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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 13
-Article 5

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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 Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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- Definition

This element represents the amount of gain (loss) on sale of properties during the reporting period net of the applicable income taxes realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 974
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-15.(a)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=6875705&loc=d3e641549-123027

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- Definition

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

+ References

No definition available.

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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
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 9
-Subparagraph (a)
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-Publisher FASB
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Reference 3: 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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- 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)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3213-108585

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- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

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- Definition

The cash inflow from the capital received in cash from a partner in a partnership during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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- Definition

The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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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=26872669&loc=d3e20235-122688

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Real Estate Partnerships (Narrative) (Details) $ in Thousands				3 Months Ended	12 Months Ended			138 Months Ended
	Sep. 02, 2014 USD ($)	Jul. 24, 2014 USD ($)	Jun. 05, 2014 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2015 USD ($) project property	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($) project property	Jan. 13, 2016 property
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| project					90			90
Gain on sale of real estate					$ 28,330	$ 4,401	$ 4,994
Federal Realty Investment Trust/Clarion Partners Partnership
Schedule of Equity Method Investments [Line Items]
Number of real estate properties \| property					6			6
Sales price		$ 34,300
Gain on sale of real estate		14,500			$ 0	$ 14,507	$ 0
Gain on sale of portfolio		32,800
Clarion \| Federal Realty Investment Trust/Clarion Partners Partnership
Schedule of Equity Method Investments [Line Items]
Ownership percentage in partnership					70.00%			70.00%
Federal Realty Investment Trust \| Federal Realty Investment Trust/Clarion Partners Partnership
Schedule of Equity Method Investments [Line Items]
Ownership percentage in partnership					30.00%			30.00%
Contributions								$ 48,800
Distributions								$ 32,400
Capital contribution to repay mortgage loan	$ 3,200		$ 3,600
Gain on sale of real estate		4,400		$ 4,400
Gain on sale of portfolio		$ 10,400
Federal Realty Investment Trust/Clarion Partners Partnership
Schedule of Equity Method Investments [Line Items]
Capital contributions from partners			11,900
Federal Realty Investment Trust/Clarion Partners Partnership
Schedule of Equity Method Investments [Line Items]
Repayments of mortgage loans	10,500		$ 11,900
Capital contributions from partners	$ 10,500
Subsequent Event \| Clarion
Schedule of Equity Method Investments [Line Items]
Ownership percentage in partnership									70.00%
Number of real estate properties \| property									6