STOCK-BASED COMPENSATION - Restricted Stock Units (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
3 Months Ended
Apr. 30, 2022
Apr. 30, 2021
Summary of award activity    
Beginning balance (in shares) 2,454 2,950
Granted (in shares) 1,557 1,262
Released (in shares) (465) (827)
Forfeited (in shares) (47) (41)
Ending balance (in shares) 3,499 3,344
Weighted-Average Grant-Date Fair Value    
Beginning balance (in dollars per share) $ 42.99 $ 35.97
Granted (in dollars per share) 56.42 48.62
Released (in dollars per share) 42.20 35.33
Forfeited (in dollars per share) 43.13 35.61
Ending balance (in dollars per share) $ 49.07 $ 40.91
Restricted Stock Units (RSUs)    
Summary of award activity    
Granted (in shares) 1,279  
Additional disclosures    
Unrecognized compensation expense $ 129.0  
Remaining weighted-average vesting period over which expense is expected to be recognized (in years) 2 years