Investments - Narrative (Details) - USD ($) $ in Millions |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jul. 31, 2026 |
Jul. 31, 2025 |
Jan. 31, 2026 |
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| Investments, Debt and Equity Securities [Abstract] | |||
| Interest receivable | $ 24 | $ 33 | |
| Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] | Prepaid expenses and other current assets | Prepaid expenses and other current assets | |
| Credit losses on debt securities | $ 0 | $ 0 | |
| Debt securities sold | 824 | $ 265 | |
| Realized gains and losses on debt securities | $ 0 | $ 0 | |
| X | ||||||||||
- Definition Amount, after allowance for credit loss, of accrued interest 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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- Definition Indicates line item in statement of financial position that includes accrued interest, after 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 realized 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 realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in net income (trading). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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- Definition Amount of cash inflow from sale of 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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