Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Payables and Accruals [Abstract]
Accounts payable	$ 4,982	$ 7,670
Oil and gas revenue suspense	3,123	2,675
Gathering and transportation payables	1,788	1,774
Production taxes payable	2,520	1,860
Accrued operating costs	875	3,155
Accrued ad valorem taxes - current	6,104	3,474
Accrued general and administrative expenses	1,750	3,111
Accrued asset retirement obligation - current	3,708	3,099	$ 769
Accrued interest	1,513	955
Accrued gas purchases	2,912	5,440
Other liabilities	1,222	1,603
Total accounts payable and accrued liabilities	$ 30,497	$ 34,816