Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 14, 2019
Net income fee to related party
Entity Registrant Name	INCOME OPPORTUNITY REALTY INVESTORS INC /TX/
Entity Central Index Key	0000949961
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity File Number	001-14784
Entity Incorporation, State or Country Code	NV
Entity's Reporting Status Current	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		4,168,214
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2019