| Document and Entity Information | Nov. 19, 2024 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | TRI-CONTINENTAL Corp |
| Entity Incorporation State Country Code | MD |
| Amendment Flag | false |
| Entity Central Index Key | 0000099614 |
| Document Type | 8-K |
| Document Period End Date | Nov. 19, 2024 |
| Entity File Number | 811-00266 |
| Entity Tax Identification Number | 13-5441850 |
| Entity Address, Address Line One | 290 Congress Street |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02210 |
| City Area Code | 800 |
| Local Phone Number | 345-6611 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock |
| Trading Symbol | TY |
| Security Exchange Name | NYSE |
| Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Preferred Stock |
| Trading Symbol | TYPR |
| Security Exchange Name | NYSE |
