Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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)(3)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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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

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

+ References

No definition available.

+ Details

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- Definition

The carrying amount of investments in unconsolidated real estate and other joint ventures not separately presented. This includes direct and indirect investments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1(d))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Investments in Unconsolidated Real Estate Partnerships - (Details 1) (USD $)	Dec. 31, 2014 Property	Dec. 31, 2013 Property	Dec. 31, 2012 Property
Schedule of Equity Method Investments [Line Items]
Aggregate investment in unconsolidated partnerships	16,000,000	16,900,000
Excess of equity method investment aggregate cost over share of underlying historical partners deficit	400,000	1,100,000
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Range of ownership interests in unconsolidated real estate partnerships	67.00%
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Range of ownership interests in unconsolidated real estate partnerships	40.00%
Unconsolidated Properties [Member]
Schedule of Equity Method Investments [Line Items]
Number of apartment communities	11	20	22