INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	May 31, 2019
Income Tax Disclosure [Abstract]
Effective income tax rate	13.90%	10.80%
Income tax net benefit, adjustments to estimate of U.S. Tax Cuts and Jobs Act of 2017 one-time transition tax and remeasurement of net deferred tax assets and liabilities		$ 153
Deferred Tax Assets, Net [Abstract]
Net deferred tax assets	$ 2,400		$ 2,400