v3.26.1
Share-based payments (Details 4) - DRL 2018 Plan [Member]
 12 Months Ended
Mar. 31, 2026
a
₨ / shares
Mar. 31, 2026
a
₨ / shares
$ / shares
Mar. 31, 2026
Number
a
₨ / shares
Mar. 31, 2026
a
₨ / shares
Mar. 31, 2026
a
mo
₨ / shares
Mar. 31, 2025
a
mo
₨ / shares
Mar. 31, 2025
a
mo
₨ / shares
$ / shares
Mar. 31, 2025
Number
a
mo
₨ / shares
Mar. 31, 2025
a
mo
₨ / shares
Mar. 31, 2025
a
mo
₨ / shares
Mar. 31, 2026
a
$ / shares
Mar. 31, 2025
a
mo
$ / shares
Statements [Line Items]                        
Shares arising out of options, Outstanding at the beginning of the year     2,399,070 2,399,070       2,087,265        
Shares arising out of options, Granted during the year | Number     915,763         706,670        
Shares arising out of options, Expired/forfeited during the year | Number     (371,675)         (229,680)        
Shares arising out of options, Exercised during the year | Number     (486,685)         (165,185)        
Shares arising out of options, Outstanding at the end of the year       2,456,473       2,399,070 2,399,070      
Shares arising out of options, Exercisable at the end of the year | a 536,635 536,635 536,635 536,635 536,635 366,420 366,420 366,420 366,420 366,420 536,635 366,420
Weighted average exercise price, Outstanding at the beginning of the year | (per share) ₨ 959.34           $ 832.8          
Weighted average exercise price, Granted during the year | ₨ / shares 1,162         ₨ 1,270            
Weighted average exercise price, Expired/forfeited during the year | ₨ / shares 1,093.04         956.89            
Weighted average exercise price, Exercised during the year | ₨ / shares 750.23         692.69            
Weighted average exercise price, Outstanding at the end of the year | ₨ / shares 1,056.09         959.34            
Weighted average exercise price, Exercisable at the end of the year | ₨ / shares ₨ 757.05 ₨ 757.05 ₨ 757.05 ₨ 757.05 ₨ 757.05 ₨ 671.61 $ 671.61 ₨ 671.61 ₨ 671.61 ₨ 671.61    
Weighted average remaining useful life, Outstanding at the beginning of the year | mo         67         70    
Weighted average remaining useful life, Granted during the year | mo         96         96    
Weighted average remaining useful life, Outstanding at the end of the year       67           67    
Weighted average remaining useful life, Exercisable at the end of the year 38 38 38 38 38 31 31 31 31 31 38 31
Bottom of range [member]                        
Statements [Line Items]                        
Range of exercise prices, Outstanding at the beginning of the year   ₨ 521.4         $ 521.4          
Range of exercise prices, Granted during the year             1,270          
Range of exercise prices, Expired/forfeited during the year   521.4         521.4          
Range of exercise prices, Exercised during the year   521.4         521.4          
Range of exercise prices, Outstanding at the end of the year   521.4         521.4          
Range of exercise prices, Exercisable at the end of the year                     $ 521.4 $ 521.4
Top of range [member]                        
Statements [Line Items]                        
Range of exercise prices, Outstanding at the beginning of the year   1,274         1,102.8          
Range of exercise prices, Granted during the year             1,274          
Range of exercise prices, Expired/forfeited during the year   1,270         1,270          
Range of exercise prices, Exercised during the year   1,060.2         1,060.2          
Range of exercise prices, Outstanding at the end of the year   1,274         $ 1,274          
Range of exercise prices, Exercisable at the end of the year                     $ 1,274 $ 1,102.8
Middle Range One [Member]                        
Statements [Line Items]                        
Range of exercise prices, Granted during the year   ₨ 1,162