Investment In Unconsolidated Joint Ventures (Summary Of Financial Information For Joint Ventures) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Net investment in properties	$ 625,075		$ 584,837
Total assets	728,716		676,015
Mortgage loans	360,581		337,953
Total liabilities	458,986		444,062
Equity (deficit)	269,730		231,953
Investment in unconsolidated joint ventures	81,411		70,504
Revenues	21,919	11,099
Property operating expense	(5,009)	(2,687)
Net operating income	16,910	8,412
Net income (loss)	5,894	4,931
Investment in and share of net income (loss)	$ 2,581	$ 2,335
2001 Sixth Avenue [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures	50.00%
33 Chun Choi Street (Hong Kong) [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in joint ventures	20.00%