CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	2 Months Ended	3 Months Ended		7 Months Ended	9 Months Ended
	Feb. 28, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating revenue:
Oil production		$ 61,841		$ 143,556
Natural gas production		5,451		14,201
Natural gas liquids production		2,473		6,264
Other operational income		9,760		9,936
Derivative income, net				1,414
Total operating revenue		79,525		175,371
Operating expenses:
Lease operating expenses		11,778		33,154
Transportation, processing and gathering expenses		1,076		3,045
Production taxes		188		446
Depreciation, depletion and amortization		27,553		76,553
Write-down of oil and gas properties		0		256,435
Accretion expense		8,095		19,698
Salaries, general and administrative expenses		15,887		37,718
Incentive compensation expense		4,646		4,646
Restructuring fees		129		739
Other operational expenses		703		3,292
Derivative expense, net		6,685		0
Total operating expenses		76,740		435,726
Gain (loss) on Appalachia Properties divestiture		(132)		(105)
Income (loss) from operations		2,653		(260,460)
Other (income) expense:
Interest expense		3,529		8,320
Interest income		(366)		(575)
Other income		(276)		(719)
Other expense		47		861
Reorganization items, net				0
Total other expense		2,934		7,887
Loss before income taxes		(281)		(268,347)
Provision (benefit) for income taxes:
Current		(1,578)		(3,570)
Deferred		0		0
Total income taxes		(1,578)		(3,570)
Net income (loss)		$ 1,297		$ (264,777)
Basic income (loss) per share (in usd per share)		$ 0.06		$ (13.24)
Diluted income (loss) per share (in usd per share)		$ 0.06		$ (13.24)
Average shares outstanding (in shares)		19,997		19,997
Average shares outstanding assuming dilution (in shares)		19,997		19,997
Predecessor
Operating revenue:
Oil production	$ 45,837		$ 71,116		$ 204,102
Natural gas production	13,476		15,601		43,327
Natural gas liquids production	8,706		6,666		15,119
Other operational income	903		1,044		1,737
Derivative income, net	0				0
Total operating revenue	68,922		94,427		264,285
Operating expenses:
Lease operating expenses	8,820		16,976		55,349
Transportation, processing and gathering expenses	6,933		10,633		18,657
Production taxes	682		835		1,894
Depreciation, depletion and amortization	37,429		58,918		166,707
Write-down of oil and gas properties	0		36,484		284,337
Accretion expense	5,447		10,082		30,147
Salaries, general and administrative expenses	9,629		15,425		48,193
Incentive compensation expense	2,008		2,160		11,809
Restructuring fees	0		5,784		16,173
Other operational expenses	530		9,059		49,266
Derivative expense, net	1,778		199		687
Total operating expenses	73,256		166,555		683,219
Gain (loss) on Appalachia Properties divestiture	213,453		0		0
Income (loss) from operations	209,119		(72,128)		(418,934)
Other (income) expense:
Interest expense	0		16,924		49,764
Interest income	(45)		(58)		(474)
Other income	(315)		(272)		(840)
Other expense	13,336		16		27
Reorganization items, net	(437,744)				0
Total other expense	(424,768)		16,610		48,477
Loss before income taxes	633,887		(88,738)		(467,411)
Provision (benefit) for income taxes:
Current	3,570		(991)		(4,178)
Deferred	0		1,888		10,947
Total income taxes	3,570		897		6,769
Net income (loss)	$ 630,317		$ (89,635)		$ (474,180)
Basic income (loss) per share (in usd per share)	$ 110.99		$ (16.01)		$ (84.90)
Diluted income (loss) per share (in usd per share)	$ 110.99		$ (16.01)		$ (84.90)
Average shares outstanding (in shares)	5,634		5,600		5,585
Average shares outstanding assuming dilution (in shares)	5,634		5,600		5,585