DERIVATIVE FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	May. 31, 2015
Foreign Currency Forward Contracts Not Designated as Hedges (Narrative) [Abstract]
Net gains (losses) related to forward contracts	$ 97	$ (31)
Foreign Currency Forward Contracts Not Designated as Hedges [Member] | Forward contracts held to purchase U.S. Dollars [Member]
Foreign Currency Forward Contracts Not Designated as Hedges (Narrative) [Abstract]
Notional amounts of forward contracts	2,000		$ 2,200
Foreign Currency Forward Contracts Not Designated as Hedges [Member] | Forward contracts held to sell U.S. Dollars [Member]
Foreign Currency Forward Contracts Not Designated as Hedges (Narrative) [Abstract]
Notional amounts of forward contracts	$ 956		$ 1,200