BASIS OF PRESENTATION AND RECENT ACCOUNTING PRONOUNCEMENTS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018	May 31, 2018
Condensed Consolidated Statement of Operations [Abstract]
Total revenues	$ 9,614	$ 9,676	$ 28,369	$ 28,369
Total operating expenses	6,215	6,361	19,091	19,266
Non-operating income, net	198	409	681	891
Provision for income taxes	343	7,238	1,059	8,206
Net income (loss)	$ 2,745	$ (4,047)	$ 7,343	$ 311
Basic earnings (loss) per share	$ 0.78	$ (0.98)	$ 1.98	$ 0.07
Diluted earnings (loss) per share	$ 0.76	$ (0.98)	$ 1.93	$ 0.07
Condensed Consolidated Balance Sheet [Abstract]
Trade receivables, net of allowances for doubtful accounts	$ 3,993		$ 3,993		$ 5,136
Prepaid expenses and other current assets	3,594		3,594		3,762
Deferred tax assets	2,033		2,033		1,395
Other non-current assets	4,137		4,137		3,975
Total current liabilities	17,986		17,986		19,124
Total non-current liabilities	67,214		67,214		71,854
Total equity	24,238	$ 49,071	24,238	$ 49,071	46,873
Acquisition Related and Other Expenses [Abstract]
Transitional and other employee related costs	13	9	39	32
Stock-based compensation	0	0	0	1
Professional fees and other, net	3	(8)	10	(1)
Business combination adjustments, net	(20)	2	(20)	0
Total acquisition related and other expenses	(4)	3	29	32
Non-Operating Income, net [Abstract]
Interest income	246	313	890	852
Foreign currency losses, net	(13)	(35)	(68)	(46)
Noncontrolling interests in income	(35)	(37)	(106)	(111)
Other (loss) income, net	0	168	(35)	196
Total non-operating income, net	$ 198	409	$ 681	891
Adoption of Topic 606 and ASU 2017-07 [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		9,676		28,369
Total operating expenses		6,361		19,266
Non-operating income, net		409		891
Provision for income taxes		7,238		8,206
Net income (loss)		$ (4,047)		$ 311
Basic earnings (loss) per share		$ (0.98)		$ 0.07
Diluted earnings (loss) per share		$ (0.98)		$ 0.07
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		$ 409		$ 891
Adoption of Topic 606 and ASU 2017-07 [Member] | As Previously Reported [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		9,771		28,579
Total operating expenses		6,361		19,280
Non-operating income, net		423		929
Provision for income taxes		7,324		8,333
Net income (loss)		$ (4,024)		$ 418
Basic earnings (loss) per share		$ (0.98)		$ 0.10
Diluted earnings (loss) per share		$ (0.98)		$ 0.10
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		$ 423		$ 929
Adoption of Topic 606 and ASU 2017-07 [Member] | Adjustments [Member]
Condensed Consolidated Statement of Operations [Abstract]
Total revenues		(95)		(210)
Total operating expenses		0		(14)
Non-operating income, net		(14)		(38)
Provision for income taxes		(86)		(127)
Net income (loss)		$ (23)		$ (107)
Basic earnings (loss) per share		$ 0		$ (0.03)
Diluted earnings (loss) per share		$ 0		$ (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		$ (14)		$ (38)