Nature of Operations (Details) Customer in Thousands, $ in Millions		9 Months Ended
Dec. 29, 2020 USD ($) county Customer	Jun. 30, 2021 county
Mountaineer \| Pending
Business Acquisition [Line Items]
Number of counties of operation \| county	50
Enterprise value \| $	$ 540
Assumption of debt \| $	$ 140
Customers served \| Customer	215
Gas Utility \| MARYLAND
Business Acquisition [Line Items]
Number of counties of operation \| county		1

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

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