FAIR VALUE MEASUREMENTS - Financial Instruments on a Recurring Basis (Details) - USD ($) $ in Thousands	Jul. 31, 2025	Jan. 31, 2025
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Available-for-sale securities	$ 296,664	$ 226,745
Level 1 Inputs \| Fair value, recurring
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Totals	89,807	93,067
Level 1 Inputs \| Fair value, recurring \| Money market fund
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Cash equivalents	89,807	93,067
Level 2 Inputs \| Fair value, recurring
Fair value of assets and liabilities measured on recurring and nonrecurring basis
Totals	296,664	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	$ 296,664	$ 226,745

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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+ Details