Property and Equipment (Details Textual)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($) USD_Bbl	Sep. 30, 2017 USD ($) USD_Bbl	Sep. 30, 2018 USD ($) USD_Bbl	Sep. 30, 2017 USD ($) USD_Bbl	Dec. 31, 2017 USD ($)
Property and Equipment (Textual)
Capitalized overhead	$ 106,000	$ 47,000	$ 306,000	$ 178,000
Depletion expense related to oil and gas properties	$ 2,400,000	$ 521,000	$ 5,600,000	$ 1,600,000
Depletion expense related to oil and gas properties (in dollars per Mcfe) | USD_Bbl	1.01	0.38	0.88	0.40
Unproved properties not subject to depletion [Member]
Property and Equipment (Textual)
Depletion expense related to oil and gas properties			$ 3,600,000		$ 1,900,000