Regulatory Matters	9 Months Ended
Regulatory Matters	Jun. 30, 2024
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 April 20, 2017 with rates becoming effective May 1, 2017 ("2017 Rate Order"). The 2017 Rate Order provided for a return on equity of 8.7% and directed the implementation of an earnings sharing mechanism to be in place beginning on April 1, 2018. On October 31, 2023, Distribution Corporation made a filing with the NYPSC seeking an increase of approximately $88 million in its total annual operating revenues for the projected rate year ending September 30, 2025, with a proposed effective date of October 1, 2024 that includes the maximum suspension period permitted under the New York Public Service Law ("2023 Rate Filing"). The Company is also proposing, among other things, to continue its leak prone pipe replacement program and to implement a number of initiatives that will facilitate achievement of the emissions reduction goals of the CLCPA. A Notice of Impending Settlement Negotiations was filed with the NYPSC on March 26, 2024 and settlement discussions with parties are ongoing. To facilitate settlement negotiations, the Company has indicated that it is willing to accept an extension of the suspension period for the effective date of new base delivery rates through and including January 31, 2025. Consistent with normal regulatory practice, the Company’s acceptance is subject to a “make-whole” provision that would permit the Company to recover or refund any revenue under-collections or over-collections, respectively, resulting from the extension period. On August 13, 2021, the NYPSC issued an order extending the date through which qualified pipeline replacement costs incurred by the Company can be recovered using the existing system modernization tracker for two years (until March 31, 2023). On December 9, 2022, the Company filed a petition with the NYPSC to effectuate a system improvement tracker through which qualified pipeline replacement costs through September 30, 2024 would be tracked and recovered, and to recover certain deferred costs associated with the existing system modernization tracker, effective April 1, 2023. The NYPSC approved the petition by order dated March 17, 2023 contingent on the Company not filing a base rate case that would result in new rates becoming effective prior to October 1, 2024. The 2023 Rate Filing proposes to stop accruing and collecting revenues under its current system modernization and system improvement trackers and shift those revenues into the Company’s new base delivery rates. In the absence of a multi-year rate plan settlement, the Company is requesting that it be allowed to reinstate a tracking mechanism similar to the existing system modernization tracker. Pennsylvania Jurisdiction On October 28, 2022, Distribution Corporation made a filing with the PaPUC seeking an increase in its annual base rate operating revenues of $28.1 million. A settlement involving all active parties to the proceeding was reached and filed with the PaPUC on April 13, 2023. The settlement provided for, among other things, an increase in Distribution Corporation’s annual base rate operating revenues of $23 million. The PaPUC approved the settlement in full, without modification or correction, on June 15, 2023 and new rates went into effect on August 1, 2023. 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. If approved as filed, beginning October 1, 2024, the Company will be able to recover costs associated with plant placed in service on and after August 1, 2024 if it exceeds approximately $781.3 million of plant as of July 31, 2024 and its quarterly rate of return does not exceed the authorized PaPUC rate of return. As of June 30, 2024, plant placed in service for Distribution Corporation’s Pennsylvania division is $763.7 million. The DSIC petition is currently pending before the PaPUC. FERC Jurisdiction Supply Corporation filed an NGA Section 4 rate case on July 31, 2023 proposing rate increases to be effective February 1, 2024. On March 8, 2024, Supply Corporation and the parties in the case reached a settlement in principle (the Settlement) to resolve the rate case. Supply Corporation’s March 11, 2024 motion to put in place Settlement Rates effective February 1, 2024, was approved by FERC’s Chief Administrative Law Judge on March 12, 2024. The Settlement was filed with FERC on March 27, 2024. A letter order approving the Settlement as filed was issued on June 11, 2024. The “black box” settlement provides for new rates and resolves all issues in the proceeding. The Settlement Rates are estimated to increase Supply Corporation’s revenues on a yearly basis by approximately $56 million, assuming current contract levels. The Settlement generally provides for the continuation of current depreciation rates with minimal changes. Under the Settlement, 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. Empire's 2019 rate settlement requires a Section 4 rate case filing no later than May 1, 2025. Empire has no rate case currently on file.