Document and Entity Information
9 Months Ended
Jun. 30, 2014
Aug. 11, 2014
Document Document And Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2014  
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q3  
Trading Symbol ARWR  
Entity Registrant Name ARROWHEAD RESEARCH CORP  
Entity Central Index Key 0000879407  
Current Fiscal Year End Date --09-30  
Entity Filer Category Smaller Reporting Company  
Entity Common Stock, Shares Outstanding   52,908,567