NATIONAL FUEL GAS CO, 10-Q filed on 1/29/2026
Quarterly Report
v3.25.4
Cover - $ / shares
 3 Months Ended
Dec. 31, 2025
Jan. 27, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Dec. 31, 2025  
Document Transition Report false  
Entity File Number 1-3880  
Entity Registrant Name NATIONAL FUEL GAS COMPANY  
Entity Incorporation, State or Country Code NJ  
Entity Tax Identification Number 13-1086010  
Entity Address, Address Line One 6363 Main Street  
Entity Address, City or Town Williamsville,  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 14221  
City Area Code 716  
Local Phone Number 857-7000  
Title of 12(b) Security Common Stock, par value $1.00 per share  
Trading Symbol NFG  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Listing, Par Value Per Share $ 1.00  
Entity Common Stock, Shares Outstanding   95,026,423
Entity Central Index Key 0000070145  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Amendment Flag false  
v3.25.4
Consolidated Statements Of Income And Earnings Reinvested In The Business (Unaudited) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
INCOME    
Operating Revenues $ 651,507 $ 549,482
Operating Expenses:    
Purchased Gas [1] 85,606 65,337
Property, Franchise and Other Taxes 24,764 22,056
Depreciation, Depletion and Amortization [1] 122,025 109,370
Impairment of Assets [1] 0 141,802
Total Operating Expenses 375,384 463,291
Operating Income 276,123 86,191
Other Income (Expense):    
Other Income 8,233 7,720
Interest Expense on Long-Term Debt (33,513) (33,362)
Other Interest Expense (9,861) (4,381)
Income Before Income Taxes 240,982 56,168
Income Tax Expense [1] 59,337 11,182
Net Income Available for Common Stock 181,645 44,986
EARNINGS REINVESTED IN THE BUSINESS    
Balance at Beginning of Period 2,012,529 1,727,326
Beginning Retained Earnings Unappropriated And Current Period Net Income 2,194,174 1,772,312
Dividends on Common Stock (50,834) (46,671)
Balance at December 31 $ 2,143,340 $ 1,698,648
Basic:    
Net Income Available for Common Stock (in dollars per share) $ 1.99 $ 0.50
Diluted:    
Net Income Available for Common Stock (in dollars per share) $ 1.98 $ 0.49
Weighted Average Common Shares Outstanding:    
Used in Basic Calculation (shares) 91,171,715 90,777,446
Used in Diluted Calculation (shares) 91,962,479 91,434,741
Dividends Per Common Share:    
Dividends Declared (in dollars per share) $ 0.535 $ 0.515
Earnings Reinvested in The Business    
Other Income (Expense):    
Net Income Available for Common Stock $ 181,645 $ 44,986
EARNINGS REINVESTED IN THE BUSINESS    
Share Repurchases 0 (26,993)
Dividends on Common Stock (50,834) (46,671)
Utility    
INCOME    
Operating Revenues 259,047 228,424
Operating Expenses:    
Operation and Maintenance 59,897 55,244
Integrated Upstream and Gathering    
INCOME    
Operating Revenues 323,223 252,308
Pipeline and Storage    
INCOME    
Operating Revenues 69,237 68,750
Operating Expenses:    
Operation and Maintenance 26,786 26,577
Integrated Upstream and Gathering and Other    
Operating Expenses:    
Operation and Maintenance $ 56,306 $ 42,905
[1] The Company considers this line to be a significant expense.
v3.25.4
Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Statement of Comprehensive Income [Abstract]    
Net Income Available for Common Stock $ 181,645 $ 44,986
Other Comprehensive Income (Loss), Before Tax:    
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period 49,098 (53,516)
Reclassification Adjustment for Realized (Gains) Losses on Derivative Financial Instruments in Net Income (13,274) (29,504)
Other Comprehensive Income (Loss), Before Tax 35,824 (83,020)
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period 13,146 (14,403)
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Derivative Financial Instruments in Net Income (3,554) (7,940)
Income Taxes (Benefits) – Net 9,592 (22,343)
Other Comprehensive Income (Loss) 26,232 (60,677)
Comprehensive Income (Loss) $ 207,877 $ (15,691)
v3.25.4
Consolidated Balance Sheets (Unaudited) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
ASSETS    
Property, Plant and Equipment $ 15,616,382 $ 15,406,329
Less - Accumulated Depreciation, Depletion and Amortization 7,800,307 7,693,687
Property, Plant and Equipment, Net, Total 7,816,075 7,712,642
Current Assets    
Cash and Temporary Cash Investments 271,398 43,166
Receivables – Net of Allowance for Uncollectible Accounts of $17,504 and $17,099, Respectively 265,897 180,801
Unbilled Revenue 69,645 16,219
Gas Stored Underground 18,978 33,468
Materials and Supplies - at average cost 49,862 50,545
Unrecovered Purchased Gas Costs 20,723 5,769
Other Current Assets 62,097 80,759
Total Current Assets 758,600 410,727
Other Assets    
Recoverable Future Taxes 92,405 89,247
Unamortized Debt Expense 5,772 6,236
Other Regulatory Assets 133,604 135,486
Deferred Charges 75,570 73,941
Other Investments 68,962 68,346
Goodwill 5,476 5,476
Prepaid Pension and Post-Retirement Benefit Costs 171,569 169,228
Fair Value of Derivative Financial Instruments 69,364 39,388
Other 8,475 8,387
Total Other Assets 631,197 595,735
Total Assets 9,205,872 8,719,104
Capitalization:    
Common Stock, $1 Par Value; Authorized - 200,000,000 Shares; Issued and Outstanding - 95,017,438 Shares and 90,379,095 Shares, Respectively 95,017 90,379
Paid in Capital 1,382,593 1,050,918
Earnings Reinvested in the Business 2,143,340 2,012,529
Accumulated Other Comprehensive Loss (32,990) (59,222)
Total Comprehensive Shareholders’ Equity 3,587,960 3,094,604
Long-Term Debt, Net of Current Portion and Unamortized Discount and Debt Issuance Costs 2,083,892 2,382,861
Total Capitalization 5,671,852 5,477,465
Current and Accrued Liabilities    
Notes Payable to Banks and Commercial Paper 90,000 150,200
Current Portion of Long-Term Debt 600,000 300,000
Accounts Payable 141,674 184,046
Amounts Payable to Customers 476 968
Dividends Payable 50,834 48,353
Interest Payable on Long-Term Debt 34,644 14,393
Customer Advances 17,108 17,188
Customer Security Deposits 29,875 29,853
Other Accruals and Current Liabilities 209,202 174,689
Fair Value of Derivative Financial Instruments 155 6,074
Total Current and Accrued Liabilities 1,173,968 925,764
Other Liabilities    
Deferred Income Taxes 1,274,254 1,225,262
Taxes Refundable to Customers 304,370 306,335
Cost of Removal Regulatory Liability 311,971 307,659
Other Regulatory Liabilities 120,230 121,944
Other Post-Retirement Liabilities 3,731 5,252
Asset Retirement Obligations 234,405 236,787
Other Liabilities 111,091 112,636
Total Other Liabilities 2,360,052 2,315,875
Commitments and Contingencies (Note 8) 0 0
Total Capitalization and Liabilities $ 9,205,872 $ 8,719,104
v3.25.4
Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Statement of Financial Position [Abstract]    
Receivables, allowance for uncollectible accounts $ 17,504 $ 17,099
Common stock, par value (in dollars per share) $ 1 $ 1
Common stock, shares authorized (in shares) 200,000,000 200,000,000
Common stock, shares issued (in shares) 95,017,438 90,379,095
Common stock, shares outstanding (in shares) 95,017,438 90,379,095
v3.25.4
Consolidated Statements Of Cash Flows (Unaudited) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
OPERATING ACTIVITIES    
Net Income Available for Common Stock $ 181,645 $ 44,986
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:    
Impairment of Assets [1] 0 141,802
Depreciation, Depletion and Amortization [1] 122,025 109,370
Deferred Income Taxes 34,277 (5,385)
Stock-Based Compensation 4,094 4,705
Other 7,701 7,146
Change in:    
Receivables and Unbilled Revenue (138,565) (115,165)
Gas Stored Underground and Materials and Supplies 15,173 10,180
Unrecovered Purchased Gas Costs (14,954) 0
Other Current Assets 18,581 8,814
Accounts Payable 21,412 9,703
Amounts Payable to Customers (492) (133)
Customer Advances (80) (4,078)
Customer Security Deposits 22 (174)
Other Accruals and Current Liabilities 37,561 21,266
Other Assets (5,085) (3,892)
Other Liabilities (8,394) (9,057)
Net Cash Provided by Operating Activities 274,921 220,088
INVESTING ACTIVITIES    
Capital Expenditures (277,631) (240,427)
Other (1,255) 5,878
Net Cash Used in Investing Activities (278,886) (234,549)
FINANCING ACTIVITIES    
Changes in Notes Payable to Banks and Commercial Paper (60,200) 109,300
Shares Repurchased Under Repurchase Plan 0 (33,524)
Dividends Paid on Common Stock (48,353) (46,872)
Net Proceeds from Common Stock Sale 347,106 0
Net Repurchases of Common Stock Under Stock and Benefit Plans (6,356) (3,971)
Net Cash Provided by Financing Activities 232,197 24,933
Net Increase in Cash and Cash Equivalents 228,232 10,472
Cash and Cash Equivalents at October 1 43,166 38,222
Cash and Cash Equivalents at December 31 271,398 48,694
Supplemental Disclosure of Cash Flow Information    
Non-Cash Capital Expenditures 70,359 71,616
Non-Cash Accrued Placement Fees from Common Stock Sale $ 8,531 $ 0
[1] The Company considers this line to be a significant expense.
v3.25.4
Summary of Significant Accounting Policies
 3 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies Summary of Significant Accounting Policies
 
Principles of Consolidation. The Company consolidates all entities in which it has a controlling financial interest. All significant intercompany balances and transactions are eliminated. The Company uses proportionate consolidation when accounting for drilling arrangements related to exploration and production properties accounted for under the full cost method of accounting.
 
    The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  Actual results could differ from those estimates.

Reclassifications. As reported in the Company's 2025 Form 10-K, during the quarter ended September 30, 2025, the segment reporting structure was modified to merge the Exploration and Production segment and Gathering segment into one reportable segment called Integrated Upstream and Gathering. As a result, revenue and operation and maintenance expense line items on the consolidated statements of income in prior periods have been reclassified to conform to the current year presentation. Additional discussion is provided at Note 9 — Business Segment Information.

Earnings for Interim Periods.  The Company, in its opinion, has included all adjustments (which consist of only normally recurring adjustments, unless otherwise disclosed in this Quarterly Report on Form 10-Q) that are necessary for a fair statement of the results of operations for the reported periods. The consolidated financial statements and notes thereto, included herein, should be read in conjunction with the financial statements and notes for the years ended September 30, 2025, 2024 and 2023 that are included in the Company's 2025 Form 10-K.  The consolidated financial statements for the year ended September 30, 2026 will be audited by the Company's independent registered public accounting firm after the end of the fiscal year.
 
    The earnings for the three months ended December 31, 2025 should not be taken as a prediction of earnings for the entire fiscal year ending September 30, 2026.  Most of the business of the Utility segment is seasonal in nature and is influenced by weather conditions.  Due to the seasonal nature of the heating business in the Utility segment, earnings during the winter months normally represent a substantial part of the earnings that this business is expected to achieve for the entire fiscal year.  The Company’s business segments are discussed more fully in Note 9 – Business Segment Information.
 
Consolidated Statements of Cash Flows.  The Statement of Cash Flows for the three months ended December 31, 2025 and the three months ended December 31, 2024 reconciles the net increase in cash and cash equivalents, which consists solely of cash and temporary cash investments for the periods presented. The Company did not have any restricted cash at December 31, 2025, October 1, 2025, December 31, 2024 or October 1, 2024. The Company considers all highly liquid debt instruments purchased with a maturity date of generally three months or less to be equivalents.
Allowance for Uncollectible Accounts. The allowance for uncollectible accounts is the Company’s best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance, the majority of which is in the Utility segment, is determined based on historical experience, the age of customer accounts, other specific information about customer accounts, and the economic and regulatory environment. Account balances have historically been written-off against the allowance approximately twelve months after the account is final billed or when it is anticipated that the receivable will not be recovered. Starting in the quarter ended March 31, 2025, account balances are being written-off against the allowance approximately three months after the account is final billed or when it is anticipated that the receivable will not be recovered. This change in policy was initiated to better match the timing of write-offs with the recovery of uncollectible expense in rates and resulted in a one-time cumulative adjustment to the allowance during the quarter ended March 31, 2025.
    Activity in the allowance for uncollectible accounts for the three months ended December 31, 2025 and 2024 are as follows (in thousands):
Balance at Beginning of PeriodAdditions Charged to Costs and ExpensesDiscounts on Purchased ReceivablesNet Accounts Receivable Written-OffBalance at End of Period
Three Months Ended December 31, 2025
Allowance for Uncollectible Accounts$17,099 $5,214 $121 $(4,930)$17,504 
Three Months Ended December 31, 2024
Allowance for Uncollectible Accounts$26,194 $4,605 $107 $(2,522)$28,384 

Gas Stored Underground.  In the Utility segment, gas stored underground is carried at lower of cost or net realizable value, on a LIFO method.  Gas stored underground normally declines during the first and second quarters of the year as storage quantities are withdrawn and increases in the third and fourth quarters as storage quantities are replenished.  In the Utility segment, the current cost of replacing gas withdrawn from storage is recorded in the Consolidated Statements of Income and a reserve for gas replacement is recorded in the Consolidated Balance Sheets under the caption “Other Accruals and Current Liabilities.”  Such reserve, which amounted to $2.8 million at December 31, 2025, is reduced to zero by September 30 of each year as the inventory is replenished.

Property, Plant and Equipment.  In the Company’s Integrated Upstream and Gathering segment, upstream property acquisition, exploration and development costs are accounted for under the full cost method of accounting. Under this methodology, all costs associated with property acquisition, exploration and development activities are capitalized, including internal costs directly identified with acquisition, exploration and development activities. The internal costs that are capitalized do not include any costs related to production, general corporate overhead, or similar activities. The Company does not recognize any gain or loss on the sale or other disposition of properties unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves attributable to a cost center. The Company's capitalized costs relating to exploration and production activities, net of accumulated depreciation, depletion and amortization, were $2.51 billion and $2.46 billion at December 31, 2025 and September 30, 2025, respectively.
 
    Capitalized costs include costs related to unproved properties, which are excluded from amortization until proved reserves are found or it is determined that the unproved properties are impaired. Such costs amounted to $105.7 million and $112.4 million at December 31, 2025 and September 30, 2025, respectively. All costs related to unproved properties are reviewed quarterly to determine if impairment has occurred. The amount of any impairment is transferred to the pool of capitalized costs being amortized.
 
    Capitalized costs are subject to the SEC full cost ceiling test. The ceiling test, which is performed each quarter, determines a limit, or ceiling, on the amount of property acquisition, exploration and development costs that can be capitalized. The ceiling under this test represents (a) the present value of estimated future net cash flows, excluding future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, using a discount factor of 10%, which is computed by applying commodity pricing (as adjusted for hedging) to estimated future production of proved reserves as of the date of the latest balance sheet, less estimated future expenditures, plus (b) the cost of unproved properties not being depleted, less (c) income tax effects related to the differences between the book and tax basis of the properties. The commodity prices used to calculate the full cost ceiling are based on an unweighted arithmetic average of first day of the month commodity price for each month within the twelve-month period prior to the end of the reporting period. If capitalized costs, net of accumulated depreciation, depletion and amortization and related deferred income taxes, exceed the ceiling at the end of any quarter, a permanent non-cash impairment is required to be charged to earnings in that quarter. At December 31, 2025, the ceiling exceeded the book value of the exploration and production properties by approximately $1.3 billion. The book value of the exploration and production properties exceeded the ceiling at December 31, 2024. As such, the Company recognized a non-cash, pre-tax ceiling test impairment charge in the Integrated Upstream and Gathering segment of $108.3 million for the quarter ended December 31, 2024. A deferred income tax benefit of $29.2 million related to the non-cash impairment charge was also recognized for the quarter ended December 31, 2024. In adjusting estimated future net cash flows for hedging under the ceiling test at December 31, 2025, estimated future net cash flows were increased by $170.7 million.

    The Integrated Upstream and Gathering segment also has items of property, plant and equipment that are accounted for outside of the provisions of the full cost method of accounting, including water disposal assets used in its upstream operations as well as gathering lines and compressor stations associated with its gathering operations, all of which are recorded at
historical cost. As discussed in Note 4 – Fair Value Measurements, an impairment charge related to certain water disposal assets was recorded in the Integrated Upstream and Gathering segment at December 31, 2024.
    
    The principal assets of the Utility and Pipeline and Storage segments, consisting primarily of gas distribution pipelines, transmission pipelines, storage facilities and compressor stations, are recorded at historical cost. There were no indications of any impairments to property, plant and equipment in the Utility and Pipeline and Storage segments at December 31, 2025.

Accumulated Other Comprehensive Income (Loss). The components of Accumulated Other Comprehensive Income (Loss) and changes for the three months ended December 31, 2025 and 2024, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands): 
 Gains and Losses on Derivative Financial InstrumentsFunded Status of the Pension and Other Post-Retirement Benefit PlansTotal
Three Months Ended December 31, 2025
Balance at October 1, 2025$19,950 $(79,172)$(59,222)
Other Comprehensive Gains and Losses Before Reclassifications
35,952 — 35,952 
Amounts Reclassified From Other Comprehensive Loss(9,720)— (9,720)
Balance at December 31, 2025$46,182 $(79,172)$(32,990)
Three Months Ended December 31, 2024
Balance at October 1, 2024$55,799 $(71,275)$(15,476)
Other Comprehensive Gains and Losses Before Reclassifications
(39,113)— (39,113)
Amounts Reclassified From Other Comprehensive Loss(21,564)— (21,564)
Balance at December 31, 2024$(4,878)$(71,275)$(76,153)
Reclassifications Out of Accumulated Other Comprehensive Income (Loss).  The details about the reclassification adjustments out of accumulated other comprehensive income (loss) for the three months ended December 31, 2025 and 2024 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands):
Details About Accumulated Other Comprehensive Income (Loss) ComponentsAmount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss)Affected Line Item in the Statement Where Net Income is Presented
Three Months Ended
December 31,
20252024
Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges:
 
     Commodity Contracts$13,395 $29,729 Operating Revenues
     Foreign Currency Contracts(121)(225)Operating Revenues
 13,274 29,504 Total Before Income Tax
 (3,554)(7,940)Income Tax Expense
 $9,720 $21,564 Net of Tax
Other Current Assets.  The components of the Company’s Other Current Assets are as follows (in thousands):
                            At December 31, 2025At September 30, 2025
Prepayments$13,854 $16,477 
Prepaid Property and Other Taxes13,855 13,920 
Federal Income Taxes Receivable— 14,511 
State Income Taxes Receivable— 489 
Regulatory Assets34,388 35,362 
 $62,097 $80,759 
 
Other Accruals and Current Liabilities.  The components of the Company’s Other Accruals and Current Liabilities are as follows (in thousands):
                            At December 31, 2025At September 30, 2025
Accrued Capital Expenditures$47,178 $45,932 
Regulatory Liabilities26,367 20,624 
Reserve for Gas Replacement2,799 — 
Liability for Royalty and Working Interests36,608 28,076 
Federal Income Taxes Payable5,384 — 
State Income Taxes Payable4,676 — 
Pennsylvania Impact Fee19,955 14,923 
Non-Qualified Benefit Plan Liability11,567 11,567 
Other54,668 53,567 
 $209,202 $174,689 
 
Earnings Per Common Share.  Basic earnings per common share is computed by dividing income or loss by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock.  For purposes of determining earnings per common share, the potentially dilutive securities the Company had outstanding were restricted stock units and performance shares. For the quarter ended December 31, 2025, the diluted weighted average shares outstanding shown on the Consolidated Statements of Income reflects the potential dilution as a result of these securities as determined using the Treasury Stock Method. Restricted stock units and performance shares that are antidilutive are excluded from the calculation of diluted earnings per common share. There were 30 securities and four securities excluded as being antidilutive for the quarters ended December 31, 2025 and December 31, 2024, respectively.

Share Repurchases. The Company considers all shares repurchased as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law. The repurchases are accounted for on the date the share repurchase is traded as an adjustment to common stock (at par value) with the excess repurchase price allocated between paid in capital and retained earnings.

Stock-Based Compensation.  The Company granted 137,995 performance shares during the quarter ended December 31, 2025. The weighted average fair value of such performance shares was $62.07 per share for the quarter ended December 31, 2025. Performance shares are an award constituting units denominated in common stock of the Company, the number of which may be adjusted over a performance cycle based upon the extent to which performance goals have been satisfied.  Earned performance shares may be distributed in the form of shares of common stock of the Company, an equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company. The performance shares do not entitle the participant to receive dividends during the vesting period.
 
    The performance shares granted during the quarter ended December 31, 2025 include awards that must meet a performance goal related to relative total shareholder return over a three-year performance cycle ("TSR Performance Shares"). The performance goal related to the TSR Performance Shares over the three-year performance cycle is the Company’s three-year total shareholder return relative to the three-year total shareholder return of other companies in a group selected by the
Compensation Committee ("Report Group").  Three-year total shareholder return for a given company will be based on the data reported for that company (with the starting and ending stock prices over the performance cycle calculated as the average closing stock price for the prior calendar month and with dividends reinvested in that company’s securities at each ex-dividend date) in the Bloomberg database.  The number of these TSR Performance Shares that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company.  The fair value price at the date of grant for the TSR Performance Shares is determined using a Monte Carlo simulation technique, which includes a reduction in value for the present value of forgone dividends over the vesting term of the award.  This price is multiplied by the number of TSR Performance Shares awarded, the result of which is recorded as compensation expense over the vesting term of the award.
 
    The Company granted 128,755 restricted stock units during the quarter ended December 31, 2025.  The weighted average fair value of such restricted stock units was $77.75 per share for the quarter ended December 31, 2025.  Restricted stock units represent the right to receive shares of common stock of the Company (or the equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company) at the end of a specified time period. These restricted stock units do not entitle the participant to receive dividends during the vesting period. The fair value at the date of grant of the restricted stock units (represented by the market value of Company common stock on the date of the award) must be reduced by the present value of forgone dividends over the vesting term of the award. The fair value of restricted stock units on the date of award is recorded as compensation expense over the vesting period.
v3.25.4
Pending Acquisition
 3 Months Ended
Dec. 31, 2025
Acquisitions [Abstract]  
Pending Acquisition
Note 2 – Pending Acquisition

    On October 20, 2025, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”) with CenterPoint Energy Resources Corp. (the “Seller”), pursuant to which, among other things, the Company agreed to acquire from the Seller all of the issued and outstanding equity interests of Vectren Energy Delivery of Ohio, LLC (“CenterPoint Ohio”) for an aggregate purchase price of $2.62 billion, subject to customary adjustments, as provided in the Purchase Agreement. This acquisition will add significant regulated scale for the Company, doubling the size of the Company’s gas utility rate base, while expanding its operations beyond New York and Pennsylvania into the neighboring state of Ohio, a state with a constructive regulatory and political environment that is supportive of natural gas. Closing is expected to occur in the fourth quarter of calendar 2026, pending completion of a notice filing and review with the PUCO, Hart-Scott-Rodino review, and other customary closing conditions. The purchase price will include a combination of $1.42 billion in cash and a $1.2 billion promissory note to be issued by the Company to the Seller at closing. The promissory note, which was part of the Seller’s desired transaction structure and was incorporated into the Company’s business valuation, will have a maturity date of 364 days post-closing and will carry an interest rate of 6.5%. Permanent financing, inclusive of the amount to repay the promissory note, will consist of long-term debt and common equity, along with expected future free cash flow. In that regard, on December 17, 2025, the Company completed the issuance and sale, in a private placement, of 4,402,513 shares of the Company's common stock, par value $1.00 per share, at a price of $79.50 per share. After deducting placement fees, the net proceeds to the Company amounted to $338.6 million.

    In connection with its entry into the Purchase Agreement, the Company entered into a senior unsecured bridge loan facility commitment letter supported by The Toronto-Dominion Bank (“TD Bank”), New York Branch and Wells Fargo Bank, National Association (together with TD Bank, the “Commitment Parties”), as well as a 364-day term loan facility commitment letter supported by the Commitment Parties and additional banks, all of which are lenders under the Company’s primary credit facility. The combination of both facilities fully supports any portion of the purchase price that has not been permanently financed.
v3.25.4
Revenue from Contracts with Customers
 3 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
Revenue from Contracts with Customers Revenue from Contracts with Customers
 
    The following tables provide a disaggregation of the Company's revenues for the three months ended December 31, 2025 and 2024, presented by type of service from each reportable segment. As reported in the Company's 2025 Form 10-K, the segment reporting structure was modified to merge the Exploration and Production segment and Gathering segment into one reportable segment called Integrated Upstream and Gathering. Prior year disaggregation of revenue information shown below has been restated to reflect this change in presentation.
Quarter Ended December 31, 2025 (Thousands)
Revenues By Type of ServiceIntegrated Upstream and GatheringPipeline and StorageUtilityTotal Reportable SegmentsAll OtherCorporate and Intersegment EliminationsTotal Consolidated
Production of Natural Gas$302,460 $— $— $302,460 $— $— $302,460 
Production of Crude Oil292 — — 292 — — 292 
Natural Gas Processing164 — — 164 — — 164 
Natural Gas Gathering Service2,767 — — 2,767 — — 2,767 
Natural Gas Transportation Service— 81,008 32,618 113,626 — (26,757)86,869 
Natural Gas Storage Service— 25,137 — 25,137 — (10,715)14,422 
Natural Gas Residential Sales— — 198,008 198,008 — — 198,008 
Natural Gas Commercial Sales— — 27,877 27,877 — — 27,877 
Natural Gas Industrial Sales— — 1,409 1,409 — (1)1,408 
Other4,145 756 (1,024)3,877 — (281)3,596 
Total Revenues from Contracts with Customers309,828 106,901 258,888 675,617 — (37,754)637,863 
Alternative Revenue Programs— — 249 249 — — 249 
Derivative Financial Instruments13,395 — — 13,395 — — 13,395 
Total Revenues$323,223 $106,901 $259,137 $689,261 $— $(37,754)$651,507 
Quarter Ended December 31, 2024 (Thousands)   
Revenues By Type of ServiceIntegrated Upstream and GatheringPipeline and StorageUtilityTotal Reportable SegmentsAll OtherCorporate and Intersegment EliminationsTotal Consolidated
Production of Natural Gas$217,458 $— $— $217,458 $— $— $217,458 
Production of Crude Oil515 — — 515 — — 515 
Natural Gas Processing275 — — 275 — — 275 
Natural Gas Gathering Service3,448 — — 3,448 — — 3,448 
Natural Gas Transportation Service— 81,204 26,921 108,125 — (27,181)80,944 
Natural Gas Storage Service— 24,993 — 24,993 — (10,504)14,489 
Natural Gas Residential Sales— — 156,350 156,350 — — 156,350 
Natural Gas Commercial Sales— — 22,243 22,243 — — 22,243 
Natural Gas Industrial Sales— — 1,338 1,338 — (1)1,337 
Other883 415 15,740 17,038 — (261)16,777 
Total Revenues from Contracts with Customers222,579 106,612 222,592 551,783 — (37,947)513,836 
Alternative Revenue Programs— — 5,917 5,917 — — 5,917 
Derivative Financial Instruments29,729 — — 29,729 — — 29,729 
Total Revenues$252,308 $106,612 $228,509 $587,429 $— $(37,947)$549,482 
    The Company records revenue related to its derivative financial instruments in the Integrated Upstream and Gathering segment. The Company also records revenue related to alternative revenue programs in its Utility segment. Revenue related to derivative financial instruments and alternative revenue programs are excluded from the scope of the authoritative guidance regarding revenue recognition since they are accounted for under other existing accounting guidance.

    The Company’s Pipeline and Storage segment expects to recognize the following revenue amounts in future periods related to “fixed” charges associated with remaining performance obligations for transportation and storage contracts: $174.8 million for the remainder of fiscal 2026; $218.7 million for fiscal 2027; $164.2 million for fiscal 2028; $130.8 million for fiscal 2029; $123.8 million for fiscal 2030; and $540.0 million thereafter.
v3.25.4
Fair Value Measurements
 3 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Fair Value Measurements Fair Value Measurements
 
    The FASB authoritative guidance regarding fair value measurements establishes a fair-value hierarchy and prioritizes the inputs used in valuation techniques that measure fair value. Those inputs are prioritized into three levels. Level 1 inputs are unadjusted quoted prices in active markets for assets or liabilities that the Company can access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly at the measurement date. Level 3 inputs are unobservable inputs for the asset or liability at the measurement date. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels.
 
    The following table sets forth, by level within the fair value hierarchy, the Company's financial assets and liabilities (as applicable) that were accounted for at fair value on a recurring basis as of December 31, 2025 and September 30, 2025. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.  
Recurring Fair Value MeasuresAt fair value as of December 31, 2025
(Thousands of Dollars)   Level 1Level 2Level 3
Netting
Adjustments(1)
Total(1)
Assets:
 
    
Cash Equivalents – Money Market Mutual Funds$260,901 $— $— $— $260,901 
Derivative Financial Instruments:     
Over the Counter Swaps – Gas— 84,228 — (32,868)51,360 
Over the Counter No Cost Collars – Gas— 26,413 — (8,154)18,259 
Foreign Currency Contracts— 184 — (439)(255)
Other Investments:     
Balanced Equity Mutual Fund14,183 — — — 14,183 
Fixed Income Mutual Fund10,203 — — — 10,203 
Total$285,287 $110,825 $— $(41,461)$354,651 
Liabilities:     
Derivative Financial Instruments:     
Over the Counter Swaps – Gas$— $32,868 $— $(32,868)$— 
Over the Counter No Cost Collars – Gas— 8,154 — (8,154)— 
Foreign Currency Contracts— 594 — (439)155 
Total$— $41,616 $— $(41,461)$155 
Total Net Assets/(Liabilities)$285,287 $69,209 $— $— $354,496 
Recurring Fair Value MeasuresAt fair value as of September 30, 2025
(Thousands of Dollars)   Level 1Level 2Level 3
Netting
Adjustments(1)
Total(1)
Assets:
Cash Equivalents – Money Market Mutual Funds$30,551 $— $— $— $30,551 
Derivative Financial Instruments:
Over the Counter Swaps – Gas— 62,190 — (33,615)28,575 
Over the Counter No Cost Collars – Gas — 24,149 — (12,805)11,344 
Foreign Currency Contracts— 144 — (675)(531)
Other Investments:
Balanced Equity Mutual Fund13,786 — — — 13,786 
Fixed Income Mutual Fund10,082 — — — 10,082 
Total$54,419 $86,483 $— $(47,095)$93,807 
Liabilities:
Derivative Financial Instruments:
Over the Counter Swaps – Gas$— $34,169 $— $(33,615)$554 
Over the Counter No Cost Collars – Gas— 18,036 — (12,805)5,231 
Foreign Currency Contracts— 893 — (675)218 
Total$— $53,098 $— $(47,095)$6,003 
Total Net Assets/(Liabilities)$54,419 $33,385 $— $— $87,804 

(1)Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.

    The following table presents impairments of assets associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy as of December 31, 2025 and 2024 (in thousands):
Impairments
Nonrecurring Fair Value MeasuresQuarter Ended December 31,
SegmentDate of MeasurementFair Value20252024
Impairment of Assets:
Water Disposal AssetsIntegrated Upstream and GatheringDecember 31, 2024$12,880 $— $33,453 

    In exploring the potential sale of certain water disposal assets during the quarter ended December 31, 2024, the Company determined that the fair market value of such assets was less than the recorded net book value resulting in an impairment charge that reduced the net book value to fair market value. These assets are used to dispose of water from operations in the Integrated Upstream and Gathering segment.
 
Derivative Financial Instruments
 
    The derivative financial instruments reported in Level 2 at December 31, 2025 and September 30, 2025 include natural gas price swap agreements, natural gas no cost collars, and foreign currency contracts, all of which are used in the Company’s Integrated Upstream and Gathering segment. The fair value of the Level 2 price swap agreements and no cost collars is based on an internal cash flow model that uses observable inputs (i.e. SOFR based discount rates for the price swap agreements and basis differential information, if applicable, at active natural gas trading markets). The fair value of the Level 2 foreign currency contracts is determined using the market approach based on observable market transactions of forward Canadian currency rates. 

    The authoritative guidance for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At December 31, 2025, the Company determined that nonperformance risk associated with the price swap agreements, no cost collars and foreign currency contracts would have no material impact on its financial position or results of operation. To assess nonperformance risk, the Company considered information such as any applicable collateral posted, master netting arrangements, and applied a market-based method by using the counterparty's (assuming the derivative is in a gain position) or the Company’s (assuming the derivative is in a loss position) credit default swaps rates.
v3.25.4
Financial Instruments
 3 Months Ended
Dec. 31, 2025
Financial Instruments, Owned, at Fair Value, by Type, Alternative [Abstract]  
Financial Instruments Financial Instruments
 
Long-Term Debt.  The fair market value of the Company’s debt, as presented in the table below, was determined using a discounted cash flow model, which incorporates the Company’s credit ratings and current market conditions in determining the yield, and subsequently, the fair market value of the debt.  Based on these criteria, the fair market value of long-term debt, including current portion, was as follows (in thousands): 
 December 31, 2025September 30, 2025
 Carrying
Amount		Fair ValueCarrying
Amount		Fair Value
Long-Term Debt$2,683,892 $2,695,409 $2,682,861 $2,696,145 
 
    The fair value amounts are not intended to reflect principal amounts that the Company will ultimately be required to pay. Carrying amounts for other financial instruments recorded on the Company’s Consolidated Balance Sheets approximate fair value. The fair value of long-term debt was calculated using observable inputs (U.S. Treasuries or SOFR for the risk-free component and company specific credit spread information – generally obtained from recent trade activity in the debt).  As such, the Company considers the debt to be Level 2.
 
Other Financial Instruments.  Any temporary cash investments, notes payable to banks and commercial paper are stated at cost. Temporary cash investments are considered Level 1, while notes payable to banks and commercial paper are considered to be Level 2.  Given the short-term nature of the notes payable to banks and commercial paper, the Company believes cost is a reasonable approximation of fair value.

Other Investments. The components of the Company's Other Investments are as follows (in thousands):
At December 31, 2025At September 30, 2025
Life Insurance Contracts$44,576 $44,478 
Equity Mutual Fund14,183 13,786 
Fixed Income Mutual Fund10,203 10,082 
$68,962 $68,346 
 
    Investments in life insurance contracts are stated at their cash surrender values or net present value. Investments in an equity mutual fund and a fixed income mutual fund are stated at fair value based on quoted market prices with changes in fair value recognized in net income. The insurance contracts and equity mutual fund are primarily informal funding mechanisms for various benefit obligations the Company has to certain employees. The fixed income mutual fund is primarily an informal funding mechanism for certain regulatory obligations that the Company has to Utility segment customers in its Pennsylvania jurisdiction and for various benefit obligations the Company has to certain employees.
 
Derivative Financial Instruments.  The Company uses derivative financial instruments to manage commodity price risk in the Integrated Upstream and Gathering segment. The Company enters into over-the-counter no cost collar and swap agreements for natural gas to manage the price risk associated with forecasted sales of natural gas. In addition, the Company also enters into foreign exchange forward contracts to manage the risk of currency fluctuations associated with transportation costs denominated in Canadian currency in the Integrated Upstream and Gathering segment. These instruments are accounted for as cash flow hedges. The duration of the Company’s cash flow hedges and foreign currency forward contracts do not typically exceed 5 years.

    The Company has presented its net derivative assets and liabilities as “Fair Value of Derivative Financial Instruments” on its Consolidated Balance Sheets at December 31, 2025 and September 30, 2025.
 
Cash Flow Hedges
 
    For derivative financial instruments that are designated and qualify as a cash flow hedge, the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the period or periods during which the hedged transaction affects earnings.
    As of December 31, 2025, the Company had 403.1 Bcf of natural gas commodity derivative contracts (swaps and no cost collars) outstanding.

    As of December 31, 2025, the Company was hedging a total of $41.0 million of forecasted transportation costs denominated in Canadian dollars with foreign currency forward contracts.

    As of December 31, 2025, the Company had $46.2 million of net hedging gains after taxes included in the accumulated other comprehensive income (loss) balance. Of this amount, it is expected that $45.9 million of unrealized gains after taxes will be reclassified into the Consolidated Statement of Income within the next 12 months as the underlying hedged transactions are recorded in earnings.
The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the
Three Months Ended December 31, 2025 and 2024 (Thousands of Dollars)
Derivatives in Cash Flow Hedging RelationshipsAmount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on
the Consolidated Statement of
Comprehensive Income (Loss)
for the
 Three Months Ended
 December 31,		Location of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of IncomeAmount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income for the
 Three Months Ended
 December 31,
 20252024 20252024
Commodity Contracts$48,880 $(51,909)Operating Revenue$13,395 $29,729 
Foreign Currency Contracts218 (1,607)Operating Revenue(121)(225)
Total$49,098 $(53,516) $13,274 $29,504 

Credit Risk

    The Company may be exposed to credit risk on any of the derivative financial instruments that are in a gain position. Credit risk relates to the risk of loss that the Company would incur as a result of nonperformance by counterparties pursuant to the terms of their contractual obligations. To mitigate such credit risk, management performs a credit check, and then on a quarterly basis monitors counterparty credit exposure. The majority of the Company’s counterparties are financial institutions and energy traders. The Company has over-the-counter swap positions, no cost collars and applicable foreign currency forward contracts with seventeen counterparties of which sixteen are in a net gain position. On average, the Company had $4.3 million of credit exposure per counterparty in a gain position at December 31, 2025. The maximum credit exposure per counterparty in a gain position at December 31, 2025 was $10.8 million. As of December 31, 2025, no collateral was received from the counterparties by the Company. The Company's gain position on such derivative financial instruments had not exceeded the established thresholds at which the counterparties would be required to post collateral, nor had the counterparties' credit ratings declined to levels at which the counterparties were required to post collateral.

    Certain counterparties to the Company’s outstanding derivative instrument contracts (specifically the over-the-counter swaps, over-the-counter no cost collars and applicable foreign currency forward contracts) had a common credit-risk related contingency feature. In the event the Company’s credit rating increases or falls below a certain threshold (applicable debt ratings), the available credit that could be extended to the Company when it is in a derivative financial liability position would either increase or decrease. A decline in the Company’s credit rating, in and of itself, would not cause the Company to be required to post or increase the level of its hedging collateral deposits (in the form of cash deposits, letters of credit or treasury debt instruments). If the Company’s outstanding derivative instrument contracts with a credit-risk contingency feature were in a liability position (or if the liability were larger) and/or the Company’s credit rating declined, then hedging collateral deposits or an increase to such deposits could be required. At December 31, 2025, the fair market value of the derivative financial instrument liabilities with a credit-risk related contingency feature was $0.2 million according to the Company's internal model (discussed in Note 4 – Fair Value Measurements), and no hedging collateral deposits were required to be posted by the Company at December 31, 2025. Depending on the movement of commodity prices in the future, it is possible that these liability positions could swing into asset positions, at which point the Company would be exposed to credit risk on its derivative financial instruments. In that case, the Company's counterparties could be required to post hedging collateral deposits.
 
    The Company’s requirement to post hedging collateral deposits and the Company's right to receive hedging collateral deposits is based on the fair value determined by the Company’s counterparties, which may differ from the Company’s assessment of fair value.
v3.25.4
Income Taxes
 3 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Income Taxes Income Taxes
    The effective tax rates for the quarters ended December 31, 2025 and December 31, 2024 were 24.6% and 19.9%, respectively. The increase in the quarterly effective income tax rate was primarily driven by the impact of the impairments of exploration and production properties under the ceiling test and other operational assets recorded during the quarter ended December 31, 2024, which resulted in a smaller income tax expense on income before income taxes during the quarter ended December 31, 2024.
v3.25.4
Capitalization
 3 Months Ended
Dec. 31, 2025
Capitalization, Long-Term Debt and Equity [Abstract]  
Capitalization Capitalization
Summary of Changes in Common Stock Equity
 Common StockPaid In
Capital		Earnings
Reinvested
in the
Business		Accumulated
Other
Comprehensive
Income (Loss)
SharesAmount
 (Thousands)
Balance at October 1, 202590,379 $90,379 $1,050,918 $2,012,529 $(59,222)
Net Income Available for Common Stock181,645 
Dividends Declared on Common Stock ($0.535 Per Share)
(50,834)
Other Comprehensive Income, Net of Tax26,232 
Share-Based Payment Expense (1)
3,427 
Common Stock Issued from Sale of Common Stock4,403 4,403 334,173 
Common Stock Issued (Repurchased) Under Stock and Benefit Plans235 235 (5,925)
Balance at December 31, 202595,017 $95,017 $1,382,593 $2,143,340 $(32,990)
Balance at October 1, 202491,006 $91,006 $1,045,487 $1,727,326 $(15,476)
Net Income Available for Common Stock44,986 
Dividends Declared on Common Stock ($0.515 Per Share)
(46,671)
Other Comprehensive Loss, Net of Tax(60,677)
Share-Based Payment Expense (1)
4,090 
Common Stock Issued (Repurchased) Under Stock and Benefit Plans156 156 (3,511)
Share Repurchases Under Repurchase Plan(549)$(549)$(6,361)$(26,993)
Balance at December 31, 202490,613 $90,613 $1,039,705 $1,698,648 $(76,153)

(1)Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.
Common Stock.  Common stock share activity during the three months ended December 31, 2025 consisted of the following items:
Three Months Ended December 31, 2025
Vesting of Restricted Stock Units138,643 
Vesting of Performance Shares167,241 
Issuance of Common Stock Pursuant to the Company's Non-Employee Director Equity
Compensation Plan and Deferred Compensation Plan for Directors and Officers
7,368 
Shares Tendered to Pay Withholding Taxes on Stock-Based Compensation Awards (1)
(77,422)
Common Stock Issued Under Stock and Benefit Plans235,830 
Common Stock Issued from Sale of Common Stock4,402,513 
Total Common Stock Issued During the Three Months Ended December 31, 20254,638,343 
(1)    The Company considers all shares tendered as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law.

    On December 17, 2025, the Company completed the issuance and sale, in a private placement, of 4,402,513 shares of the Company's common stock, par value $1.00 per share, at a price of $79.50 per share. After deducting placement fees, the net proceeds to the Company amounted to $338.6 million. The proceeds of this issuance were used for general corporate purposes, including to fund a portion of the purchase price of the Company's previously announced acquisition of CenterPoint Energy Resources Corp.'s Ohio regulated gas utility business. Refer to Note 2 – Pending Acquisition for further discussion.
 
Current Portion of Long-Term Debt. The Current Portion of Long-Term Debt at December 31, 2025 consisted of a $300.0 million long-term delayed draw term loan scheduled to mature in February 2026 that was repaid in January 2026 and $300.0 million of 5.50% notes with a maturity date in October 2026. The Current Portion of Long-Term Debt at September 30, 2025 consisted of the aforementioned $300.0 million long-term delayed draw term loan with a maturity date in February 2026.
Delayed Draw Term Loan. On February 14, 2024, the Company entered into a Term Loan Agreement (the “Term Loan Agreement”) with six lenders, all of which are lenders under the Credit Agreement. As of January 22, 2026, the Company repaid the $300.0 million drawn under the Term Loan Agreement and the agreement was therefore terminated. The Term Loan Agreement provided a $300.0 million unsecured committed delayed draw term loan facility with a maturity date of February 14, 2026, and the Company had the ability to select interest periods of one, three or six months for borrowings. In April 2024, pursuant to the delayed draw mechanism, the Company elected to draw a total of $300.0 million under the facility. After deducting debt issuance costs, the net proceeds to the Company amounted to $299.4 million. Borrowings under the Term Loan Agreement bear interest at a rate equal to SOFR for the applicable interest period, plus an adjustment of 0.10%, plus a spread of 1.375%.
v3.25.4
Commitments and Contingencies
 3 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies Commitments and Contingencies
 
Environmental Matters.  The Company is subject to various federal, state and local laws and regulations relating to the protection of the environment.  The Company has established procedures for the ongoing evaluation of its operations to identify potential environmental exposures and to comply with regulatory requirements.  It is the Company’s policy to accrue estimated environmental clean-up costs (investigation and remediation) when such amounts can reasonably be estimated and it is probable that the Company will be required to incur such costs.
    
    At December 31, 2025, the Company has estimated its remaining clean-up costs related to former manufactured gas plant sites will be approximately $2.9 million.  The Company's liability for such clean-up costs has been recorded in Other Liabilities on the Consolidated Balance Sheet at December 31, 2025. The Company has a regulatory liability of $1.5 million related to environmental clean-up costs at December 31, 2025 and is currently not aware of any material additional exposure to environmental liabilities.  However, changes in environmental laws and regulations, new information or other factors could have an adverse financial impact on the Company.
 
Other.  The Company is involved in other litigation and regulatory matters arising in the normal course of business.  These other matters may include, for example, negligence claims and tax, regulatory or other governmental audits, inspections, investigations and other proceedings.  These matters may involve state and federal taxes, safety, compliance with regulations, rate base, cost of service and purchased gas cost issues, among other things.  While these other matters arising in the normal
course of business could have a material effect on earnings and cash flows in the period in which they are resolved, an estimate of the possible loss or range of loss, if any, cannot be made at this time.
v3.25.4
Business Segment Information
 3 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Business Segment Information Business Segment Information    
 
    The Company reports financial results for three segments: Integrated Upstream and Gathering, Pipeline and Storage, and Utility. The division of the Company’s operations into reportable segments is based on a combination of factors including differences in products and services as well as regulatory environments. As reported in the Company's 2025 Form 10-K, the segment reporting structure was modified to merge the Exploration and Production segment and Gathering segment into one reportable segment called Integrated Upstream and Gathering. Prior year segment information shown below has been recast to reflect this change in presentation. The Company's Chief Executive Officer, its Chief Operating Decision Maker (CODM), evaluates segment performance primarily using earnings attributable to the Company. External reporting is consistent with the internal financial reports used by the CODM to regularly assess performance of the business, make operating decisions and allocate resources.

    The Integrated Upstream and Gathering segment is composed of the operations of Seneca and Midstream Company. Seneca is engaged in the exploration for and development of natural gas reserves in the Appalachian region of the United States. Midstream Company builds, owns and operates natural gas processing and pipeline gathering facilities in the Appalachian region, primarily providing gathering services to Seneca.

    The Pipeline and Storage segment operations are regulated by the FERC for both Supply Corporation and Empire. Supply Corporation transports and stores natural gas for utilities (including Distribution Corporation), natural gas marketers, exploration and production companies (including Seneca) and pipeline companies serving northeastern United States markets. Empire transports and stores natural gas for major industrial companies, utilities (including Distribution Corporation) and power producers in New York State. Empire also transports natural gas for utilities (including Distribution Corporation), natural gas marketers and exploration and production companies (including Seneca) from producing areas in Pennsylvania to markets in New York and to interstate pipeline delivery points with access to additional markets in the northeastern United States and Canada.

    The Utility segment operations are regulated by the NYPSC and the PaPUC and are carried out by Distribution Corporation. Distribution Corporation sells natural gas to retail customers and provides natural gas transportation services in western New York and northwestern Pennsylvania.

    The data presented in the tables below reflects financial information for the segments and reconciles to consolidated amounts.  As stated in the 2025 Form 10-K, the Company evaluates segment performance based on income before discontinued operations, when applicable.  If discontinued operations are not applicable, the Company evaluates performance based on net income.  There have been no changes in the basis of segmentation or in the basis of measuring segment profit or loss from those used in the Company’s 2025 Form 10-K.  A listing of segment assets at December 31, 2025 and December 31, 2024 is shown in the tables below.
Three Months Ended December 31, 2025
 Integrated Upstream and GatheringPipeline
and
Storage		UtilityTotal
Reportable
Segments
All
   Other(4)
Corporate
and
Intersegment
  Eliminations(4)
Total
Consolidated
 (Thousands)
Revenue from External Customers(1)
$323,223 $69,237 $259,047 $651,507 $— $— $651,507 
Intersegment Revenues
— 37,664 90 37,754 — (37,754)— 
  Total Revenues323,223 106,901 259,137 689,261 — (37,754)651,507 
Operation and Maintenance Expense(2):
Upstream General and Administrative Expense19,406 — — 19,406 — (63)19,343 
Lease Operating Expense16,826 — — 16,826 — (789)16,037 
Gathering Operation and Maintenance Expense10,388 — — 10,388 — (69)10,319 
All Other Operation and Maintenance Expense3,378 27,263 60,997 91,638 — 5,652 97,290 
Purchased Gas Expense(2)
— — 122,285 122,285 — (36,679)85,606 
Depreciation, Depletion and Amortization Expense(2)
84,263 19,102 18,479 121,844 — 181 122,025 
Impairment of Assets (Significant Non-Cash Item)(2)
— — — — — — — 
Interest Expense(2)
16,133 11,801 11,606 39,540 136 3,698 43,374 
Interest Income(193)(964)(1,039)(2,196)(10)(571)(2,777)
Income Tax Expense (Benefit)(2)
44,111 10,366 7,335 61,812 (37)(2,438)59,337 
Other Expense (Income) Items(3)
4,864 8,114 5,384 18,362 33 913 19,308 
Segment Profit: Net Income (Loss)
$124,047 $31,219 $34,090 $189,356 $(122)$(7,589)$181,645 
Expenditures for Additions to Long-Lived Assets
$141,849 $37,602 $43,094 $222,545 $— $176 $222,721 
 Integrated Upstream and GatheringPipeline
and
Storage		UtilityTotal
Reportable
Segments
All
   Other(4)
Corporate
and
Intersegment
  Eliminations(4)
Total
Consolidated
 (Thousands)
Segment Assets:
At December 31, 2025$3,925,191 $2,504,541 $2,645,957 $9,075,689 $8,565 $121,618 $9,205,872 
At September 30, 2025$3,701,646 $2,412,747 $2,534,289 $8,648,682 $8,704 $61,718 $8,719,104 
Three Months Ended December 31, 2024
 Integrated Upstream and GatheringPipeline
and
Storage		UtilityTotal
Reportable
Segments
All
   Other(4)
Corporate and
Intersegment
  Eliminations(4)
Total
Consolidated
 (Thousands)
Revenue from External Customers(1)
$252,308 $68,750 $228,424 $549,482 $— $— $549,482 
Intersegment Revenues
— 37,862 85 37,947 — (37,947)— 
  Total Revenues252,308 106,612 228,509 587,429 — (37,947)549,482 
Operation and Maintenance Expense(2):
Upstream General and Administrative Expense19,326 — — 19,326 — (59)19,267 
Lease Operating Expense10,651 — — 10,651 — (1,587)9,064 
Gathering Operation and Maintenance Expense6,735 — — 6,735 — (65)6,670 
All Other Operation and Maintenance Expense3,867 27,034 56,260 87,161 — 2,564 89,725 
Purchased Gas Expense(2)
— — 101,473 101,473 — (36,136)65,337 
Depreciation, Depletion and Amortization Expense(2)
73,819 18,585 16,827 109,231 — 139 109,370 
Impairment of Assets (Significant Non-Cash Item)(2)
141,802 — — 141,802 — — 141,802 
Interest Expense(2)
19,410 11,729 10,716 41,855 116 (4,228)37,743 
Interest Income(679)(2,006)(648)(3,333)— 1,650 (1,683)
Income Tax Expense (Benefit)(2)
(6,451)11,177 7,022 11,748 (59)(507)11,182 
Other Expense (Income) Items(3)
3,460 7,639 4,360 15,459 136 424 16,019 
Segment Profit: Net Income (Loss)
$(19,632)$32,454 $32,499 $45,321 $(193)$(142)$44,986 
Expenditures for Additions to Long-Lived Assets
$135,629 $19,792 $36,430 $191,851 $— $204 $192,055 
(1)All Revenue from External Customers originated in the United States.
(2)The Company considers this line to be a significant expense.
(3)Consists of Property, Franchise and Other Taxes, Non-Service Pension and Post-Retirement Benefits Costs (Credits), Other (Income) Deductions, and Purchased Gas Expense for the Pipeline and Storage Segment.
(4)Corporate and All Other categories primarily represent other non-segment business activities and eliminating entries.
v3.25.4
Retirement Plan and Other Post-Retirement Benefits
 3 Months Ended
Dec. 31, 2025
Retirement Benefits [Abstract]  
Retirement Plan and Other Post-Retirement Benefits Retirement Plan and Other Post-Retirement Benefits
 
    Components of Net Periodic Benefit Cost (in thousands):
 
 Retirement PlanOther Post-Retirement Benefits
Three Months Ended December 31,2025202420252024
Service Cost$861 $1,023 $105 $130 
Interest Cost8,944 9,223 3,836 3,625 
Expected Return on Plan Assets(14,710)(14,647)(7,374)(6,536)
Amortization of Prior Service Cost (Credit)63 76 (65)(107)
Amortization of (Gains) Losses2,421 1,620 152 9 
Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1)
(98)(165)(148)(727)
Net Periodic Benefit Cost (Income)$(2,519)$(2,870)$(3,494)$(3,606)
(1)The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.
 
    The components of net periodic benefit cost other than service cost are presented in Other Income (Deductions) on the Consolidated Statements of Income.

Employer Contributions.    The Company did not make any contributions to its tax-qualified, noncontributory defined benefit retirement plan (Retirement Plan) during the three months ended December 31, 2025, and does not anticipate making any such contributions during the remainder of fiscal 2026. The Company also did not make any contributions to its VEBA trusts for its other post-retirement benefits during the three months ended December 31, 2025, and does not anticipate making any such contributions during the remainder of fiscal 2026.
v3.25.4
Regulatory Matters
 3 Months Ended
Dec. 31, 2025
Regulatory Assets and Liabilities, Other Disclosure [Abstract]  
Regulatory Matters Regulatory Matters
New York Jurisdiction
    
    Distribution Corporation's current delivery rates in its New York jurisdiction were approved by the NYPSC in an order issued on December 19, 2024 with rates effective January 1, 2025 (“2024 Rate Order”). The 2024 Rate Order authorizes a three-year rate plan effective October 1, 2024, with a make-whole provision allowing full recovery of revenues that would have been billed at the new rates between October 1, 2024 and December 31, 2024. It also reflects a return on equity of 9.7% and authorized a revenue requirement increase of $57.3 million in fiscal 2025, an additional revenue requirement increase of $15.8 million in fiscal 2026, and an additional revenue requirement increase of $12.7 million in fiscal 2027. These revenue requirement increases are being reflected in customer bills on a levelized basis over the three-year rate plan. The revenue requirement for each year of the three-year plan has been reduced by $14 million for actuarial projections of income that is expected to be recognized for qualified pension and other post-retirement benefits. Qualified pension and other post-retirement benefit income or costs are matched with amounts included in revenue resulting in zero impact to earnings. The 2024 Rate Order approves the continuation of several ratemaking mechanisms, including revenue decoupling and WNA, and establishes a number of new cost trackers and regulatory deferrals. It also includes an earnings sharing mechanism, gas safety and customer service performance metrics (including maintaining the Company’s leak prone pipe replacement program), and provisions that will facilitate achievement of the emissions reduction goals of the CLCPA.

Pennsylvania Jurisdiction

    Distribution Corporation’s current delivery rates in its Pennsylvania jurisdiction were approved by the PaPUC in an order issued on June 15, 2023 with rates effective August 1, 2023 (“2023 Rate Order”). The 2023 Rate Order provided for, among other things, an increase in Distribution Corporation’s annual base rate operating revenues of $23 million and authorized a new weather normalization adjustment mechanism. On January 28, 2026, Distribution Corporation made a filing with the PaPUC seeking an increase in its annual base rate operating revenues of $19.7 million with a proposed effective date of March 29, 2026. The Company is proposing, among other things, a new residential energy efficiency pilot program and to make
permanent its weather normalization adjustment mechanism.  The Company is also proposing reactivation of the OPEB surcredit (Rider I) to refund $7.2 million for customer bill relief.  The filing will be suspended for seven months by operation of law unless directed otherwise by the PaPUC.

    On April 10, 2024, Distribution Corporation filed with the PaPUC a petition for approval of a distribution system improvement charge (“DSIC”) to recover, between base rate cases, capital expenses related to eligible property constructed or installed to rehabilitate, improve and replace portions of the Company’s natural gas distribution system. The DSIC petition was approved by the PaPUC on December 5, 2024, and on January 1, 2025, the Company initiated recovery of eligible costs on incremental rate base added after September 30, 2024. During the quarter ended December 31, 2025, Distribution Corporation recovered $1.1 million from customers. The DSIC will be reset to zero when new base rates become effective as a result of the Company's recent rate filing.

FERC Jurisdiction

    Supply Corporation’s rate settlement was approved June 11, 2024, with rates effective February 1, 2024, and provides that Supply Corporation may make a rate filing for new rates to be effective at any time. As well, any party can make a filing under NGA Section 5. Supply Corporation has no rate case currently on file.

    On March 17, 2025, FERC approved an amendment to Empire's 2019 rate case settlement, which provides for a modest reduction in Empire’s transportation unit rates, effective November 1, 2025. This settlement amendment is estimated to decrease Empire's revenues on a yearly basis by approximately $0.5 million. Empire will not be able to file a new Section 4 rate case before April 30, 2027 and is required to file a Section 4 rate case by May 31, 2031.
v3.25.4
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2025
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.4
Summary of Significant Accounting Policies (Policy)
 3 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Principles of Consolidation
Principles of Consolidation. The Company consolidates all entities in which it has a controlling financial interest. All significant intercompany balances and transactions are eliminated. The Company uses proportionate consolidation when accounting for drilling arrangements related to exploration and production properties accounted for under the full cost method of accounting.
 
    The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  Actual results could differ from those estimates.
Reclassifications
Reclassifications. As reported in the Company's 2025 Form 10-K, during the quarter ended September 30, 2025, the segment reporting structure was modified to merge the Exploration and Production segment and Gathering segment into one reportable segment called Integrated Upstream and Gathering. As a result, revenue and operation and maintenance expense line items on the consolidated statements of income in prior periods have been reclassified to conform to the current year presentation. Additional discussion is provided at Note 9 — Business Segment Information.
Earnings For Interim Periods
Earnings for Interim Periods.  The Company, in its opinion, has included all adjustments (which consist of only normally recurring adjustments, unless otherwise disclosed in this Quarterly Report on Form 10-Q) that are necessary for a fair statement of the results of operations for the reported periods. The consolidated financial statements and notes thereto, included herein, should be read in conjunction with the financial statements and notes for the years ended September 30, 2025, 2024 and 2023 that are included in the Company's 2025 Form 10-K.  The consolidated financial statements for the year ended September 30, 2026 will be audited by the Company's independent registered public accounting firm after the end of the fiscal year.
 
    The earnings for the three months ended December 31, 2025 should not be taken as a prediction of earnings for the entire fiscal year ending September 30, 2026.  Most of the business of the Utility segment is seasonal in nature and is influenced by weather conditions.  Due to the seasonal nature of the heating business in the Utility segment, earnings during the winter months normally represent a substantial part of the earnings that this business is expected to achieve for the entire fiscal year.  The Company’s business segments are discussed more fully in Note 9 – Business Segment Information.
Consolidated Statements of Cash Flows Consolidated Statements of Cash Flows.  The Statement of Cash Flows for the three months ended December 31, 2025 and the three months ended December 31, 2024 reconciles the net increase in cash and cash equivalents, which consists solely of cash and temporary cash investments for the periods presented. The Company did not have any restricted cash at December 31, 2025, October 1, 2025, December 31, 2024 or October 1, 2024. The Company considers all highly liquid debt instruments purchased with a maturity date of generally three months or less to be equivalents.
Allowance for Uncollectible Accounts
Allowance for Uncollectible Accounts. The allowance for uncollectible accounts is the Company’s best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance, the majority of which is in the Utility segment, is determined based on historical experience, the age of customer accounts, other specific information about customer accounts, and the economic and regulatory environment. Account balances have historically been written-off against the allowance approximately twelve months after the account is final billed or when it is anticipated that the receivable will not be recovered. Starting in the quarter ended March 31, 2025, account balances are being written-off against the allowance approximately three months after the account is final billed or when it is anticipated that the receivable will not be recovered. This change in policy was initiated to better match the timing of write-offs with the recovery of uncollectible expense in rates and resulted in a one-time cumulative adjustment to the allowance during the quarter ended March 31, 2025.
Gas Stored Underground
Gas Stored Underground.  In the Utility segment, gas stored underground is carried at lower of cost or net realizable value, on a LIFO method.  Gas stored underground normally declines during the first and second quarters of the year as storage quantities are withdrawn and increases in the third and fourth quarters as storage quantities are replenished.  In the Utility segment, the current cost of replacing gas withdrawn from storage is recorded in the Consolidated Statements of Income and a reserve for gas replacement is recorded in the Consolidated Balance Sheets under the caption “Other Accruals and Current Liabilities.”  Such reserve, which amounted to $2.8 million at December 31, 2025, is reduced to zero by September 30 of each year as the inventory is replenished.
Property, Plant and Equipment
Property, Plant and Equipment.  In the Company’s Integrated Upstream and Gathering segment, upstream property acquisition, exploration and development costs are accounted for under the full cost method of accounting. Under this methodology, all costs associated with property acquisition, exploration and development activities are capitalized, including internal costs directly identified with acquisition, exploration and development activities. The internal costs that are capitalized do not include any costs related to production, general corporate overhead, or similar activities. The Company does not recognize any gain or loss on the sale or other disposition of properties unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves attributable to a cost center. The Company's capitalized costs relating to exploration and production activities, net of accumulated depreciation, depletion and amortization, were $2.51 billion and $2.46 billion at December 31, 2025 and September 30, 2025, respectively.
 
    Capitalized costs include costs related to unproved properties, which are excluded from amortization until proved reserves are found or it is determined that the unproved properties are impaired. Such costs amounted to $105.7 million and $112.4 million at December 31, 2025 and September 30, 2025, respectively. All costs related to unproved properties are reviewed quarterly to determine if impairment has occurred. The amount of any impairment is transferred to the pool of capitalized costs being amortized.
 
    Capitalized costs are subject to the SEC full cost ceiling test. The ceiling test, which is performed each quarter, determines a limit, or ceiling, on the amount of property acquisition, exploration and development costs that can be capitalized. The ceiling under this test represents (a) the present value of estimated future net cash flows, excluding future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, using a discount factor of 10%, which is computed by applying commodity pricing (as adjusted for hedging) to estimated future production of proved reserves as of the date of the latest balance sheet, less estimated future expenditures, plus (b) the cost of unproved properties not being depleted, less (c) income tax effects related to the differences between the book and tax basis of the properties. The commodity prices used to calculate the full cost ceiling are based on an unweighted arithmetic average of first day of the month commodity price for each month within the twelve-month period prior to the end of the reporting period. If capitalized costs, net of accumulated depreciation, depletion and amortization and related deferred income taxes, exceed the ceiling at the end of any quarter, a permanent non-cash impairment is required to be charged to earnings in that quarter. At December 31, 2025, the ceiling exceeded the book value of the exploration and production properties by approximately $1.3 billion. The book value of the exploration and production properties exceeded the ceiling at December 31, 2024. As such, the Company recognized a non-cash, pre-tax ceiling test impairment charge in the Integrated Upstream and Gathering segment of $108.3 million for the quarter ended December 31, 2024. A deferred income tax benefit of $29.2 million related to the non-cash impairment charge was also recognized for the quarter ended December 31, 2024. In adjusting estimated future net cash flows for hedging under the ceiling test at December 31, 2025, estimated future net cash flows were increased by $170.7 million.

    The Integrated Upstream and Gathering segment also has items of property, plant and equipment that are accounted for outside of the provisions of the full cost method of accounting, including water disposal assets used in its upstream operations as well as gathering lines and compressor stations associated with its gathering operations, all of which are recorded at
historical cost. As discussed in Note 4 – Fair Value Measurements, an impairment charge related to certain water disposal assets was recorded in the Integrated Upstream and Gathering segment at December 31, 2024.
    
    The principal assets of the Utility and Pipeline and Storage segments, consisting primarily of gas distribution pipelines, transmission pipelines, storage facilities and compressor stations, are recorded at historical cost. There were no indications of any impairments to property, plant and equipment in the Utility and Pipeline and Storage segments at December 31, 2025.
Earnings Per Common Share
Earnings Per Common Share.  Basic earnings per common share is computed by dividing income or loss by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock.  For purposes of determining earnings per common share, the potentially dilutive securities the Company had outstanding were restricted stock units and performance shares. For the quarter ended December 31, 2025, the diluted weighted average shares outstanding shown on the Consolidated Statements of Income reflects the potential dilution as a result of these securities as determined using the Treasury Stock Method. Restricted stock units and performance shares that are antidilutive are excluded from the calculation of diluted earnings per common share. There were 30 securities and four securities excluded as being antidilutive for the quarters ended December 31, 2025 and December 31, 2024, respectively.
Share Repurchases
Share Repurchases. The Company considers all shares repurchased as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law. The repurchases are accounted for on the date the share repurchase is traded as an adjustment to common stock (at par value) with the excess repurchase price allocated between paid in capital and retained earnings.
Stock-Based Compensation
Stock-Based Compensation.  The Company granted 137,995 performance shares during the quarter ended December 31, 2025. The weighted average fair value of such performance shares was $62.07 per share for the quarter ended December 31, 2025. Performance shares are an award constituting units denominated in common stock of the Company, the number of which may be adjusted over a performance cycle based upon the extent to which performance goals have been satisfied.  Earned performance shares may be distributed in the form of shares of common stock of the Company, an equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company. The performance shares do not entitle the participant to receive dividends during the vesting period.
 
    The performance shares granted during the quarter ended December 31, 2025 include awards that must meet a performance goal related to relative total shareholder return over a three-year performance cycle ("TSR Performance Shares"). The performance goal related to the TSR Performance Shares over the three-year performance cycle is the Company’s three-year total shareholder return relative to the three-year total shareholder return of other companies in a group selected by the
Compensation Committee ("Report Group").  Three-year total shareholder return for a given company will be based on the data reported for that company (with the starting and ending stock prices over the performance cycle calculated as the average closing stock price for the prior calendar month and with dividends reinvested in that company’s securities at each ex-dividend date) in the Bloomberg database.  The number of these TSR Performance Shares that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company.  The fair value price at the date of grant for the TSR Performance Shares is determined using a Monte Carlo simulation technique, which includes a reduction in value for the present value of forgone dividends over the vesting term of the award.  This price is multiplied by the number of TSR Performance Shares awarded, the result of which is recorded as compensation expense over the vesting term of the award.
 
    The Company granted 128,755 restricted stock units during the quarter ended December 31, 2025.  The weighted average fair value of such restricted stock units was $77.75 per share for the quarter ended December 31, 2025.  Restricted stock units represent the right to receive shares of common stock of the Company (or the equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company) at the end of a specified time period. These restricted stock units do not entitle the participant to receive dividends during the vesting period. The fair value at the date of grant of the restricted stock units (represented by the market value of Company common stock on the date of the award) must be reduced by the present value of forgone dividends over the vesting term of the award. The fair value of restricted stock units on the date of award is recorded as compensation expense over the vesting period.
v3.25.4
Summary of Significant Accounting Policies (Tables)
 3 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Schedule of Allowance for Uncollectible Accounts Activity in the allowance for uncollectible accounts for the three months ended December 31, 2025 and 2024 are as follows (in thousands):
Balance at Beginning of PeriodAdditions Charged to Costs and ExpensesDiscounts on Purchased ReceivablesNet Accounts Receivable Written-OffBalance at End of Period
Three Months Ended December 31, 2025
Allowance for Uncollectible Accounts$17,099 $5,214 $121 $(4,930)$17,504 
Three Months Ended December 31, 2024
Allowance for Uncollectible Accounts$26,194 $4,605 $107 $(2,522)$28,384 
Schedule of Components of Accumulated Other Comprehensive Income (Loss) The components of Accumulated Other Comprehensive Income (Loss) and changes for the three months ended December 31, 2025 and 2024, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands): 
 Gains and Losses on Derivative Financial InstrumentsFunded Status of the Pension and Other Post-Retirement Benefit PlansTotal
Three Months Ended December 31, 2025
Balance at October 1, 2025$19,950 $(79,172)$(59,222)
Other Comprehensive Gains and Losses Before Reclassifications
35,952 — 35,952 
Amounts Reclassified From Other Comprehensive Loss(9,720)— (9,720)
Balance at December 31, 2025$46,182 $(79,172)$(32,990)
Three Months Ended December 31, 2024
Balance at October 1, 2024$55,799 $(71,275)$(15,476)
Other Comprehensive Gains and Losses Before Reclassifications
(39,113)— (39,113)
Amounts Reclassified From Other Comprehensive Loss(21,564)— (21,564)
Balance at December 31, 2024$(4,878)$(71,275)$(76,153)
Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) The details about the reclassification adjustments out of accumulated other comprehensive income (loss) for the three months ended December 31, 2025 and 2024 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands):
Details About Accumulated Other Comprehensive Income (Loss) ComponentsAmount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss)Affected Line Item in the Statement Where Net Income is Presented
Three Months Ended
December 31,
20252024
Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges:
 
     Commodity Contracts$13,395 $29,729 Operating Revenues
     Foreign Currency Contracts(121)(225)Operating Revenues
 13,274 29,504 Total Before Income Tax
 (3,554)(7,940)Income Tax Expense
 $9,720 $21,564 Net of Tax
Schedule of Other Current Assets The components of the Company’s Other Current Assets are as follows (in thousands):
                            At December 31, 2025At September 30, 2025
Prepayments$13,854 $16,477 
Prepaid Property and Other Taxes13,855 13,920 
Federal Income Taxes Receivable— 14,511 
State Income Taxes Receivable— 489 
Regulatory Assets34,388 35,362 
 $62,097 $80,759 
Schedule of Other Accruals and Current Liabilities The components of the Company’s Other Accruals and Current Liabilities are as follows (in thousands):
                            At December 31, 2025At September 30, 2025
Accrued Capital Expenditures$47,178 $45,932 
Regulatory Liabilities26,367 20,624 
Reserve for Gas Replacement2,799 — 
Liability for Royalty and Working Interests36,608 28,076 
Federal Income Taxes Payable5,384 — 
State Income Taxes Payable4,676 — 
Pennsylvania Impact Fee19,955 14,923 
Non-Qualified Benefit Plan Liability11,567 11,567 
Other54,668 53,567 
 $209,202 $174,689 
v3.25.4
Revenue from Contracts with Customers (Tables)
 3 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
Schedule of Disaggregation of Revenue The following tables provide a disaggregation of the Company's revenues for the three months ended December 31, 2025 and 2024, presented by type of service from each reportable segment. As reported in the Company's 2025 Form 10-K, the segment reporting structure was modified to merge the Exploration and Production segment and Gathering segment into one reportable segment called Integrated Upstream and Gathering. Prior year disaggregation of revenue information shown below has been restated to reflect this change in presentation.
Quarter Ended December 31, 2025 (Thousands)
Revenues By Type of ServiceIntegrated Upstream and GatheringPipeline and StorageUtilityTotal Reportable SegmentsAll OtherCorporate and Intersegment EliminationsTotal Consolidated
Production of Natural Gas$302,460 $— $— $302,460 $— $— $302,460 
Production of Crude Oil292 — — 292 — — 292 
Natural Gas Processing164 — — 164 — — 164 
Natural Gas Gathering Service2,767 — — 2,767 — — 2,767 
Natural Gas Transportation Service— 81,008 32,618 113,626 — (26,757)86,869 
Natural Gas Storage Service— 25,137 — 25,137 — (10,715)14,422 
Natural Gas Residential Sales— — 198,008 198,008 — — 198,008 
Natural Gas Commercial Sales— — 27,877 27,877 — — 27,877 
Natural Gas Industrial Sales— — 1,409 1,409 — (1)1,408 
Other4,145 756 (1,024)3,877 — (281)3,596 
Total Revenues from Contracts with Customers309,828 106,901 258,888 675,617 — (37,754)637,863 
Alternative Revenue Programs— — 249 249 — — 249 
Derivative Financial Instruments13,395 — — 13,395 — — 13,395 
Total Revenues$323,223 $106,901 $259,137 $689,261 $— $(37,754)$651,507 
Quarter Ended December 31, 2024 (Thousands)   
Revenues By Type of ServiceIntegrated Upstream and GatheringPipeline and StorageUtilityTotal Reportable SegmentsAll OtherCorporate and Intersegment EliminationsTotal Consolidated
Production of Natural Gas$217,458 $— $— $217,458 $— $— $217,458 
Production of Crude Oil515 — — 515 — — 515 
Natural Gas Processing275 — — 275 — — 275 
Natural Gas Gathering Service3,448 — — 3,448 — — 3,448 
Natural Gas Transportation Service— 81,204 26,921 108,125 — (27,181)80,944 
Natural Gas Storage Service— 24,993 — 24,993 — (10,504)14,489 
Natural Gas Residential Sales— — 156,350 156,350 — — 156,350 
Natural Gas Commercial Sales— — 22,243 22,243 — — 22,243 
Natural Gas Industrial Sales— — 1,338 1,338 — (1)1,337 
Other883 415 15,740 17,038 — (261)16,777 
Total Revenues from Contracts with Customers222,579 106,612 222,592 551,783 — (37,947)513,836 
Alternative Revenue Programs— — 5,917 5,917 — — 5,917 
Derivative Financial Instruments29,729 — — 29,729 — — 29,729 
Total Revenues$252,308 $106,612 $228,509 $587,429 $— $(37,947)$549,482 
v3.25.4
Fair Value Measurements (Tables)
 3 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis The following table sets forth, by level within the fair value hierarchy, the Company's financial assets and liabilities (as applicable) that were accounted for at fair value on a recurring basis as of December 31, 2025 and September 30, 2025. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.  
Recurring Fair Value MeasuresAt fair value as of December 31, 2025
(Thousands of Dollars)   Level 1Level 2Level 3
Netting
Adjustments(1)
Total(1)
Assets:
 
    
Cash Equivalents – Money Market Mutual Funds$260,901 $— $— $— $260,901 
Derivative Financial Instruments:     
Over the Counter Swaps – Gas— 84,228 — (32,868)51,360 
Over the Counter No Cost Collars – Gas— 26,413 — (8,154)18,259 
Foreign Currency Contracts— 184 — (439)(255)
Other Investments:     
Balanced Equity Mutual Fund14,183 — — — 14,183 
Fixed Income Mutual Fund10,203 — — — 10,203 
Total$285,287 $110,825 $— $(41,461)$354,651 
Liabilities:     
Derivative Financial Instruments:     
Over the Counter Swaps – Gas$— $32,868 $— $(32,868)$— 
Over the Counter No Cost Collars – Gas— 8,154 — (8,154)— 
Foreign Currency Contracts— 594 — (439)155 
Total$— $41,616 $— $(41,461)$155 
Total Net Assets/(Liabilities)$285,287 $69,209 $— $— $354,496 
Recurring Fair Value MeasuresAt fair value as of September 30, 2025
(Thousands of Dollars)   Level 1Level 2Level 3
Netting
Adjustments(1)
Total(1)
Assets:
Cash Equivalents – Money Market Mutual Funds$30,551 $— $— $— $30,551 
Derivative Financial Instruments:
Over the Counter Swaps – Gas— 62,190 — (33,615)28,575 
Over the Counter No Cost Collars – Gas — 24,149 — (12,805)11,344 
Foreign Currency Contracts— 144 — (675)(531)
Other Investments:
Balanced Equity Mutual Fund13,786 — — — 13,786 
Fixed Income Mutual Fund10,082 — — — 10,082 
Total$54,419 $86,483 $— $(47,095)$93,807 
Liabilities:
Derivative Financial Instruments:
Over the Counter Swaps – Gas$— $34,169 $— $(33,615)$554 
Over the Counter No Cost Collars – Gas— 18,036 — (12,805)5,231 
Foreign Currency Contracts— 893 — (675)218 
Total$— $53,098 $— $(47,095)$6,003 
Total Net Assets/(Liabilities)$54,419 $33,385 $— $— $87,804 

(1)Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.
Schedule of Fair Value Measurements, Nonrecurring The following table presents impairments of assets associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy as of December 31, 2025 and 2024 (in thousands):
Impairments
Nonrecurring Fair Value MeasuresQuarter Ended December 31,
SegmentDate of MeasurementFair Value20252024
Impairment of Assets:
Water Disposal AssetsIntegrated Upstream and GatheringDecember 31, 2024$12,880 $— $33,453 
v3.25.4
Financial Instruments (Tables)
 3 Months Ended
Dec. 31, 2025
Financial Instruments, Owned, at Fair Value, by Type, Alternative [Abstract]  
Schedule of Long-Term Debt Based on these criteria, the fair market value of long-term debt, including current portion, was as follows (in thousands): 
 December 31, 2025September 30, 2025
 Carrying
Amount		Fair ValueCarrying
Amount		Fair Value
Long-Term Debt$2,683,892 $2,695,409 $2,682,861 $2,696,145 
Schedule of Other Investments The components of the Company's Other Investments are as follows (in thousands):
At December 31, 2025At September 30, 2025
Life Insurance Contracts$44,576 $44,478 
Equity Mutual Fund14,183 13,786 
Fixed Income Mutual Fund10,203 10,082 
$68,962 $68,346 
Schedule of Cash Flow Hedges
The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the
Three Months Ended December 31, 2025 and 2024 (Thousands of Dollars)
Derivatives in Cash Flow Hedging RelationshipsAmount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on
the Consolidated Statement of
Comprehensive Income (Loss)
for the
 Three Months Ended
 December 31,		Location of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of IncomeAmount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income for the
 Three Months Ended
 December 31,
 20252024 20252024
Commodity Contracts$48,880 $(51,909)Operating Revenue$13,395 $29,729 
Foreign Currency Contracts218 (1,607)Operating Revenue(121)(225)
Total$49,098 $(53,516) $13,274 $29,504 
v3.25.4
Capitalization (Tables)
 3 Months Ended
Dec. 31, 2025
Capitalization, Long-Term Debt and Equity [Abstract]  
Schedule of Changes in Common Stock Equity
Summary of Changes in Common Stock Equity
 Common StockPaid In
Capital		Earnings
Reinvested
in the
Business		Accumulated
Other
Comprehensive
Income (Loss)
SharesAmount
 (Thousands)
Balance at October 1, 202590,379 $90,379 $1,050,918 $2,012,529 $(59,222)
Net Income Available for Common Stock181,645 
Dividends Declared on Common Stock ($0.535 Per Share)
(50,834)
Other Comprehensive Income, Net of Tax26,232 
Share-Based Payment Expense (1)
3,427 
Common Stock Issued from Sale of Common Stock4,403 4,403 334,173 
Common Stock Issued (Repurchased) Under Stock and Benefit Plans235 235 (5,925)
Balance at December 31, 202595,017 $95,017 $1,382,593 $2,143,340 $(32,990)
Balance at October 1, 202491,006 $91,006 $1,045,487 $1,727,326 $(15,476)
Net Income Available for Common Stock44,986 
Dividends Declared on Common Stock ($0.515 Per Share)
(46,671)
Other Comprehensive Loss, Net of Tax(60,677)
Share-Based Payment Expense (1)
4,090 
Common Stock Issued (Repurchased) Under Stock and Benefit Plans156 156 (3,511)
Share Repurchases Under Repurchase Plan(549)$(549)$(6,361)$(26,993)
Balance at December 31, 202490,613 $90,613 $1,039,705 $1,698,648 $(76,153)

(1)Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.
Schedule of Common Stock Share Activity Common stock share activity during the three months ended December 31, 2025 consisted of the following items:
Three Months Ended December 31, 2025
Vesting of Restricted Stock Units138,643 
Vesting of Performance Shares167,241 
Issuance of Common Stock Pursuant to the Company's Non-Employee Director Equity
Compensation Plan and Deferred Compensation Plan for Directors and Officers
7,368 
Shares Tendered to Pay Withholding Taxes on Stock-Based Compensation Awards (1)
(77,422)
Common Stock Issued Under Stock and Benefit Plans235,830 
Common Stock Issued from Sale of Common Stock4,402,513 
Total Common Stock Issued During the Three Months Ended December 31, 20254,638,343 
(1)    The Company considers all shares tendered as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law.
v3.25.4
Business Segment Information (Tables)
 3 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Schedule of Financial Segment Information by Segment A listing of segment assets at December 31, 2025 and December 31, 2024 is shown in the tables below.
Three Months Ended December 31, 2025
 Integrated Upstream and GatheringPipeline
and
Storage		UtilityTotal
Reportable
Segments
All
   Other(4)
Corporate
and
Intersegment
  Eliminations(4)
Total
Consolidated
 (Thousands)
Revenue from External Customers(1)
$323,223 $69,237 $259,047 $651,507 $— $— $651,507 
Intersegment Revenues
— 37,664 90 37,754 — (37,754)— 
  Total Revenues323,223 106,901 259,137 689,261 — (37,754)651,507 
Operation and Maintenance Expense(2):
Upstream General and Administrative Expense19,406 — — 19,406 — (63)19,343 
Lease Operating Expense16,826 — — 16,826 — (789)16,037 
Gathering Operation and Maintenance Expense10,388 — — 10,388 — (69)10,319 
All Other Operation and Maintenance Expense3,378 27,263 60,997 91,638 — 5,652 97,290 
Purchased Gas Expense(2)
— — 122,285 122,285 — (36,679)85,606 
Depreciation, Depletion and Amortization Expense(2)
84,263 19,102 18,479 121,844 — 181 122,025 
Impairment of Assets (Significant Non-Cash Item)(2)
— — — — — — — 
Interest Expense(2)
16,133 11,801 11,606 39,540 136 3,698 43,374 
Interest Income(193)(964)(1,039)(2,196)(10)(571)(2,777)
Income Tax Expense (Benefit)(2)
44,111 10,366 7,335 61,812 (37)(2,438)59,337 
Other Expense (Income) Items(3)
4,864 8,114 5,384 18,362 33 913 19,308 
Segment Profit: Net Income (Loss)
$124,047 $31,219 $34,090 $189,356 $(122)$(7,589)$181,645 
Expenditures for Additions to Long-Lived Assets
$141,849 $37,602 $43,094 $222,545 $— $176 $222,721 
 Integrated Upstream and GatheringPipeline
and
Storage		UtilityTotal
Reportable
Segments
All
   Other(4)
Corporate
and
Intersegment
  Eliminations(4)
Total
Consolidated
 (Thousands)
Segment Assets:
At December 31, 2025$3,925,191 $2,504,541 $2,645,957 $9,075,689 $8,565 $121,618 $9,205,872 
At September 30, 2025$3,701,646 $2,412,747 $2,534,289 $8,648,682 $8,704 $61,718 $8,719,104 
Three Months Ended December 31, 2024
 Integrated Upstream and GatheringPipeline
and
Storage		UtilityTotal
Reportable
Segments
All
   Other(4)
Corporate and
Intersegment
  Eliminations(4)
Total
Consolidated
 (Thousands)
Revenue from External Customers(1)
$252,308 $68,750 $228,424 $549,482 $— $— $549,482 
Intersegment Revenues
— 37,862 85 37,947 — (37,947)— 
  Total Revenues252,308 106,612 228,509 587,429 — (37,947)549,482 
Operation and Maintenance Expense(2):
Upstream General and Administrative Expense19,326 — — 19,326 — (59)19,267 
Lease Operating Expense10,651 — — 10,651 — (1,587)9,064 
Gathering Operation and Maintenance Expense6,735 — — 6,735 — (65)6,670 
All Other Operation and Maintenance Expense3,867 27,034 56,260 87,161 — 2,564 89,725 
Purchased Gas Expense(2)
— — 101,473 101,473 — (36,136)65,337 
Depreciation, Depletion and Amortization Expense(2)
73,819 18,585 16,827 109,231 — 139 109,370 
Impairment of Assets (Significant Non-Cash Item)(2)
141,802 — — 141,802 — — 141,802 
Interest Expense(2)
19,410 11,729 10,716 41,855 116 (4,228)37,743 
Interest Income(679)(2,006)(648)(3,333)— 1,650 (1,683)
Income Tax Expense (Benefit)(2)
(6,451)11,177 7,022 11,748 (59)(507)11,182 
Other Expense (Income) Items(3)
3,460 7,639 4,360 15,459 136 424 16,019 
Segment Profit: Net Income (Loss)
$(19,632)$32,454 $32,499 $45,321 $(193)$(142)$44,986 
Expenditures for Additions to Long-Lived Assets
$135,629 $19,792 $36,430 $191,851 $— $204 $192,055 
(1)All Revenue from External Customers originated in the United States.
(2)The Company considers this line to be a significant expense.
(3)Consists of Property, Franchise and Other Taxes, Non-Service Pension and Post-Retirement Benefits Costs (Credits), Other (Income) Deductions, and Purchased Gas Expense for the Pipeline and Storage Segment.
(4)Corporate and All Other categories primarily represent other non-segment business activities and eliminating entries.
v3.25.4
Retirement Plan and Other Post-Retirement Benefits (Tables)
 3 Months Ended
Dec. 31, 2025
Retirement Benefits [Abstract]  
Schedule of Components of Net Periodic Benefit Cost (Income) Components of Net Periodic Benefit Cost (in thousands):
 
 Retirement PlanOther Post-Retirement Benefits
Three Months Ended December 31,2025202420252024
Service Cost$861 $1,023 $105 $130 
Interest Cost8,944 9,223 3,836 3,625 
Expected Return on Plan Assets(14,710)(14,647)(7,374)(6,536)
Amortization of Prior Service Cost (Credit)63 76 (65)(107)
Amortization of (Gains) Losses2,421 1,620 152 9 
Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1)
(98)(165)(148)(727)
Net Periodic Benefit Cost (Income)$(2,519)$(2,870)$(3,494)$(3,606)
(1)The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.
v3.25.4
Summary Of Significant Accounting Policies (Narrative) (Details)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2025
USD ($)
$ / shares
shares
Sep. 30, 2025
USD ($)
segment
Dec. 31, 2024
USD ($)
shares
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Gas Stored Underground $ 18,978 $ 33,468   $ 33,468  
Capitalized costs relating to exploration and production activities, net 2,510,000 $ 2,460,000   2,460,000  
Capitalized costs of unproved properties excluded from amortization $ 105,700     $ 112,400  
Full cost ceiling test discount factor (as a percent) 10.00%        
Amount full cost ceiling exceeds book value of exploration and production properties $ 1,300,000        
Impairment of exploration and production properties     $ 108,300    
Increase estimated future net cash flows $ 170,700        
Antidilutive securities (in shares) | shares 30   4    
Impairment of Exploration and Production Properties          
Summary Of Significant Accounting Policies [Line Items]          
Deferred income tax benefit     $ 29,200    
Reserve For Gas Replacement          
Summary Of Significant Accounting Policies [Line Items]          
Gas Stored Underground $ 2,800        
Reserve For Gas Replacement | Forecast          
Summary Of Significant Accounting Policies [Line Items]          
Gas Stored Underground         $ 0
Exploration and Production & Gathering Segments          
Summary Of Significant Accounting Policies [Line Items]          
Number of operating segments | segment   1      
Restricted Stock Units          
Summary Of Significant Accounting Policies [Line Items]          
Share based compensation other than options grants in period (in shares) | shares 128,755        
Granted in fiscal year, weighted average grant date fair value (in USD per share) | $ / shares $ 77.75        
Vesting of Performance Shares          
Summary Of Significant Accounting Policies [Line Items]          
Share based compensation other than options grants in period (in shares) | shares 137,995        
Granted in fiscal year, weighted average grant date fair value (in USD per share) | $ / shares $ 62.07        
Relative shareholder return, performance cycle (in years) 3 years        
v3.25.4
Summary of Significant Accounting Policies (Schedule of Allowance for Uncollectible Accounts) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Allowance for Uncollectible Accounts [Roll Forward]    
Balance at Beginning of Period $ 17,099 $ 26,194
Additions Charged to Costs and Expenses 5,214 4,605
Discounts on Purchased Receivables 121 107
Net Accounts Receivable Written-Off (4,930) (2,522)
Balance at End of Period $ 17,504 $ 28,384
v3.25.4
Summary of Significant Accounting Policies (Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Roll Forward]    
Other Comprehensive Gains and Losses Before Reclassifications $ 35,952 $ (39,113)
Amounts Reclassified From Other Comprehensive Income (Loss) (9,720) (21,564)
Gains and Losses on Derivative Financial Instruments    
Accumulated Other Comprehensive Income (Loss) [Roll Forward]    
Beginning balance 19,950 55,799
Other Comprehensive Gains and Losses Before Reclassifications 35,952 (39,113)
Amounts Reclassified From Other Comprehensive Income (Loss) (9,720) (21,564)
Ending balance 46,182 (4,878)
Funded Status of the Pension and Other Post-Retirement Benefit Plans    
Accumulated Other Comprehensive Income (Loss) [Roll Forward]    
Beginning balance (79,172) (71,275)
Other Comprehensive Gains and Losses Before Reclassifications 0 0
Amounts Reclassified From Other Comprehensive Income (Loss) 0 0
Ending balance (79,172) (71,275)
Accumulated Other Comprehensive Income (Loss)    
Accumulated Other Comprehensive Income (Loss) [Roll Forward]    
Beginning balance (59,222) (15,476)
Ending balance $ (32,990) $ (76,153)
v3.25.4
Summary of Significant Accounting Policies (Schedule of Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]    
Operating Revenues $ 651,507 $ 549,482
Total Before Income Tax 240,982 56,168
Income Tax Expense [1] (59,337) (11,182)
Net Income Available for Common Stock 181,645 44,986
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss)    
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]    
Total Before Income Tax 13,274 29,504
Income Tax Expense (3,554) (7,940)
Net Income Available for Common Stock 9,720 21,564
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) | Commodity Contracts | Gains and Losses on Derivative Financial Instruments    
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]    
Operating Revenues 13,395 29,729
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) | Foreign Currency Contracts | Gains and Losses on Derivative Financial Instruments    
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]    
Operating Revenues $ (121) $ (225)
[1] The Company considers this line to be a significant expense.
v3.25.4
Summary of Significant Accounting Policies (Schedule of Components of Other Current Assets) (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Summary Of Significant Accounting Policies [Line Items]    
Prepayments $ 13,854 $ 16,477
Prepaid Property and Other Taxes 13,855 13,920
Regulatory Assets 34,388 35,362
Other Current Assets 62,097 80,759
Federal Income Taxes Receivable    
Summary Of Significant Accounting Policies [Line Items]    
Income Taxes Receivable 0 14,511
State Income Taxes Receivable    
Summary Of Significant Accounting Policies [Line Items]    
Income Taxes Receivable $ 0 $ 489
v3.25.4
Summary of Significant Accounting Policies (Schedule of Other Accruals and Current Liabilities) (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Summary Of Significant Accounting Policies [Line Items]    
Accrued Capital Expenditures $ 47,178 $ 45,932
Regulatory Liabilities 26,367 20,624
Reserve for Gas Replacement 2,799 0
Liability for Royalty and Working Interests 36,608 28,076
Pennsylvania Impact Fee 19,955 14,923
Non-Qualified Benefit Plan Liability 11,567 11,567
Other 54,668 53,567
Other Accruals and Current Liabilities 209,202 174,689
Federal Income Taxes Payable    
Summary Of Significant Accounting Policies [Line Items]    
Federal Income Taxes Payable 5,384 0
State Income Taxes Payable    
Summary Of Significant Accounting Policies [Line Items]    
Federal Income Taxes Payable $ 4,676 $ 0
v3.25.4
Pending Acquisition (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Dec. 17, 2025
Nov. 06, 2025
Dec. 31, 2026
Dec. 31, 2025
Dec. 31, 2024
Sep. 30, 2025
Business Combination [Line Items]            
Common stock, par value (in dollars per share)       $ 1   $ 1
Net Proceeds from Common Stock Sale       $ 347,106 $ 0  
Sale of Common Stock            
Business Combination [Line Items]            
Common stock issued from sale of common stock (in shares) 4,402,513     4,402,513    
Common stock, par value (in dollars per share) $ 1.00          
Per share or per unit amount of equity securities issued (in dollars per share) $ 79.50          
Net Proceeds from Common Stock Sale $ 338,600          
Vectren Energy Delivery of Ohio, LLC | Term Loan Facility, Commitment Letter            
Business Combination [Line Items]            
Debt instrument, term   364 days        
Forecast | Vectren Energy Delivery of Ohio, LLC            
Business Combination [Line Items]            
Total consideration     $ 2,620,000      
Payments to acquire businesses, gross     1,420,000      
Forecast | Vectren Energy Delivery of Ohio, LLC | Promissory Note            
Business Combination [Line Items]            
Long-term debt, face amount     $ 1,200,000      
Debt instrument, term     364 days      
Interest rate (in percent)     6.50%      
v3.25.4
Revenue from Contracts with Customers (Schedule of Disaggregation of Revenue) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers $ 637,863 $ 513,836
Alternative Revenue Programs 249 5,917
Derivative Financial Instruments 13,395 29,729
Total Revenues 651,507 549,482
Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 675,617 551,783
Alternative Revenue Programs 249 5,917
Derivative Financial Instruments 13,395 29,729
Total Revenues 689,261 587,429
All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Alternative Revenue Programs 0 0
Derivative Financial Instruments 0 0
Total Revenues 0 0
Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers (37,754) (37,947)
Alternative Revenue Programs 0 0
Derivative Financial Instruments 0 0
Total Revenues [1] (37,754) (37,947)
Integrated Upstream and Gathering    
Disaggregation of Revenue [Line Items]    
Total Revenues 323,223 252,308
Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 309,828 222,579
Alternative Revenue Programs 0 0
Derivative Financial Instruments 13,395 29,729
Total Revenues 323,223 252,308
Pipeline and Storage    
Disaggregation of Revenue [Line Items]    
Total Revenues 69,237 68,750
Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 106,901 106,612
Alternative Revenue Programs 0 0
Derivative Financial Instruments 0 0
Total Revenues 106,901 106,612
Utility    
Disaggregation of Revenue [Line Items]    
Total Revenues 259,047 228,424
Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 258,888 222,592
Alternative Revenue Programs 249 5,917
Derivative Financial Instruments 0 0
Total Revenues 259,137 228,509
Production of Natural Gas    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 302,460 217,458
Production of Natural Gas | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 302,460 217,458
Production of Natural Gas | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Natural Gas | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Natural Gas | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 302,460 217,458
Production of Natural Gas | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Natural Gas | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Crude Oil    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 292 515
Production of Crude Oil | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 292 515
Production of Crude Oil | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Crude Oil | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Crude Oil | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 292 515
Production of Crude Oil | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Production of Crude Oil | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Processing    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 164 275
Natural Gas Processing | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 164 275
Natural Gas Processing | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Processing | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Processing | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 164 275
Natural Gas Processing | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Processing | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Gathering Service    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 2,767 3,448
Natural Gas Gathering Service | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 2,767 3,448
Natural Gas Gathering Service | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Gathering Service | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Gathering Service | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 2,767 3,448
Natural Gas Gathering Service | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Gathering Service | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Transportation Service    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 86,869 80,944
Natural Gas Transportation Service | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 113,626 108,125
Natural Gas Transportation Service | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Transportation Service | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers (26,757) (27,181)
Natural Gas Transportation Service | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Transportation Service | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 81,008 81,204
Natural Gas Transportation Service | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 32,618 26,921
Natural Gas Storage Service    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 14,422 14,489
Natural Gas Storage Service | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 25,137 24,993
Natural Gas Storage Service | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Storage Service | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers (10,715) (10,504)
Natural Gas Storage Service | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Storage Service | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 25,137 24,993
Natural Gas Storage Service | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Residential Sales    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 198,008 156,350
Natural Gas Residential Sales | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 198,008 156,350
Natural Gas Residential Sales | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Residential Sales | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Residential Sales | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Residential Sales | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Residential Sales | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 198,008 156,350
Natural Gas Commercial Sales    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 27,877 22,243
Natural Gas Commercial Sales | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 27,877 22,243
Natural Gas Commercial Sales | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Commercial Sales | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Commercial Sales | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Commercial Sales | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Commercial Sales | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 27,877 22,243
Natural Gas Industrial Sales    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 1,408 1,337
Natural Gas Industrial Sales | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 1,409 1,338
Natural Gas Industrial Sales | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Industrial Sales | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers (1) (1)
Natural Gas Industrial Sales | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Industrial Sales | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Natural Gas Industrial Sales | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 1,409 1,338
Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 3,596 16,777
Other | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 3,877 17,038
Other | All Other    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 0 0
Other | Corporate and Intersegment Eliminations    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers (281) (261)
Other | Integrated Upstream and Gathering | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 4,145 883
Other | Pipeline and Storage | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers 756 415
Other | Utility | Operating Segments    
Disaggregation of Revenue [Line Items]    
Total Revenues from Contracts with Customers $ (1,024) $ 15,740
[1] Corporate and All Other categories primarily represent other non-segment business activities and eliminating entries.
v3.25.4
Revenue from Contracts with Customers (Narrative) (Details)
$ in Millions
 3 Months Ended
Sep. 30, 2025
segment
Dec. 31, 2025
USD ($)
Exploration and Production & Gathering Segments    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Number of operating segments | segment 1  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligations   $ 174.8
Remaining performance obligation, period   9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligations   $ 218.7
Remaining performance obligation, period   1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligations   $ 164.2
Remaining performance obligation, period   1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligations   $ 130.8
Remaining performance obligation, period   1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligations   $ 123.8
Remaining performance obligation, period   1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-10-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligations   $ 540.0
Remaining performance obligation, period  
v3.25.4
Fair Value Measurements (Schedule of Recurring Fair Value Measures of Assets and Liabilities) (Details) - Fair Value, Recurring - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Derivative Financial Instruments:    
Derivative Asset Netting Adjustment [1] $ (41,461) $ (47,095)
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Fair Value of Derivative Financial Instruments Fair Value of Derivative Financial Instruments
Total Assets [1] $ 354,651 $ 93,807
Derivative Financial Instruments:    
Derivative Liability Netting Adjustments [1] $ (41,461) $ (47,095)
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Fair Value of Derivative Financial Instruments Fair Value of Derivative Financial Instruments
Total Liabilities [1] $ 155 $ 6,003
Total Net Assets/(Liabilities) Netting Adjustments [1] 0 0
Total Net Assets/(Liabilities) [1] 354,496 87,804
Money Market Funds    
Assets:    
Cash Equivalents – Money Market Mutual Funds [1] 260,901 30,551
Over the Counter Swaps — Gas    
Derivative Financial Instruments:    
Derivative Asset Netting Adjustment [1] (32,868) (33,615)
Derivative asset [1] 51,360 28,575
Derivative Financial Instruments:    
Derivative Liability Netting Adjustments [1] (32,868) (33,615)
Derivative liability [1] 0 554
Over the Counter No Cost Collars – Gas    
Derivative Financial Instruments:    
Derivative Asset Netting Adjustment [1] (8,154) (12,805)
Derivative asset [1] 18,259 11,344
Derivative Financial Instruments:    
Derivative Liability Netting Adjustments [1] (8,154) (12,805)
Derivative liability [1] 0 5,231
Foreign Currency Contracts    
Derivative Financial Instruments:    
Derivative Asset Netting Adjustment [1] (439) (675)
Derivative asset [1] (255) (531)
Derivative Financial Instruments:    
Derivative Liability Netting Adjustments [1] (439) (675)
Derivative liability [1] 155 218
Balanced Equity Mutual Fund    
Derivative Financial Instruments:    
Other Investments [1] 14,183 13,786
Fixed Income Mutual Fund    
Derivative Financial Instruments:    
Other Investments [1] 10,203 10,082
Level 1    
Derivative Financial Instruments:    
Total Assets 285,287 54,419
Derivative Financial Instruments:    
Total Liabilities 0 0
Total Net Assets/(Liabilities) 285,287 54,419
Level 1 | Money Market Funds    
Assets:    
Cash Equivalents – Money Market Mutual Funds 260,901 30,551
Level 1 | Over the Counter Swaps — Gas    
Derivative Financial Instruments:    
Derivative Asset 0 0
Derivative Financial Instruments:    
Derivative Liability 0 0
Level 1 | Over the Counter No Cost Collars – Gas    
Derivative Financial Instruments:    
Derivative Asset 0 0
Derivative Financial Instruments:    
Derivative Liability 0 0
Level 1 | Foreign Currency Contracts    
Derivative Financial Instruments:    
Derivative Asset 0 0
Derivative Financial Instruments:    
Derivative Liability 0 0
Level 1 | Balanced Equity Mutual Fund    
Derivative Financial Instruments:    
Other Investments 14,183 13,786
Level 1 | Fixed Income Mutual Fund    
Derivative Financial Instruments:    
Other Investments 10,203 10,082
Level 2    
Derivative Financial Instruments:    
Total Assets 110,825 86,483
Derivative Financial Instruments:    
Total Liabilities 41,616 53,098
Total Net Assets/(Liabilities) 69,209 33,385
Level 2 | Money Market Funds    
Assets:    
Cash Equivalents – Money Market Mutual Funds 0 0
Level 2 | Over the Counter Swaps — Gas    
Derivative Financial Instruments:    
Derivative Asset 84,228 62,190
Derivative Financial Instruments:    
Derivative Liability 32,868 34,169
Level 2 | Over the Counter No Cost Collars – Gas    
Derivative Financial Instruments:    
Derivative Asset 26,413 24,149
Derivative Financial Instruments:    
Derivative Liability 8,154 18,036
Level 2 | Foreign Currency Contracts    
Derivative Financial Instruments:    
Derivative Asset 184 144
Derivative Financial Instruments:    
Derivative Liability 594 893
Level 2 | Balanced Equity Mutual Fund    
Derivative Financial Instruments:    
Other Investments 0 0
Level 2 | Fixed Income Mutual Fund    
Derivative Financial Instruments:    
Other Investments 0 0
Level 3    
Derivative Financial Instruments:    
Total Assets 0 0
Derivative Financial Instruments:    
Total Liabilities 0 0
Total Net Assets/(Liabilities) 0 0
Level 3 | Money Market Funds    
Assets:    
Cash Equivalents – Money Market Mutual Funds 0 0
Level 3 | Over the Counter Swaps — Gas    
Derivative Financial Instruments:    
Derivative Asset 0 0
Derivative Financial Instruments:    
Derivative Liability 0 0
Level 3 | Over the Counter No Cost Collars – Gas    
Derivative Financial Instruments:    
Derivative Asset 0 0
Derivative Financial Instruments:    
Derivative Liability 0 0
Level 3 | Foreign Currency Contracts    
Derivative Financial Instruments:    
Derivative Asset 0 0
Derivative Financial Instruments:    
Derivative Liability 0 0
Level 3 | Balanced Equity Mutual Fund    
Derivative Financial Instruments:    
Other Investments 0 0
Level 3 | Fixed Income Mutual Fund    
Derivative Financial Instruments:    
Other Investments $ 0 $ 0
[1] Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.
v3.25.4
Fair Value Measures and Disclosures (Schedule of Nonrecurring Fair Value Measures Within Level 3) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Impairment of Assets [1] $ 0 $ 141,802
Level 3 | Fair Value, Nonrecurring | Integrated Upstream and Gathering    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Impairment of Assets $ 0 33,453
Property, plant, and equipment, fair value   $ 12,880
[1] The Company considers this line to be a significant expense.
v3.25.4
Financial Instruments (Schedule of Long-Term Debt) (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Financial Instruments, Owned, at Fair Value, by Type, Alternative [Abstract]    
Carrying Amount $ 2,683,892 $ 2,682,861
Fair Value $ 2,695,409 $ 2,696,145
v3.25.4
Financial Instruments (Schedule of Other Investments) (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Sep. 30, 2025
Investment Holdings [Line Items]    
Life Insurance Contracts $ 44,576 $ 44,478
Other Investments 68,962 68,346
Equity Mutual Fund    
Investment Holdings [Line Items]    
Mutual Funds 14,183 13,786
Fixed Income Mutual Fund    
Investment Holdings [Line Items]    
Mutual Funds $ 10,203 $ 10,082
v3.25.4
Financial Instruments (Narrative) (Details)
$ in Millions, Bcf in Billions
 3 Months Ended
Dec. 31, 2025
USD ($)
counterparty
Bcf
Derivative Instruments, Gain (Loss) [Line Items]  
After tax net hedging gains in accumulated other comprehensive income (loss) $ 46.2
After tax net hedging gains reclassified within twelve months 45.9
Fair market value of derivative liability with a credit-risk related contingency 0.2
Hedging Collateral Deposits 0.0
Foreign Currency Contracts  
Derivative Instruments, Gain (Loss) [Line Items]  
Hedging notional amount of forecasted transportation costs $ 41.0
Over the Counter Swaps, No Cost Collars and Foreign Currency Forward Contracts  
Derivative Instruments, Gain (Loss) [Line Items]  
Number of counterparties in which the company holds over-the-counter swap positions | counterparty 17
Number of counterparties in net gain position | counterparty 16
Credit risk exposure per counterparty $ 4.3
Maximum credit risk exposure per counterparty 10.8
Collateral received by the company $ 0.0
Cash Flow Hedges  
Derivative Instruments, Gain (Loss) [Line Items]  
Hedge duration 5 years
Cash Flow Hedges | Natural Gas Bcf  
Derivative Instruments, Gain (Loss) [Line Items]  
Nonmonetary notional amount of price risk cash flow hedge derivatives, natural gas | Bcf 403.1
v3.25.4
Financial Instruments (Schedule of Cash Flow Hedges) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss) $ 49,098 $ (53,516)
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income 13,274 29,504
Commodity Contracts | Operating Revenues    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss) 48,880 (51,909)
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income 13,395 29,729
Foreign Currency Contracts | Operating Revenues    
Derivative Instruments, Gain (Loss) [Line Items]    
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss) 218 (1,607)
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income $ (121) $ (225)
v3.25.4
Income Taxes (Details)
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Income Tax Disclosure [Abstract]    
Effective tax rate 24.60% 19.90%
v3.25.4
Capitalization (Schedule of Changes in Common Stock Equity) (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Dec. 17, 2025
Dec. 31, 2025
Dec. 31, 2024
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Beginning balance (in shares)   90,379,095  
Beginning balance   $ 3,094,604  
Net Income Available for Common Stock   181,645 $ 44,986
Dividends Declared on Common Stock   (50,834) (46,671)
Other Comprehensive Income (Loss), Net of Tax   $ 26,232 $ (60,677)
Ending balance (in shares)   95,017,438  
Ending balance   $ 3,587,960  
Dividends per share (in dollars per share)   $ 0.535 $ 0.515
Sale of Common Stock      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Common Stock Issued from Sale of Common Stock (in shares) 4,402,513 4,402,513  
Stock and Benefit Plans      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Common Stock Issued Under Stock and Benefit Plans (in shares)   235,830  
Common Stock      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Beginning balance (in shares)   90,379,000 91,006,000
Beginning balance   $ 90,379 $ 91,006
Common Stock Issued Under Stock and Benefit Plans (in shares)   235,000 156,000
Common Stock Issued Under Stock and Benefit Plans   $ 235 $ 156
Ending balance (in shares)   95,017,000 90,613,000
Ending balance   $ 95,017 $ 90,613
Common Stock | Sale of Common Stock      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Common Stock Issued from Sale of Common Stock (in shares)   4,403,000  
Common Stock Issued from Sale of Common Stock   $ 4,403  
Common Stock | Share Repurchase Plan      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Share Repurchases (in shares)     (549,000)
Share Repurchases     $ (549)
Paid In Capital      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Beginning balance   1,050,918 1,045,487
Share-Based Payment Expense [1]   3,427 4,090
Ending balance   1,382,593 1,039,705
Paid In Capital | Sale of Common Stock      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Common Stock Issued from Sale of Common Stock   334,173  
Paid In Capital | Stock and Benefit Plans      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Share Repurchases   (5,925) (3,511)
Paid In Capital | Share Repurchase Plan      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Share Repurchases     (6,361)
Earnings Reinvested in the Business      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Beginning balance   2,012,529 1,727,326
Net Income Available for Common Stock   181,645 44,986
Dividends Declared on Common Stock   (50,834) (46,671)
Share Repurchases   0 (26,993)
Ending balance   2,143,340 1,698,648
Earnings Reinvested in the Business | Share Repurchase Plan      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Share Repurchases     (26,993)
Accumulated Other Comprehensive Income (Loss)      
Increase (Decrease) in Stockholders' Equity [Roll Forward]      
Beginning balance   (59,222) (15,476)
Other Comprehensive Income (Loss), Net of Tax   26,232 (60,677)
Ending balance   $ (32,990) $ (76,153)
[1] Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.
v3.25.4
Capitalization (Schedule of Common Stock Share Activity) (Details) - shares
 3 Months Ended
Dec. 17, 2025
Dec. 31, 2025
Schedule of Capitalization, Equity [Line Items]    
Total Common Stock Issued (in shares)   4,638,343
Sale of Common Stock    
Schedule of Capitalization, Equity [Line Items]    
Common Stock Issued from Sale of Common Stock (in shares) 4,402,513 4,402,513
Director Equity Compensation Plan And Director And Officer DCP Plan    
Schedule of Capitalization, Equity [Line Items]    
Common stock issued (in shares)   7,368
Shares Tendered to Pay Withholding Taxes on Stock-Based Compensation Awards    
Schedule of Capitalization, Equity [Line Items]    
Share Repurchases (in shares) [1]   (77,422)
Stock and Benefit Plans    
Schedule of Capitalization, Equity [Line Items]    
Common stock issued (in shares)   235,830
Vesting of Restricted Stock Units    
Schedule of Capitalization, Equity [Line Items]    
Common stock issued (in shares)   138,643
Vesting of Performance Shares    
Schedule of Capitalization, Equity [Line Items]    
Common stock issued (in shares)   167,241
[1] The Company considers all shares tendered as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law.
v3.25.4
Capitalization (Narrative) (Details)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Jan. 22, 2026
USD ($)
Dec. 17, 2025
USD ($)
$ / shares
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2024
USD ($)
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
$ / shares
Apr. 30, 2024
USD ($)
Feb. 14, 2024
USD ($)
lender
Debt Instrument [Line Items]                
Common stock, par value (in dollars per share) | $ / shares     $ 1     $ 1    
Net Proceeds from Common Stock Sale     $ 347,106 $ 0        
Current Portion of Long-Term Debt     600,000     $ 300,000    
5.50% Through October 2026                
Debt Instrument [Line Items]                
Current Portion of Long-Term Debt     $ 300,000          
Long-term debt, interest rate     5.50%          
Term Loan Agreement                
Debt Instrument [Line Items]                
Current Portion of Long-Term Debt     $ 300,000     $ 300,000    
Number of lenders | lender               6
Maximum borrowing capacity               $ 300,000
Long-term debt, face amount             $ 300,000  
Net Proceeds from Issuance of Long-Term Debt         $ 299,400      
Rate adjustment to SOFR     0.0010          
Spread on variable rate     1.375%          
Term Loan Agreement | Subsequent Event                
Debt Instrument [Line Items]                
Repayment of delayed draw term loan $ 300,000              
Sale of Common Stock                
Debt Instrument [Line Items]                
Common Stock Issued from Sale of Common Stock (in shares) | shares   4,402,513 4,402,513          
Common stock, par value (in dollars per share) | $ / shares   $ 1.00            
Per share or per unit amount of equity securities issued (in dollars per share) | $ / shares   $ 79.50            
Net Proceeds from Common Stock Sale   $ 338,600            
v3.25.4
Commitments and Contingencies (Details)
$ in Millions
Dec. 31, 2025
USD ($)
Other Commitments [Line Items]  
Estimated minimum liability for environmental remediation $ 2.9
Environmental Site Remediation Costs  
Other Commitments [Line Items]  
Other Regulatory Liabilities $ 1.5
v3.25.4
Business Segment Information (Narrative) (Details) - segment
 3 Months Ended
Dec. 31, 2025
Sep. 30, 2025
Segment Reporting Information [Line Items]    
Number of reportable segments 3  
Exploration and Production & Gathering Segments    
Segment Reporting Information [Line Items]    
Number of operating segments   1
v3.25.4
Business Segment Information - (Schedule of Information By Segment) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Sep. 30, 2025
Segment Reporting Information [Line Items]      
Revenues From External Customers [1] $ 651,507 $ 549,482  
Intersegment Revenues 0 0  
Total Revenues 651,507 549,482  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2] 19,343 19,267  
Lease Operating Expense [2] 16,037 9,064  
Gathering Operation and Maintenance Expense [2] 10,319 6,670  
All Other Operation and Maintenance Expense [2] 97,290 89,725  
Purchased Gas [2] 85,606 65,337  
Depreciation, Depletion and Amortization [2] 122,025 109,370  
Impairment of Assets (Significant Non-Cash Item) [2] 0 141,802  
Interest Expense [2] 43,374 37,743  
Interest Income (2,777) (1,683)  
Income Tax Expense (Benefit) [2] 59,337 11,182  
Other Expense (Income) Items [3] 19,308 16,019  
Segment Profit: Net Income (Loss) 181,645 44,986  
Expenditures for Additions to Long-Lived Assets 222,721 192,055  
Segment Assets: 9,205,872   $ 8,719,104
Operating Segments      
Segment Reporting Information [Line Items]      
Total Revenues 689,261 587,429  
All Other      
Segment Reporting Information [Line Items]      
Total Revenues 0 0  
Corporate      
Segment Reporting Information [Line Items]      
Revenues From External Customers [1],[4] 0 0  
Corporate and Intersegment Eliminations      
Segment Reporting Information [Line Items]      
Intersegment Revenues [4] (37,754) (37,947)  
Total Revenues [4] (37,754) (37,947)  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2],[4] (63) (59)  
Lease Operating Expense [2],[4] (789) (1,587)  
Gathering Operation and Maintenance Expense [2],[4] (69) (65)  
All Other Operation and Maintenance Expense [2],[4] 5,652 2,564  
Purchased Gas [2],[4] (36,679) (36,136)  
Depreciation, Depletion and Amortization [2],[4] 181 139  
Impairment of Assets (Significant Non-Cash Item) [2],[4] 0 0  
Interest Expense [2],[4] 3,698 (4,228)  
Interest Income [4] (571) 1,650  
Income Tax Expense (Benefit) [2],[4] (2,438) (507)  
Other Expense (Income) Items [3],[4] 913 424  
Segment Profit: Net Income (Loss) [4] (7,589) (142)  
Expenditures for Additions to Long-Lived Assets [4] 176 204  
Segment Assets: [4] 121,618   61,718
Total Reportable Segments | Operating Segments      
Segment Reporting Information [Line Items]      
Revenues From External Customers [1] 651,507 549,482  
Intersegment Revenues 37,754 37,947  
Total Revenues 689,261 587,429  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2] 19,406 19,326  
Lease Operating Expense [2] 16,826 10,651  
Gathering Operation and Maintenance Expense [2] 10,388 6,735  
All Other Operation and Maintenance Expense [2] 91,638 87,161  
Purchased Gas [2] 122,285 101,473  
Depreciation, Depletion and Amortization [2] 121,844 109,231  
Impairment of Assets (Significant Non-Cash Item) [2] 0 141,802  
Interest Expense [2] 39,540 41,855  
Interest Income (2,196) (3,333)  
Income Tax Expense (Benefit) [2] 61,812 11,748  
Other Expense (Income) Items [3] 18,362 15,459  
Segment Profit: Net Income (Loss) 189,356 45,321  
Expenditures for Additions to Long-Lived Assets 222,545 191,851  
Segment Assets: 9,075,689   8,648,682
Integrated Upstream and Gathering      
Segment Reporting Information [Line Items]      
Total Revenues 323,223 252,308  
Integrated Upstream and Gathering | Operating Segments      
Segment Reporting Information [Line Items]      
Revenues From External Customers [1] 323,223 252,308  
Intersegment Revenues 0 0  
Total Revenues 323,223 252,308  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2] 19,406 19,326  
Lease Operating Expense [2] 16,826 10,651  
Gathering Operation and Maintenance Expense [2] 10,388 6,735  
All Other Operation and Maintenance Expense [2] 3,378 3,867  
Purchased Gas [2] 0 0  
Depreciation, Depletion and Amortization [2] 84,263 73,819  
Impairment of Assets (Significant Non-Cash Item) [2] 0 141,802  
Interest Expense [2] 16,133 19,410  
Interest Income (193) (679)  
Income Tax Expense (Benefit) [2] 44,111 (6,451)  
Other Expense (Income) Items [3] 4,864 3,460  
Segment Profit: Net Income (Loss) 124,047 (19,632)  
Expenditures for Additions to Long-Lived Assets 141,849 135,629  
Segment Assets: 3,925,191   3,701,646
Pipeline and Storage      
Segment Reporting Information [Line Items]      
Total Revenues 69,237 68,750  
Pipeline and Storage | Operating Segments      
Segment Reporting Information [Line Items]      
Revenues From External Customers [1] 69,237 68,750  
Intersegment Revenues 37,664 37,862  
Total Revenues 106,901 106,612  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2] 0 0  
Lease Operating Expense [2] 0 0  
Gathering Operation and Maintenance Expense [2] 0 0  
All Other Operation and Maintenance Expense [2] 27,263 27,034  
Purchased Gas [2] 0 0  
Depreciation, Depletion and Amortization [2] 19,102 18,585  
Impairment of Assets (Significant Non-Cash Item) [2] 0 0  
Interest Expense [2] 11,801 11,729  
Interest Income (964) (2,006)  
Income Tax Expense (Benefit) [2] 10,366 11,177  
Other Expense (Income) Items [3] 8,114 7,639  
Segment Profit: Net Income (Loss) 31,219 32,454  
Expenditures for Additions to Long-Lived Assets 37,602 19,792  
Segment Assets: 2,504,541   2,412,747
Utility      
Segment Reporting Information [Line Items]      
Total Revenues 259,047 228,424  
Utility | Operating Segments      
Segment Reporting Information [Line Items]      
Revenues From External Customers [1] 259,047 228,424  
Intersegment Revenues 90 85  
Total Revenues 259,137 228,509  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2] 0 0  
Lease Operating Expense [2] 0 0  
Gathering Operation and Maintenance Expense [2] 0 0  
All Other Operation and Maintenance Expense [2] 60,997 56,260  
Purchased Gas [2] 122,285 101,473  
Depreciation, Depletion and Amortization [2] 18,479 16,827  
Impairment of Assets (Significant Non-Cash Item) [2] 0 0  
Interest Expense [2] 11,606 10,716  
Interest Income (1,039) (648)  
Income Tax Expense (Benefit) [2] 7,335 7,022  
Other Expense (Income) Items [3] 5,384 4,360  
Segment Profit: Net Income (Loss) 34,090 32,499  
Expenditures for Additions to Long-Lived Assets 43,094 36,430  
Segment Assets: 2,645,957   2,534,289
All Other | All Other      
Segment Reporting Information [Line Items]      
Revenues From External Customers [1],[4] 0 0  
Intersegment Revenues [4] 0 0  
Total Revenues [4] 0 0  
Operation and Maintenance Expense      
Upstream General and Administrative Expense [2],[4] 0 0  
Lease Operating Expense [2],[4] 0 0  
Gathering Operation and Maintenance Expense [2],[4] 0 0  
All Other Operation and Maintenance Expense [2],[4] 0 0  
Purchased Gas [2],[4] 0 0  
Depreciation, Depletion and Amortization [2],[4] 0 0  
Impairment of Assets (Significant Non-Cash Item) [2],[4] 0 0  
Interest Expense [2],[4] 136 116  
Interest Income [4] (10) 0  
Income Tax Expense (Benefit) [2],[4] (37) (59)  
Other Expense (Income) Items [3],[4] 33 136  
Segment Profit: Net Income (Loss) [4] (122) (193)  
Expenditures for Additions to Long-Lived Assets [4] 0 $ 0  
Segment Assets: [4] $ 8,565   $ 8,704
[1] All Revenue from External Customers originated in the United States.
[2] The Company considers this line to be a significant expense.
[3] Consists of Property, Franchise and Other Taxes, Non-Service Pension and Post-Retirement Benefits Costs (Credits), Other (Income) Deductions, and Purchased Gas Expense for the Pipeline and Storage Segment.
[4] Corporate and All Other categories primarily represent other non-segment business activities and eliminating entries.
v3.25.4
Retirement Plan and Other Post-Retirement Benefits (Schedule of Components of Net Periodic Benefit Cost) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Retirement Plan    
Defined Benefit Plan Disclosure [Line Items]    
Service Cost $ 861 $ 1,023
Interest Cost 8,944 9,223
Expected Return on Plan Assets (14,710) (14,647)
Amortization of Prior Service Cost (Credit) 63 76
Amortization of (Gains) Losses 2,421 1,620
Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) [1] (98) (165)
Net Periodic Benefit Cost (Income) (2,519) (2,870)
Other Post-Retirement Benefits    
Defined Benefit Plan Disclosure [Line Items]    
Service Cost 105 130
Interest Cost 3,836 3,625
Expected Return on Plan Assets (7,374) (6,536)
Amortization of Prior Service Cost (Credit) (65) (107)
Amortization of (Gains) Losses 152 9
Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) [1] (148) (727)
Net Periodic Benefit Cost (Income) $ (3,494) $ (3,606)
[1] The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.
v3.25.4
Retirement Plan and Other Post-Retirement Benefits (Narrative) (Details)
 3 Months Ended
Dec. 31, 2025
USD ($)
Retirement Plan  
Defined Benefit Plan Disclosure [Line Items]  
Company's contributions $ 0
Estimated future contributions in remainder of fiscal year 0
VEBA Trusts  
Defined Benefit Plan Disclosure [Line Items]  
Company's contributions 0
Estimated future contributions in remainder of fiscal year $ 0
v3.25.4
Regulatory Matters (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended 36 Months Ended
Jan. 28, 2026
Aug. 01, 2023
Dec. 31, 2025
Sep. 30, 2027
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2027
Nov. 01, 2025
NEW YORK                
Regulatory Matters [Line Items]                
Increase in annual revenue requirement in first year           $ 57.3    
Reduction to annual revenue requirement for actuarial projections of pension and other-post retirement benefit income expected to be recognized           $ 14.0    
NEW YORK | Forecast                
Regulatory Matters [Line Items]                
Rate plan period             3 years  
Approved return on equity (as a percent)             9.70%  
Additional increase in annual revenue requirement in second year         $ 15.8      
Additional increase in annual revenue requirement in third year       $ 12.7        
Reduction to annual revenue requirement for actuarial projections of pension and other-post retirement benefit income expected to be recognized       $ 14.0 $ 14.0      
PENNSYLVANIA                
Regulatory Matters [Line Items]                
Public utilities authorized rate increase, amount   $ 23.0            
Public utilities distribution system improvement charge recovered from customers     $ 1.1          
PENNSYLVANIA | Subsequent Event                
Regulatory Matters [Line Items]                
Requested base rate increase $ 19.7              
Public utilities, requested OPEB surcredit for customer refund $ 7.2              
Empire                
Regulatory Matters [Line Items]                
FERC estimated annual reduction of revenue amount               $ 0.5