Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v2.4.1.9
Income Taxes - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Income Taxes [Line Items]    
Applicable statutory tax rate 34.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate  
Increase in valuation allowance $ 7,137,214us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount  
Liability for unrecognized tax positions 0us-gaap_UnrecognizedTaxBenefits  
Germany [Member]    
Income Taxes [Line Items]    
Applicable statutory tax rate 29.13%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
29.13%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
Operating loss carryforward reductions during period 619,820us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
 
Germany [Member] | Corporate Income Tax [Member]    
Income Taxes [Line Items]    
Operating loss carryforward 34,168,814us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= pirs_CorporateIncomeTaxMember
57,795,357us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= pirs_CorporateIncomeTaxMember
Operating loss carryforward 22,915,150us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromAcquisition
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= pirs_CorporateIncomeTaxMember
 
Germany [Member] | Trade Tax [Member]    
Income Taxes [Line Items]    
Operating loss carryforward 34,168,814us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= us-gaap_GeneralBusinessMember
56,420,412us-gaap_OperatingLossCarryforwards
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= us-gaap_GeneralBusinessMember
Operating loss carryforward 21,582,596us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromAcquisition
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= us-gaap_GeneralBusinessMember
 
Operating loss carryforward reductions during period $ 644,795us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions
/ us-gaap_IncomeTaxAuthorityAxis
= country_DE
/ us-gaap_TaxCreditCarryforwardAxis
= us-gaap_GeneralBusinessMember