Marketable Securities - Narrative (Details) - USD ($) |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jul. 31, 2023 |
Jul. 31, 2022 |
Jul. 31, 2023 |
Jul. 31, 2022 |
Jan. 31, 2023 |
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| Investments, Debt and Equity Securities [Abstract] | |||||
| Investment income, interest | $ 7,900,000 | $ 1,200,000 | $ 13,900,000 | $ 1,600,000 | |
| Debt securities, available-for-sale, unrealized loss position, fair value | 422,800,000 | 422,800,000 | $ 220,900,000 | ||
| 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 Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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