Business Acquisition Cost of Acquired Entity Cash Paid and Total Debt Assumed, if any

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- Definition

Gain loss on sale of properties in real estate partnership

+ References

No definition available.

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- Definition

Number of Real Estate Properties Acquired

+ References

No definition available.

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- Definition

Repayment of collateralized debt obligations for which we are the lender

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities.

+ References

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 9

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 6

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 1

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

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-Paragraph 19

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

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-Paragraph 2

-Subparagraph (SX 210.5-03.12)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 11

-Article 7

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

The net cash inflow or outflow from the sale or purchase of and distributions from real estate partnership investment during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

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-Number 95

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

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-Subparagraph (a)

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 17

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

Revenue from the sale of commercial, industrial, or residential property during the period. This element is more likely than not relevant to an entity for which real estate operations are a principal activity. If real estate operations are not a principal activity, the reporting entity would likely use a gain (loss) on sale of property, plant, or equipment type element.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 66

-Paragraph 44, 45

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Real Estate Partnerships (Narrative) (Details) (USD $)	12 Months Ended			0 Months Ended			3 Months Ended	12 Months Ended								114 Months Ended
Real Estate Partnerships (Narrative) (Details) (USD $)	Dec. 31, 2013 properties	Dec. 31, 2012	Dec. 31, 2011	Oct. 31, 2011 Newbury Street Partnership [Member]	May 26, 2011 Newbury Street Partnership [Member]	May 26, 2010 Newbury Street Partnership [Member] Building	Mar. 31, 2012 Newbury Street Partnership [Member]	Dec. 31, 2011 Newbury Street Partnership [Member]	Dec. 31, 2013 Federal / Lion Venture LP [Member] properties	Dec. 31, 2012 Federal / Lion Venture LP [Member]	Dec. 31, 2011 Federal / Lion Venture LP [Member]	May 26, 2010 Loan Secured By Two Buildings [Member] Newbury Street Partnership [Member]	May 26, 2011 Loan Secured by One Building [Member] Newbury Street Partnership [Member]	Oct. 31, 2011 Taurus Investment Holdings [Member] Newbury Street Partnership [Member]	Oct. 31, 2011 Federal Realty Investment Trust [Member] Newbury Street Partnership [Member]	Dec. 31, 2013 Federal Realty Investment Trust [Member] Federal / Lion Venture LP [Member]	Dec. 31, 2013 Clarion [Member] Federal / Lion Venture LP [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest in partnership														15.00%	85.00%	30.00%	70.00%
Total number of properties in the portfolio	87								7
Sales of Real Estate				$ 44,000,000
Business Acquisition Cost of Acquired Entity Cash Paid and Total Debt Assumed					6,200,000	17,500,000
Contributed towards acquisition of property					2,800,000	7,800,000										42,100,000
Equity Method Investment, Dividends or Distributions																18,000,000
Secured loan					11,800,000							8,800,000	3,100,000
Loan interest rate					LIBOR plus 400 basis points
Our share of net income from real estate partnership	1,498,000	1,757,000	1,808,000					100,000	1,498,000	1,815,000	1,771,000
Number of Real Estate Properties Acquired						2
Payments for (Proceeds from) Real Estate Partnership Investment, Net	0	0	(34,617,000)	34,600,000
Repayment Of Secured Debt FRT				11,800,000
Gain Loss On Sale Of Properties in Real Estate Partnership							$ 11,900,000