Fair Value Measurements - Schedule of Investments (Details) - USD ($) $ in Thousands	Jan. 31, 2025	Jan. 31, 2024
Cash and cash equivalents:
Amortized Cost	$ 186,574	$ 256,651
Short-term investments:
Amortized Cost	534,391	671,897
Gross Unrealized Gains	1,022	30
Gross Unrealized Losses	(82)	(2,622)
Short-term investments	535,331	669,305
Long-term investments:
Amortized Cost	395,444	188,069
Gross Unrealized Gains	1,360	703
Gross Unrealized Losses	(597)	(115)
Estimated Fair Value	396,207	188,657
Total assets measured at fair value, Amortized Cost	1,116,408	1,116,617
Total assets measured at fair value, Gross Unrealized Gains	2,385	733
Total assets measured at fair value, Gross Unrealized Losses	(681)	(2,737)
Total assets measured at fair value, Estimated Fair Value	1,118,112	1,114,613
Cash
Cash and cash equivalents:
Amortized Cost	94,728	43,925
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	94,728	43,925
Total cash and cash equivalents
Cash and cash equivalents:
Amortized Cost	186,573	256,651
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(2)	0
Estimated Fair Value	186,574	256,651
Level 1 | U.S. Treasury securities
Short-term investments:
Amortized Cost	208,918	234,776
Gross Unrealized Gains	284	0
Gross Unrealized Losses	(74)	(1,053)
Short-term investments	209,128	233,723
Long-term investments:
Amortized Cost	208,104	27,175
Gross Unrealized Gains	787	121
Gross Unrealized Losses	(203)	0
Estimated Fair Value	208,688	27,296
Level 1 | Commercial paper
Short-term investments:
Amortized Cost	24,606
Gross Unrealized Gains	1
Gross Unrealized Losses	(2)
Short-term investments	24,605
Level 1 | Money market funds
Cash and cash equivalents:
Amortized Cost	61,962	204,481
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	61,962	204,481
Level 1 | 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 1 | Commercial paper
Cash and cash equivalents:
Amortized Cost	19,914
Gross Unrealized Gains	0
Gross Unrealized Losses	(2)
Estimated Fair Value	19,912
Level 1 | Corporate notes and bonds
Short-term investments:
Amortized Cost	238,610	279,248
Gross Unrealized Gains	586	12
Gross Unrealized Losses	(6)	(1,068)
Short-term investments	239,190	278,192
Long-term investments:
Amortized Cost	173,882	69,970
Gross Unrealized Gains	573	279
Gross Unrealized Losses	(331)	(67)
Estimated Fair Value	174,124	70,182
Level 1 | U.S. agency securities
Short-term investments:
Amortized Cost	62,257	157,873
Gross Unrealized Gains	151	18
Gross Unrealized Losses	0	(501)
Short-term investments	62,408	157,390
Long-term investments:
Amortized Cost	13,458	90,924
Gross Unrealized Gains	0	303
Gross Unrealized Losses	(63)	(48)
Estimated Fair Value	$ 13,395	91,179
Level 1 | Certificates of deposit
Cash and cash equivalents:
Amortized Cost		8,245
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		$ 8,245