Fresh Start Accounting (Details Textuals) - USD ($) $ / shares in Units, $ in Thousands			2 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 18, 2020	Sep. 18, 2020	Sep. 18, 2020	Sep. 18, 2020
Reorganizations [Abstract]
Decrease to deferred taxes		$ 128,600	$ 128,600	$ 128,600	$ 128,600
Decrease to deferred tax liabilities related to fresh start accounting adjustments		414,120	414,120	414,120	414,120
Reorganization Value [Line Items]
Enterprise value		1,280,856	1,280,856	1,280,856	1,280,856
Contractual interest expense on prepetition liabilities not recognized in statement of operations			22,000
Cash outflow related to payment of professional service provider fees and success fees					12,700
DIP credit agreement fees				3,107	3,100
Capitalized costs of proved and unproved properties		$ 865,400	865,400	865,400	865,400
Expected annual dividend yield for warrants		0.00%
Minimum
Reorganization Value [Line Items]
Enterprise value		$ 1,100,000	1,100,000	1,100,000	1,100,000
Useful life	20 years
Useful life of CO2 contracts	7 years
Maximum
Reorganization Value [Line Items]
Enterprise value		1,500,000	1,500,000	1,500,000	1,500,000
Useful life	43 years
Useful life of CO2 contracts	14 years
Median
Reorganization Value [Line Items]
Enterprise value		$ 1,300,000	$ 1,300,000	$ 1,300,000	$ 1,300,000
Series A Warrants
Reorganization Value [Line Items]
Exercise price of warrants		$ 32.59	$ 32.59	$ 32.59	$ 32.59
Expected volatility of warrants		49.30%
Risk free interest rate associated with warrants		0.30%
Term of warrants		5 years	5 years	5 years	5 years
Series B Warrants
Reorganization Value [Line Items]
Exercise price of warrants		$ 35.41	$ 35.41	$ 35.41	$ 35.41
Expected volatility of warrants		53.60%
Risk free interest rate associated with warrants		0.20%
Term of warrants		3 years	3 years	3 years	3 years
Measurement Input, Share Price [Member]
Reorganization Value [Line Items]
Implied stock price		$ 22.14	$ 22.14	$ 22.14	$ 22.14