Derivative Financial Instruments Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	$ 158,822	$ (142,528)	$ 266,707	$ (215,965)
Net derivative (gain) loss	370,348	167,200	715,037	(378,140)
Oil Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	134,298	(138,606)	190,627	(192,188)
Net derivative (gain) loss	277,215	151,250	543,030	(391,290)
Gas Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	12,232	(1,054)	52,680	(15,679)
Net derivative (gain) loss	61,364	8,261	110,286	14,989
NGL Contracts [Member]
Derivative Instruments, (Gain) Loss [Line Items]
Derivative settlement (gain) loss	12,292	(2,868)	23,400	(8,098)
Net derivative (gain) loss	$ 31,769	$ 7,689	$ 61,721	$ (1,839)