Investments In Unconsolidated Joint Ventures (Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures $ 1,572 $ (51)
Amortization of basis difference 289 259
Urby At Harborside [Member]    
Schedule of Equity Method Investments [Line Items]    
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] | Marbella [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 91 109
Unconsolidated Joint Venture Multi-Family Properties [Member] | Metropolitan At 40 Park [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures (75) (85)
Unconsolidated Joint Venture Multi-Family Properties [Member] | RiverTrace At Port Imperial [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 44 48
Unconsolidated Joint Venture Multi-Family Properties [Member] | Crystal House [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures (162) (293)
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Riverwalk C [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures   (131)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella II [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 22 27
Unconsolidated Joint Venture Multi-Family Properties [Member] | Riverpark At Harrison [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures (63) (11)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Station House [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures (428) (375)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Urby At Harborside [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 1,721 [1] (145)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Liberty Landing [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures   (15)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Hillsborough 206 [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 16 (25)
Unconsolidated Joint Venture Office Buildings [Member] | Red Bank [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures (74) 106
Unconsolidated Joint Venture Office Buildings [Member] | 12 Vreeland Rd [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 59 77
Unconsolidated Joint Venture Office Buildings [Member] | Offices At Crystal Lake [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 26 6
Unconsolidated Joint Venture Other Property [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures [2] 1,572 (51)
Unconsolidated Joint Venture Other Property [Member] | Riverwalk Retail [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures (25) (11)
Unconsolidated Joint Venture Other Property [Member] | Hyatt Regency Jersey City [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures 310 587
Unconsolidated Joint Venture Other Property [Member] | Other [Member]    
Schedule of Equity Method Investments [Line Items]    
Company's equity in earnings of unconsolidated joint ventures $ 110 $ 80
[1] Includes $2.6 million of the Company's share of the venture's income from its first annual sale of an economic tax credit certificate from the State of New Jersey to a third party. The venture has an agreement with a third party to sell it the tax credits over the next nine years for $3 million per year for a total of $27 million. The sales are subject to the venture obtaining the tax credits from the State of New Jersey and transferring the credit certificates each year.
[2] Amounts are net of amortization of basis differences of $289 and $259 for the three months ended March 31, 2018 and 2017, respectively.