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v3.25.3

Summary of Significant Accounting Policies [Table Text Block] | 12 Months Ended
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Sep. 30, 2025
Accounting Policies [Abstract] |
Property, Plant, and Equipment Depreciation Rates | Average depreciation rates by asset class are as follows:
Property, Plant, and Equipment Depreciation Rates At September 30 (percent)
| 2025 |  | 2024 |  | 2023
Asset Class |  |  |  |  |
Nuclear | 2.71 |  |  | 2.71 |  |  | 2.73 |
Coal-fired(1) | 4.82 |  |  | 4.13 |  |  | 4.98 |
Hydroelectric | 1.82 |  |  | 1.83 |  |  | 1.82 |
Gas and oil-fired | 3.16 |  |  | 3.31 |  |  | 3.17 |
Transmission | 1.55 |  |  | 1.52 |  |  | 1.52 |
Other | 5.22 |  |  | 4.98 |  |  | 4.43 |
Schedule of Cash and Cash Equivalents | The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported on the Consolidated Balance Sheets and Consolidated Statements of Cash Flows:
Cash, Cash Equivalents, and Restricted Cash At September 30 (in millions)
| 2025 |  | 2024
Cash and cash equivalents | $ | 1,576 |  |  | $ | 502 |
Restricted cash and cash equivalents included in Other long-term assets | 21 |  |  | 21 |
Total cash, cash equivalents, and restricted cash | $ | 1,597 |  |  | $ | 523 |

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