Annual report pursuant to Section 13 and 15(d)

Related Party Expenses (Detail)

v2.4.1.9
Related Party Expenses (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Related Party Transaction [Line Items]    
Research $ 5,600,421us-gaap_ResearchAndDevelopmentExpense $ 9,411,856us-gaap_ResearchAndDevelopmentExpense
TUM [Member]    
Related Party Transaction [Line Items]    
Transfer of licenses and protective rights 66,461us-gaap_LicenseCosts
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
66,390us-gaap_LicenseCosts
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
Research   22,573us-gaap_ResearchAndDevelopmentExpense
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
Total expenses $ 66,461us-gaap_CostsAndExpensesRelatedParty
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember
$ 88,963us-gaap_CostsAndExpensesRelatedParty
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= pirs_TumMember