Fair Value Measurements (Assets and Liabilities Measured on Recurring Basis) (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	$ 99,850	$ 197,918	$ 367,167
Provisionally priced contracts	(105,117)	(136,337)	(21,503)
Convertible preferred securities	20,628	16,278	16,946
Other assets and liabilities	44,309	31,191	29,557
Total	59,670	109,050	392,167
Level 1
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	54,324	54,516	110,025
Provisionally priced contracts	(80,657)	(20,960)	19,685
Convertible preferred securities	0	0	0
Other assets and liabilities	2,331	(209)	(3,037)
Total	(24,002)	33,347	126,673
Level 2
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	45,526	143,402	257,142
Provisionally priced contracts	(24,460)	(115,377)	(41,188)
Convertible preferred securities	0	0	0
Other assets and liabilities	41,978	31,400	32,594
Total	63,044	59,425	248,548
Level 3
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives, net	0	0	0
Provisionally priced contracts	0	0	0
Convertible preferred securities	20,628	16,278	16,946
Other assets and liabilities	0	0	0
Total	$ 20,628	$ 16,278	$ 16,946