Net Gain on Disposition of Interest in Unconsolidated Entities (Details Textuals) - Apartment Communities transaction [Member]	Apr. 30, 2015 properties
Disposal Group, not including discontinued operations [Line Items]
Partner's equity ownership acquired	50.00%
Number of properties acquired	3
Company's equity ownership exchanged	50.00%
Number of properties exchanged	5

Percentage of voting equity interests acquired at the acquisition date in the business combination.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant