CASH AND CASH EQUIVALENTS, INVESTMENTS, AND FAIR VALUE MEASUREMENTS - Schedule of Fair Value, Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Oct. 31, 2024	Jan. 31, 2024
Cash and cash equivalents:
Amortized Cost	$ 235,742	$ 256,651
Short-term investments:
Amortized Cost	423,794	671,897
Gross Unrealized Gains	783	30
Gross Unrealized Losses	(60)	(2,622)
Estimated Fair Value	424,517	669,305
Long-term investments:
Amortized Cost	438,971	188,069
Gross Unrealized Gains	2,156	703
Gross Unrealized Losses	(746)	(115)
Estimated Fair Value	440,381	188,657
Total assets measured at fair value, Amortized Cost	1,098,507	1,116,617
Total assets measured at fair value, Gross Unrealized Gains	2,939	733
Total assets measured at fair value, Gross Unrealized Losses	(806)	(2,737)
Total assets measured at fair value, Estimated Fair Value	1,100,640	1,114,613
Cash
Cash and cash equivalents:
Amortized Cost	86,320
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	86,320
Total cash and cash equivalents
Cash and cash equivalents:
Amortized Cost	235,742	256,651
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	235,742	256,651
Level 1 | U.S. Treasury securities
Short-term investments:
Amortized Cost	102,526	234,776
Gross Unrealized Gains	146	0
Gross Unrealized Losses	(1)	(1,053)
Estimated Fair Value	102,671	233,723
Long-term investments:
Amortized Cost	208,798	27,175
Gross Unrealized Gains	1,107	121
Gross Unrealized Losses	(291)	0
Estimated Fair Value	209,614	27,296
Level 1 | Cash
Cash and cash equivalents:
Amortized Cost		43,925
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		43,925
Level 1 | Money market funds
Cash and cash equivalents:
Amortized Cost	149,422	204,481
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	149,422	204,481
Level 2 | Corporate notes and bonds
Short-term investments:
Amortized Cost	207,437	279,248
Gross Unrealized Gains	441	12
Gross Unrealized Losses	(46)	(1,068)
Estimated Fair Value	207,832	278,192
Long-term investments:
Amortized Cost	216,716	69,970
Gross Unrealized Gains	1,045	279
Gross Unrealized Losses	(373)	(67)
Estimated Fair Value	217,388	70,182
Level 2 | U.S. agency securities
Short-term investments:
Amortized Cost	113,831	157,873
Gross Unrealized Gains	196	18
Gross Unrealized Losses	(13)	(501)
Estimated Fair Value	114,014	157,390
Long-term investments:
Amortized Cost	13,457	90,924
Gross Unrealized Gains	4	303
Gross Unrealized Losses	(82)	(48)
Estimated Fair Value	$ 13,379	91,179
Level 2 | Certificates of deposit
Cash and cash equivalents:
Amortized Cost		8,245
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		$ 8,245