Summary Of Significant Accounting Policies And Recent Accounting Pronouncements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements
Capitalized interest	$ 2.5	$ 1.3	$ 6.1	$ 4.0
Capitalized real estate taxes	$ 0.4	$ 0.1	$ 1.0	$ 0.6
Percentage of rental revenue and other income from leasing of apartment homes	98.00%	98.00%	98.00%	98.00%

The amount of interest that was capitalized during the period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 34

-Paragraph 21

-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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Name:	us-gaap_InterestCostsCapitalized
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration