Asset Acquisitions and Divestitures (Narrative) (Details) - California Asset Sale [Member] - USD ($)	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2022	Jun. 30, 2022
Asset Acquisitions 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 Payments			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
Minimum [Member]
Asset Acquisitions and Divestitures [Line Items]
ICE Brent Average per Barrel			95
Maximum [Member]
Asset Acquisitions and Divestitures [Line Items]
ICE Brent Average per Barrel			105
Present Value of Contingent Consideration [Member]
Asset Acquisitions and Divestitures [Line Items]
Value of Contingent Consideration from Asset Sale	$ 8,200,000	$ 8,400,000	12,600,000
Full Cost Method of Accounting Assets [Member]
Asset Acquisitions and Divestitures [Line Items]
Property, Plant and Equipment Disposal			220,700,000
Assets Not Subject to Full Cost Method of Accounting [Member]
Asset Acquisitions and Divestitures [Line Items]
Property, Plant and Equipment Disposal			$ 32,800,000