DEFERRED COMPENSATION PLANS (Details) - Other Postretirement Plans [Member] - USD ($) $ in Millions |
May 31, 2019 |
May 31, 2018 |
|---|---|---|
| Deferred Compensation Plan Disclosure [Line Items] | ||
| Deferred compensation plan assets | $ 566 | $ 555 |
| Deferred compensation plan liabilities | $ 566 | $ 555 |