Supplemental Disclosures (Details 1) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Interest Paid, Net	$ 14,286	$ 15,875
(Decrease) increase in liabilities for oil and natural gas properties capital expenditures	(26,389)	43,797
(Decrease) increase in liabilities for midstream properties capital expenditures	(2,371)	1,838
Stock-based compensation expense recognized as liability	(93)	(339)
Increase (decrease) in liabilities for accrued cost to issue equity	73	(343)
Transfer of inventory from (to) oil and natural gas properties	343	(228)
Transfer of inventory to other property and equipment	(2,390)	0
Mineral Properties
Condensed Cash Flow Statements, Captions [Line Items]
Increase (decrease) in asset retirement obligations	834	1,978
Midstream Properties
Condensed Cash Flow Statements, Captions [Line Items]
Increase (decrease) in asset retirement obligations	$ 296	$ (138)