Income Taxes (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Oct. 20, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes
Estimated Amount of Cancellation of Indebtedness Income						$ 1,200,000
Estimated deduction associated with cost of qualified asset		$ 10,900
Valuation allowance	$ 160,789	120,091			$ 120,091	160,789
Valuation allowance related to property and equipment		72,600			72,600
Increase in valuation allowance					32,500
Decrease in valuation allowance due to Tax act					73,200
Income tax payments expected in the upcoming four quarterly reporting periods					0
Reconciliation of income tax expense
Income (loss) before taxes	$ 9,930				$ (85,077)
Statutory rate	35.00%				35.00%
Income tax provision (benefit) computed at statutory rate	$ 3,475				$ (29,777)
Reconciling items:
State income taxes, net of federal benefit	296				(2,864)
Change in valuation allowance	(3,876)				(40,700)
Adjustment to deferred tax assets and liabilities for enacted change in federal tax rate					73,182
Change in state rate	(1)				(606)
Deferred tax true-ups	74				(140)
Other, net	32				905
Deferred tax assets
Federal tax loss carryforwards		36,429			36,429
Derivative instruments and other		813			813
State tax loss carryforwards		7,195			7,195
Employee benefit plans	3,649	3,053			3,053	3,649
Oil and gas properties and equipment	157,113	72,568			72,568	157,113
Other	27	33			33	27
Less valuation allowance	$ (160,789)	$ (120,091)			$ (120,091)	$ (160,789)
Predecessor
Deferred
United States							$ (3,864)
State							(5,777)
Total deferred							(9,641)
Total income tax provision (benefit)							(9,641)
Reconciliation of income tax expense
Income (loss) before taxes			$ 1,323,079				$ (1,806,836)
Statutory rate			35.00%				35.00%
Income tax provision (benefit) computed at statutory rate			$ 463,078				$ (632,393)
Reconciling items:
State income taxes, net of federal benefit			39,424				(65,904)
Change in valuation allowance			(528,706)				689,419
Change in state rate			(153)				(612)
Bankruptcy items			12,262
Deferred tax true-ups			9,891
Other, net			$ 4,204				(151)
Total income tax provision (benefit)							$ (9,641)
Forecast
Reconciliation of income tax expense
Statutory rate				21.00%