Unproved Oil and Gas Properties, Full Cost Method (Details 1) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Excluded from amortization base:
Drilling costs, and other operational related costs		$ 1	$ 7,326
Capitalized salary costs		89	423
Capitalized interest costs		38	156
Legal costs, license fees and other preparation costs		268	596
Other costs		11	143
Changes in unproved oil and gas properties	[1]	$ 407	$ 8,644

[1] Inclusive of non-cash amounts of approximately $174,000 and $3,872,000 during the six months ended June 30, 2019, and 2018, respectively.