Risk Management Activities and Derivative Transactions Collateral (Details) - USD ($) $ in Millions |
Jun. 30, 2025 |
Sep. 30, 2024 |
|---|---|---|
| Derivative | ||
| Amount of letters of credit outstanding | $ 6 | |
| Forward Contract Derivative Asset, at Fair Value | 18 | $ 11 |
| Likely cash collateral obligation increase | 22 | |
| Derivative Liability, Subject to Master Netting Arrangement, after Offset | 794 | 1,122 |
| Collateralized Securities [Member] | ||
| Derivative | ||
| Derivative, Collateral, Right to Reclaim Cash | 439 | |
| Credit Risk | ||
| Derivative | ||
| Derivative Liability, Subject to Master Netting Arrangement, after Offset | 794 | |
| Letter of Credit | ||
| Derivative | ||
| Amount of letters of credit outstanding | 517 | 566 |
| Interest Swap Collateral | ||
| Derivative | ||
| Amount of letters of credit outstanding | 411 | |
| Interest rate swap collateral | ||
| Derivative | ||
| Amount of letters of credit outstanding | 535 | |
| Fair Value, Inputs, Level 2 | ||
| Derivative | ||
| Forward Contract Derivative Asset, at Fair Value | $ 18 | $ 11 |
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- Definition Fair value as of the balance sheet date of forward contract derivative assets. No definition available.
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- Definition The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value, after effect of master netting arrangement, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and contract can be net settled by means outside contract or delivery of asset. Includes derivative subject to master netting arrangement not elected or qualified to offset. Excludes derivative not subject to master netting arrangement or similar agreement. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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