v3.26.1
Commitments and Contingencies - Movement in Provision for Credit Card and Debit Card Reward Points (Detail) - Credit card and debit card reward points
₨ in Millions, $ in Millions
12 Months Ended
Mar. 31, 2026
INR (₨)
Mar. 31, 2026
USD ($)
Mar. 31, 2025
INR (₨)
Valuation and Qualifying Accounts Disclosure [Line Items]      
Opening provision of reward points ₨ 10,474.4 $ 111.6 ₨ 8,635.5
Provision made during the year 10,065.2 107.3 9,335.1
Utilization/write back of provision (8,836.5) (94.2) (7,496.2)
Closing provision of reward points 11,703.1 124.7 10,474.4
Change in Rate of Accrual of Reward Points      
Valuation and Qualifying Accounts Disclosure [Line Items]      
Effect of change in rate of accrual of reward points ₨ 0.0 $ 0.0 ₨ 0.0