DERIVATIVE FINANCIAL INSTRUMENTS EFFECTS ON EARNINGS AND AOCL (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
Derivative [Line Items]
Non-operating income, net	$ 282	$ 162	$ 815
Interest expense	(2,496)	(1,995)	(2,082)
Cash flow hedges [Member] | Cross-Currency Swap Agreements [Member]
Derivative [Line Items]
Cross-currency swap agreements designated as cash flow hedges	129	(43)	(105)
Non-Operating Income, Net [Member]
Derivative [Line Items]
Non-operating income, net	282	162	815
Total gain (loss) on hedges recognized in income	153	(25)	(53)
Non-Operating Income, Net [Member] | Fair value hedges [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative instruments	0	0	0
Hedged items	0	0	0
Non-Operating Income, Net [Member] | Fair value hedges [Member] | Cross-currency interest rate swap agreements [Member]
Derivative [Line Items]
Derivative instruments	101	(7)	(38)
Hedged items	(85)	3	38
Non-Operating Income, Net [Member] | Cash flow hedges [Member] | Cross-Currency Swaps [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from accumulated OCI or OCL	137	(21)	(53)
Interest Expense [Member]
Derivative [Line Items]
Interest expense	(2,496)	(1,995)	(2,082)
Total gain (loss) on hedges recognized in income	0	0	0
Interest Expense [Member] | Fair value hedges [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative instruments	(26)	29	31
Hedged items	26	(29)	(31)
Interest Expense [Member] | Fair value hedges [Member] | Cross-currency interest rate swap agreements [Member]
Derivative [Line Items]
Derivative instruments	(6)	7	27
Hedged items	6	(7)	(27)
Interest Expense [Member] | Cash flow hedges [Member] | Cross-Currency Swaps [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from accumulated OCI or OCL	$ 0	$ 0	$ 0