v3.26.1
Fair value measurement - Investments Measured at Fair Value on Recurring Basis (Detail)
₨ in Millions, $ in Millions
Mar. 31, 2026
INR (₨)
Mar. 31, 2026
USD ($)
Mar. 31, 2025
INR (₨)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities ₨ 848,427.6 $ 9,042.2 ₨ 625,388.5
Securities Available-for-Sale 10,247,500.8 109,213.5 9,910,174.3
Separate Account Assets 1,051,916.1 11,210.9 1,016,281.4
Fair Value Measurements Using Quoted Prices In Active Markets for Identical Assets (Level 1)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 388,678.9   340,388.3
Securities Available-for-Sale 262,623.5   1,435,936.3
Separate Account Assets 814,016.6   873,154.4
Fair Value Measurements Using Significant other observable inputs (Level 2)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 409,980.5   250,009.3
Securities Available-for-Sale 9,871,669.4   8,360,598.8
Separate Account Assets 237,899.5   143,127.0
Fair Value Measurements Using Significant unobservable inputs (Level 3)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 49,768.2   34,990.9
Securities Available-for-Sale 113,207.9   113,639.2
Separate Account Assets 0.0   0.0
Fair Value, Measurements, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 848,427.6   625,388.5
Securities Available-for-Sale 10,247,500.8   9,910,174.3
Equity securities [1] 48,067.3   129,984.8
Other securities [2] 19,600.3    
Separate Account Assets 1,051,916.1   1,016,281.4
Total 12,215,512.1 130,187.7 11,681,829.0
Liabilities on policies in force 211.8   482.9
Total 211.8 2.3 482.9
Fair Value, Measurements, Recurring | Fair Value Measurements Using Quoted Prices In Active Markets for Identical Assets (Level 1)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 388,678.9   336,658.0
Securities Available-for-Sale 262,623.5   1,435,936.2
Equity securities [1] 20,369.5   20,404.1
Other securities [2] 5,308.7    
Separate Account Assets 814,016.6   873,154.4
Total 1,490,997.2 15,890.4 2,666,152.7
Liabilities on policies in force 0.0   0.0
Total 0.0 0.0 0.0
Fair Value, Measurements, Recurring | Fair Value Measurements Using Significant other observable inputs (Level 2)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 409,980.5   253,739.6
Securities Available-for-Sale 9,871,669.4   8,360,598.9
Equity securities [1] 0.0   109,013.3
Other securities [2] 0.0    
Separate Account Assets 237,899.5   143,127.0
Total 10,519,549.4 112,112.9 8,866,478.8
Liabilities on policies in force 211.8   482.9
Total 211.8 2.3 482.9
Fair Value, Measurements, Recurring | Fair Value Measurements Using Significant unobservable inputs (Level 3)      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Trading account securities 49,768.2   34,990.9
Securities Available-for-Sale 113,207.9   113,639.2
Equity securities [1] 27,697.8   567.4
Other securities [2] 14,291.6    
Separate Account Assets 0.0   0.0
Total 204,965.5 2,184.4 149,197.5
Liabilities on policies in force 0.0   0.0
Total ₨ 0.0 $ 0.0 ₨ 0.0
[1] Equity securities classified within other assets.
[2] Other securities classified within other assets include security receipts, alternative investment funds, pass-through certificates and others.