Name:	pshg_NewbuildingVesselsDeliveryAndVesselsAcquisitionsAbstract
Namespace Prefix:	pshg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of memoranda of agreements entered into with unrelated parties by the Company to acquire vessels.

No definition available.

Name:	pshg_NumberOfMemorandaOfAgreements
Namespace Prefix:	pshg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of vessels acquired by the entity.

No definition available.

Name:	pshg_NumberOfVesselsAcquired
Namespace Prefix:	pshg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Deadweight tonnage (DWT) is a measure of vessels capacity in weight, and does not include the weight of the vessel.

No definition available.

Name:	pshg_VesselDeadWeightTonnage
Namespace Prefix:	pshg_
Data Type:	dtr-types:massItemType
Balance Type:	na
Period Type:	duration

Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of increase (decrease) of physical assets used in the normal conduct of business and not intended for resale, from reclassification, impairment, donation, or changes classified as other. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-2