DERIVATIVE FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015	May. 31, 2015
Foreign Currency Forward Contracts Not Designated as Hedges (Narrative) [Abstract]
Net gains related to forward contracts	$ 93	$ 14	$ 163	$ 49
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	2,100		2,100		$ 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	$ 1,200		$ 1,200		$ 1,200