CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Thousands	2 Months Ended	10 Months Ended	12 Months Ended
	Feb. 28, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating revenue:
Oil production		$ 211,792,000
Natural gas production		18,874,000
Natural gas liquids production		9,610,000
Other operational income		10,008,000
Derivative income, net		0
Total operating revenue		250,284,000
Operating expenses:
Lease operating expenses		49,800,000
Transportation, processing and gathering expenses		4,084,000
Production taxes		629,000
Depreciation, depletion and amortization		99,890,000
Write-down of oil and gas properties		256,435,000
Accretion expense		21,151,000
Salaries, general and administrative expenses		47,817,000
Incentive compensation expense		8,045,000
Restructuring fees		739,000
Other operational expenses		3,359,000
Derivative expense, net		13,388,000
Total operating expenses		505,337,000
Gain (loss) on Appalachia Properties divestiture		(105,000)
Income (loss) from operations		(255,158,000)
Other (income) expense:
Interest expense		11,744,000
Interest income		(998,000)
Other income		(1,156,000)
Other expense		1,230,000
Reorganization items, net		0
Total other (income) expense		10,820,000
Income (loss) before income taxes		(265,978,000)
Provision (benefit) for income taxes:
Current		(18,339,000)
Deferred		0
Total income taxes		(18,339,000)
Net income (loss)		$ (247,639,000)
Basic income (loss) per share (in usd per share)		$ (12.38)
Diluted income (loss) per share (in usd per share)		$ (12.38)
Average shares outstanding (in shares)		19,997
Average shares outstanding assuming dilution (in shares)		19,997
Predecessor
Operating revenue:
Oil production	$ 45,837,000		$ 281,246,000	$ 416,497,000
Natural gas production	13,476,000		64,601,000	83,509,000
Natural gas liquids production	8,706,000		28,888,000	32,322,000
Other operational income	903,000		2,657,000	4,369,000
Derivative income, net	0		0	7,952,000
Total operating revenue	68,922,000		377,392,000	544,649,000
Operating expenses:
Lease operating expenses	8,820,000		79,650,000	100,139,000
Transportation, processing and gathering expenses	6,933,000		27,760,000	58,847,000
Production taxes	682,000		3,148,000	6,877,000
Depreciation, depletion and amortization	37,429,000		220,079,000	281,688,000
Write-down of oil and gas properties	0		357,431,000	1,362,447,000
Accretion expense	5,447,000		40,229,000	25,988,000
Salaries, general and administrative expenses	9,629,000		58,928,000	69,384,000
Incentive compensation expense	2,008,000		13,475,000	2,242,000
Restructuring fees	0		29,597,000	0
Other operational expenses	530,000		55,453,000	2,360,000
Derivative expense, net	1,778,000		810,000	0
Total operating expenses	73,256,000		886,560,000	1,909,972,000
Gain (loss) on Appalachia Properties divestiture	213,453,000		0	0
Income (loss) from operations	209,119,000		(509,168,000)	(1,365,323,000)
Other (income) expense:
Interest expense	0		64,458,000	43,928,000
Interest income	(45,000)		(550,000)	(580,000)
Other income	(315,000)		(1,439,000)	(1,783,000)
Other expense	13,336,000		596,000	434,000
Reorganization items, net	(437,744,000)		10,947,000	0
Total other (income) expense	(424,768,000)		74,012,000	41,999,000
Income (loss) before income taxes	633,887,000		(583,180,000)	(1,407,322,000)
Provision (benefit) for income taxes:
Current	3,570,000		(5,674,000)	(44,096,000)
Deferred	0		13,080,000	(272,311,000)
Total income taxes	3,570,000		7,406,000	(316,407,000)
Net income (loss)	$ 630,317,000		$ (590,586,000)	$ (1,090,915,000)
Basic income (loss) per share (in usd per share)	$ 110.99		$ (105.63)	$ (197.45)
Diluted income (loss) per share (in usd per share)	$ 110.99		$ (105.63)	$ (197.45)
Average shares outstanding (in shares)	5,634		5,591	5,525
Average shares outstanding assuming dilution (in shares)	5,634		5,591	5,525