Long-Term Debt (Covenants) (Details)								12 Months Ended
	Jun. 20, 2018 USD ($)	Jun. 04, 2018 USD ($)	Mar. 16, 2018 USD ($)	Jan. 31, 2018 USD ($)	Dec. 08, 2017 USD ($)	Nov. 07, 2017 USD ($)	Jun. 08, 2017 USD ($) item	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Jul. 23, 2019 USD ($)	May 31, 2017 USD ($) item	Mar. 31, 2015 USD ($)
Long-Term Debt
Deferred financing fees								$ 40,547	$ 628,144	$ 3,113,425
2015 Debt Facility
Long-Term Debt
Number of debt principal payments with relaxed covenants | item												2
Minimum cash balance requirement through six months from the Amendment Date												$ 18,000,000
Minimum cash per mortgaged vessel through six months from the Amendment Date												1,000,000
Minimum cash balance requirement from six months from the amendment date through first anniversary												29,000,000
Minimum cash per mortgaged vessel from six months from the Amendment Date through first anniversary												1,600,000
Minimum cash balance requirement from first anniversary through thereafter												40,000,000
Minimum cash per mortgaged vessel from first anniversary through thereafter												2,200,000
Minimum stock offering for recalculation of restricted cash covenants												$ 50,000,000
Percent of principal debt outstanding for recalculation of restricted cash covenants (as a percent)												5.00%
Minimum cash balance required to be maintained if common stock offering met required threshold												$ 20,000,000
Minimum cash per mortgaged vessel if common stock offering met threshold												$ 1,100,000
Minimum interest coverage ratio for following 12 month period (as a percent)												125.00%
Minimum interest coverage ratio for following subsequent year (as a percent)												150.00%
Minimum interest coverage ratio for thereafter (as a percent)											250.00%	250.00%
Minimum fair market value of mortgaged ships plus any additional security over the outstanding loan balance through March 31, 2018												125.00%
Minimum fair market value of mortgaged ships plus any additional security over the outstanding loan balance from April 1, 2018 through March 31, 2019												130.00%
Minimum fair market value of mortgaged ships plus any additional security over the outstanding loan balance thereafter												135.00%
Amendment fees											$ 100,000	$ 1,100,000
Repayment of debt			$ 33,700,000	$ 35,100,000
Original loan amount													$ 758,000,000
The amount of restricted cash released			$ 1,600,000	$ 1,600,000								$ 26,800,000
Maximum consolidated net debt to consolidated total capitalization ratio (as a percent)								60.00%
Minimum stockholder's equity balance								$ 400,000,000
Percent of any new equity raised after closing date (as a percent)								50.00%
Percent of positive net income for the immediately preceding financial year (as a percent)								25.00%
Current assets and long-term restricted cash divided by current liabilities ratio (as a percent)								100.00%
Amendment to the 2015 Debt Facility
Minimum interest coverage ratio for following 9 month period (as a percent)											200.00%
Minimum interest coverage ratio for thereafter (as a percent)											250.00%	250.00%
Minimum consolidated liquidity if interest coverage ratio of consolidated EBITDA is less than required											$ 47,500,000
Ownership percentage of common shares by any shareholder other than certain entities or directors or officers that permits lenders to accelerate indebtedness (as a percent)											33.30%
2017 Bridge Loan
Long-Term Debt
Repayment of debt	$ 44,600,000	$ 22,300,000				$ 30,100,000
Original loan amount							$ 97,000,000
Deferred financing fees					$ 200,000
Number of VLGC secured by loan agreement | item							4
2017 Bridge Loan | LIBOR | Period Ending December 7, 2017
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							2.50%
2017 Bridge Loan | LIBOR | December 8, 2017 until March 7, 2018
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							4.50%
2017 Bridge Loan | LIBOR | March 8, 2018 until June 7, 2018
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							6.50%
2017 Bridge Loan | LIBOR | June 8, 2018 until Maturity Date
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							8.50%
2017 Bridge Loan | LIBOR | Period Ending March 31, 2018
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							2.50%
2017 Bridge Loan | LIBOR | April 1, 2018 until June 30, 2018
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							6.50%
2017 Bridge Loan | LIBOR | July 1, 2018 until December 31, 2018
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)							8.50%
Royal Bank of Scotland plc (RBS)
Long-Term Debt
Debt redemption price (as a percent)							96.00%