| Cover | Mar. 25, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Mar. 26, 2021 |
| Entity Registrant Name | Transcontinental Realty Investors, Inc. |
| Entity Incorporation, State or Country Code | NV |
| Entity File Number | 001-09240 |
| Entity Tax Identification Number | 94-6565852 |
| Entity Address, Address Line One | 1603 LBJ Freeway, |
| Entity Address, Address Line Two | Suite 800 |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75234 |
| City Area Code | 469 |
| Local Phone Number | 522-4200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | TCI |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000733590 |
| Amendment Flag | false |
