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Capital Structure (UNITED DOMINION REALTY, L.P.) (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Limited Partners' Capital Account [Line Items]
Balance	183,278,698	183,278,698	184,281,254
Partners' Capital Account, Units, Redeemed	0	0	0
OP Units issued for acquisitions of real estate			(1,002,556)
Balance	183,278,698	183,278,698	183,278,698
UDR, Inc.
Limited Partners' Capital Account [Line Items]
Balance	174,002,342
Balance	174,114,516	174,002,342
Class A Limited Partner
Limited Partners' Capital Account [Line Items]
Balance	1,751,671
Limited Partner
Limited Partners' Capital Account [Line Items]
Balance	7,413,802	7,567,253	7,643,548
Partners' Capital Account, Units, Redeemed	(112,174)	(153,451)	(76,295)
OP Units issued for acquisitions of real estate			0
Balance	7,301,628	7,413,802	7,567,253
Limited Partner | UDR, Inc.
Limited Partners' Capital Account [Line Items]
Limited Partners' Capital Account, Units Redeemed		1,002,556
Balance	174,002,342	173,848,891	174,775,152
Partners' Capital Account, Units, Redeemed	(112,174)	(153,451)	(76,295)
OP Units issued for acquisitions of real estate			(1,002,556)
Balance	174,114,516	174,002,342	173,848,891
Limited Partner | Class A Limited Partner
Limited Partners' Capital Account [Line Items]
Balance	1,751,671	1,751,671	1,751,671
Partners' Capital Account, Units, Redeemed	0	0	0
OP Units issued for acquisitions of real estate			0
Balance	1,751,671	1,751,671	1,751,671
General Partner | UDR, Inc.
Limited Partners' Capital Account [Line Items]
Balance	110,883	110,883	110,883
Partners' Capital Account, Units, Redeemed	0	0	0
OP Units issued for acquisitions of real estate			0
Balance	110,883	110,883	110,883

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Limited Partners' Capital Account, Units Redeemed

+ References

No definition available.

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Limited Partners' Capital Account, Units Redeemed for Cash

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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.

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- Definition

The number of limited partner units outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB TOPIC 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section F

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- Definition

The number of units redeemed during the year of each class of partners' capital account. Units represent shares of ownership of the general, limited, and preferred partners.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB TOPIC 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 16
-Subparagraph a, b
-Article 6

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