Regulatory Matters (Tables)

12 Months Ended

Sep. 30, 2025

Regulatory Assets and Liabilities, Other Disclosure [Abstract]

Schedule of Regulatory Assets and Liabilities

The Company has recorded the following regulatory assets and liabilities:

	At September 30
	2025		2024
	(Thousands)
Regulatory Assets:
Recoverable Future Taxes (Note G)	$	89,247	$	80,084
Unamortized Debt Expense (Note A)	6,236		5,604
Other Regulatory Assets:
Pension Costs (Note K)	42,602		30,259
NY Rate Case Levelization and Tracking Mechanisms(1)	28,688		—
Asset Retirement Obligations (Note E)	24,634		21,951
Post-Retirement Benefit Costs (Note K)	13,306		7,932
System Modernization / Improvement Tracker (See Regulatory Mechanisms in Note A)	12,625		31,362
Other	13,631		16,518
Total Long-Term Regulatory Assets	$	230,969	$	193,710
Current Regulatory Assets:
Unrecovered Purchased Gas Costs (See Regulatory Mechanisms in Note A)	5,769		—
Other Current Assets:
System Modernization / Improvement Tracker (See Regulatory Mechanisms in Note A)	14,481		15,681
Other	20,881		22,583
Total Regulatory Assets	$	272,100	$	231,974

(1)New York Rate Case Levelization and Tracking Mechanisms were approved in accordance with Distribution Corporation’s New York rate settlement on December 19, 2024, as discussed below. The mechanisms include: (a) levelization deferral of $17.8 million which relates to a volumetric surcredit within the Company’s delivery adjustment charge that minimizes customer bill impacts, (b) uncollectible expense tracker of $9.8 million, which tracks and reconciles the actual uncollectible expense to the amounts recovered in base rates and, (c) property tax tracker of $1.1 million, which represents the amount deferred between actual property taxes incurred and the level included in customer rates.

	At September 30
	2025		2024
	(Thousands)
Regulatory Liabilities:
Taxes Refundable to Customers (Note G)	$	306,335	$	305,645
Cost of Removal Regulatory Liability	307,659		292,477
Other Regulatory Liabilities:
Post-Retirement Benefit Costs (Note K)	108,714		135,399
Environmental Site Remediation Costs (Note L)	1,800		5,390
Other	11,430		10,663
Total Long-Term Regulatory Liabilities	$	735,938	$	749,574
Current Regulatory Liabilities:
Amounts Payable to Customers (See Regulatory Mechanisms in Note A)	968		42,720
Other Current and Accrued Liabilities:
Post-Retirement Benefit Costs (Note K)	5,800		5,800
Other	14,824		23,552
Total Regulatory Liabilities	$	757,530	$	821,646