Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Additional Information (Details)

v3.10.0.1
Fair Value - Additional Information (Details)
 3 Months Ended 6 Months Ended
Dec. 21, 2017
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2017
USD ($)
Jun. 30, 2018
USD ($)
Bcf / d
Jun. 30, 2017
USD ($)
Dec. 31, 2017
USD ($)
Schedule of Equity Method Investments [Line Items]            
Net realized and unrealized gain (loss) on other equity securities   $ (881,100) $ 614,634 $ (867,134) $ 70,426  
Investments at fair value   $ 2,091,181   $ 2,091,181   $ 2,958,315
Lightfoot Capital Partners LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Equity interest percentage   6.60%   6.60%   6.60%
Net realized and unrealized gain (loss) on other equity securities   $ (881,000)   $ (867,000)    
Lightfoot GP [Member]            
Schedule of Equity Method Investments [Line Items]            
Equity interest percentage   1.50%   1.50%   1.50%
Lightfoot Capital Partners LP [Member] | Gulf LNG [Member]            
Schedule of Equity Method Investments [Line Items]            
Receiving and regasification terminal, volume per day (bcf/d) | Bcf / d       1.5    
Arc Terminal Joliet Holdings [Member]            
Schedule of Equity Method Investments [Line Items]            
Equity interest percentage   0.60%   0.60%    
Lightfoot and Arc Terminal Joliet Holdings [Member]            
Schedule of Equity Method Investments [Line Items]            
Investment percentage of total assets   0.50%   0.50%    
Gulf LNG [Member] | Zenith [Member]            
Schedule of Equity Method Investments [Line Items]            
Percentage of interest acquired 4.16%          
Payment to acquire $ 27,300,000