FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Nov. 30, 2015

Fair Value Measurements [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	November 30, 2015						May 31, 2015
	Fair Value Measurements Using Input Types						Fair Value Measurements Using Input Types
(in millions)	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
U.S. Treasury securities	$	255	$	—	$	255	$	668	$	—	$	668
Commercial paper debt securities		—		6,351		6,351		—		9,203		9,203
Corporate debt securities and other		170		33,259		33,429		190		28,654		28,844
Derivative financial instruments		—		88		88		—		74		74
Total assets	$	425	$	39,698	$	40,123	$	858	$	37,931	$	38,789
Liabilities:
Derivative financial instruments	$	—	$	289	$	289	$	—	$	244	$	244