Investments in Partnerships - Summary of Equity Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investments in real estate, at cost:
Operating properties	$ 587,779	$ 575,149
Construction in progress	444,080	420,771
Total investments in real estate	1,031,859	995,920
Accumulated depreciation	(219,159)	(212,574)
Net investments in real estate	812,700	783,346
Cash and cash equivalents	29,431	20,446
Deferred costs and other assets, net	33,099	30,549
Total assets	875,230	834,341
LIABILITIES AND PARTNERS’ INVESTMENT:
Mortgage loans payable, net	503,068	507,090
FDP Term Loan, net	248,159	247,901
Other liabilities	34,875	34,463
Total liabilities	786,102	789,454
Net investment	89,128	44,887
Partners’ share	42,837	21,583
PREIT’s share	46,291	23,304
Excess investment	17,375	15,763
Net investments and advances	63,666	39,067
Reconciliation to comparable GAAP balance sheet item:
Investment in partnerships, at equity	153,318	131,124
Distributions in excess of partnership investments	(89,652)	(92,057)
Net investment	$ 63,666	$ 39,067