities [Abstract]
Contingent consideration payable	$ 387