Fair Value Measurements and Investments - Schedule of Investment Income (Expense) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Sep. 30, 2025 |
Sep. 30, 2024 |
Sep. 30, 2023 |
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| Fair Value Disclosures [Abstract] | |||
| Interest and dividend income on cash and investments | $ 791 | $ 992 | $ 745 |
| Gains (losses) on investments, net | (51) | (44) | (82) |
| Investment income (expense) | $ 740 | $ 948 | $ 663 |
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- References No definition available.
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- Definition Amount of realized and unrealized gain (loss) on investment. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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