Fair Value Measurements - Schedule of Investments (Details) - USD ($) $ in Thousands	Jan. 31, 2024	Jan. 31, 2023
Cash and cash equivalents:
Amortized Cost	$ 256,651	$ 137,941
Short-term investments:
Amortized Cost	671,897	487,200
Gross Unrealized Gains	30	49
Gross Unrealized Losses	(2,622)	(1,665)
Short-term investments	669,305	485,584
Long-term investments:
Amortized Cost	188,069	528,127
Gross Unrealized Gains	703	205
Gross Unrealized Losses	(115)	(5,410)
Estimated Fair Value	188,657	522,922
Total assets measured at fair value, Amortized Cost	1,116,617	1,153,268
Total assets measured at fair value, Gross Unrealized Gains	733	254
Total assets measured at fair value, Gross Unrealized Losses	(2,737)	(7,075)
Total assets measured at fair value, Estimated Fair Value	1,114,613	1,146,447
Cash
Cash and cash equivalents:
Amortized Cost	43,925	35,055
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	43,925	35,055
Total cash and cash equivalents
Cash and cash equivalents:
Amortized Cost	256,651	137,941
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	256,651	137,941
Level 1 | US Treasury securities
Short-term investments:
Amortized Cost	234,776	144,392
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(1,053)	(501)
Short-term investments	233,723	143,892
Long-term investments:
Amortized Cost	27,175	192,337
Gross Unrealized Gains	121	0
Gross Unrealized Losses	0	(2,460)
Estimated Fair Value	27,296	189,877
Level 1 | Money market funds
Cash and cash equivalents:
Amortized Cost	204,481	102,886
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	204,481	102,886
Level 2 | Commercial paper
Short-term investments:
Amortized Cost		230,305
Gross Unrealized Gains		30
Gross Unrealized Losses		(667)
Short-term investments		229,668
Level 2 | Corporate notes and bonds
Short-term investments:
Amortized Cost	279,248	38,443
Gross Unrealized Gains	12	15
Gross Unrealized Losses	(1,068)	(148)
Short-term investments	278,192	38,310
Long-term investments:
Amortized Cost	69,970	233,946
Gross Unrealized Gains	279	178
Gross Unrealized Losses	(67)	(2,029)
Estimated Fair Value	70,182	232,095
Level 2 | US agency securities
Short-term investments:
Amortized Cost	157,873	74,060
Gross Unrealized Gains	18	3
Gross Unrealized Losses	(501)	(349)
Short-term investments	157,390	73,714
Long-term investments:
Amortized Cost	90,924	101,844
Gross Unrealized Gains	303	27
Gross Unrealized Losses	(48)	(921)
Estimated Fair Value	91,179	$ 100,950
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