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ICE Brent Average per Barrel

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Incremental Dollar Per Barrel That ICE Brent Average Exceeds Price

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Maximum Annual Contingent Payment

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- Definition

Net acres acquired in Appalachia as part of the Company's acquisition of certain upstream assets and gathering assets.

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Net acres acquired in Tioga County as part of the Company's acquisition of certain upstream assets and midstream gathering assets in Pennsylvania.

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The cash inflow to dispose of long-lived, physical assets and timber properties used for normal timber operations.

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Value of Contingent Consideration from Asset Sale

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Purchase of minerals in place.

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Amount of consideration transferred in asset acquisition. Includes, but is not limited to, cash, liability incurred by acquirer, and equity interest issued by acquirer.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

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Amount classified as property, plant and equipment attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations.

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Asset Acquisitions and Divestitures (Narrative) (Details)	12 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($) a Bcf	Jun. 30, 2022 USD ($)
Asset Acquisition and Divestitures [Line Items]
Net Proceeds from Sale of Oil and Gas Producing Properties	$ 254,439,000	$ 0	$ 0
Gain on Sale of Assets	12,736,000	51,066,000	0
Asset Retirement Obligation Reduction	71,171,000	14,270,000	7,268,000
Net Proceeds from Sale of Timber Properties	0	104,582,000	0
Gain on Sale of Timber Properties		$ 51,100,000
Shell Acquisition [Member]
Asset Acquisition and Divestitures [Line Items]
Total Consideration for Asset Acquisition			$ 506,258,000
Net Acres Acquired in Appalachia \| a			400,000
Net Acres Acquired in Tioga County \| a			200,000
Proved Developed Reserves (Volume) \| Bcf			684,141
California Asset Sale [Member]
Asset Acquisition and Divestitures [Line Items]
Consideration for Asset Sale	253,500,000
Net Proceeds from Sale of Oil and Gas Producing Properties	240,900,000
Maximum Annual Contingent Payment	10,000,000
Amount of Each Incremental Contingent Payment	1,000,000
Incremental Dollar Per Barrel That ICE Brent Average Exceeds Price	1
Gain on Sale of Assets	12,700,000
Asset Retirement Obligation Reduction	50,100,000
California Asset Sale [Member] \| Full Cost Method of Accounting Assets [Member]
Asset Acquisition and Divestitures [Line Items]
Property, Plant and Equipment Disposal	220,700,000
California Asset Sale [Member] \| Assets Not Subject to Full Cost Method of Accounting [Member]
Asset Acquisition and Divestitures [Line Items]
Property, Plant and Equipment Disposal	32,800,000
California Asset Sale [Member] \| Minimum [Member]
Asset Acquisition and Divestitures [Line Items]
ICE Brent Average per Barrel	95
California Asset Sale [Member] \| Maximum [Member]
Asset Acquisition and Divestitures [Line Items]
ICE Brent Average per Barrel	105
California Asset Sale [Member] \| Present Value of Contingent Consideration [Member]
Asset Acquisition and Divestitures [Line Items]
Value of Contingent Consideration from Asset Sale	$ 8,200,000			$ 12,600,000