v2.4.0.6
Document And Entity Information (USD $)
12 Months Ended
Dec. 31, 2012
Feb. 26, 2013
Jun. 30, 2012
Document and Entity Information [Abstract]      
Entity Registrant Name Retail Opportunity Investments Corp    
Document Type 10-K    
Current Fiscal Year End Date --12-31    
Entity Common Stock, Shares Outstanding   57,933,379  
Entity Public Float     $ 602,995,478
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 Dec. 31, 2012    
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus FY