ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2017	May 31, 2016
Condensed Consolidated Statement of Operations [Abstract]
Total revenues	$ 39,506	$ 39,383	$ 37,792
Total operating expenses	25,971	26,119	24,879
Non-operating income, net	815	1,185	565
Provision for income taxes	1,185	8,837	2,228
Net income	$ 11,083	$ 3,587	$ 9,452
Basic earnings per share	$ 3.05	$ 0.87	$ 2.30
Diluted earnings per share	$ 2.97	$ 0.85	$ 2.24
Condensed Consolidated Balance Sheet [Abstract]
Trade receivables, net of allowances for doubtful accounts	$ 5,134	$ 5,136
Prepaid expenses and other current assets	3,425	3,762
Deferred tax assets	2,696	1,395
Other non-current assets	4,317	3,975
Total current liabilities	18,630	19,124
Total non-current liabilities	67,716	71,854
Total equity	22,363	46,873	$ 55,130	$ 47,790
Acquisition Related and Other Expenses [Abstract]
Transitional and other employee related costs	49	48	41
Stock-based compensation	0	1	35
Professional fees and other, net	16	3	33
Business combination adjustments, net	(21)	0	(6)
Total acquisition related and other expenses	44	52	103
Non-Operating Income, net [Abstract]
Interest income	1,092	1,203	804
Foreign currency losses, net	(111)	(74)	(152)
Noncontrolling interests in income	(152)	(135)	(118)
Other income, net	(14)	191	31
Total non-operating income, net	$ 815	1,185	565
Adoption of Topic 606 and ASU 2017-07 [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		39,383	37,792
Total operating expenses		26,119	24,879
Non-operating income, net		1,185	565
Provision for income taxes		8,837	2,228
Net income		$ 3,587	$ 9,452
Basic earnings per share		$ 0.87	$ 2.30
Diluted earnings per share		$ 0.85	$ 2.24
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
Total current liabilities		19,124
Total non-current liabilities		71,854
Total equity		46,873
Non-Operating Income, net [Abstract]
Total non-operating income, net		1,185	$ 565
Adoption of Topic 606 and ASU 2017-07 [Member] | As Previously Reported [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		39,831	37,728
Total operating expenses		26,152	25,018
Non-operating income, net		1,237	605
Provision for income taxes		9,066	2,182
Net income		$ 3,825	$ 9,335
Basic earnings per share		$ 0.93	$ 2.27
Diluted earnings per share		$ 0.90	$ 2.21
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
Total current liabilities		19,195
Total non-current liabilities		71,845
Total equity		46,224
Non-Operating Income, net [Abstract]
Total non-operating income, net		1,237	$ 605
Adoption of Topic 606 and ASU 2017-07 [Member] | Adjustments [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		(448)	64
Total operating expenses		(33)	(139)
Non-operating income, net		(52)	(40)
Provision for income taxes		(229)	46
Net income		$ (238)	$ 117
Basic earnings per share		$ (0.06)	$ 0.03
Diluted earnings per share		$ (0.05)	$ 0.03
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
Total current liabilities		(71)
Total non-current liabilities		9
Total equity		649
Non-Operating Income, net [Abstract]
Total non-operating income, net		$ (52)	$ (40)