Supplemental Oil And Natural Gas Disclosures (Results of Operations) (Details) - USD ($) $ in Thousands	1 Months Ended	11 Months Ended	12 Months Ended
	Feb. 08, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reserve Quantities [Line Items]
Operating revenue		$ 414,507
Production expense		247,748
Depreciation, depletion and amortization		133,554
Exploration expense		34,085
Impairment expense		2,033,712
Income tax expense (benefit)		4
Results of operations		$ (2,034,596)
Predecessor
Reserve Quantities [Line Items]
Operating revenue	$ 40,136		$ 269,386	$ 142,356
Production expense	30,743		138,833	87,869
Depreciation, depletion and amortization	11,670		89,115	53,755
Exploration expense	7,003		13,563	17,230
Impairment expense	0		1,188	382
Income tax expense (benefit)	0		6	0
Results of operations	$ (9,280)		$ 26,681	$ (16,880)