CASH AND CASH EQUIVALENTS, INVESTMENTS, AND FAIR VALUE MEASUREMENTS - Schedule of Fair Value, Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Apr. 30, 2025	Jan. 31, 2025
Cash and cash equivalents:
Amortized Cost	$ 188,624	$ 186,574
Short-term investments:
Amortized Cost	576,893	534,391
Gross Unrealized Gains	1,434	1,022
Gross Unrealized Losses	(33)	(82)
Estimated Fair Value	578,294	535,331
Long-term investments:
Amortized Cost	410,464	395,444
Gross Unrealized Gains	2,327	1,360
Gross Unrealized Losses	(129)	(597)
Estimated Fair Value	412,662	396,207
Total assets measured at fair value, Amortized Cost	1,175,981	1,116,408
Total assets measured at fair value, Gross Unrealized Gains	3,761	2,385
Total assets measured at fair value, Gross Unrealized Losses	(162)	(681)
Total assets measured at fair value, Estimated Fair Value	1,179,580	1,118,112
Cash
Cash and cash equivalents:
Amortized Cost	114,678
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	114,678
Total cash and cash equivalents
Cash and cash equivalents:
Amortized Cost	188,624	186,573
Gross Unrealized Gains	0	3
Gross Unrealized Losses	0	(2)
Estimated Fair Value	188,624	186,574
Level 1 | U.S. treasury securities
Short-term investments:
Amortized Cost	239,096	208,918
Gross Unrealized Gains	702	284
Gross Unrealized Losses	(27)	(74)
Estimated Fair Value	239,771	209,128
Long-term investments:
Amortized Cost	211,592	208,104
Gross Unrealized Gains	1,358	787
Gross Unrealized Losses	0	(203)
Estimated Fair Value	212,950	208,688
Level 1 | Cash
Cash and cash equivalents:
Amortized Cost		94,728
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		94,728
Level 1 | Money market funds
Cash and cash equivalents:
Amortized Cost	73,946	61,962
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	73,946	61,962
Level 2 | Commercial paper
Short-term investments:
Amortized Cost	14,865	24,606
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(1)	(2)
Estimated Fair Value	14,864	24,605
Level 2 | Corporate notes and bonds
Short-term investments:
Amortized Cost	273,260	238,610
Gross Unrealized Gains	663	586
Gross Unrealized Losses	(5)	(6)
Estimated Fair Value	273,918	239,190
Long-term investments:
Amortized Cost	190,372	173,882
Gross Unrealized Gains	969	573
Gross Unrealized Losses	(119)	(331)
Estimated Fair Value	191,222	174,124
Level 2 | U.S. agency securities
Short-term investments:
Amortized Cost	49,672	62,257
Gross Unrealized Gains	69	151
Gross Unrealized Losses	0	0
Estimated Fair Value	49,741	62,408
Long-term investments:
Amortized Cost	8,500	13,458
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(10)	(63)
Estimated Fair Value	$ 8,490	13,395
Level 2 | U.S. treasury securities
Cash and cash equivalents:
Amortized Cost		9,969
Gross Unrealized Gains		3
Gross Unrealized Losses		0
Estimated Fair Value		9,972
Level 2 | Commercial paper
Cash and cash equivalents:
Amortized Cost		19,914
Gross Unrealized Gains		0
Gross Unrealized Losses		(2)
Estimated Fair Value		$ 19,912