CHAPTER 11 PROCEEDINGS (Statement of Operations) (Details) - USD ($) $ in Thousands	1 Months Ended	11 Months Ended	12 Months Ended
	Feb. 08, 2018	Dec. 31, 2018	Dec. 31, 2019
Revenue
Operating revenue	$ 40,136	$ 473,473	$ 500,220
Gain on sale of assets	840	4,751	1,382
Gain (loss) on derivatives	6,663	(10,247)	(11,744)
Total revenue	47,639	467,977	489,858
Operating expenses
Lease operating	4,408	56,827	63,755
Transportation and marketing	3,725	19,293	21,042
Production taxes	953	16,865	19,455
Workovers	423	5,563	3,189
Exploration	7,003	34,085	52,354
Depreciation, depletion and amortization	11,670	160,942	132,292
Impairment of assets	0	3,205,051	905,293
General and administrative	21,234	131,052	107,655
Total operating expenses	49,416	3,676,146	1,364,283
Operating income	(1,777)	(3,208,169)	(874,425)
Other income (expense)
Interest expense	(5,511)	(43,296)	(61,459)
Interest income	172	2,049	243
Reorganization items, net	0	0	(197)
Total other income (expense), net	(5,339)	(41,247)	(55,197)
Loss from continuing operations before income taxes	(7,116)	(3,249,416)	(929,622)
Income tax expense (benefit)	0	(69)	0
Net loss	(14,862)	(3,249,347)	(929,622)
Oil
Revenue
Operating revenue	30,972	323,299	328,386
Natural gas
Revenue
Operating revenue	4,276	43,407	53,693
Natural Gas Liquids
Revenue
Operating revenue	4,000	43,039	40,026
Other
Revenue
Operating revenue	$ 888	$ 4,762	10,330
Debtor-In-Possession
Revenue
Operating revenue			423,576
Gain on sale of assets			1,488
Gain (loss) on derivatives			(11,744)
Total revenue			413,320
Operating expenses
Lease operating			79,884
Transportation and marketing			70,324
Production taxes			19,455
Workovers			2,652
Exploration			52,354
Depreciation, depletion and amortization			120,617
Impairment of assets			556,427
General and administrative			71,823
Total operating expenses			973,536
Operating income			(560,216)
Other income (expense)
Interest expense			(49,823)
Interest income			154
Reorganization items, net			(197)
Total other income (expense), net			(49,866)
Loss from continuing operations before income taxes			(610,082)
Income tax expense (benefit)			0
Net loss			(610,082)
Debtor-In-Possession | Oil
Revenue
Operating revenue			328,386
Debtor-In-Possession | Natural gas
Revenue
Operating revenue			53,693
Debtor-In-Possession | Natural Gas Liquids
Revenue
Operating revenue			40,026
Debtor-In-Possession | Other
Revenue
Operating revenue			$ 1,471