Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 17, 2020	Jun. 28, 2019
Entity information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2019
Entity File Number	1-10524
Entity Registrant Name	UDR, Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	54-0857512
Entity Address, Address Line One	1745 Shea Center Drive, Suite 200
Entity Address, City or Town	Highlands Ranch
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80129
City Area Code	720
Local Phone Number	283-6120
Title of 12(b) Security	Common Stock
Trading Symbol	UDR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		294,631,463
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0000074208
Amendment Flag	false
Entity Public Float			$ 4.9
United Dominion Realty L.P.
Entity information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2019
Entity File Number	333-156002-01
Entity Registrant Name	United Dominion Realty, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	54-1776887
Entity Address, Address Line One	1745 Shea Center Drive, Suite 200
Entity Address, City or Town	Highlands Ranch
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80129
City Area Code	720
Local Phone Number	283-6120
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001018254
Amendment Flag	false