Financial Instruments - Narrative (Details) - USD ($) |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jul. 31, 2026 |
Jul. 31, 2025 |
Jul. 31, 2026 |
Jul. 31, 2025 |
Jan. 31, 2026 |
|
| Investments, All Other Investments [Abstract] | |||||
| Securities in continuous unrealized loss position for greater than twelve months | $ 0 | $ 0 | $ 0 | ||
| Allowance for credit loss | 0 | 0 | 0 | ||
| Write offs of accrued interest receivables | 0 | $ 0 | |||
| Available-for-sale securities gross gains (losses) | 0 | $ 0 | 0 | $ 0 | |
| Direct investments in privately held companies | $ 392,000,000 | $ 392,000,000 | $ 346,000,000 | ||
| 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 writeoff 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 accumulated unrealized loss on 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 12 months or longer, 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 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). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount of investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- References No definition available.
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