Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Apr. 30, 2024	Jan. 31, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	$ 773,197	$ 723,206
Gross Unrealized Gains	5	264
Gross Unrealized Losses	(1,763)	(771)
Estimated Fair Value	771,439	722,699
Cash	454,500	444,800
Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	435,306	424,689
Gross Unrealized Gains	5	264
Gross Unrealized Losses	(1,763)	(771)
Estimated Fair Value	433,548	424,182
Money market funds \| Level 1 \| Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	337,891	298,517
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	337,891	298,517
Commercial paper \| Level 2 \| Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	25,046	43,845
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6)	(9)
Estimated Fair Value	25,040	43,836
Commercial paper \| Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	64,466	42,958
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(129)	(25)
Estimated Fair Value	64,337	42,935
Corporate notes and bonds \| Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	304,672	299,166
Gross Unrealized Gains	4	262
Gross Unrealized Losses	(1,538)	(670)
Estimated Fair Value	303,138	298,758
U.S. governmental securities \| Level 2 \| Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost		9,968
Gross Unrealized Gains		0
Gross Unrealized Losses		(1)
Estimated Fair Value		9,967
U.S. governmental securities \| Level 2 \| Available-for-sale securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	41,122	28,752
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(90)	(66)
Estimated Fair Value	$ 41,033	$ 28,686

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.

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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).

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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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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