Consolidated Statements of Cash Flows - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 22, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2015
Successor [Member]
Cash Flows from Operating Activities:
Net Income (Loss)		$ (156,288)	$ 71,971
Adjustments to reconcile net income to net cash provided by operation activities -
Write-down of oil and gas properties		133,496	0
Depreciation, depletion, and amortization		36,436	46,933
Accretion of asset retirement obligation		2,878	2,322
Deferred income taxes		0	0
Stock-based compensation expense		3,618	6,849
Gain (Loss) on Sale of Derivatives		19,676	(17,913)
Cash Received (Paid) On Settlements of Derivative Contracts		(1,928)	(1,411)
Asset Retirement Obligation, Cash Paid to Settle		(2,993)	(2,335)
Write off of Deferred Debt Issuance Cost		0	2,676
Reorganization items (non-cash)		0	0
Other Noncash Income (Expense)		1,351	(559)
Change in assets and liabilities-
(Increase) decrease in accounts receivable and other assets		16,812	(7,169)
Increase (decrease) in accounts payable and accrued liabilities		6,689	(6,089)
Increase (decrease) in income taxes payable		0	0
Increase (decrease) in accrued interest		1,058	385
Net Cash Provided by Operating Activities		47,427	107,838
Cash Flows from Investing Activities:
Additions to property and equipment		(45,671)	(192,982)
Acquisition of properties		0	(9,426)
Proceeds from the sale of property and equipment		45,985	702
Net Cash Used in Investing Activities		314	(201,706)
Cash Flows from Financing Activities:
Proceeds from long-term debt issuances		0	198,000
Proceeds from bank borrowings		84,000	404,700
Payments of bank borrowings		(139,000)	(529,700)
Net proceeds from issuances of common stock		0	39,179
Purchase of treasury shares		(675)	(777)
Payments of debt issuance costs		(502)	(10,031)
Net Cash Provided by (Used in) Financing Activities		(56,177)	101,371
Net Increase (decrease) in Cash and Cash Equivalents		(8,436)	7,503
Cash and Cash Equivalents at Beginning of Period		8,739	303
Cash and Cash Equivalents at End of Period	$ 8,739	303	7,806
Supplemental Disclosures of Cash Flows Information:
Cash paid during period for interest, net of amounts capitalized		12,517	10,428
Cash paid during period for income taxes		0	0
Payments for Restructuring		12,929	0
Increase (decrease) in accrued payables for capital		(6,265)	9,894
Increase (decrease) in other long-term liabilities for capital expenditures		0	$ 5,000
Predecessor [Member]
Cash Flows from Operating Activities:
Net Income (Loss)	851,611			$ (1,653,971)
Adjustments to reconcile net income to net cash provided by operation activities -
Write-down of oil and gas properties	77,732			1,562,086
Depreciation, depletion, and amortization	20,439			177,512
Accretion of asset retirement obligation	1,610			5,572
Deferred income taxes	0			(80,133)
Stock-based compensation expense	886			4,435
Gain (Loss) on Sale of Derivatives	0			(186)
Cash Received (Paid) On Settlements of Derivative Contracts	0			2,544
Asset Retirement Obligation, Cash Paid to Settle	(848)			0
Write off of Deferred Debt Issuance Cost	0			0
Reorganization items (non-cash)	(977,696)			6,565
Other Noncash Income (Expense)	229			(3,189)
Change in assets and liabilities-
(Increase) decrease in accounts receivable and other assets	(5,474)			26,747
Increase (decrease) in accounts payable and accrued liabilities	9,647			15,003
Increase (decrease) in income taxes payable	0			435
Increase (decrease) in accrued interest	(308)			9,730
Net Cash Provided by Operating Activities	(41,466)			42,274
Cash Flows from Investing Activities:
Additions to property and equipment	(24,530)			(139,688)
Acquisition of properties	0			0
Proceeds from the sale of property and equipment	48,661			1,164
Net Cash Used in Investing Activities	24,131			(138,524)
Cash Flows from Financing Activities:
Proceeds from long-term debt issuances	0			0
Proceeds from bank borrowings	328,000			281,100
Payments of bank borrowings	(324,900)			(153,500)
Net proceeds from issuances of common stock	0			302
Purchase of treasury shares	(4)			(154)
Payments of debt issuance costs	(6,482)			(2,444)
Net Cash Provided by (Used in) Financing Activities	(3,386)			125,304
Net Increase (decrease) in Cash and Cash Equivalents	(20,721)			29,054
Cash and Cash Equivalents at Beginning of Period	29,460	$ 8,739		406
Cash and Cash Equivalents at End of Period	8,739			29,460
Supplemental Disclosures of Cash Flows Information:
Cash paid during period for interest, net of amounts capitalized	10,367			63,132
Cash paid during period for income taxes	0			450
Payments for Restructuring	15,643			0
Increase (decrease) in accrued payables for capital	1,843			(27,611)
Increase (decrease) in other long-term liabilities for capital expenditures	$ 0			$ 0