Basis of Presentation and Significant Accounting Policies (Details 1) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) swaps	Dec. 31, 2014 USD ($) swaps	Dec. 31, 2013 USD ($)
Basis of Presentation and Significant Accounting Policies [Abstract]
Number of interest rate swaps | swaps		2	1
Schedule Of Equity Method Investments [Line Items]
Non cash impairment losses			$ 85,459	$ 281,098
Significant Policies Other Details [Abstract]
Tenant and other receivables, allowance for doubtful accounts (in US dollars)		$ 11,908	12,210
Receivables Arising From Straight Lining Of Rents Allowance		2,751	3,188
Toys R Us [Member]
Schedule Of Equity Method Investments [Line Items]
Non cash impairment losses	$ (75,196)	$ 0	$ 75,196	$ 240,757