DERIVATIVE FINANCIAL INSTRUMENTS EFFECTS ON EARNINGS AND AOCL (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2020	May 31, 2019	May 31, 2018
Derivative [Line Items]
Non-operating income, net	$ 162	$ 815	$ 1,185
Interest expense	(1,995)	(2,082)	(2,025)
Cash flow hedges [Member] \| Cross-Currency Swap Agreements [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Cross-currency swap agreements designated as cash flow hedges	(43)	(105)	88
Non-Operating Income, Net [Member]
Derivative [Line Items]
Non-operating income, net	162	815	1,185
Effects of derivative instruments designated as hedges on income [Abstract]:
Total gain (loss) on hedges recognized in income	(25)	(53)	51
Non-Operating Income, Net [Member] \| Fair value hedges [Member] \| Interest Rate Swaps [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
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]
Effects of derivative instruments designated as hedges on income [Abstract]:
Derivative instruments	(7)	(38)	0
Hedged items	3	38	0
Non-Operating Income, Net [Member] \| Cash flow hedges [Member] \| Cross-Currency Swaps [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Amount of gain (loss) reclassified from accumulated OCI or OCL	(21)	(53)	51
Interest Expense [Member]
Derivative [Line Items]
Interest expense	(1,995)	(2,082)	(2,025)
Effects of derivative instruments designated as hedges on income [Abstract]:
Total gain (loss) on hedges recognized in income	0	0	0
Interest Expense [Member] \| Fair value hedges [Member] \| Interest Rate Swaps [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Derivative instruments	29	31	(66)
Hedged items	(29)	(31)	66
Interest Expense [Member] \| Fair value hedges [Member] \| Cross-currency interest rate swap agreements [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Derivative instruments	7	27	0
Hedged items	(7)	(27)	0
Interest Expense [Member] \| Cash flow hedges [Member] \| Cross-Currency Swaps [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Amount of gain (loss) reclassified from accumulated OCI or OCL	$ 0	$ 0	$ 0

Nonoperating income expense including elimination of net income loss attributable to noncontrolling interests.

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount, before tax and after reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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