BASIS OF PRESENTATION AND RECENT ACCOUNTING PRONOUNCEMENTS Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	May 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Operating expense	$ 6,415	$ 6,355
Non-operating income, net	291	220
Retained earnings	12,022		$ 19,111
Contract with Customer, Asset and Liability [Abstract]
Trade receivables	3,729		5,136
Contract liability (deferred revenues)	11,019		8,966
Revenues recognized included in opening deferred revenue balance	3,500
Revenue, Performance Obligation [Abstract]
Remaining Performance Obligation, Amount, Total	$ 31,300
Remaining Performance Obligation, Percentage, to be recognized in the next 12 months	64.00%
Restricted Cash Equivalents [Abstract]
Restricted cash and cash equivalent item, description	Restricted cash that was included within cash and cash equivalents as presented within our condensed consolidated balance sheets as of August 31, 2018 and May 31, 2018 and our condensed consolidated statements of cash flows for the three months ended August 31, 2018 and 2017 was nominal.
Sales of Financing Receivables [Abstract]
Sales of financing receivables	$ 822	818
ASU 2017-07 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Operating expense		(13)
Non-operating income, net		$ (13)
ASU 2016-16 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Prepaid assets			(110)
Retained earnings			$ (110)