Basis of Presentation and General Information (General) (Details)	6 Months Ended
	Sep. 30, 2018 item
Basis of Presentation and General Information
Total number of vessels	22
Number of fuel-efficient ECO-design VLGCs having 84,000 cbm	19
Number of VLGCs having 82,000 cbm	3
The number of vessels that have exhaust gas cleaning systems	2
The number of vessels with contracts to purchase exhaust gas cleaning systems	7
The number of vessels with options to purchase exhaust gas cleaning systems	3