Derivatives (Gross Current and Noncurrent Assets and Liabilities) (Details) - Commodity - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Derivatives, Fair Value [Line Items]
Commodity derivative assets	$ 319,554	$ 346,670	$ 562,830
Commodity derivative liabilities	(235,825)	(213,282)	(348,266)
Cash collateral paid	16,121
Cash collateral paid		64,530	152,603
Total	99,850	197,918	367,167
Commodity Derivative Assets - Current
Derivatives, Fair Value [Line Items]
Commodity derivative assets	301,990	325,762	529,456
Commodity derivative liabilities	(78,516)	(94,704)	(179,962)
Cash collateral paid	16,121
Cash collateral paid		64,530	152,603
Derivative assets	239,595	295,588	502,097
Commodity Derivative Assets - Noncurrent
Derivatives, Fair Value [Line Items]
Commodity derivative assets	4,730	1,796	7,743
Commodity derivative liabilities	(396)	(149)	(1,008)
Cash collateral paid	0
Cash collateral paid		0	0
Derivative assets	4,334	1,647	6,735
Commodity Derivative Liabilities - Current
Derivatives, Fair Value [Line Items]
Commodity derivative assets	12,733	18,426	24,143
Commodity derivative liabilities	(155,244)	(116,945)	(161,311)
Cash collateral paid	0
Cash collateral paid		0	0
Derivative Liability	(142,511)	(98,519)	(137,168)
Commodity Derivative Liabilities - Noncurrent
Derivatives, Fair Value [Line Items]
Commodity derivative assets	101	686	1,488
Commodity derivative liabilities	(1,669)	(1,484)	(5,985)
Cash collateral paid	0
Cash collateral paid		0	0
Derivative Liability	$ (1,568)	$ (798)	$ (4,497)