Fresh Start Accounting - Reorganization and Application of ASC 852 on Condensed Consolidated Balance Sheet (Details) $ in Thousands	Apr. 22, 2016 USD ($)
Preconfirmation, Assets [Abstract]
Cash and cash equivalents	$ 57,599
Accounts receivable	34,278
Other current assets	3,503
Total current assets	95,380
Property and equipment	6,007,326
Less - accumulated depreciation, depletion and amortization	(5,676,252)
Property and equipment, net	331,074
Other Long-Term Assets	4,629
Total Assets	431,083
Postconfirmation, Assets [Abstract]
Cash and cash equivalents	8,739
Accounts receivable	33,681
Other current assets	3,503
Total current assets	45,923
Property and equipment	558,567
Less - accumulated depreciation, depletion and amortization	0
Property and equipment, net	558,567
Other Long-Term Assets	10,219
Total Assets	614,709
Preconfirmation, Liabilities and Stockholders' Equity [Abstract]
Accounts payable and accrued liabilities	64,324
Accrued capital costs	5,410
Accrued interest	768
Undistributed oil and gas revenues	8,471
Current portion of debt	364,500
Total current liabilities	443,473
Long-Term Debt	0
Asset retirement obligation	51,800
Other long-term liabilities	2,124
Liabilities subject to compromise	911,381
Total Liabilities	1,408,778
Common stock (Predecessor)	450
Additional paid-in capital (Predecessor)	777,475
Treasury stock held at cost	(2,496)
Retained earnings (accumulated deficit)	(1,753,124)
Total Stockholders' Equity (Deficit)	(977,695)
Total Liabilities and Stockholders' Equity	431,083
Postconfirmation, Liabilities and Stockholders' Equity [Abstract]
Accounts payable and accrued liabilities	58,773
Accrued capital costs	5,410
Accrued interest	664
Undistributed oil and gas revenues	8,471
Current portion of debt	0
Total current liabilities	73,318
Long-Term Debt	253,000
Asset retirement obligation	57,901
Other long-term liabilities	1,091
Liabilities subject to compromise	0
Total Liabilities	385,310
Common stock (Successor)	100
Additional paid-in capital (Successor)	229,299
Treasury stock held at cost	0
Retained earnings (accumulated deficit)	0
Total Stockholders' Equity (Deficit)	229,399
Total Liabilities and Stockholders' Equity	614,709
Reorganization Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Cash and cash equivalents	(48,860)
Accounts receivable	(597)
Other current assets	0
Total current assets	(49,457)
Property and equipment	0
Less - accumulated depreciation, depletion and amortization	0
Net Oil and Gas Properties, Furniture and fixtures and accumulated depreciation	0
Other Long-Term Assets	6,388
Total Assets	(43,069)
Fresh-Start Adjustment, Increase (Decrease), Liabilities and Stockholders' Equity [Abstract]
Accounts payable and accrued liabilities	(4,666)
Accrued capital costs	0
Accrued interest	(104)
Undistributed oil and gas revenues	0
Current portion of debt	(364,500)
Total current liabilities	(369,270)
Long-Term Debt	253,000
Asset retirement obligation	0
Other long-term liabilities	0
Liabilities subject to compromise	(911,381)
Total Liabilities	(1,027,651)
Treasury stock held at cost	2,496
Retained earnings (accumulated deficit)	1,530,612
Total Stockholders' Equity (Deficit)	984,582
Total Liabilities and Stockholders' Equity	(43,069)
Fresh Start Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Cash and cash equivalents	0
Accounts receivable	0
Other current assets	0
Total current assets	0
Property and equipment	(5,448,759)
Less - accumulated depreciation, depletion and amortization	5,676,252
Net Oil and Gas Properties, Furniture and fixtures and accumulated depreciation	227,493
Other Long-Term Assets	(798)
Total Assets	226,695
Fresh-Start Adjustment, Increase (Decrease), Liabilities and Stockholders' Equity [Abstract]
Accounts payable and accrued liabilities	(885)
Accrued capital costs	0
Accrued interest	0
Undistributed oil and gas revenues	0
Current portion of debt	0
Total current liabilities	(885)
Long-Term Debt	0
Asset retirement obligation	6,101
Other long-term liabilities	(1,033)
Liabilities subject to compromise	0
Total Liabilities	4,183
Treasury stock held at cost	0
Retained earnings (accumulated deficit)	222,512
Total Stockholders' Equity (Deficit)	222,512
Total Liabilities and Stockholders' Equity	226,695
Predecessor [Member]
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Net Oil and Gas Properties, Furniture and fixtures and accumulated depreciation	331,074
Predecessor [Member] | Reorganization Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Liabilities and Stockholders' Equity [Abstract]
Common stock	(450)
Additional paid-in capital	(777,475)
Predecessor [Member] | Fresh Start Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Liabilities and Stockholders' Equity [Abstract]
Common stock	0
Additional paid-in capital	0
Successor [Member]
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Net Oil and Gas Properties, Furniture and fixtures and accumulated depreciation	558,567
Successor [Member] | Reorganization Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Liabilities and Stockholders' Equity [Abstract]
Common stock	100
Additional paid-in capital	229,299
Successor [Member] | Fresh Start Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Liabilities and Stockholders' Equity [Abstract]
Common stock	0
Additional paid-in capital	$ 0