v3.23.1
Equity-based compensation - Stock option activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Jan. 31, 2023
Jan. 31, 2022
Jan. 31, 2021
Number of options      
Number of options outstanding at beginning of period (in shares) 1,705,150 3,211,354 5,516,452
Granted (in shares) 0 0 0
Exercised (in shares) (311,743) (1,439,186) (2,216,368)
Forfeited and expired (in shares) (8,214) (67,018) (88,730)
Number of options outstanding at end of period (in shares) 1,385,193 1,705,150 3,211,354
Exercisable (in shares) 1,362,903    
Amount vested at the end of the period (in shares) 258,735    
Weighted- average exercise price      
Weighted- average exercise price outstanding at beginning of period (in dollars per share) $ 6.01 $ 4.67 $ 3.80
Granted (in dollars per share) 0 0 0
Exercised (in dollars per share) 4.92 2.88 2.39
Forfeited and expired (in dollars per share) 4.68 9.02 7.45
Weighted- average exercise price outstanding at end of period (in dollars per share) 6.26 $ 6.01 $ 4.67
Exercisable (in dollars per share) 6.12    
Amount vested at the end of the period (in dollars per share) $ 8.27    
Weighted-average remaining contractual life of options outstanding and expected to vest (in years) 5 years 21 days 5 years 11 months 8 days 5 years 11 months 26 days
Weighted-average remaining contractual life of options exercisable (in years) 5 years 10 days    
Aggregate intrinsic value outstanding and expected to vest $ 43,341 $ 42,938 $ 194,676
Aggregate intrinsic value exercisable $ 42,750