v3.25.2
Share based payment - Schedule of Information about Fair Value of Inputs to Option Pricing Model Share Options Granted (Detail)
12 Months Ended
Mar. 31, 2025
₨ / shares
Mar. 31, 2025
$ / shares
Mar. 31, 2024
$ / shares
Share Based Payment Arrangements [Line Items]      
Dividend yield (%) 0.00% 0.00%  
Weighted average share price | ₨ / shares ₨ 606.96    
Holding Company Stock Option Plans      
Share Based Payment Arrangements [Line Items]      
Dividend yield (%) 0.00% 0.00%  
Weighted average share price   $ 8.17  
2021 Incentive Award Plan      
Share Based Payment Arrangements [Line Items]      
Dividend yield (%) 0.00% 0.00% 0.00%
Bottom of range [member]      
Share Based Payment Arrangements [Line Items]      
Expected volatility (%) 25.67% 25.67%  
Risk–free interest rate (%) 3.29% 3.29%  
Weighted average remaining contractual life of options granted during current period 25 days 25 days  
Bottom of range [member] | Holding Company Stock Option Plans      
Share Based Payment Arrangements [Line Items]      
Expected volatility (%) 33.43% 33.43%  
Risk–free interest rate (%) 0.05% 0.05%  
Weighted average remaining contractual life of options granted during current period 25 days 25 days  
Bottom of range [member] | 2021 Incentive Award Plan      
Share Based Payment Arrangements [Line Items]      
Expected volatility (%) 28.52% 28.52% 25.68%
Risk–free interest rate (%) 3.64% 3.64% 0.78%
Weighted average remaining contractual life of options granted during current period 8 years 8 years 8 years
Weighted average share price   $ 5.22 $ 4.98
Top of range [member]      
Share Based Payment Arrangements [Line Items]      
Expected volatility (%) 37.87% 37.87%  
Risk–free interest rate (%) 6.39% 6.39%  
Weighted average remaining contractual life of options granted during current period 6 years 10 months 9 days 6 years 10 months 9 days  
Top of range [member] | Holding Company Stock Option Plans      
Share Based Payment Arrangements [Line Items]      
Expected volatility (%) 49.97% 49.97%  
Risk–free interest rate (%) 1.03% 1.03%  
Weighted average remaining contractual life of options granted during current period 6 years 10 months 9 days 6 years 10 months 9 days  
Top of range [member] | 2021 Incentive Award Plan      
Share Based Payment Arrangements [Line Items]      
Expected volatility (%) 33.90% 33.90% 41.23%
Risk–free interest rate (%) 5.21% 5.21% 5.42%
Weighted average remaining contractual life of options granted during current period 10 years 10 years 10 years
Weighted average share price   $ 7.46 $ 9.65