Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Summary of reconciliation of the ARO
Balance at beginning of period	$ 5,120	$ 3,095
Accretion expense	155	70
Additions during period	5	5
Reconciliation of the ARO, gross	5,280	3,170
Less: ARO recognized as a current liability	(183)
Balance at end of period	$ 5,097	$ 3,170