Employment benefit plans - Summary of Maturity Analysis of Defined Benefit Payments (Detail) ₨ in Millions, $ in Millions |
12 Months Ended | ||
|---|---|---|---|
|
Mar. 31, 2026
INR (₨)
|
Mar. 31, 2026
USD ($)
|
Mar. 31, 2025
INR (₨)
|
|
| Within next 12 months [Member] | |||
| Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items] | |||
| Cash flow | ₨ 91 | $ 1 | ₨ 52 |
| From 2nd to 5th year [Member] | |||
| Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items] | |||
| Cash flow | 342 | 4 | 192 |
| From 6th to 9th year [Member] | |||
| Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items] | |||
| Cash flow | 178 | 2 | 117 |
| From 10th year and beyond [Member] | |||
| Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items] | |||
| Cash flow | ₨ 148 | $ 2 | ₨ 108 |