Document and Entity Information (USD $) In Billions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Feb. 19, 2015
Entity Information [Line Items]
Entity Registrant Name	UDR, Inc.
Entity Central Index Key	0000074208
Document Type	10-K
Document Period End Date	Dec. 31, 2014
Amendment Flag	false
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float	$ 3.0
Entity Common Stock, Shares Outstanding		258,765,713
United Dominion Reality L.P.
Entity Information [Line Items]
Entity Registrant Name	United Dominion Realty L.P.
Entity Central Index Key	0001018254
Document Period End Date	Dec. 31, 2014
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float
Entity Common Stock, Shares Outstanding		0