Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 336,181	$ 224,288
Number of segments | segment	2
Realized (loss) gain on derivatives	$ (25,913)	10,867
Unrealized (loss) gain on derivatives	(43,423)	136,430
Expenses	174,182	178,053
Operating (loss) income	92,663	193,532
Total assets	3,738,881	4,333,671	$ 3,687,280
Capital expenditures	144,771	278,595
Depletion, depreciation and amortization	74,863	90,707
Corporate
Segment Reporting Information [Line Items]
Realized (loss) gain on derivatives	0	0
Unrealized (loss) gain on derivatives	0	0
Expenses	19,962	14,317
Operating (loss) income	(19,962)	(14,317)
Total assets	26,400	47,001
Capital expenditures	133	787
Depletion, depreciation and amortization	700	700
Consolidations and Eliminations
Segment Reporting Information [Line Items]
Realized (loss) gain on derivatives	0	0
Unrealized (loss) gain on derivatives	0	0
Expenses	(28,471)	(21,919)
Operating (loss) income	0	0
Total assets	0	0
Capital expenditures	0	0
Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Realized (loss) gain on derivatives	(25,913)	10,867
Unrealized (loss) gain on derivatives	(43,423)	136,430
Expenses	156,444	161,325
Operating (loss) income	91,328	186,362
Total assets	2,881,242	3,571,257
Capital expenditures	134,865	209,735
Depletion, depreciation and amortization	66,400	85,200
Capital expenditures attributable to land and seismic acquisition expenditures	8,700	39,700
Midstream | Operating Segments
Segment Reporting Information [Line Items]
Realized (loss) gain on derivatives	0	0
Unrealized (loss) gain on derivatives	0	0
Expenses	26,247	24,330
Operating (loss) income	21,297	21,487
Total assets	831,239	715,413
Capital expenditures	9,773	68,073
Depletion, depreciation and amortization	7,800	4,800
Net income attributable to non-controlling interest in subsidiaries		(9,400)
Capital expenditures attributable to non-controlling interest	4,400	47,600
Operating Income (Loss) | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Net income attributable to non-controlling interest in subsidiaries	(8,900)
Oil and natural gas revenues
Segment Reporting Information [Line Items]
Revenues	316,233	197,914
Oil and natural gas revenues | Corporate
Segment Reporting Information [Line Items]
Revenues	0	0
Oil and natural gas revenues | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues	0	0
Oil and natural gas revenues | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues	314,646	196,795
Oil and natural gas revenues | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues	1,587	1,119
Third-party midstream services revenues
Segment Reporting Information [Line Items]
Revenues	15,438	15,830
Third-party midstream services revenues | Corporate
Segment Reporting Information [Line Items]
Revenues	0	0
Third-party midstream services revenues | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues	(28,471)	(21,919)
Third-party midstream services revenues | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues	0	0
Third-party midstream services revenues | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues	43,909	37,749
Sales of purchased natural gas
Segment Reporting Information [Line Items]
Revenues	4,510	10,544
Sales of purchased natural gas | Corporate
Segment Reporting Information [Line Items]
Revenues	0	0
Sales of purchased natural gas | Consolidations and Eliminations
Segment Reporting Information [Line Items]
Revenues	0	0
Sales of purchased natural gas | Exploration and Production | Operating Segments
Segment Reporting Information [Line Items]
Revenues	2,462	3,595
Sales of purchased natural gas | Midstream | Operating Segments
Segment Reporting Information [Line Items]
Revenues	$ 2,048	$ 6,949