v3.25.2
Investments, Available for Sale Debt Securities -Summary of Allowances for Available for sale debt Securities (Detail)
₨ in Millions, $ in Millions
 12 Months Ended
Mar. 31, 2025
INR (₨)
Mar. 31, 2025
USD ($)
Mar. 31, 2024
INR (₨)
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]      
Allowance for credit losses, beginning of the period ₨ 0.0 $ 0 ₨ 70.9
Write- offs 0.0 0 0.0
Net allowance for credit losses 0.0 0 (70.9)
Allowance for credit losses, end of the period 0.0 $ 0 0.0
Credit Substitutes      
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]      
Allowance for credit losses, beginning of the period 0.0   70.9
Write- offs 0.0   0.0
Net allowance for credit losses 0.0   (70.9)
Allowance for credit losses, end of the period 0.0   0.0
Other corporate/financial institution bonds      
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]      
Allowance for credit losses, beginning of the period 0.0   0.0
Write- offs 0.0   0.0
Net allowance for credit losses 0.0   0.0
Allowance for credit losses, end of the period ₨ 0.0   ₨ 0.0