v3.26.1
Material Accounting Policy Information - Additional Information (Detail)
₨ / shares in Units, ₨ in Millions
12 Months Ended
Mar. 31, 2026
INR (₨)
Vote
₨ / shares
shares
Mar. 31, 2025
INR (₨)
₨ / shares
Dec. 03, 2024
₨ / shares
Mar. 31, 2024
INR (₨)
₨ / shares
Disclosure of classes of share capital [line items]        
Authorized share capital | ₨ ₨ 25,352      
Par value per share   ₨ 2 ₨ 2 ₨ 2
Number of vote | Vote 1      
Capital redemption reserve | ₨ ₨ 0 ₨ 0   ₨ 1,661
Bottom of range [member]        
Disclosure of classes of share capital [line items]        
Percentage of voting power of another entity 20.00%      
Top of range [member]        
Disclosure of classes of share capital [line items]        
Percentage of voting power of another entity 50.00%      
Capital reserve [member]        
Disclosure of classes of share capital [line items]        
Undistributed earnings after taxes freely available for distribution - Capital Reserve | ₨ ₨ 1,139 ₨ 1,139   ₨ 1,139
Ordinary Shares [member]        
Disclosure of classes of share capital [line items]        
Authorized shares | shares 12,543,500,000      
Par value per share ₨ 2      
Preference shares [member]        
Disclosure of classes of share capital [line items]        
Authorized shares | shares 25,000,000      
Par value per share ₨ 10      
10% Optionally Convertible Cumulative Preference Shares [member]        
Disclosure of classes of share capital [line items]        
Authorized shares | shares 150,000      
Par value per share ₨ 100