Vessels, Net (Details)	9 Months Ended
	Dec. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($)	Mar. 31, 2017 USD ($)
Accumulated depreciation
Vessels, net	$ 1,555,034,707		$ 1,603,469,247
Vessels
Cost
Balance at the beginning of the period	1,728,769,295
Other additions	218,685
Balance at the end of the period	1,728,987,980
Accumulated depreciation
Balance at the beginning of the period	(125,300,048)
Impairment	0	$ 0
Depreciation	(48,653,225)
Balance at the end of the period	$ (173,953,273)
Number of vessels with capital improvements | item	1
Mortgaged VLGC vessels, carrying value	$ 1,555,000,000		$ 1,603,500,000