CASH, CASH EQUIVALENTS AND INVESTMENTS - Available-for-Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2024	Oct. 31, 2023	Oct. 31, 2024	Oct. 31, 2023	Jan. 31, 2024
Cash and Cash Equivalents
Interest receivable	$ 1,300		$ 1,300		$ 1,300
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	206,394		206,394		$ 105,623
Gross Unrealized Gains	1,074		1,074		568
Gross Unrealized Losses	1,025		1,025		307
Fair Value	206,443		206,443		105,884
US Treasury notes
Available-for-sale securities
Amortized cost, Due within one year	50,323		50,323
Amortized cost, Due in one to three years	72,751		72,751		96,217
Amortized Cost, Due in three to five years	73,274		73,274
Gross Unrealized Gains, Due within one year	161		161
Gross Unrealized Gains, Due in one to three years	488		488		568
Gross Unrealized Gains, Due in three to five years	425		425
Gross Unrealized Losses, Due within one year	32		32
Gross Unrealized Losses, Due in one to three years	96		96		230
Gross Unrealized Losses, Due in three to five years	784		784
Fair Value, Due in within one year	50,452		50,452
Fair Value, Due in one to three years	73,143		73,143		96,555
Fair Value, Due in three to five years	72,915		72,915
U.S. corporate debt security
Available-for-sale securities
Amortized cost, Due in one to three years	10,046		10,046		9,406
Gross Unrealized Losses, Due in one to three years	113		113		77
Fair Value, Due in one to three years	$ 9,933		$ 9,933		$ 9,329