Quarterly report pursuant to Section 13 or 15(d)

Related Party Transaction - Additional Information (Detail)

v2.4.1.9
Related Party Transaction - Additional Information (Detail) (USD $)
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Patent No. 8,420,051 [Member]    
Related Party Transaction [Line Items]    
Expected patent expiration year 2029  
Consulting Agreement [Member]    
Related Party Transaction [Line Items]    
Consulting agreement fees paid to Prof. Dr. Skerra $ 5,623us-gaap_ProfessionalAndContractServicesExpense
/ us-gaap_RelatedPartyTransactionAxis
= pirs_ConsultingAgreementMember 		$ 6,853us-gaap_ProfessionalAndContractServicesExpense
/ us-gaap_RelatedPartyTransactionAxis
= pirs_ConsultingAgreementMember
TUM [Member]    
Related Party Transaction [Line Items]    
Patent expiration year 2027  
TUM [Member] | License Agreement [Member]    
Related Party Transaction [Line Items]    
Contingent accrual liability for research and licensing agreement $ 291,081us-gaap_LossContingencyAccrualAtCarryingValue
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
/ us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis
= pirs_LicenseAgreementMember 		$ 373,357us-gaap_LossContingencyAccrualAtCarryingValue
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
/ us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis
= pirs_LicenseAgreementMember