Share based payment - Summary of Expense Recognized For Employee Services Received during the Year (Detail) - Global Incentive Plan 2024 - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Expense from share-based payment transactions [abstract] | |||
| Expense arising from equity-settled share-based payment transactions | $ 1,779 | $ 2,402 | $ 2,278 |
| Expense arising from cash settled share based payments transactions | 325 | ||
| Total expense arising from share-based payment transactions | $ 2,104 | $ 2,402 | $ 2,278 |