Marketable Securities - Narrative (Details) |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
|
Oct. 31, 2024
USD ($)
security
|
Oct. 31, 2023
USD ($)
|
Oct. 31, 2024
USD ($)
security
|
Oct. 31, 2023
USD ($)
|
Jan. 31, 2024
USD ($)
security
|
|
| Investments, Debt and Equity Securities [Abstract] | |||||
| Investment income, interest | $ 5,600,000 | $ 7,800,000 | $ 20,900,000 | $ 21,700,000 | |
| Debt securities, available-for-sale, unrealized loss position, number of positions | security | 44 | 44 | 64 | ||
| Debt securities, available-for-sale, unrealized loss position, fair value | $ 159,800,000 | $ 159,800,000 | $ 178,700,000 | ||
| Debt securities, available-for-sale, allowance for credit loss | $ 0 | $ 0 | $ 0 | ||
| X | ||||||||||
- Definition Amount of allowance for credit loss 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
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| X | ||||||||||
- Definition 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 less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
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| X | ||||||||||
- Definition Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
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