Derivative Financial Instruments - Schedule of Location and Fair Value Amounts of All Derivative Instruments (Details) - Derivatives Not Designated as Hedging Contracts - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Derivative asset - current | Commodity contracts
Derivative Asset [Abstract]
Gross Recognized Assets	$ 2,127	$ 11,071
Gross Amounts Offset, Assets	(2,055)	(3,562)
Total financial assets	72	7,509
Derivative liability - current | Commodity contracts
Derivative Liability [Abstract]
Gross Recognized Liabilities	59,820	4,492
Gross Amounts Offset, Liabilities	(2,055)	(3,562)
Total financial liabilities	57,765	930
Derivative liability - current | Interest rate swaps
Derivative Liability [Abstract]
Gross Recognized Liabilities	192	205
Gross Amounts Offset, Liabilities	0	0
Total financial liabilities	192	205
Derivative asset - noncurrent | Commodity contracts
Derivative Asset [Abstract]
Gross Recognized Assets	856	396
Gross Amounts Offset, Assets	(617)	0
Total financial assets	239	396
Derivative asset - noncurrent | Interest rate swaps
Derivative Asset [Abstract]
Gross Recognized Assets	455	0
Gross Amounts Offset, Assets	0	0
Total financial assets	455	0
Derivative liability - noncurrent | Commodity contracts
Derivative Liability [Abstract]
Gross Recognized Liabilities	6,018	0
Gross Amounts Offset, Liabilities	(617)	0
Total financial liabilities	5,401	0
Derivative liability - noncurrent | Interest rate swaps
Derivative Liability [Abstract]
Gross Recognized Liabilities	0	173
Gross Amounts Offset, Liabilities	0	0
Total financial liabilities	$ 0	$ 173