General form of registration statement for all companies including face-amount certificate companies

Related Party Expenses (Detail)

v2.4.1.9
Related Party Expenses (Detail) (USD $)
9 Months Ended 12 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Dec. 31, 2013
Dec. 31, 2012
Schedule of Other Related Party Transactions [Line Items]        
Research $ 3,268,262us-gaap_ResearchAndDevelopmentExpense $ 7,562,760us-gaap_ResearchAndDevelopmentExpense $ 9,411,856us-gaap_ResearchAndDevelopmentExpense $ 10,854,761us-gaap_ResearchAndDevelopmentExpense
TUM        
Schedule of Other Related Party Transactions [Line Items]        
Transfer of licenses and protective right 50,839us-gaap_LicenseCosts
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
49,405us-gaap_LicenseCosts
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
66,390us-gaap_LicenseCosts
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
19,290us-gaap_LicenseCosts
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
Research   22,454us-gaap_ResearchAndDevelopmentExpense
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
22,573us-gaap_ResearchAndDevelopmentExpense
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
131,172us-gaap_ResearchAndDevelopmentExpense
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
Total expenses $ 50,839us-gaap_CostsAndExpensesRelatedParty
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
$ 71,859us-gaap_CostsAndExpensesRelatedParty
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
$ 88,963us-gaap_CostsAndExpensesRelatedParty
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
$ 150,462us-gaap_CostsAndExpensesRelatedParty
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember