Basis of Presentation and General Information (ConRisk) (Details) - item	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Charterers individually accounting for more than 10% of revenues
Percent of voyage charters revenue to total revenue (as a percent)	1.30%
Revenue | Customer concentration
Charterers individually accounting for more than 10% of revenues
Number of charterers	2	2	1
Revenue | Customer concentration | Helios LPG Pool LLC
Charterers individually accounting for more than 10% of revenues
Percentage of total revenues	67.00%	69.00%	70.00%
Revenue | Customer concentration | Customer Two
Charterers individually accounting for more than 10% of revenues
Percentage of total revenues	13.00%	13.00%	12.00%
Revenue | Customer concentration | Customer Three
Charterers individually accounting for more than 10% of revenues
Percentage of total revenues	11.00%	10.00%