Fresh Start Accounting (Liabilities Subject to Compromise) (Details 6) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Sep. 18, 2020
Reorganization Value [Line Items]
Current maturities of long-term debt	$ 0	$ 68,008	$ 73,563
Oil and gas production payable			56,077
Operating lease liabilities - current	4,677	1,350	728
Long-term debt, net of current portion	35,000	70,000	157,459
Asset retirement obligations	284,238	179,338	158,438
Operating lease liabilities - long-term	17,094	19,460	525
Other long-term liabilities	$ 22,910	$ 20,872	22,139
Senior secured second lien notes			1,629,457
Convertible senior notes			234,015
Senior subordinated notes			251,480
Total settled liabilities subject to compromise			2,114,952
Accounts payable and accrued liabilities			101,431
Deferred tax liabilities			289,389
Total reinstated liabilities subject to compromise			708,554
Total liabilities subject to compromise			2,823,506
Issuance of New Common Stock to second lien note holders			(1,014,608)
Issuance of New Common Stock to convertible note holders			(53,400)
Issuance of series A warrants to convertible note holders			(15,683)
Issuance of series B warrants to senior subordinated note holders			(6,398)
Reinstatement of liabilities subject to compromise			(708,553)
Gain on settlement of liabilities subject to compromise			1,024,864
Reorganization Adjustments
Reorganization Value [Line Items]
Current maturities of long-term debt			73,199
Oil and gas production payable			16,705
Operating lease liabilities - current			757
Long-term debt, net of current portion			42,610
Asset retirement obligations			180,408
Operating lease liabilities - long-term			515
Other long-term liabilities			3,540
Total liabilities subject to compromise			$ (2,823,506)