Significant Accounting Policies (Predecessor) (Details 2) (USD $)	12 Months Ended	0 Months Ended
Mar. 31, 2015	Jul. 28, 2013
Vessels
Vessels, Net
Useful life of vessels	25 years
Initial drydocking period	5 years
Number of years for initial drydocking requirement	15 years
Drydocking period after 15 years	2 years 6 months
Predecessor \| Vessels
Vessels, Net
Estimated scrap rate per lightweight ton		$ 400
Initial drydocking period		5 years
Number of years for initial drydocking requirement		15 years
Drydocking period after 15 years		2 years 6 months
Predecessor \| VLGC vessels
Vessels, Net
Useful life of vessels		20 years
Predecessor \| PGC vessels
Vessels, Net
Useful life of vessels		25 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

- Details

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

- Definition

The estimated or actual value of the asset at the end of its useful life or when it is no longer serviceable (cannot be used for its original purpose).

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentSalvageValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: