Investments in Partnerships - Summary of Share of Equity in (Loss) Income of Partnerships (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Real estate revenue	$ 24,198	$ 23,742	$ 75,484	$ 70,636
Operating expenses:
Property operating and other expenses	(13,924)	(8,805)	(35,884)	(24,331)
Interest expense	(6,038)	(5,771)	(18,008)	(17,428)
Depreciation and amortization	(10,570)	(5,317)	(25,965)	(14,675)
Total expenses	(30,532)	(19,893)	(79,857)	(56,434)
Net (loss) income	(6,334)	3,849	(4,373)	14,202
Partners’ share	3,183	(2,191)	1,884	(7,777)
PREIT’s share	(3,151)	1,658	(2,489)	6,425
Amortization of and adjustments to excess investment, net	(108)	(127)	(309)	(289)
Equity in (loss) income of partnerships	(3,259)	1,531	(2,798)	6,136
Total assets	1,073,593		1,073,593		$ 982,924
FDP Term Loan, net	299,575		299,575		299,091
Lehigh Valley Associates, LP
Operating expenses:
Total assets	64,971		64,971		62,504
Mortgage loan payable, net	189,360		189,360		191,998
Revenue	6,596	8,006	21,243	24,589
Property operating expenses	(1,984)	(2,138)	(6,568)	(6,351)
Interest expense	(1,944)	(2,027)	(5,803)	(6,055)
Net income (loss)	1,864	3,059	6,402	9,768
PREIT’s share of equity in (loss) income of partnership	932	1,529	3,201	4,884
Fashion District Philadelphia
Operating expenses:
Total assets	725,087		725,087		641,377
Revenue	4,763	1,271	15,276	2,667
Property operating expenses	(6,228)	(1,901)	(14,305)	(3,100)
Interest expense	(933)	(2)	(2,137)	(2)
Net income (loss)	(9,365)	(2,553)	(16,304)	(4,879)
PREIT’s share of equity in (loss) income of partnership	(4,690)	$ (1,262)	(8,164)	$ (2,299)
FDP Term Loan, net	$ 299,575		$ 299,575		$ 299,091
Lehigh Valley Associates, LP | Lehigh Valley Associates, LP
Operating expenses:
Ownership percentage		50.00%		50.00%
Fashion District Philadelphia | Fashion District Philadelphia
Operating expenses:
Ownership percentage		50.00%		50.00%