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v3.25.3

Debt and Other Obligations Debt and Other Obligations - Debt Securities Activity (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2023 | Oct. 02, 2024 | Sep. 30, 2013
Debt Instrument |  |  |  |  |
Face Amount | $ 40 |  |  |  | $ 360
Discount on debt issues | (33) | $ (9) |  |  |
Redemptions/Maturities of variable interest entities | 41 | 35 | $ 39 |  |
Redemptions/Maturities of power bonds | 1,022 | 1,022 | $ 29 |  |
Total Current maturities of power bonds issued at par | 1,370 | 1,022 |  |  |
Short-term debt, net of discounts | 0 | 1,167 |  |  |
Current maturities of long-term debt of variable interest entities issued at par | 49 | 37 |  |  |
Variable Interest Entity, Primary Beneficiary [Member] |  |  |  |  |
Debt Instrument |  |  |  |  |
Debt and Lease Obligation |  | 0 |  | $ 800 |
880591EF5 (12.15.20) |  |  |  |  |
Debt Instrument |  |  |  |  |
Total Current maturities of power bonds issued at par | $ 20 | 1 |  |  |
Interest rate | 3.77% |  |  |  |
Debt Instrument, Maturity Date | Dec. 15, 2025 |  |  |  |
880591EF5 (6.15.21) |  |  |  |  |
Debt Instrument |  |  |  |  |
Total Current maturities of power bonds issued at par | $ 0 | 21 |  |  |
Interest rate | 3.77% |  |  |  |
Debt Instrument, Maturity Date | Jun. 15, 2026 |  |  |  |
880591EW8 [Member] |  |  |  |  |
Debt Instrument |  |  |  |  |
Total Current maturities of power bonds issued at par | $ 0 | 1,000 |  |  |
Interest rate | 0.75% |  |  |  |
Debt Instrument, Maturity Date | May 15, 2025 |  |  |  |
880591CJ9 |  |  |  |  |
Debt Instrument |  |  |  |  |
Total Current maturities of power bonds issued at par | $ 1,350 | $ 0 |  |  |
Interest rate | 6.75% |  |  |  |
Debt Instrument, Maturity Date | Nov. 01, 2025 |  |  |  |
Total |  |  |  |  |
Debt Instrument |  |  |  |  |
Debt Instrument, Redemption Period, End Date | 1,063 | 1,057 |  |  |
Percent of par value | 100.00% |  |  |  |
Debt of variable interest entities |  |  |  |  |
Debt Instrument |  |  |  |  |
Redemptions/Maturities of variable interest entities | $ 41 | $ 35 |  |  |
2009 Series B |  |  |  |  |
Debt Instrument |  |  |  |  |
Redemptions/Maturities of power bonds | 22 | 22 |  |  |
2012 Series A |  |  |  |  |
Debt Instrument |  |  |  |  |
Redemptions/Maturities of power bonds | 0 | 1,000 |  |  |
2020 Series A |  |  |  |  |
Debt Instrument |  |  |  |  |
Redemptions/Maturities of power bonds | 1,000 | 0 |  |  |
Total |  |  |  |  |
Debt Instrument |  |  |  |  |
Debt Securities Issues | $ 4,767 | 991 |  |  |
880591EY4 |  |  |  |  |
Debt Instrument |  |  |  |  |
Interest rate | 4.25% |  |  |  |
Debt Instrument, Maturity Date | Sep. 15, 2052 |  |  |  |
880591EX6 |  |  |  |  |
Debt Instrument |  |  |  |  |
Interest rate | 1.50% |  |  |  |
Debt Instrument, Maturity Date | Sep. 15, 2031 |  |  |  |
880591EZ1 |  |  |  |  |
Debt Instrument |  |  |  |  |
Interest rate | 3.875% |  |  |  |
Debt Instrument, Maturity Date | Mar. 15, 2028 |  |  |  |
880591FB3 |  |  |  |  |
Debt Instrument |  |  |  |  |
Percent of par value | 99.109% |  |  |  |
Interest rate | 4.375% |  |  |  |
Debt Instrument, Maturity Date | Aug. 01, 2034 |  |  |  |
Debt Instrument, Issued, Principal | $ 0 | 1,000 |  |  |
880591FC1 |  |  |  |  |
Debt Instrument |  |  |  |  |
Percent of par value | 98.517% |  |  |  |
Interest rate | 5.25% |  |  |  |
Debt Instrument, Maturity Date | Feb. 01, 2055 |  |  |  |
Debt Instrument, Issued, Principal | $ 1,250 | 0 |  |  |
880591FD9 |  |  |  |  |
Debt Instrument |  |  |  |  |
Percent of par value | 99.36% |  |  |  |
Interest rate | 4.875% |  |  |  |
Debt Instrument, Maturity Date | May 15, 2035 |  |  |  |
Debt Instrument, Issued, Principal | $ 1,500 | 0 |  |  |
880591FE7 |  |  |  |  |
Debt Instrument |  |  |  |  |
Percent of par value | 99.593% |  |  |  |
Interest rate | 3.875% |  |  |  |
Debt Instrument, Maturity Date | Aug. 01, 2030 |  |  |  |
Debt Instrument, Issued, Principal | $ 1,250 | $ 0 |  |  |

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