CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		3 Months Ended	9 Months Ended		12 Months Ended
	Oct. 01, 2019	Dec. 31, 2019	Oct. 01, 2019	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 02, 2019	Jan. 01, 2019	Dec. 31, 2016
CONSOLIDATED BALANCE SHEETS
Financial Designation, Predecessor and Successor [Fixed List]	Predecessor	Successor	Predecessor	Predecessor	Predecessor	Predecessor
Current assets:
Cash and cash equivalents	$ 15,546	$ 5,701	$ 15,546		$ 46,866		$ 15,546
Accounts receivable, net	37,826	48,504	37,826		35,718		37,826
Assets from derivative contracts	15,310	4,995	15,310		57,280		15,310
Restricted cash		4,574
Prepaids and other	14,642	7,379	14,642		4,788		10,290
Total current assets	84,787	71,153	84,787		144,652		92,811
Oil and natural gas properties (full cost method):
Evaluated	2,155,288	420,609	2,155,288		1,470,509		380,364
Unevaluated	438,365	105,009	438,365		971,918		108,954
Gross oil and natural gas properties	2,593,653	525,618	2,593,653		2,442,427		489,318
Less - accumulated depletion	(1,709,719)	(19,474)	(1,709,719)		(639,951)
Net oil and natural gas properties	883,934	506,144	883,934		1,802,476		489,318
Other operating property and equipment:
Other operating property and equipment	203,373	3,655	203,373		130,251		3,655
Less - accumulated depreciation	(14,416)	(378)	(14,416)		(8,388)
Net other operating property and equipment	188,957	3,277	188,957		121,863		3,655
Other noncurrent assets:
Assets from derivative contracts	4,120	224	4,120		12,437		4,120
Operating lease right of use assets	3,694	3,165	3,694				3,394	$ 5,462
Funds in escrow and other	1,138	703	1,138		2,181		1,138
Total assets	1,166,630	584,666	1,166,630		2,083,609		594,436
Current liabilities:
Accounts payable and accrued liabilities	112,578	97,333	112,578		157,848		115,305	157,763
Liabilities from derivative contracts	6,829	8,069	6,829		3,768		6,829
Current portion of long-term debt, net	258,234		258,234
Operating lease liabilities	1,337	923	1,337				913	2,103
Asset retirement obligations		109			126
Total current liabilities	378,978	106,434	378,978		161,742		123,047
Long-term debt, net		144,000			613,105		130,000
Liabilities subject to compromise	625,005		625,005
Other noncurrent liabilities:
Liabilities from derivative contracts	1,625	4,854	1,625		9,139		1,625
Asset retirement obligations	10,153	10,481	10,153		6,788		10,153
Operating lease liabilities	2,438	2,247	2,438				2,482	$ 3,444
Deferred income taxes					95,791
Commitments and contingencies (Note 12)
Stockholders' equity:
Common stock	16	2	16		16		2
Additional paid-in capital	1,087,441	327,108	1,087,441		1,095,367		327,127
Retained earnings (accumulated deficit)	(939,026)	(10,460)	(939,026)		101,661
Total stockholders' equity	148,431	316,650	148,431	$ 30,477	1,197,044	$ 1,071,998	327,129		$ 112,688
Total liabilities and stockholders' equity	$ 1,166,630	$ 584,666	$ 1,166,630		$ 2,083,609		$ 594,436