Investments in Unconsolidated Companies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) entities	Dec. 31, 2015 USD ($) entities	Dec. 31, 2014 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated joint ventures in which equity interests held | entities	13
Impairment Charges	$ 18,018	$ 22,932	$ 49,106
Equity Method Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Impairment Charges		$ 30,000
Number of Impaired Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated joint ventures in which equity interests held | entities		3
Land [Member]
Schedule of Equity Method Investments [Line Items]
Impairment Charges	$ 14,299	$ 19,526	$ 33,700
Linden, New Jersey [Member] | Land [Member] | Equity Method Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Impairment Charges		$ 19,500