Unproved Oil and Gas Properties, Full Cost Method (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Excluded from amortization base:
Drilling costs, and other operational related costs	$ 1,227	$ 1,242
Capitalized salary costs	1,759	1,579
Capitalized interest costs	990	677
Legal and seismic costs, license fees and other preparation costs	6,636	3,216
Other costs	25
Total unproved oil and gas properties, full cost method	10,637	6,714
Oil and Gas Properties [Member]
Excluded from amortization base:
Drilling costs, and other operational related costs	244	27,371
Capitalized salary costs		1,006
Legal and seismic costs, license fees and other preparation costs		2,039
Other costs	70	490
Total unproved oil and gas properties, full cost method	$ 314	$ 30,906