Investments in Partnerships - Summary of Equity Investments (Detail) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Total assets		$ 759,531	$ 668,020
Investments in real estate, at cost:
Operating properties		639,533	649,960
Construction in progress		247,574	160,699
Total investments in real estate		887,107	810,659
Accumulated depreciation		(216,581)	(207,987)
Net investments in real estate		670,526	602,672
Cash and cash equivalents		47,932	27,643
Deferred costs and other assets, net		41,073	37,705
Total assets		759,531	668,020
LIABILITIES AND PARTNERS’ INVESTMENT:
Mortgage loans payable, net		441,956	445,224
Other liabilities		44,698	23,945
Total liabilities		486,654	469,169
Net investment		272,877	198,851
Partners’ share		137,455	101,045
PREIT’s share		135,422	97,806
Excess investment	[1]	10,537	8,969
Net investments and advances		145,959	106,775
Investment in partnerships, at equity		206,618	168,608
Distributions in excess of partnership investments		$ (60,659)	$ (61,833)

[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.”