Investments in Partnerships - Summary of Equity Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Investments in real estate, at cost:
Operating properties	$ 573,939	$ 575,149
Construction in progress	441,678	420,771
Total investments in real estate	1,015,617	995,920
Accumulated depreciation	(214,905)	(212,574)
Net investments in real estate	800,712	783,346
Cash and cash equivalents	34,968	20,446
Deferred costs and other assets, net	30,284	30,549
Total assets	865,964	834,341
LIABILITIES AND PARTNERS’ INVESTMENT:
Mortgage loans payable, net	505,086	507,090
FDP Term Loan, net	248,030	247,901
Other liabilities	31,460	34,463
Total liabilities	784,576	789,454
Net investment	81,388	44,887
Partners’ share	39,296	21,583
PREIT’s share	42,092	23,304
Excess investment	16,476	15,763
Net investments and advances	58,568	39,067
Investment in partnerships, at equity	149,795	131,124
Distributions in excess of partnership investments	$ (91,227)	$ (92,057)