Discontinued Operations (Narrative) (Details) - Barnett Shale [Member] $ in Millions		3 Months Ended	48 Months Ended
	Oct. 01, 2020 USD ($) $ / MMBTU $ / bbl	Mar. 31, 2021 USD ($)	Dec. 31, 2024 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Contingent payments valuation		$ 66
BKV [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from the sale of business	$ 490
Contingent earnout payments	$ 260
Henry Hub gas price for contingent earnout payment upside | $ / MMBTU	2.75
WTI oil price for contingent earnout payment upside | $ / bbl	50
Contingent earnout payment period		The contingent payment period commenced on January 1, 2021 and has a term of four years.
Scenario Forecast [Member] | BKV [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Contingent earnout payment period			The contingent payment period commenced on January 1, 2021 and has a term of four years.
Scenario Forecast [Member] | Maximum [Member] | BKV [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Contingent earnout payments			$ 260