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COMMITMENTS AND CONTINGENT LIABILITIES - LEGAL PROCEEDINGS (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023
Loss Contingencies [Line Items] |  |
Manufactured gas plant remediation | $ 161,650 | $ 169,390
Recovery from third party of environmental remediation cost, period | 7 years |
Regulatory assets | $ 609,192 | $ 584,830
Expended, net of recoveries |  |
Loss Contingencies [Line Items] |  |
Regulatory assets | 77,500 |
Minimum |  |
Loss Contingencies [Line Items] |  |
Product liability contingency, loss exposure in excess of accrual, best estimate | 130,900 |
Maximum |  |
Loss Contingencies [Line Items] |  |
Product liability contingency, loss exposure in excess of accrual, best estimate | $ 194,600 |

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