BASIS OF PRESENTATION AND RECENT ACCOUNTING PRONOUNCEMENTS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	May 31, 2018
Condensed Consolidated Statement of Operations [Abstract]
Total revenues	$ 9,193	$ 9,104
Total operating expenses	6,415	6,355
Non-operating income, net	291	220
Provision for income taxes	275	356
Net income	$ 2,265	$ 2,144
Basic earnings per share	$ 0.58	$ 0.52
Diluted earnings per share	$ 0.57	$ 0.50
Condensed Consolidated Balance Sheet [Abstract]
Trade receivables, net of allowances for doubtful accounts	$ 3,729		$ 5,136
Prepaid expenses and other current assets	3,186		3,762
Deferred tax assets	1,433		1,395
Other non-current assets	4,001		3,975
Deferred revenues	10,349		8,341
Income taxes payable, non-current	13,513		13,429
Other non-current liabilities	2,333		2,297
Total equity	38,564		46,873
Acquisition Related and Other Expenses [Abstract]
Transitional and other employee related costs	14	$ 9
Stock-based compensation	0	1
Professional fees and other, net	2	3
Business combination adjustments, net	(2)	(1)
Total acquisition related and other expenses	14	12
Non-Operating Income, net [Abstract]
Interest income	348	257
Foreign currency losses, net	(34)	(4)
Noncontrolling interests in income	(39)	(46)
Other income, net	16	13
Total non-operating income, net	$ 291	220
Adoption of Topic 606 and ASU 2017-07 [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		9,104
Total operating expenses		6,355
Non-operating income, net		220
Provision for income taxes		356
Net income		$ 2,144
Basic earnings per share		$ 0.52
Diluted earnings per share		$ 0.50
Condensed Consolidated Balance Sheet [Abstract]
Trade receivables, net of allowances for doubtful accounts			5,136
Prepaid expenses and other current assets			3,762
Deferred tax assets			1,395
Other non-current assets			3,975
Deferred revenues			8,341
Income taxes payable, non-current			13,429
Other non-current liabilities			2,297
Total equity			46,873
Adoption of Topic 606 and ASU 2017-07 [Member] | As Previously Reported [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		$ 9,187
Total operating expenses		6,366
Non-operating income, net		233
Provision for income taxes		375
Net income		$ 2,210
Basic earnings per share		$ 0.53
Diluted earnings per share		$ 0.52
Condensed Consolidated Balance Sheet [Abstract]
Trade receivables, net of allowances for doubtful accounts			5,279
Prepaid expenses and other current assets			3,424
Deferred tax assets			1,491
Other non-current assets			3,487
Deferred revenues			8,429
Income taxes payable, non-current			13,422
Other non-current liabilities			2,295
Total equity			46,224
Adoption of Topic 606 and ASU 2017-07 [Member] | Adjustments [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		$ (83)
Total operating expenses		(11)
Non-operating income, net		(13)
Provision for income taxes		(19)
Net income		$ (66)
Basic earnings per share		$ (0.01)
Diluted earnings per share		$ (0.02)
Condensed Consolidated Balance Sheet [Abstract]
Trade receivables, net of allowances for doubtful accounts			(143)
Prepaid expenses and other current assets			338
Deferred tax assets			(96)
Other non-current assets			488
Deferred revenues			(88)
Income taxes payable, non-current			7
Other non-current liabilities			2
Total equity			$ 649