INCOME/(LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Jul. 31, 2021
Antidilutive securities
Net income/(loss)	$ 46,310	$ 32,925
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(3,149)	(1,953)
Net (income)/loss attributable to noncontrolling interests	(12)	(8)
Net income/(loss) attributable to UDR, Inc.	43,149	30,964
Distributions to preferred stockholders - Series E (Convertible)	(1,231)	(1,183)
Net income/(loss) attributable to common stockholders	41,918	29,781
Income/(loss) attributable to common stockholders - diluted	$ 41,918	$ 29,781
Denominator for income/(loss) per share:
Weighted average common shares outstanding	329,244,000	329,165,000
Unvested restricted stock awards	(421,000)	(376,000)
Denominator for basic income/(loss) per share	328,823,000	328,789,000
Incremental shares issuable from assumed conversion of unvested LTIP Units, performance units, unvested restricted stock and shares issuable upon settlement of forward sales agreements	131,000	632,000
Denominator for diluted income/(loss) per share	328,954,000	329,421,000
Income/(loss) per weighted average common share - basic	$ 0.13	$ 0.09
Income/(loss) per weighted average common share - diluted	$ 0.13	$ 0.09
Number of shares authorized	450,000,000		450,000,000
OP/DownREIT Units
Denominator for income/(loss) per share:
Antidilutive securities	24,418,000	21,323,000
Convertible Preferred Stock
Denominator for income/(loss) per share:
Antidilutive securities	2,908,000	2,909,000
Unvested LTIP Units and unvested restricted stock
Denominator for income/(loss) per share:
Antidilutive securities	131,000	632,000
ATM
Denominator for income/(loss) per share:
Number of shares authorized				20,000,000.0
Shares of common stock available for future issuance	14,000,000.0