Revenues (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Revenues.
Net pool revenues—related party	$ 22,301,512	$ 66,044,777	$ 80,798,208	$ 130,701,023
Time charter revenues	11,921,875	11,237,746	36,919,910	26,169,581
Voyage charter revenues	1,296,952	15,567,844	1,296,952	46,013,858
Other revenues	214,649	433,341	846,927	988,138
Total revenues	$ 35,734,988	$ 93,283,708	$ 119,861,997	$ 203,872,600