Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2012
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In addition to related party transactions discussed elsewhere in this Annual Report, the Company has an indemnity obligation to Vornado Realty Trust, one of its significant shareholders, with respect to actions by the Company that affect Vornado Realty Trust's status as a REIT. All related party acquisitions, sales and loans were approved by the independent members of the Company's Board of Trustees or the Audit Committee. During 2011 and 2010, the Company advanced an aggregate $20,077 and $7,614, respectively, to NLS entities in the form of interest bearing, non-recourse mortgage notes to satisfy maturing non-recourse mortgages. These advances were satisfied in full in 2011. The Company leases certain properties to entities in which Vornado Realty Trust, a significant shareholder, has an interest. During 2012, 2011 and 2010, the Company recognized $842, $864 and $905, respectively, in rental revenue from these properties. The Company leases its corporate office from an affiliate of Vornado Realty Trust. Rent expense for this property was $919, $1,281 and $1,272 in 2012, 2011 and 2010, respectively. The Company's Board of Trustees granted a waiver of the Company's Code of Business Conduct and Ethics to allow the Company to enter into a joint venture with an affiliate of its Chairman, which intends to raise capital from foreign investors seeking entry into the United States of America. As of the date of filing this Annual Report, no joint venture agreement has been entered into by the Company with the affiliate of its Chairman.

The entire disclosure for related party transactions, including the nature of the relationship(s), a description of the transactions, the amount of the transactions, the effects of any change in the method of establishing the terms of the transaction from the previous period, stated interest rate, expiration date, terms and manner of settlement per the agreement with the related party, and amounts due to or from related parties. If the entity and one or more other entities are under common ownership or management control and this control affects the operating results or financial position, disclosure includes the nature of the control relationship even if there are no transactions between the entities. Disclosure may also include the aggregate amount of current and deferred tax expense for each statement of earnings presented where the entity is a member of a group that files a consolidated tax return, the amount of any tax related balances due to or from affiliates as of the date of each statement of financial position presented, the principal provisions of the method by which the consolidated amount of current and deferred tax expense is allocated to the members of the group and the nature and effect of any changes in that method. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

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+ Details