Income Taxes - Reconciliation of Changes in Gross Balance of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
May 31, 2019 |
May 31, 2018 |
May 31, 2017 |
|
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Unrecognized tax benefits, as of the beginning of the period | $ 698 | $ 461 | $ 506 |
| Gross increases related to prior period tax positions | 85 | 19 | 31 |
| Gross decreases related to prior period tax positions | (32) | (12) | (163) |
| Gross increases related to current period tax positions | 81 | 249 | 115 |
| Settlements | 0 | 0 | (12) |
| Lapse of statute of limitations | (35) | (20) | (21) |
| Changes due to currency translation | 11 | 1 | 5 |
| UNRECOGNIZED TAX BENEFITS, AS OF THE END OF THE PERIOD | $ 808 | $ 698 | $ 461 |