| Cover | Jun. 28, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 28, 2021 |
| Entity File Number | 001-08546 |
| Entity Registrant Name | Trinity Place Holdings Inc. |
| Entity Central Index Key | 0000724742 |
| Entity Tax Identification Number | 22-2465228 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 340 Madison Avenue |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10173 |
| City Area Code | 212 |
| Local Phone Number | 235-2190 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock $0.01 Par Value Per Share |
| Trading Symbol | TPHS |
| Security Exchange Name | NYSEAMER |
| Entity Emerging Growth Company | false |
