| Document and Entity Information | Dec. 10, 2021 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0000077281 |
| Document Type | 8-K |
| Document Period End Date | Dec. 10, 2021 |
| Entity Registrant Name | Pennsylvania Real Estate Investment Trust |
| Entity Incorporation State Country Code | PA |
| Entity File Number | 001-6300 |
| Entity Tax Identification Number | 23-6216339 |
| Entity Address, Address Line One | One Commerce Square |
| Entity Address, Address Line Two | 2005 Market Street |
| Entity Address, Address Line Three | Suite 1000 |
| Entity Address, City or Town | Philadelphia |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19103 |
| City Area Code | (215) |
| Local Phone Number | 875-0700 |
| 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 | Shares of Beneficial Interest, par value $1.00 per share |
| Trading Symbol | PEI |
| Security Exchange Name | NYSE |
| Series B Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Series B Preferred Shares, par value $0.01 per share |
| Trading Symbol | PEIPrB |
| Security Exchange Name | NYSE |
| Series C Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Series C Preferred Shares, par value $0.01 per share |
| Trading Symbol | PEIPrC |
| Security Exchange Name | NYSE |
| Series D Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Series D Preferred Shares, par value $0.01 per share |
| Trading Symbol | PEIPrD |
| Security Exchange Name | NYSE |
