Other Liabilities (Details) - Non Current Liabilities - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule of Other Liabilities [Line Items]
Production Tax Liability	$ 50,806	$ 65,592
Deferred oil gathering credits	17,085	18,090
Deferred Midstream gathering credits	164,637	168,478
Operating and Finance Lease Liability, Noncurrent	8,873	10,763
Other Accrued Liabilities	739	1,111
Other Accrued Liabilities, Noncurrent	$ 242,140	$ 264,034