v3.25.2
Fair value measurement - Information about Changes in Fair Value of Level 3 Assets (Detail) - Available-for-Sale Debt Securities - INR (₨)
₨ in Millions
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Beginning balance ₨ 160,865.0 ₨ 148,435.6
Total gains or losses (realized/unrealized) — Included in net income 5,864.3 614.5
Total gains or losses (realized/unrealized) — Included in other comprehensive income 1,351.8 1,531.8
Purchases/additions 65,272.1 113,003.2
Sales (546.6) (619.8)
Issuances   0.0
Settlements (83,818.7) (101,447.7)
Transfers into Level 3 209.6 0.0
Transfers out of Level 3 0.0 (652.6)
Foreign currency translation adjustment   0.0
Ending Balance 149,197.5 160,865.0
Total amount of gains/ (losses) included in net income attributable to change in unrealized gains/ (losses) relating to assets still held at reporting date 5,830.7 650.2
Change in unrealized gains/ (losses) for the period included in other comprehensive income for assets held at the end of the reporting period ₨ 433.0 ₨ 1,196.9