Document And Entity Information
9 Months Ended
Sep. 30, 2013
Oct. 28, 2013
Document and Entity Information [Abstract]    
Entity Registrant Name Retail Opportunity Investments Corp  
Document Type 10-Q  
Current Fiscal Year End Date --12-31  
Entity Common Stock, Shares Outstanding   72,062,585
Amendment Flag false  
Entity Central Index Key 0001407623  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
Entity Filer Category Accelerated Filer  
Entity Well-known Seasoned Issuer No  
Document Period End Date Sep. 30, 2013  
Document Fiscal Year Focus 2013  
Document Fiscal Period Focus Q3