Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	6 Months Ended		12 Months Ended
		Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Summary of Significant Accounting Policies (Textual)
Common stock equivalents excluded from EPS as the inclusion would be anti-dilutive			9,644,820	9,265,636
Common stock, par value			$ 0.01		$ 0.01
Impairment of unproved oil and gas properties					$ 30,906
Capitalized exploration costs	[1]		$ 7,121		6,714
Post-impairment charge		$ 65	228
Deferred offering costs			$ 50		$ 63

[1] The unproved oil and gas properties balance at June 30, 2019 and at December 31, 2018 contains approximately $136,000 and $2,946,000, respectively, in unpaid amounts.