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Risk Management Activities and Derivative Transactions Derivatives Under FTP (Details) - USD ($) $ in Millions | Mar. 31, 2025 | Sep. 30, 2024
--- | --- | ---
Derivative |  |
Forward Contract Derivative Asset, at Fair Value | $ 16 | $ 11
Fair value | 13 | 64
Commodity Contract under FHP |  |
Derivative |  |
Fair value | 95 | (161)
Fair Value, Inputs, Level 2 |  |
Derivative |  |
Forward Contract Derivative Asset, at Fair Value | $ 16 | $ 11

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