v3.26.1
Share-based compensation - Reconciliation of RSU and DSU Options Outstanding (Details)
 12 Months Ended
Mar. 31, 2026
shares
$ / shares
Mar. 31, 2025
shares
$ / shares
Disclosure of range of exercise prices of outstanding share options [line items]    
Outstanding - Beginning of year (in shares) 10,322,548 11,083,212
Granted (in shares) 3,453,170 2,637,460
Forfeited (in shares) (3,409,694) (3,086,817)
Outstanding - End of fiscal year (in shares) 10,204,326 10,322,548
Weighted average exercise price, options outstanding, beginning of year (in USD per share) | $ / shares $ 22.12 $ 24.73
Weighted average exercise price, options granted (in USD per share) | $ / shares 10.70 14.03
Weighted average exercise price, options forfeited (in USD per share) | $ / shares 28.62 25.78
Weighted average exercise price, options outstanding, end of year (in USD per share) | $ / shares $ 16.85 $ 22.12
RSU    
Disclosure of range of exercise prices of outstanding share options [line items]    
Outstanding - Beginning of year (in shares) 6,760,182 6,200,768
Granted (in shares) 5,304,962 4,124,890
Settled (in shares) (2,742,874) (2,318,732)
Forfeited (in shares) (1,170,705) (1,246,744)
Outstanding - End of fiscal year (in shares) 8,151,565 6,760,182
Weighted average exercise price, options outstanding, beginning of year (in USD per share) | $ / shares $ 15.56 $ 22.02
Weighted average exercise price, options granted (in USD per share) | $ / shares 10.91 13.85
Weighted average exercise price, options released (in USD per share) | $ / shares 17.32 29.20
Weighted average exercise price, options forfeited (in USD per share) | $ / shares 13.08 16.67
Weighted average exercise price, options outstanding, end of year (in USD per share) | $ / shares $ 12.30 $ 15.56
DSU    
Disclosure of range of exercise prices of outstanding share options [line items]    
Outstanding - Beginning of year (in shares) 160,824 119,541
Granted (in shares) 146,660 41,283
Settled (in shares) (79,718) 0
Forfeited (in shares) 0 0
Outstanding - End of fiscal year (in shares) 227,766 160,824
Weighted average exercise price, options outstanding, beginning of year (in USD per share) | $ / shares $ 18.68 $ 19.99
Weighted average exercise price, options granted (in USD per share) | $ / shares 11.08 14.90
Weighted average exercise price, options released (in USD per share) | $ / shares 18.51 0
Weighted average exercise price, options forfeited (in USD per share) | $ / shares 0 0
Weighted average exercise price, options outstanding, end of year (in USD per share) | $ / shares $ 13.84 $ 18.68
Non-treasury RSU    
Disclosure of range of exercise prices of outstanding share options [line items]    
Outstanding - End of fiscal year (in shares) 2,023,195