CASH AND CASH EQUIVALENTS, INVESTMENTS, AND FAIR VALUE MEASUREMENTS - Schedule of Fair Value, Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2026	Jan. 31, 2026
Cash and cash equivalents:
Amortized Cost	$ 153,228	$ 169,627
Short-term investments:
Amortized Cost	502,962	457,646
Gross Unrealized Gains	680	1,396
Gross Unrealized Losses	(83)	(1)
Estimated Fair Value	503,559	459,041
Long-term investments:
Amortized Cost		104,227
Gross Unrealized Gains		465
Gross Unrealized Losses		0
Estimated Fair Value		104,692
Total assets measured at fair value, Amortized Cost		731,500
Total assets measured at fair value, Gross Unrealized Gains		1,861
Total assets measured at fair value, Gross Unrealized Losses		(1)
Total assets measured at fair value, Estimated Fair Value	660,134	733,360
Unrealized losses	1,000
Level 1 | U.S. treasury securities
Short-term investments:
Amortized Cost	286,587	271,254
Gross Unrealized Gains	420	786
Gross Unrealized Losses	(6)	0
Estimated Fair Value	287,001	272,040
Long-term investments:
Amortized Cost		45,754
Gross Unrealized Gains		227
Gross Unrealized Losses		0
Estimated Fair Value	3,347	45,981
Level 2 | Commercial paper
Short-term investments:
Amortized Cost	29,077
Gross Unrealized Gains	0
Gross Unrealized Losses	(22)
Estimated Fair Value	29,055
Level 2 | Corporate notes and bonds
Short-term investments:
Amortized Cost	178,798	177,892
Gross Unrealized Gains	260	610
Gross Unrealized Losses	(52)	0
Estimated Fair Value	179,006	178,502
Long-term investments:
Amortized Cost		58,473
Gross Unrealized Gains		238
Gross Unrealized Losses		0
Estimated Fair Value		58,711
Level 2 | U.S. agency securities
Short-term investments:
Amortized Cost	8,500	8,500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(3)	(1)
Estimated Fair Value	8,497	8,499
Cash
Cash and cash equivalents:
Amortized Cost	93,301
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	93,301
Cash | Level 1
Cash and cash equivalents:
Amortized Cost		124,873
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		124,873
Money market funds | Level 1
Cash and cash equivalents:
Amortized Cost	59,927	44,754
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	59,927	44,754
Total cash and cash equivalents
Cash and cash equivalents:
Amortized Cost	153,228	169,627
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 153,228	$ 169,627