Investments In Unconsolidated Joint Ventures (Summary Of Company's Equity In Earnings (Loss) Of Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands				12 Months Ended
	Sep. 01, 2021	Apr. 29, 2021	Mar. 12, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures				$ (4,251)	$ (3,832)	$ (1,319)
Amortization of basis difference				138	143
Sale price	$ 1,900
Crystal House [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale					35,100
Riverpark At Harrison [Member]
Schedule of Equity Method Investments [Line Items]
Litigation Settlement, Expense				$ 900
Urby At Harborside [Member]
Schedule of Equity Method Investments [Line Items]
Company's Effective Ownership %				85.00%
12 Vreeland Road [Member]
Schedule of Equity Method Investments [Line Items]
Sale price		$ 2,000
Offices At Crystal Lake [Member]
Schedule of Equity Method Investments [Line Items]
Loss on Sale of Investments	1,900
Sale price	1,900
Riverwalk Retail [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of additional interest acquired			80.00%
Unconsolidated Joint Venture Multi-Family Properties [Member] | Metropolitan And Lofts At 40 Park [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures				$ (801)	(1,010)	(422)
Company's Effective Ownership %				25.00%
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				$ 92	111	317
Company's Effective Ownership %				22.50%
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					(924)	(687)
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North - Riverwalk C [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures				$ (506)	(368)	(279)
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				$ (1,153)	(273)	(172)
Company's Effective Ownership %				45.00%
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				$ (1,647)	(1,650)	(2,000)
Company's Effective Ownership %				50.00%
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				$ (580)	1,095	1,587
Company's Effective Ownership %				85.00%
Unconsolidated Joint Venture Multi-Family Properties [Member] | PI North Pier Land [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures				$ (250)
Unconsolidated Joint Venture Multi-Family Properties [Member] | Liberty Landing [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures				$ (40)	(5)
Company's Effective Ownership %				50.00%
Unconsolidated Joint Venture Office Buildings [Member] | Crystal House [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale				$ 35,100
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				$ 2	(2,035)	(3,172)
Company's Effective Ownership %				50.00%
Sale price		$ 2,000
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				$ (113)	224	79
Company's Effective Ownership %				31.25%
Loss on Sale of Investments				$ (1,900)
Sale price	$ 1,900
Unconsolidated Joint Venture Other Property [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures				(4,251)	(3,832)	(1,319)
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					(10)	(72)
Unconsolidated Joint Venture Other Property [Member] | Hyatt Regency Hotel Jersey City [Member]
Schedule of Equity Method Investments [Line Items]
Company's equity in earnings (loss) of unconsolidated joint ventures					625	3,388
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				$ 745	$ 388	$ 114