Annual report pursuant to Section 13 and 15(d)

Property and Equipment, Net - Summary of Property and Equipment (Detail)

v2.4.1.9
Property and Equipment, Net - Summary of Property and Equipment (Detail) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Property, Plant and Equipment [Line Items]    
Property and equipment at cost $ 4,234,994us-gaap_PropertyPlantAndEquipmentGross $ 4,540,852us-gaap_PropertyPlantAndEquipmentGross
Accumulated depreciation (2,182,773)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment (2,103,175)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Property and equipment, net 2,052,221us-gaap_PropertyPlantAndEquipmentNet 2,437,677us-gaap_PropertyPlantAndEquipmentNet
Leasehold Improvements [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment at cost 50,791us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
57,779us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
Accumulated depreciation (41,606)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
(37,904)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
Laboratory Equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment at cost 3,840,368us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= pirs_LaboratoryEquipmentMember
4,093,704us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= pirs_LaboratoryEquipmentMember
Accumulated depreciation (1,886,807)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= pirs_LaboratoryEquipmentMember
(1,845,098)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= pirs_LaboratoryEquipmentMember
Office and Computer Equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment at cost 343,835us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_MachineryAndEquipmentMember
389,368us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_MachineryAndEquipmentMember
Accumulated depreciation $ (254,360)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_MachineryAndEquipmentMember
$ (220,172)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_MachineryAndEquipmentMember