FAIR VALUE MEASUREMENTS - Financial Instruments on a Recurring Basis (Details) - USD ($) $ in Thousands	Apr. 30, 2025	Jan. 31, 2025
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Available-for-sale securities	$ 242,158	$ 226,745
Level 1 Inputs | Fair value, recurring
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Totals	78,977	93,067
Level 1 Inputs | Fair value, recurring | Money market funds
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents	78,977	93,067
Level 2 Inputs | Fair value, recurring
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Totals	242,158	226,745
Level 2 Inputs | Fair value, recurring | U.S. Treasury notes
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Available-for-sale securities	$ 242,158	$ 226,745