v3.25.1
Share-Based Compensation (SARs Activity) (Details) - Hindalco SARs [Member]
$ / shares in Units, $ in Millions
12 Months Ended
Mar. 31, 2025
USD ($)
$ / shares
shares
Mar. 31, 2025
USD ($)
₨ / shares
shares
Mar. 31, 2024
USD ($)
shares
Mar. 31, 2024
₨ / shares
Mar. 31, 2023
USD ($)
shares
Mar. 31, 2023
₨ / shares
Mar. 31, 2025
₨ / shares
Aggregate Intrinsic Value              
Total share-based liabilities paid | $ $ 12   $ 5   $ 8    
SARs [Member]              
Number of SARs              
Outstanding, beginning of period (shares) | shares 6,778,329            
Granted (shares) | shares 1,451,753   2,620,019   2,393,378    
Exercised (shares) | shares (3,152,929)            
Forfeited/Cancelled (shares) | shares (162,551)            
Outstanding, end of period (shares) | shares 4,914,602   6,778,329        
Number of Shares, Exercisable | shares 1,103,304 1,103,304          
Weighted Average Exercise Price              
Outstanding, beginning of period (Indian Rupees/USD per share) | ₨ / shares   ₨ 405.50          
Granted (Indian Rupees/USD per share) | ₨ / shares   684.10   ₨ 417.90   ₨ 411.10  
Exercised (Indian Rupees/USD per share) | ₨ / shares   400.11          
Forfeited/Cancelled (Indian Rupees/USD per share) | ₨ / shares   441.18          
Outstanding, end of period (Indian Rupees/USD per share) | ₨ / shares   ₨ 490.07   ₨ 405.50      
Weighted Average Exercise Price (Indian Rupees/USD per share), Exercisable | ₨ / shares             ₨ 397.67
Weighted Average Remaining Contractual Term              
Weighted Average Remaining Contractual Term, Outstanding 5 years 2 months 12 days   5 years 3 months 18 days        
Weighted Average Remaining Contractual Term, Granted 6 years 3 months 18 days            
Weighted Average Remaining Contractual Term, Outstanding 5 years 2 months 12 days   5 years 3 months 18 days        
Weighted Average Remaining Contractual Term, Exercisable 4 years 1 month 6 days            
Aggregate Intrinsic Value              
Aggregate Intrinsic Value, Outstanding | $ $ 13            
Aggregate Intrinsic Value, Granted | $ 0            
Aggregate Intrinsic Value, Exercised | $ $ 12   $ 5   $ 8    
Aggregate Intrinsic Value, Forfeited/Cancelled | $ / shares $ 0            
Aggregate Intrinsic Value, Outstanding | $ $ 12   $ 13        
Aggregate Intrinsic Value, Exercisable | $ $ 4 ₨ 4          
SARs [Member] | Minimum              
Aggregate Intrinsic Value              
Risk-free interest rate 6.61%   6.95%   3.11%    
Volatility 29.00%   26.00%   32.00%