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Extension Option Period

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The number of properties securing loans.

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Carrying value as of the balance sheet date of collateralized debt obligations for which we are the lender.

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Month, date and year in which the acquirer obtains control of the acquiree.

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Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

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Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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The number of real estate properties owned as of the balance sheet date.

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The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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Real Estate Partnerships (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended								0 Months Ended	1 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended
Real Estate Partnerships (Narrative) (Details) (USD $)	Sep. 30, 2011 properties	Sep. 30, 2010	Sep. 30, 2011 properties	Sep. 30, 2010	Dec. 31, 2010	Sep. 30, 2011 Taurus Investment Holdings [Member] Newbury Street Partnership [Member]	Sep. 30, 2011 Federal Realty Investment Trust [Member] Newbury Street Partnership [Member]	Sep. 30, 2011 Federal Realty Investment Trust [Member] Federal / Lion Venture LP [Member]	Sep. 30, 2011 Clarion [Member] Federal / Lion Venture LP [Member]	Sep. 30, 2011 Loan Secured By Two Buildings [Member] Newbury Street Partnership [Member] properties	May 26, 2011 Newbury Street Partnership [Member]	May 31, 2010 Newbury Street Partnership [Member]	Sep. 30, 2011 Newbury Street Partnership [Member] properties	Sep. 30, 2010 Newbury Street Partnership [Member]	Dec. 31, 2010 Newbury Street Partnership [Member]	Sep. 30, 2011 Federal / Lion Venture LP [Member] properties	Sep. 30, 2010 Federal / Lion Venture LP [Member]	Sep. 30, 2011 Federal / Lion Venture LP [Member] properties	Sep. 30, 2010 Federal / Lion Venture LP [Member]	Dec. 31, 2010 Federal / Lion Venture LP [Member]
Number of properties secured by loans										2
Ownership interest in partnership						15.00%	85.00%	30.00%	70.00%
Date of Acquisition of Newbury Partnership Property											May 26, 2011
Total number of properties in the portfolio	85		85										3			7		7
Acquisition of real estate											$ 6,200,000
Leasable area (square feet)											6,700		41,000
Contributed towards acquisition of property											2,800,000
Our investment in real estate partnership	57,828,000		57,828,000		51,606,000								22,800,000		16,100,000	35,028,000		35,028,000		35,504,000
Secured loan										8,800,000	3,100,000
Debt Instrument, Maturity Date													May 25, 2012
Loan interest rate													LIBOR plus 400 basis points
Buy-sell date												buy-sell can be exercised only in certain circumstances through May 2014
Extension Option Period													1 year
Basis Points Spread Over LIBOR													400
Income (Loss) from Equity Method Investments	$ 434,000	$ 125,000	$ 1,201,000	$ 506,000									$ (100,000)	$ (400,000)		$ 452,000	$ 355,000	$ 1,253,000	$ 901,000