v3.26.1
Earnings per equity share - Reconciliations of Basic and Diluted Earnings Per Equity Share and Earnings per American Depositary Shares (Detail)
12 Months Ended
Mar. 31, 2026
₨ / shares
Mar. 31, 2026
$ / shares
Mar. 31, 2025
₨ / shares
Mar. 31, 2024
₨ / shares
Earnings Per Share Disclosure [Line Items]        
Basic earnings per share | (per share) ₨ 45.89 $ 0.49 ₨ 45.01 ₨ 44.33
Effect of potential equity shares for stock options outstanding | (per share) 0.14 0.01 0.19 0.17
Diluted earnings per share | (per share) 45.75 0.48 44.82 44.16
Basic earnings per share | (per share) 137.67 1.47 135.02 132.99
Diluted earnings per share | (per share) 137.25 1.44 134.45 132.46
American Depository Shares | Stock Compensation Plan        
Earnings Per Share Disclosure [Line Items]        
Effect of potential equity shares for stock options outstanding | (per share) ₨ 0.42 $ 0.03 ₨ 0.57 ₨ 0.53