CONSOLIDATED BALANCE SHEETS PARENTHETICAL - USD ($) $ in Millions |
May 31, 2019 |
May 31, 2018 |
|---|---|---|
| Statement Of Financial Position [Abstract] | ||
| Allowance for doubtful accounts receivable | $ 371 | $ 370 |
| Preferred stock par value per share | $ 0.01 | $ 0.01 |
| Preferred stock shares authorized | 1,000,000 | 1,000,000 |
| Preferred stock shares outstanding | 0 | 0 |
| Common stock par value per share | $ 0.01 | $ 0.01 |
| Common stock shares authorized | 11,000,000,000 | 11,000,000,000 |
| Common stock shares outstanding | 3,359,000,000 | 3,997,000,000 |