v3.19.1
Document And Entity Information - shares
3 Months Ended
Mar. 31, 2019
Apr. 19, 2019
Document Information [Line Items]    
Entity Registrant Name RETAIL OPPORTUNITY INVESTMENTS CORP  
Trading Symbol roic  
Document Type 10-Q  
Current Fiscal Year End Date --12-31  
Entity Common Stock, Shares Outstanding (in shares)   114,311,788
Amendment Flag false  
Entity Central Index Key 0001407623  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Entity Emerging Growth Company false  
Entity Small Business false  
Retail Opportunity Investments Partnership L.P.    
Document Information [Line Items]    
Entity Registrant Name Retail Opportunity Investments Partnerships L.P.  
Current Fiscal Year End Date --12-31  
Entity Central Index Key 0001577230  
Entity Filer Category Non-accelerated Filer