Lease liabilities - Summary of Lease Liabilities (Detail) ₨ in Millions, $ in Millions |
Mar. 31, 2026
INR (₨)
|
Mar. 31, 2026
USD ($)
|
Mar. 31, 2025
INR (₨)
|
Mar. 31, 2024
INR (₨)
|
|---|---|---|---|---|
| Presentation of leases for lessee [abstract] | ||||
| Non-current lease liabilities | ₨ 11,343 | $ 121 | ₨ 8,282 | ₨ 7,477 |
| Current lease liabilities | ₨ 1,090 | $ 12 | ₨ 977 | ₨ 868 |