v3.25.2
Deferred tax assets (DTA) (net) / deferred tax liabilities (DTL) (net) - Additional Information (Detail)
₨ in Millions, $ in Millions
12 Months Ended
Mar. 31, 2025
INR (₨)
Mar. 31, 2024
INR (₨)
Mar. 31, 2023
INR (₨)
Mar. 31, 2025
USD ($)
Statement [Line Items]        
Deferred tax assets ₨ 7,073 ₨ 5,556   $ 83
Percentage of performed sensitivities reduced in revenues 5.00%      
Disallowances of share-based payment expenses, interest expense and other ₨ 1,675 1,675    
Unabsorbed Depreciation        
Statement [Line Items]        
Unabsorbed depreciation ₨ 13 5,187 ₨ 5,917  
Unused tax credits        
Statement [Line Items]        
Temporary difference unused tax losses and unused tax credits, maximum period 15 years      
Unused tax credit ₨ 16 ₨ 22 ₨ 213  
Unused tax credits | Top of range [member]        
Statement [Line Items]        
Temporary difference, unused tax losses and unused tax credits, Expiry terms 5 years 8 years 6 years  
Unused tax credits | Bottom of range [member]        
Statement [Line Items]        
Temporary difference, unused tax losses and unused tax credits, Expiry terms 15 years 15 years 15 years  
Unused tax losses        
Statement [Line Items]        
Temporary difference unused tax losses and unused tax credits, maximum period 8 years      
Group Tax Losses        
Statement [Line Items]        
Unabsorbed depreciation ₨ 15,002 ₨ 17,538 ₨ 9,052  
Group Tax Losses | Top of range [member]        
Statement [Line Items]        
Temporary difference, unused tax losses and unused tax credits, Expiry terms 1 year 1 year 1 year  
Group Tax Losses | Bottom of range [member]        
Statement [Line Items]        
Temporary difference, unused tax losses and unused tax credits, Expiry terms 8 years 8 years 8 years