| Cover | May 02, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 2, 2022 |
| Entity File Number | 001-40496 |
| Entity Registrant Name | TERRA PROPERTY TRUST, INC. |
| Entity Central Index Key | 0001674356 |
| Entity Tax Identification Number | 81-0963486 |
| Entity Incorporation, State or Country Code | MD |
| Entity Address, Address Line One | 550 Fifth Avenue |
| Entity Address, Address Line Two | 6th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10036 |
| City Area Code | 212 |
| Local Phone Number | 753-5100 |
| Written Communications | true |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | 6.00% Notes due 2026 |
| Trading Symbol | TPTA |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | true |
