Revenues (Details) - USD ($)	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Revenues.
Net pool revenues—related party	$ 28,475,359	$ 37,659,385
Time charter revenues	12,564,655	12,532,351
Other revenues, net	(14,542)	324,040
Total revenues	$ 41,025,472	$ 50,515,776