Financial Instruments - Details of Guarantees and Documentary Credits Outstanding (Detail) ₨ in Millions, $ in Millions |
Mar. 31, 2025
INR (₨)
|
Mar. 31, 2025
USD ($)
|
Mar. 31, 2024
INR (₨)
|
|---|---|---|---|
| Guarantor Obligations [Line Items] | |||
| Bank guarantees | ₨ 2,462,279.4 | $ 28,822.2 | ₨ 1,973,917.9 |
| Estimated fair values of bank guarantees | (12,875.5) | (150.7) | (10,085.1) |
| Financial guarantees | |||
| Guarantor Obligations [Line Items] | |||
| Bank guarantees | 714,278.7 | 8,361.0 | 610,381.3 |
| Performance guarantees | |||
| Guarantor Obligations [Line Items] | |||
| Bank guarantees | 781,152.1 | 9,143.8 | 653,452.8 |
| Documentary credits | |||
| Guarantor Obligations [Line Items] | |||
| Bank guarantees | 966,848.6 | 11,317.4 | 710,083.8 |
| Estimated fair values of bank guarantees | (1,462.5) | (17.1) | (1,018.9) |
| Guarantees [Member] | |||
| Guarantor Obligations [Line Items] | |||
| Estimated fair values of bank guarantees | ₨ (11,413.0) | $ (133.6) | ₨ (9,066.2) |