Retirement Plans - Schedule of Retirement Plan Costs (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Nov. 30, 2022 |
Nov. 30, 2021 |
Nov. 30, 2022 |
Nov. 30, 2021 |
|
| Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract] | ||||
| Defined benefit pension plans, net | $ 58 | $ (2) | $ 117 | $ (5) |
| Defined contribution plans | 228 | 171 | 472 | 351 |
| Postretirement healthcare plans | 23 | 23 | 46 | 45 |
| Retirement plans mark-to-market adjustments | 260 | 260 | ||
| Retirement plans costs | $ 309 | $ 452 | $ 635 | $ 651 |