v3.26.1
Share-Based Compensation (Fair Value Assumptions) (Details) - SARs [Member] - Hindalco SARs [Member]
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Assumptions used in estimating fair value of SARs      
Dividend yield 0.58% 0.50% 0.54%
Minimum      
Assumptions used in estimating fair value of SARs      
Risk-free interest rate 6.23% 6.61% 6.95%
Volatility 28.00% 29.00% 26.00%
Maximum      
Assumptions used in estimating fair value of SARs      
Risk-free interest rate 6.82% 6.71% 7.15%
Volatility 39.00% 40.00% 43.00%