DERIVATIVE FINANCIAL INSTRUMENTS EFFECTS ON EARNINGS AND AOCL (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2019	May 31, 2018	May 31, 2017
Derivative [Line Items]
Non-operating income, net	$ 815	$ 1,185	$ 565
Consolidated statements of income line amounts in which the hedge effects were recorded	2,082	2,025	1,798
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	(105)	88	27
Non-Operating Income, Net [Member]
Derivative [Line Items]
Non-operating income, net	815	1,185	565
Effects of derivative instruments designated as hedges on income [Abstract]:
Total gain (loss) on hedges recognized in income	(53)	51	2
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 Swaps [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Derivative instruments	(38)	0	0
Hedged items	38	0	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	(53)	51	2
Interest Expense [Member]
Derivative [Line Items]
Consolidated statements of income line amounts in which the hedge effects were recorded	2,082	2,025	1,798
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	31	(66)	(82)
Hedged items	(31)	66	82
Interest Expense [Member] \| Fair value hedges [Member] \| Cross-Currency Interest Rate Swaps [Member]
Effects of derivative instruments designated as hedges on income [Abstract]:
Derivative instruments	27	0	0
Hedged items	(27)	0	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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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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