Investments In Unconsolidated Joint Ventures (Summary Of Unconsolidated Joint Ventures) (Details)
$ in Thousands
 3 Months Ended
Mar. 30, 2018
USD ($)
item
Feb. 03, 2017
USD ($)
Mar. 31, 2018
USD ($)
ft²
item
Mar. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
Schedule of Equity Method Investments [Line Items]          
Number of units | item     365    
Carrying Value     $ 249,513   $ 252,626
Proceeds from the sale of investments in unconsolidated joint ventures       $ 14,849  
Minimum [Member]          
Schedule of Equity Method Investments [Line Items]          
Company's Effective Ownership %     12.50%    
Maximum [Member]          
Schedule of Equity Method Investments [Line Items]          
Company's Effective Ownership %     85.00%    
Crystal House [Member]          
Schedule of Equity Method Investments [Line Items]          
Percentage of interest in developable land     50.00%    
Number of units available for development | item     295    
Number of approved units available for development | item     252    
Marbella II [Member] | Construction Loan [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of extension options | item 4        
Loan extension period 3 months        
Extension fee 0.0625%        
Maximum borrowing capacity $ 75,000        
Urby At Harborside [Member] | Construction/Permanent Loan [Member]          
Schedule of Equity Method Investments [Line Items]          
Company's Effective Ownership %     85.00%    
Maximum borrowing capacity     $ 192,000    
PI North - Land [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     836    
Residual ownership interest     20.00%    
The Shops At 40 Park Property [Member] | Metropolitan At 40 Park [Member]          
Schedule of Equity Method Investments [Line Items]          
Rentable Square Feet (sf) | ft²     50,973    
Property Debt, Balance     $ 6,140    
Property Debt, Maturity Date     Aug. 01, 2018    
Property Debt, Interest Rate     3.63%    
Residual ownership interest     12.50%    
Lofts At 40 Park Property [Member] | Metropolitan At 40 Park [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     59    
Indirect ownership interest     25.00%    
Number of stories | item     5    
Lofts At 40 Park Property [Member] | Metropolitan At 40 Park [Member] | Construction Loan [Member]          
Schedule of Equity Method Investments [Line Items]          
Property Debt, Balance   $ 12,190      
Property Debt, Maturity Date     Feb. 01, 2020    
Property Debt, Interest Rate, Spread Over LIBOR   2.50%      
Maximum borrowing capacity   $ 13,950      
Metropolitan Property [Member] | Metropolitan At 40 Park [Member]          
Schedule of Equity Method Investments [Line Items]          
Property Debt, Balance     $ 36,632    
Property Debt, Maturity Date     Sep. 01, 2020    
Property Debt, Interest Rate     3.25%    
Unconsolidated Joint Venture Multi-Family Properties [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     3,275    
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     412    
Company's Effective Ownership % [1]     24.27%    
Carrying Value     $ 14,353   14,544
Property Debt, Balance     $ 95,000    
Property Debt, Maturity Date     May 01, 2019    
Property Debt, Interest Rate, LIBOR     L+1.50    
Property Debt, Interest Rate, Spread Over LIBOR     1.50%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | Metropolitan At 40 Park [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item [2],[3]     130    
Company's Effective Ownership % [1],[2],[3]     12.50%    
Carrying Value [2],[3]     $ 6,759   6,834
Property Debt, Balance [2],[3],[4]     $ 54,962    
Property Debt, Interest Rate [2],[3]        
Unconsolidated Joint Venture Multi-Family Properties [Member] | RiverTrace At Port Imperial [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     316    
Company's Effective Ownership % [1]     22.50%    
Carrying Value     $ 8,662   8,864
Property Debt, Balance     $ 82,000    
Property Debt, Maturity Date     Nov. 10, 2026    
Property Debt, Interest Rate     3.21%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | Crystal House [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item [5]     825    
Company's Effective Ownership % [1],[5]     25.00%    
Carrying Value [5]     $ 30,075   30,570
Property Debt, Balance [5]     $ 165,000    
Property Debt, Maturity Date [5]     Apr. 01, 2020    
Property Debt, Interest Rate [5]     3.17%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Riverwalk C [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     360    
Company's Effective Ownership % [1]     40.00%    
Carrying Value     $ 18,018   16,844
Unconsolidated Joint Venture Multi-Family Properties [Member] | Marbella II [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     311    
Company's Effective Ownership % [1]     24.27%    
Carrying Value     $ 16,199   16,471
Property Debt, Balance     $ 74,690    
Property Debt, Maturity Date     Mar. 30, 2019    
Property Debt, Interest Rate, LIBOR [6]     L+2.25    
Property Debt, Interest Rate, Spread Over LIBOR [6]     2.25%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | Riverpark At Harrison [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     141    
Company's Effective Ownership % [1]     45.00%    
Carrying Value     $ 1,504   1,604
Property Debt, Balance     $ 30,000    
Property Debt, Maturity Date     Aug. 01, 2025    
Property Debt, Interest Rate     3.70%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | Station House [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     378    
Company's Effective Ownership % [1]     50.00%    
Carrying Value     $ 39,603   40,124
Property Debt, Balance     $ 99,685    
Property Debt, Maturity Date     Jul. 01, 2033    
Property Debt, Interest Rate     4.82%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | Urby At Harborside [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     762    
Company's Effective Ownership % [1]     85.00%    
Carrying Value     $ 92,692   94,429
Property Debt, Balance     $ 190,495    
Property Debt, Maturity Date     Aug. 01, 2029    
Property Debt, Interest Rate [7]     5.197%    
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Land [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item [8]     836    
Company's Effective Ownership % [1],[8]     20.00%    
Carrying Value [8]     $ 1,678   1,678
Unconsolidated Joint Venture Multi-Family Properties [Member] | Liberty Landing [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     850    
Company's Effective Ownership % [1]     50.00%    
Carrying Value     $ 337   337
Unconsolidated Joint Venture Multi-Family Properties [Member] | Hillsborough 206 [Member]          
Schedule of Equity Method Investments [Line Items]          
Rentable Square Feet (sf) | ft²     160,000    
Company's Effective Ownership % [1]     50.00%    
Carrying Value     $ 1,962   1,962
Unconsolidated Joint Venture Office Buildings [Member] | Red Bank [Member]          
Schedule of Equity Method Investments [Line Items]          
Rentable Square Feet (sf) | ft²     92,878    
Company's Effective Ownership % [1]     50.00%    
Carrying Value     $ 4,528   4,602
Property Debt, Balance     $ 13,726    
Property Debt, Maturity Date     May 17, 2018    
Property Debt, Interest Rate, LIBOR [9]     L+3.00    
Property Debt, Interest Rate, Spread Over LIBOR [9]     3.00%    
Unconsolidated Joint Venture Office Buildings [Member] | 12 Vreeland Rd [Member]          
Schedule of Equity Method Investments [Line Items]          
Rentable Square Feet (sf) | ft²     139,750    
Company's Effective Ownership % [1]     50.00%    
Carrying Value     $ 6,792   6,734
Property Debt, Balance     $ 9,101    
Property Debt, Maturity Date     Jul. 01, 2023    
Property Debt, Interest Rate     2.87%    
Unconsolidated Joint Venture Office Buildings [Member] | Offices At Crystal Lake [Member]          
Schedule of Equity Method Investments [Line Items]          
Rentable Square Feet (sf) | ft²     106,345    
Company's Effective Ownership % [1]     31.25%    
Carrying Value     $ 3,395   3,369
Property Debt, Balance     $ 4,618    
Property Debt, Maturity Date     Nov. 01, 2023    
Property Debt, Interest Rate     4.76%    
Unconsolidated Joint Venture Other Property [Member]          
Schedule of Equity Method Investments [Line Items]          
Carrying Value     $ 249,513   252,626
Property Debt, Balance     $ 919,277    
Unconsolidated Joint Venture Other Property [Member] | Riverwalk Retail [Member]          
Schedule of Equity Method Investments [Line Items]          
Rentable Square Feet (sf) | ft²     30,745    
Company's Effective Ownership % [1]     20.00%    
Carrying Value     $ 1,600   1,625
Unconsolidated Joint Venture Other Property [Member] | Hyatt Regency Jersey City [Member]          
Schedule of Equity Method Investments [Line Items]          
Number of units | item     350    
Company's Effective Ownership % [1]     50.00%    
Carrying Value       440
Property Debt, Balance     $ 100,000    
Property Debt, Maturity Date     Oct. 01, 2026    
Property Debt, Interest Rate     3.668%    
Unconsolidated Joint Venture Other Property [Member] | Other [Member]          
Schedule of Equity Method Investments [Line Items]          
Carrying Value [10]     $ 1,356   $ 1,595
[1] Company's effective ownership % represents the Company's entitlement to residual distributions after payments of priority returns, where applicable.
[2] The Company's ownership interests in this venture are subordinate to its partner's preferred capital balance and the Company is not expected to meaningfully participate in the venture's cash flows in the near term.
[3] Through the joint venture, the Company also owns a 12.5 percent interest in a 50,973 square feet retail building ("Shops at 40 Park") and a 25 percent interest in a to-be-built 59-unit, five story multi-family rental development property ("Lofts at 40 Park").
[4] Property debt balance consists of: (i) an amortizable loan, collateralized by the Metropolitan at 40 Park, with a balance of $36,632, bears interest at 3.25 percent, matures in September 2020; (ii) an amortizable loan, collateralized by the Shops at 40 Park, with a balance of $6,140, bears interest at 3.63 percent, matures in August 2018. On February 3, 2017, the venture obtained a construction loan with a maximum borrowing amount of $13,950 for the Lofts at 40 Park with a balance of $12,190, which bears interest at LIBOR plus 250 basis points and matures in February 2020.
[5] Included in this is the Company's unconsolidated 50 percent interest in a vacant land to accommodate the development of approximately 295 additional units of which 252 are currently approved.
[6] The construction loan which had a maximum borrowing amount of $75,000 was amended on 3/30/18 and, subject to certain conditions, provided for four 3-month extension options with a fee of 6.25 basis points for each extension.
[7] The construction/permanent loan has a maximum borrowing amount of $192,000. The Company owns an 85 percent interest with shared control over major decisions such as, approval of budgets, property financings and leasing guidelines. The development project was placed in service in second quarter 2017.
[8] The Company also owns a 20 percent residual interest in undeveloped land parcels: parcels 6, I, and J that can accommodate the development of 836 apartment units.
[9] The venture plans to refinance its mortgage loan at maturity.
[10] The Company owns other interests in various unconsolidated joint ventures, including interests in assets previously owned and interest in ventures whose businesses are related to its core operations. These ventures are not expected to significantly impact the Company's operations in the near term.