v3.26.1
Share-based payments (Details 1) - Category B Par Value Options [Member] - Exercise Prices Rs 5 [Member]
 12 Months Ended
Mar. 31, 2026
INR (₨)
Number
mo
₨ / shares
Mar. 31, 2026
INR (₨)
Number
mo
₨ / shares
Mar. 31, 2026
INR (₨)
Number
mo
₨ / shares
$ / shares
Mar. 31, 2026
INR (₨)
Number
mo
₨ / shares
Mar. 31, 2026
INR (₨)
Number
a
mo
₨ / shares
Mar. 31, 2026
INR (₨)
Number
mo
₨ / shares
Mar. 31, 2025
INR (₨)
Number
a
mo
₨ / shares
Mar. 31, 2025
INR (₨)
Number
a
mo
₨ / shares
Mar. 31, 2025
INR (₨)
Number
a
mo
₨ / shares
$ / shares
Mar. 31, 2025
INR (₨)
Number
a
mo
₨ / shares
Mar. 31, 2025
INR (₨)
Number
a
mo
₨ / shares
Mar. 31, 2025
INR (₨)
Number
a
mo
₨ / shares
DRL 2002 Plan [Member]                        
Stock options activity under this category [Line Items]                        
Shares arising out of options, Outstanding at the beginning of the year | Number       313,790           501,045    
Shares arising out of options, Expired/forfeited during the year | Number       (3,910)           (21,435)    
Shares arising out of options, Exercised during the year | Number       (128,895)           (165,820)    
Shares arising out of options, Outstanding at the end of the year | Number       180,985           313,790    
Shares arising out of options, Exercisable at the end of the year | Number 167,660 167,660 167,660 167,660 167,660 167,660 245,745 245,745 245,745 245,745 245,745 245,745
Ranges of exercise prices, Outstanding at the beginning of the year ₨ 1           ₨ 1          
Ranges of exercise prices, Expired/forfeited during the year 1           1          
Ranges of exercise prices, Exercised during the year 1           1          
Ranges of exercise prices, Outstanding at the end of the year 1           1          
Ranges of exercise prices, Exercisable at the end of the year ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1
Weighted average exercise price, Outstanding at the beginning of the year | ₨ / shares   ₨ 1           ₨ 1        
Weighted average exercise price, Expired/forfeited during the year | ₨ / shares   1           1        
Weighted average exercise price, Exercised during the year | ₨ / shares   1           1        
Weighted average exercise price, Outstanding at the end of the year | ₨ / shares   1           1        
Weighted average exercise price, Exercisable at the end of the year | ₨ / shares ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1
Weighted average remaining useful life, Outstanding at the beginning of the year | mo           44           55
Weighted average remaining useful life, Outstanding at the end of the year | mo           32           44
Weighted average remaining useful life, Exercisable at the end of the year | mo 29 29 29 29 29 29 38 38 38 38 38 38
DRL 2007 Plan [Member]                        
Stock options activity under this category [Line Items]                        
Shares arising out of options, Outstanding at the beginning of the year       124,940 124,940         302,575    
Shares arising out of options, Expired/forfeited during the year | Number       (9,725)           (83,885)    
Shares arising out of options, Exercised during the year | Number       (26,305)           (93,750)    
Shares arising out of options, Outstanding at the end of the year       88,910           124,940 124,940  
Shares arising out of options, Exercisable at the end of the year 88,910 88,910 88,910 88,910 88,910 88,910 71,130 71,130 71,130 71,130 71,130 71,130
Ranges of exercise prices, Outstanding at the beginning of the year ₨ 1           ₨ 1          
Ranges of exercise prices, Expired/forfeited during the year 1           1          
Ranges of exercise prices, Exercised during the year 1           1          
Ranges of exercise prices, Outstanding at the end of the year 1           1          
Ranges of exercise prices, Exercisable at the end of the year ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1
Weighted average exercise price, Outstanding at the beginning of the year | (per share)   ₨ 1 ₨ 1         ₨ 1        
Weighted average exercise price, Expired/forfeited during the year | ₨ / shares   1           1        
Weighted average exercise price, Exercised during the year | ₨ / shares   1           1        
Weighted average exercise price, Outstanding at the end of the year | (per share)   1           1 ₨ 1      
Weighted average exercise price, Exercisable at the end of the year | ₨ / shares ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1 ₨ 1
Weighted average remaining useful life, Outstanding at the beginning of the year | mo           43           61
Weighted average remaining useful life, Outstanding at the end of the year | mo           34           43
Weighted average remaining useful life, Exercisable at the end of the year | mo 34 34 34 34 34 34 29 29 29 29 29 29