Annual report pursuant to Section 13 and 15(d)

Related Party Transaction - Additional Information (Detail)

v2.4.1.9
Related Party Transaction - Additional Information (Detail) (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Related Party Transaction [Line Items]    
Contingent accrual liability for research and licensing agreement $ 327,937us-gaap_LossContingencyAccrualAtCarryingValue $ 373,059us-gaap_LossContingencyAccrualAtCarryingValue
Consulting Agreement [Member]    
Related Party Transaction [Line Items]    
Consulting agreement fees paid to Prof. Dr. Skerra 26,593us-gaap_ProfessionalAndContractServicesExpense
/ us-gaap_RelatedPartyTransactionAxis
= pirs_ConsultingAgreementMember 		26,556us-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 $ 327,937us-gaap_LossContingencyAccrualAtCarryingValue
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
/ us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis
= pirs_LicenseAgreementMember 		$ 373,059us-gaap_LossContingencyAccrualAtCarryingValue
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
/ us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis
= pirs_LicenseAgreementMember