v3.25.2
Share capital - Summary of Issued Share Capital (Detail)
₨ in Millions, $ in Millions
 12 Months Ended
Mar. 31, 2025
INR (₨)
shares
Mar. 31, 2025
USD ($)
shares
Mar. 31, 2024
INR (₨)
shares
Mar. 31, 2023
INR (₨)
shares
Disclosure Of Reconciliation Of Issued Capital [line Items]        
Beginning balance ₨ 4,808      
Shares issued during the year 0   ₨ 2 ₨ 15
Ending balance 4,808 $ 56 4,808  
Issued capital        
Disclosure Of Reconciliation Of Issued Capital [line Items]        
Shares issued during the year 0   0 0
Share premium        
Disclosure Of Reconciliation Of Issued Capital [line Items]        
Shares issued during the year ₨ 51   ₨ 17 ₨ 85
Ordinary Shares | Issued capital        
Disclosure Of Reconciliation Of Issued Capital [line Items]        
Beginning balance, shares | shares 362,630,592 362,630,592 373,037,667 399,177,640
Shares issued during the year, shares | shares 138,553 138,553 280,940 215,000
Shares bought back, held as treasury stock | shares     (10,688,015) (26,354,973)
Ending balance, shares | shares 362,769,145 362,769,145 362,630,592 373,037,667
Beginning balance ₨ 4,808   ₨ 4,808 ₨ 4,808
Shares issued during the year 0   0 0
Shares bought back, held as treasury stock amount     (0) 0
Ending balance 4,808 $ 56 4,808 4,808
Ordinary Shares | Share premium        
Disclosure Of Reconciliation Of Issued Capital [line Items]        
Beginning balance 154,153   154,136 154,051
Shares issued during the year 51   17 85
Shares bought back, held as treasury stock amount     0 0
Ending balance ₨ 154,204 $ 1,805 ₨ 154,153 ₨ 154,136