Basis of Presentation and Significant Accounting Policies (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property Plant And Equipment [Line Items]
Impairment losses, acquisition related costs and tenant buy-outs	$ 57,300	$ 114,886	$ 35,299
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net By Investment Category [Line Items]
Equity in net loss (income) of partially owned entities including Toys "R" Us	338,785	(423,126)	(118,612)
Significant Policies Other Details [Abstract]
Tenant and other receivables, net of allowance for doubtful accounts (in US dollars)	21,869	37,674
Receivables Arising From Straight Lining Of Rents Allowance	4,355	3,165
Equity Method Investments [Member]
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net By Investment Category [Line Items]
Other than Temporary Impairment Losses, Investments	281,098	44,936	13,974
Toys R Us [Member]
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net By Investment Category [Line Items]
Equity in net loss (income) of partially owned entities including Toys "R" Us	240,757	40,000
Impairment Loss [Member]
Property Plant And Equipment [Line Items]
Impairment losses, acquisition related costs and tenant buy-outs	32,443	103,638	5,228
Acquisitions related costs [Member]
Property Plant And Equipment [Line Items]
Impairment losses, acquisition related costs and tenant buy-outs	24,857	11,248	5,925
Penalty on early repayment of loan	10,949
Tenant Buy Outs [Member]
Property Plant And Equipment [Line Items]
Impairment losses, acquisition related costs and tenant buy-outs	$ 0	$ 0	$ 24,146