ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES Narrative (Details) - USD ($)	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Total net tax benefit	$ 2,300,000,000
Deferred tax assets	16,847,000,000	$ 5,511,000,000
Contract with Customer, Asset and Liability [Abstract]
Revenues recognized included in opening deferred revenue balance	8,000,000,000.0	8,400,000,000
Revenue, Performance Obligation [Abstract]
Remaining performance obligation, amount	41,300,000,000
Sales of Financing Receivables [Abstract]
Sales of financing receivables	1,700,000,000	1,500,000,000	$ 1,800,000,000
Non-marketable equity securities and related instruments	971,000,000	219,000,000
Inventory Net [Abstract]
Total inventories	142,000,000	211,000,000
Other Receivables [Narrative] [Abstract]
Other receivables included in prepaid expenses and other current assets	798,000,000	778,000,000
Goodwill, Intangible Assets and Impairment Assessments [Abstract]
Goodwill impairment loss	0	0	0
Foreign Currency [Abstract]
Net foreign exchange transaction losses included in non-operating income, net	$ 112,000,000	185,000,000	111,000,000
Stock-Based Compensation [Abstract]
Service period of award	4 years
Advertising [Abstract]
Advertising expenses	$ 202,000,000	$ 178,000,000	$ 169,000,000
Non-marketable equity securities, upward adjustments	299,000,000
Marketable equity securities held for certain employee benefit plans, Trading	$ 193,000,000
Minimum [Member]
Property, Plant and Equipment [Abstract]
Property, plant and equipment, estimated useful lives	1 year
Goodwill, Intangible Assets and Impairment Assessments [Abstract]
Finite lived intangible assets, useful life	1 year
Maximum [Member]
Property, Plant and Equipment [Abstract]
Property, plant and equipment, estimated useful lives	40 years
Goodwill, Intangible Assets and Impairment Assessments [Abstract]
Finite lived intangible assets, useful life	10 years
Intellectual Property [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Total net tax benefit	$ 2,300,000,000
Deferred tax assets	11,300,000,000
Non-current deferred tax liability	$ 9,100,000,000