Deferred Drydock Costs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in Deferred Drydock Costs [Roll Forward]
Beginning Balance	$ 9,749,751	$ 11,507,309	$ 11,146,009
Drydocking costs	8,323,191	2,579,111	3,688,711
Drydock amortization	(5,353,102)	(4,336,669)	(3,327,411)
Write-off due to sale of vessels	(533,484)	0	0
Ending Balance	$ 12,186,356	$ 9,749,751	$ 11,507,309