RETIREMENT PLANS - Schedule of Retirement Plan Costs (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
May 31, 2025 |
May 31, 2024 |
May 31, 2023 |
|
| Retirement Benefits [Abstract] | |||
| Defined benefit pension plans | $ 278 | $ 363 | $ 236 |
| Defined contribution plans | 1,144 | 968 | 955 |
| Postretirement healthcare plans | 87 | 85 | 92 |
| Pension plans MTM gain | (515) | (561) | (650) |
| Retirement plans costs | $ 994 | $ 855 | $ 633 |