BASIS OF PRESENTATION, RECENT ACCOUNTING PRONOUNCEMENTS AND OTHER (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Acquisition Related and Other Expenses [Abstract]
Transitional and other employee related costs	$ 3	$ 11	$ 7	$ 25
Business combination adjustments, net	(4)	3	2	1
Other, net	13	4	28	6
Total acquisition related and other expenses	12	18	37	32
Non-Operating Income, net [Abstract]
Interest income	145	296	335	644
Foreign currency losses, net	(26)	(22)	(80)	(55)
Noncontrolling interests in income	(46)	(32)	(87)	(71)
Other income (loss), net	19	(50)	23	(34)
Total non-operating income, net	$ 92	$ 192	$ 191	$ 484