v3.26.1
Earnings per equity share - Weighted Average Number of Equity Shares Used in Computing Earnings Per Equity Share (Detail) - shares
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Schedule of Weighted Average Number of Diluted Shares Outstanding [Line Items]      
Weighted average number of equity shares used in computing basic earnings per equity share 15,357,462,189 15,255,283,286 14,158,592,110
Effect of potential equity shares for stock options outstanding 48,909,382 63,584,926 56,312,746
Weighted average number of equity shares used in computing diluted earnings per equity share 15,406,371,571 15,318,868,212 14,214,904,856