XML 148 R128.htm IDEA: XBRL DOCUMENT v3.21.2
Fair value measurements - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Detail) - $ / shares
12 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Risk-free rate 0.94% 0.87%
Expected volatility 44.41% 43.49%
Expected expiry years (in years) 10 years 10 years
Derivative Financial Instruments, Liabilities [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Risk-free rate   0.19%
Risk-free rate , Minimum 0.00%  
Risk-free rate , Maximum 0.90%  
Expected volatility   55.14%
Expected volatility , Minimum 41.05%  
Expected volatility , Maximum 52.33%  
Expected expiry years (in years)   6 months
Maximum [Member] | Derivative Financial Instruments, Liabilities [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Share Price $ 7.19 $ 10.74
Expected expiry years (in years) 4 years 6 months 21 days  
Minimum [Member] | Derivative Financial Instruments, Liabilities [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Share Price $ 5.57 $ 8.24
Expected expiry years (in years) 6 months