Investments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2024	Jul. 31, 2023	Jan. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Unrealized losses for securities in unrealized loss position for less than 12 months	$ 2.9		$ 2.9		$ 6.0
Unrealized losses for securities in unrealized loss position for 12 months or longer	3.4		3.4		$ 4.8
Available-for-sale, realized gains or losses	$ 0.0	$ 0.0	$ 0.0	$ 0.0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479081/326-30-55-8

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-7

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-5

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