Investments In Unconsolidated Joint Ventures (Summary Of Company's Investment In Unconsolidated Joint Ventures) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Dec. 23, 2013
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	$ 179,656,000		$ 181,129,000
Accounts payable, accrued expenses and other liabilities	147,357,000		121,286,000
Plaza VIII & IX Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	3,804,000		3,702,000
South Pier At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures		[1]		[1]
Accounts payable, accrued expenses and other liabilities	2,308,018		1,706,000
Red Bank Corporate Plaza, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	4,153,000		4,046,000
12 Vreeland Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	5,604,000		5,514,000
Stamford SM LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	36,835,000		36,258,000
Marbella RoseGarden, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	15,791,000		15,797,000
RoseGarden Monaco Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	2,925,000		3,201,000
Rosewood Lafayette Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	641,000		857,000
Rosewood Morristown, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	6,336,000		6,455,000
Roseland/North Retail, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	1,906,000		1,930,000
BNES Associates III [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	1,790,000		1,753,000
Portside Master Company, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	2,950,000		3,207,000
PruRose Port Imperial South 13, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	1,982,000		2,206,000
Roseland/Port Imperial Partners, L.P. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	2,017,000		2,068,000
RoseGarden Marbella South, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	7,951,000		7,567,000
PruRose Riverwalk G, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	2,579,000		3,117,000
Elmajo Urban Renewal Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	91,000		203,000
Estuary Urban Renewal Unit B, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures			24,000
RiverPark At Harrison I, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	3,808,000		3,655,000
RoseGarden Monaco, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	1,239,000		1,224,000
Hillsborough 206 Holdings, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	1,962,000		1,962,000
Grand Jersey Waterfront Urban Renewal Associates, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	337,000		337,000
Crystal House Apartments Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	26,326,000		26,838,000
KPG-P 100 IMW JV, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	1,234,000		1,887,000
Capitol Place Mezz LLC [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	47,302,000		46,628,000		46,500,000
Other [Member]
Schedule of Equity Method Investments [Line Items]
Company's investments in unconsolidated joint ventures	$ 93,000		$ 693,000

[1] The negative investment balance for this joint venture of $2,308,018 and $1,706,000 as of March 31, 2014 and December 31, 2013, respectively, were included in accounts payable, accrued expenses and other liabilities.