Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2011
Commitments and Contingencies (Textuals) [Abstract]
300 properties designed and built in violation of accessibility requirements	300
$0.1 million additional reserve	$ 0.1
$0.6 million of paid claims	0.6
$0.3 million released of reserves	0.3
$2.5 million reserve balance	2.5
Four projects in various stages of development	4
Number of units in various stages of development	747
Various stages of development with estimated completion dates ranging through September 30, 2011	Sep. 30, 2013
Consolidated project under development commitment fund	133.5
Number of unconsolidated projects	1
Number of apartments in development under unconsolidated projects	501
Unconsolidated project under development commitment fund	$ 2.4

Commitments and Contingencies.

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- Definition

Represents the company's remaining funding obligation (i.e. total project costs less book value) for consolidated projects that are under development.

+ Details

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- Definition

The reduction of loss contingency reserves for settlement of claims.

+ Details

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- Definition

Total number of unconsolidated units that are associated with open development projects. May include projects that are held for and/or under development, completed and not stabilized or completed and stablilzed.

+ Details

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- Definition

Total number of consolidated open development projects. May include projects that are held for and/or under development, completed and not stabilized or completed and stabilized.

+ Details

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- Definition

Total number of unconsolidated open development projects. May include projects that are held for and/or under development, completed and not stabilized or completed and stablilzed.

+ Details

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- Definition

Total number of consolidated units that are associated with open development projects. May include projects that are held for and/or under development, completed and not stabilized or completed and stabilized.

+ Details

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- Definition

Number of rental properties that are party to a lawsuit.

+ Details

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- Definition

Represents the company's remaining funding obligation(i.e. total project costs less book value) for unconsolidated projects that are under development.

+ Details

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- Definition

Represents the latest completion date for the current projects under development.

+ Details

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- Definition

The carrying amount as of the balance sheet date of the combined total of loss contingency liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12
-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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14326-108349

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The payments made in the period which reduced loss contingency liabilities.

+ References

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The charge against earnings in the period to increase loss contingency liabilities, net of any adjustments to reduce previously estimated charges.

+ References

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