Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Apr. 30, 2025	Jan. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	$ 721,283	$ 632,786
Gross Unrealized Gains	618	535
Gross Unrealized Losses	(235)	(407)
Estimated Fair Value	721,666	632,914
Cash	387,200	464,700
Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	456,234	448,901
Gross Unrealized Gains	618	535
Gross Unrealized Losses	(235)	(407)
Estimated Fair Value	456,617	449,029
Money market funds \| Level 1 \| Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	265,049	183,885
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	265,049	183,885
Commercial paper \| Level 2 \| Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	5,186
Gross Unrealized Gains	0
Gross Unrealized Losses	(1)
Estimated Fair Value	5,185
Commercial paper \| Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	17,124	31,367
Gross Unrealized Gains	3	12
Gross Unrealized Losses	(9)	(8)
Estimated Fair Value	17,118	31,371
Corporate notes and bonds \| Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	406,674	399,034
Gross Unrealized Gains	615	522
Gross Unrealized Losses	(210)	(378)
Estimated Fair Value	407,079	399,178
U.S. governmental securities \| Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	27,250	18,500
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(15)	(21)
Estimated Fair Value	$ 27,235	$ 18,480

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

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Amortized cost excluding accrued interest, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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