Document And Entity Information
6 Months Ended
Jun. 30, 2012
Aug. 02, 2012
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   51,215,601
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 Jun. 30, 2012  
Document Fiscal Year Focus 2012  
Document Fiscal Period Focus Q2