Investments in Partnerships - Summary of Equity Investments (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Total assets		$ 663,507	$ 653,645
Investments in real estate, at cost:
Operating properties		646,247	636,774
Construction in progress		147,686	126,199
Total investments in real estate		793,933	762,973
Accumulated depreciation		(201,602)	(186,580)
Net investments in real estate		592,331	576,393
Cash and cash equivalents		34,505	37,362
Deferred costs and other assets, net(1)		36,671	39,890
Total assets		663,507	653,645
LIABILITIES AND PARTNERS’ INVESTMENT:
Mortgage loans payable(1)		444,955	440,450
Other liabilities		22,131	30,425
Total liabilities		467,086	470,875
Net investment		196,421	182,770
Partners’ share		100,374	95,165
PREIT’s share		96,047	87,605
Excess investment	[1]	8,485	7,877
Net investments and advances		104,532	95,482
Investment in partnerships, at equity		166,149	161,029
Distributions in excess of partnership investments		$ (61,617)	$ (65,547)

[1] Excess investment represents the unamortized difference between our investment and our share of the equity in the underlying net investment in the unconsolidated partnerships. The excess investment is amortized over the life of the properties, and the amortization is included in “Equity in income of partnerships.”