Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Other current assets:
Capitalized Costs - Crude Oil in Storage	$ 800
Tubular and Well Materials Purchase	3,900
Drilling and Completion Prepayment	3,600
Tubular inventory and well materials 1	6,430	$ 2,989
Prepaid expenses 1	6,406	1,469
Other Assets, Current	12,836	4,458
Other assets:
Deferred issuance costs of the Revolver	2,524	3,952
Operating Lease, Right-of-Use Asset	2,625	2,740
Other	110	32
Other assets	5,259	6,724
Accounts payable and accrued liabilities:
Trade accounts payable	3,522	30,098
Drilling costs	4,651	18,832
Royalties	27,936	44,537
Production, ad valorem and other taxes	5,352	3,244
Compensation	3,877	5,272
Interest	647	730
Operating Lease, Liability, Current	953	847	$ 953
Other	1,407	2,264
Accounts payable and accrued liabilities	48,345	105,824
Other liabilities:
Asset retirement obligations	5,321	4,934
Noncurrent operating lease obligations	1,948	2,232
Defined benefit pension obligations	785	873
Postretirement health care benefit obligations	389	343
Other liabilities	$ 8,443	$ 8,382