v3.19.3.a.u2
INCOME TAXES (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Nov. 30, 2019
Nov. 30, 2018
Nov. 30, 2019
Nov. 30, 2018
May 31, 2019
Income Tax Disclosure [Abstract]          
Effective income tax rate 17.70% 15.90% 16.00% 13.50%  
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 $ 2,600   $ 2,600   $ 2,400