Other Liabilities (Details) - Non Current Liabilities - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Other Liabilities [Line Items]
Production Tax Liability	$ 46,500	$ 68,020
Deferred oil gathering credits	18,593	20,100
Deferred Midstream gathering credits	170,508	175,897
Operating and Finance Lease Liability, Noncurrent	12,494	15,779
Other Accrued Liabilities	2,440	3,337
Other Accrued Liabilities, Noncurrent	$ 250,535	$ 283,133