v2.4.0.8
Document and Entity Information
6 Months Ended
Jun. 30, 2014
Jul. 25, 2014
Document Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2014  
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q2  
Trading Symbol PRTA  
Entity Registrant Name Prothena Corp plc  
Entity Central Index Key 0001559053  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Ordinary Shares Outstanding   27,375,937