Significant Accounting Policies (Details 2)	12 Months Ended
Mar. 31, 2015 item
Segment reporting:
Number of reportable segment	1us-gaap_NumberOfReportableSegments
Vessels
Vessels, Net
Useful life of vessels	25 years
Initial drydocking period	5 years
Drydocking period after 15 years	2 years 6 months
Number of years for initial drydocking requirement	15 years

Represents the first incremental time between required drydocking.

No definition available.

Name:	lpg_DrydockingIncrementalPeriodOne
Namespace Prefix:	lpg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the second incremental time between required drydocking.

+ References

No definition available.

+ Details

Name:	lpg_DrydockingIncrementalPeriodTwo
Namespace Prefix:	lpg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum specified time for the initial incremental time between required drydocking.

+ References

No definition available.

+ Details

Name:	lpg_DrydockingMaximumInitialPeriod
Namespace Prefix:	lpg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MaritimeEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: