v3.25.2
CASH, CASH EQUIVALENTS AND INVESTMENTS - Available-for-Sale Securities (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2025
Jul. 31, 2024
Jul. 31, 2025
Jul. 31, 2024
Jan. 31, 2025
Cash and Cash Equivalents          
Interest receivable $ 2,500   $ 2,500   $ 2,100
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Current, Statement of Financial Position [Extensible Enumeration] Investments   Investments   Investments
Proceeds from sale of debt securities, available-for-sale $ 0 $ 0 $ 0 $ 0  
Amounts of gains or losses reclassified out of other comprehensive income 0 $ 0 0 $ 0  
Available-for-sale securities          
Amortized Cost 294,953   294,953   $ 227,156
Gross Unrealized Gains 2,228   2,228   631
Gross Unrealized Losses 517   517   1,042
Estimated Fair Value 296,664   296,664   226,745
US Treasury notes          
Available-for-sale securities          
Amortized Cost, Due within one year 60,809   60,809   50,676
Amortized Cost, Due in one to three years 69,085   69,085   84,881
Amortized Cost, Due in three to five years 165,059   165,059   91,599
Gross Unrealized Gains, Due within one year 33   33   126
Gross Unrealized Gains, Due in one to three years 661   661   381
Gross Unrealized Gains, Due in three to five years 1,534   1,534   124
Gross Unrealized Losses, Due within one year 38   38   7
Gross Unrealized Losses, Due in one to three years 10   10   105
Gross Unrealized Losses, Due in three to five years 469   469   930
Estimated Fair Value, Due within one year 60,804   60,804   50,795
Estimated Fair Value, Due in one to three years 69,736   69,736   85,157
Estimated Fair Value, Due in three to five years $ 166,124   $ 166,124   $ 90,793