Long-Term Debt (Other) (Details)											1 Months Ended	12 Months Ended
	Jun. 26, 2018 USD ($)	Jun. 25, 2018 USD ($)	Jun. 20, 2018 USD ($)	Jun. 11, 2018 USD ($)	Jun. 04, 2018 USD ($)	Mar. 16, 2018 USD ($)	Jan. 31, 2018 USD ($)	Dec. 08, 2017 USD ($)	Nov. 07, 2017 USD ($)	Jun. 08, 2017 USD ($)	Mar. 31, 2015 USD ($) item	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	May 31, 2017 USD ($)
Long-Term Debt
Financing costs paid												$ 628,144	$ 3,113,425	$ 99,785
Drawdowns												65,137,500	261,000,000
Presented as follows:
Total debt obligations															$ 710,096,616	$ 775,164,186
Less: deferred financing fees												16,061,034	20,138,480	20,138,480	14,005,830	16,061,034
Current portion of long-term debt															63,968,414	65,067,569
Long-term debt—net of current portion and deferred financing fees															632,122,372	694,035,583
Total															696,090,786	759,103,152
Long-term Debt, Other Disclosures [Abstract]
Deferred finance fees, beginning												16,061,034	20,138,480
Additions												1,080,847	3,255,859
Amortization												(3,136,051)	(7,506,509)	(3,709,421)
Gain early extinguishment of debt													173,204
Deferred finance fees, end												$ 14,005,830	$ 16,061,034	$ 20,138,480
Corsair LPG Transport LLC
Long-Term Debt
Value of vessel transferred									$ 65,000,000
Term of Charter Agreement									12 years
Period until purchase option exercisable									2 years
Proceeds from sale of vessel									$ 52,000,000
Deposit retained by buyer									13,000,000
Concorde LPG Transport LLC
Long-Term Debt
Value of vessel transferred							$ 70,000,000
Term of Charter Agreement							13 years
Period until purchase option exercisable							3 years
Proceeds from sale of vessel							$ 56,000,000
Deposit retained by buyer							14,000,000
Corvette LPG Transport LLC
Long-Term Debt
Value of vessel transferred						$ 70,000,000
Term of Charter Agreement						13 years
Period until purchase option exercisable						3 years
Proceeds from sale of vessel						$ 56,000,000
Deposit retained by buyer						14,000,000
CJNP LPG Transport LLC
Long-Term Debt
Value of vessel transferred				$ 48,300,000
Term of Charter Agreement				6 years
Period until purchase option exercisable				2 years
Proceeds from sale of vessel				$ 21,700,000
Deposit retained by buyer				$ 26,600,000
CMNL LPG Transport LLC
Long-Term Debt
Value of vessel transferred		$ 45,800,000
Term of Charter Agreement		7 years
Period until purchase option exercisable		2 years
Proceeds from sale of vessel		$ 20,600,000
Deposit retained by buyer		$ 25,200,000
CNML LPG Transport LLC
Long-Term Debt
Value of vessel transferred	$ 50,800,000
Term of Charter Agreement	7 years
Period until purchase option exercisable	2 years
Proceeds from sale of vessel	$ 22,900,000
Deposit retained by buyer	$ 27,900,000
2015 Debt Facility
Long-Term Debt
Original loan amount											$ 758,000,000
Number of tranches in which loan facility is divided | item											4
Number of VLGC newbuildings secured by loan | item											16
Loan-to-contract cost ratio before fees (as a percent)											55.00%
Commitment fee (as a percent)											40.00%
Repayment of debt						33,700,000	35,100,000
The amount of restricted cash released						$ 1,600,000	$ 1,600,000										$ 26,800,000
Presented as follows:
Total debt obligations															$ 496,620,495	546,654,871
2015 Debt Facility | LIBOR
Long-Term Debt
Interest Rate															2.61%
Commercial Financing
Long-Term Debt
Original loan amount											$ 249,000,000
Term											7 years
Interest Rate															5.36%
Presented as follows:
Total debt obligations															$ 175,687,613	187,989,229
Commercial Financing | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)											2.75%	2.75%
Commercial Financing | 50% or more but less than 75% vessels financed are employed under time charters | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)											2.50%
Commercial Financing | 75% or more vessels financed are employed under time charters | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)											2.25%
Commercial Financing | Minimum | 50% or more but less than 75% vessels financed are employed under time charters
Long-Term Debt
Percent of vessels financed that are employed under time charters											50.00%
Commercial Financing | Minimum | 75% or more vessels financed are employed under time charters
Long-Term Debt
Percent of vessels financed that are employed under time charters											75.00%
Commercial Financing | Maximum | 50% or more but less than 75% vessels financed are employed under time charters
Long-Term Debt
Percent of vessels financed that are employed under time charters											75.00%
KEXIM Direct Financing
Long-Term Debt
Original loan amount											$ 204,000,000
Term											12 years
Interest Rate															5.06%
Presented as follows:
Total debt obligations															$ 125,860,144	141,004,162
KEXIM Direct Financing | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)											2.45%
KEXIM Guaranteed and K-sure Insured
Long-Term Debt
Original loan amount											$ 305,000,000
KEXIM Guaranteed
Long-Term Debt
Original loan amount											$ 202,000,000
Term											12 years
Interest Rate															4.01%
Presented as follows:
Total debt obligations															$ 130,366,568	145,348,064
KEXIM Guaranteed | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)											1.40%
K-sure Insured
Long-Term Debt
Original loan amount											$ 103,000,000
Term											12 years
Interest Rate															4.11%
Presented as follows:
Total debt obligations															$ 64,706,170	72,313,416
K-sure Insured | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)											1.50%
2017 Bridge Loan
Long-Term Debt
Original loan amount										$ 97,000,000
Financing costs paid								$ 200,000
Repayment of debt			$ 44,600,000		$ 22,300,000				$ 30,100,000
Presented as follows:
Total debt obligations																66,940,405
2017 Bridge Loan | Period Ending December 7, 2017 | LIBOR
Long-Term Debt
Margin added to LIBOR for interest rate on loan facility (as a percent)										2.50%
CMNL LPG Transport LLC
Long-Term Debt
Repayment of debt			23,400,000
CNML LPG Transport LLC
Long-Term Debt
Repayment of debt			$ 21,200,000
Japanese Financing Agreement [Member]
Presented as follows:
Total debt obligations															213,476,121	161,568,910
Corsair Japanese Financing
Long-Term Debt
Stated rate (as a percent)									4.90%
Financing cost to be incurred									$ 100,000
Monthly brokerage commission (as a percent)									1.25%
Brokerage commission fee on exercised purchase option (as a percent)									1.00%
Periodic principal payment amount									$ 300,000
Principal payment frequency									monthly
Balloon payment amount									$ 13,000,000
Presented as follows:
Total debt obligations															47,395,833	50,645,833
Concorde Japanese Financing
Long-Term Debt
Stated rate (as a percent)							4.90%
Financing cost to be incurred							$ 100,000
Monthly brokerage commission (as a percent)							1.25%
Brokerage commission fee on exercised purchase option (as a percent)							1.00%
Periodic principal payment amount							$ 300,000
Principal payment frequency							monthly
Balloon payment amount							$ 14,000,000
Presented as follows:
Total debt obligations															51,961,538	55,192,308
Corvette Japanese Financing
Long-Term Debt
Stated rate (as a percent)						4.90%
Financing cost to be incurred						$ 100,000
Monthly brokerage commission (as a percent)						1.25%
Brokerage commission fee on exercised purchase option (as a percent)						1.00%
Periodic principal payment amount						$ 300,000
Principal payment frequency						monthly
Balloon payment amount						$ 14,000,000
Presented as follows:
Total debt obligations															52,500,000	$ 55,730,769
CJNP Japanese Financing
Long-Term Debt
Stated rate (as a percent)				6.00%
Financing cost to be incurred				$ 100,000
Monthly brokerage commission (as a percent)				1.25%
Brokerage Commission Fee on delivery Purchase Option (as a percent)				0.50%
Brokerage commission fee on exercised purchase option (as a percent)				0.50%
Periodic principal payment amount				$ 100,000
Principal payment frequency				monthly
Balloon payment amount				$ 13,000,000
Presented as follows:
Total debt obligations															20,506,250
CMNL Japanese Financing
Long-Term Debt
Stated rate (as a percent)		6.00%
Financing cost to be incurred		$ 100,000
Monthly brokerage commission (as a percent)		1.25%
Brokerage Commission Fee on delivery Purchase Option (as a percent)		0.50%
Brokerage commission fee on exercised purchase option (as a percent)		0.50%
Periodic principal payment amount		$ 100,000
Principal payment frequency		monthly
Balloon payment amount		$ 11,000,000
Presented as follows:
Total debt obligations															19,446,131
CNML Japanese Financing
Long-Term Debt
Stated rate (as a percent)	6.00%
Financing cost to be incurred	$ 100,000
Monthly brokerage commission (as a percent)	1.25%
Brokerage Commission Fee on delivery Purchase Option (as a percent)	0.50%
Brokerage commission fee on exercised purchase option (as a percent)	0.50%
Periodic principal payment amount	$ 100,000
Principal payment frequency	monthly
Balloon payment amount	$ 13,000,000
Presented as follows:
Total debt obligations															$ 21,666,369