BASIS OF PRESENTATION (Details) shares in Millions	3 Months Ended
Mar. 31, 2026 home item community shares
Consolidation And Basis Of Presentation
Number of real estate properties \| community	161
Number of apartment homes owned and consolidated \| home	54,081
Number of markets operating within \| item	21
Joint venture, number of completed or to be completed homes in communities \| home	9,018
Preferred equity investment,, number of apartment homes \| home	3,617
Operating partnership outstanding units	190.4
United Dominion Reality L.P.
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	176.7
General Partners' ownership (as a percent)	92.80%
General partnership units outstanding	0.1
UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Operating partnership outstanding units	23.4
General Partners' ownership (as a percent)	72.20%
UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Operating partnership outstanding units	32.4
Non-affiliated Partners \| United Dominion Reality L.P.
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	13.7
Percentage of units outstanding in Partnership	7.20%
Non-affiliated Partners \| UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Operating partnership outstanding units	9.0
Percentage of units outstanding in Partnership	27.80%

Consolidation and basis of presentation.

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General Partners Capital Account Units Owned Percentage.

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Represent element information joint venture number of completed or to be completed apartment homes in operating communities.

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Limited Partners Capital Account Units Outstanding Percentage.

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Number Of Apartment Homes Owned And Consolidated By Company

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Represents the number of apartment homes with ownership interest through preferred equity investments.

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Number of Markets Operating Within

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The number of general partner units outstanding.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-5

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The number of limited partner units outstanding.

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

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The number of each class of partnership units outstanding at the balance sheet date. Units represent shares of ownership of the general, limited, and preferred partners.

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