XML 12 R1.htm IDEA: XBRL DOCUMENT v3.19.1
Document and Entity Information - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Mar. 29, 2019
Jun. 30, 2018
Net income fee to related party      
Entity Registrant Name INCOME OPPORTUNITY REALTY INVESTORS INC /TX/    
Entity Central Index Key 0000949961    
Document Type 10-K    
Document Period End Date Dec. 31, 2018    
Trading Symbol IOR    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity's Reporting Status Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Public Float     $ 10,429,607
Entity Common Stock, Shares Outstanding   4,168,214  
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2018    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false