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Risk Management Activities and Derivative Transactions Derivatives Under FTP (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Sep. 30, 2022
--- | --- | ---
Derivative |  |
Forward Contract Derivative Asset, at Fair Value | $ 9 | $ 4
Natural Gas Contract Derivatives |  |
Derivative |  |
Fair value | 71 | 145
Commodity Contract under FHP |  |
Derivative |  |
Fair value | (121) | 115
Fair Value, Inputs, Level 2 |  |
Derivative |  |
Forward Contract Derivative Asset, at Fair Value | $ 9 | $ 4

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- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611 + Details
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