Other equity - Summary of Share Based Payment Reserve (Detail) ₨ in Millions, $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
|
Mar. 31, 2025
INR (₨)
|
Mar. 31, 2025
USD ($)
|
Mar. 31, 2024
INR (₨)
|
Mar. 31, 2023
INR (₨)
|
|
| Disclosure Of Detailed Information About Reserve Of Share Based Payments Of Equity [line Items] | ||||
| Expense for the year | ₨ 2,402 | ₨ 2,278 | ₨ 2,512 | |
| Shares issued during the year | 0 | 2 | 15 | |
| Share based payment reserve | ||||
| Disclosure Of Detailed Information About Reserve Of Share Based Payments Of Equity [line Items] | ||||
| Beginning balance | 8,149 | 5,886 | 3,444 | |
| Expense for the year | 2,402 | 2,278 | 2,512 | |
| Forfeiture of vested options | (103) | |||
| Shares issued during the year | (51) | (15) | (70) | |
| Ending balance | ₨ 10,397 | $ 122 | ₨ 8,149 | ₨ 5,886 |