INCOME TAXES (Details) - USD ($) $ in Billions	3 Months Ended		9 Months Ended
	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020	May 31, 2020
Income Tax Disclosure [Abstract]
Total net deferred tax benefit	$ 2.3		$ 2.3
Effective tax (benefit) expense rate	(53.30%)	16.40%	(9.80%)	16.10%
Deferred Tax Assets, Net [Abstract]
Net deferred tax assets	$ 5.8		$ 5.8		$ 3.2