Investments In Unconsolidated Joint Ventures (Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Feb. 28, 2019
Jan. 31, 2019
Jan. 30, 2019
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       $ (88) $ (52) $ (769) $ 1,520
Amortization of basis difference       156 289 328 579
PI North - Riverwalk C [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (62) (37) (132,000) (37,000)
Red Bank [Member]              
Schedule of Equity Method Investments [Line Items]              
Percentage of interest sold 50.00%            
Gain on sale $ 900            
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella I [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures         93   184,000
Unconsolidated Joint Venture Multi-Family Properties [Member] | Metropolitan At 40 Park [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (121) (156) (198,000) (231,000)
Unconsolidated Joint Venture Multi-Family Properties [Member] | RiverTrace At Port Imperial [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       52 45 90,000 89,000
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella Tower Urban Renewal Associates LLC [Member]              
Schedule of Equity Method Investments [Line Items]              
Percentage of additional interest acquired   50.00% 50.00%        
Unconsolidated Joint Venture Multi-Family Properties [Member] | Crystal House [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (184) (263) (409,000) (425,000)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella II [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures         8 (15,000) 30,000
Unconsolidated Joint Venture Multi-Family Properties [Member] | Riverpark At Harrison [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (65) (85) (125,000) (148,000)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Station House [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (538) (484) (1,094,000) (912,000)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Urby At Harborside [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (290) (574) (749,000) 1,147,000
Economic tax credit certificate income           $ 2,600  
Period of venture agreement to sell economic tax credit           9 years  
Annual proceeds from economic tax credit           $ 3,000  
Total proceeds from economic tax credit           27,000  
Unconsolidated Joint Venture Multi-Family Properties [Member] | Hillsborough 206 [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures             15,000
Unconsolidated Joint Venture Office Buildings [Member] | Red Bank [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures         (55) 8,000 (128,000)
Gain on sale $ 900            
Unconsolidated Joint Venture Office Buildings [Member] | 12 Vreeland Road [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       112 (21) 157,000 38,000
Unconsolidated Joint Venture Office Buildings [Member] | Offices At Crystal Lake [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (16) (6) 29,000 20,000
Unconsolidated Joint Venture Other Property [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (88) (52) (769) 1,520
Unconsolidated Joint Venture Other Property [Member] | Riverwalk Retail [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       (21) (20) (42,000) (45,000)
Unconsolidated Joint Venture Other Property [Member] | Hyatt Regency Jersey City [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       1,000 1,226 1,638,000 1,536,000
Unconsolidated Joint Venture Other Property [Member] | Other [Member]              
Schedule of Equity Method Investments [Line Items]              
Company's equity in earnings (loss) of unconsolidated joint ventures       $ 45 $ 277 $ 73,000 $ 387,000