Basis of Presentation and General Information (General) (Details)	6 Months Ended
Sep. 30, 2019 item
Basis of Presentation and General Information
Total number of vessels	23
Number of fuel-efficient ECO-design VLGCs having 84,000 cbm	19
Number of VLGCs having 82,000 cbm	3
Number of time chartered-in VLGC	1
The number of vessels that have exhaust gas cleaning systems	3
Number of VLGCs with scrubber purchase commitments	10
Number of VLGCs with scrubber purchase commitments that remain to be installed	9

Represents the number of fuel-efficient Eco-design Very Large Gas Carrier vessels in current fleet having a capacity of 84,000 cubic meters.

No definition available.

Name:	lpg_NumberOfFuelEfficientVeryLargeGasCarrierVesselsEightyFourThousandCapacity
Namespace Prefix:	lpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of very large gas carrier VLGC time chartered-in vessels.

No definition available.

Name:	lpg_NumberOfVeryLargeGasCarrierTimeCharteredInVessels
Namespace Prefix:	lpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of Very Large Gas Carrier vessels in current fleet having a capacity of 82,000 cubic meters.

No definition available.

Name:	lpg_NumberOfVeryLargeGasCarrierVesselsEightyTwoThousandCapacity
Namespace Prefix:	lpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of Very Large Gas Carrier vessels that have been contracted to add scrubber.

No definition available.

Name:	lpg_NumberOfVeryLargeGasCarrierVesselsThatHaveBeenContractedToAddScrubber
Namespace Prefix:	lpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of Very Large Gas Carrier vessels that have been contracted to add scrubber that remain to be installed.

No definition available.

Name:	lpg_NumberOfVeryLargeGasCarrierVesselsThatHaveBeenContractedToAddScrubberThatRemainToBeInstalled
Namespace Prefix:	lpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the total number of vessels owned by the entity.

No definition available.

The number of vessels that have exhaust gas cleaning systems.

No definition available.

Name:	lpg_NumberOfVesselsThatHaveExhaustGasCleaningScrubbers
Namespace Prefix:	lpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

No definition available.

Name:	us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration