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Details of Selected Financial Statement Captions - Other Current Assets (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Sep. 30, 2024
--- | --- | ---
Balance Sheet Related Disclosures [Abstract] |  |
Deferred gas costs | $ 140,626 | $ 159,762
Winter Storm Uri incremental costs | 5,841 | 3,949
Prepaid expenses | 80,495 | 74,780
Taxes receivable | 8,948 | 14,332
Materials and supplies | 20,076 | 16,961
Assets from risk management activities | 5,303 | 2,091
Regulatory assets (See Note 3) | 33,311 | 12,297
Other | 7,027 | 3,896
Total | $ 301,627 | $ 288,068

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