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v3.25.3

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Sep. 30, 2024
--- | --- | ---
Deferred tax assets: |  |
Employee benefit plans | $ 34,202 | $ 41,184
Net operating loss carryforwards | 473,642 | 484,816
Charitable and other credit carryforwards | 14,200 | 12,301
Regulatory excess deferred tax | 31,387 | 46,330
Lease asset | 72,973 | 63,747
Other | 31,145 | 34,934
Total deferred tax assets | 657,549 | 683,312
Valuation allowance | (1,365) | (1,457)
Net deferred tax assets | 656,184 | 681,855
Deferred tax liabilities: |  |
Difference in net book value and net tax value of assets | (3,200,535) | (2,914,854)
Gas cost adjustments | (43,819) | (49,443)
Winter Storm Uri regulatory asset | (17,993) | (20,846)
Lease liability | (66,831) | (57,177)
Rate deferral adjustment | (64,640) | (50,571)
Interest rate agreements | (135,640) | (134,536)
Other | (45,073) | (47,770)
Total deferred tax liabilities | (3,574,531) | (3,275,197)
Net deferred tax liabilities | $ (2,918,347) | $ (2,593,342)

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