JOINT VENTURES AND PARTNERSHIPS - Commitments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Joint Ventures
Investment in unconsolidated entities	$ 945,364		$ 944,071
Deferred fees from the sale of properties	7,500		7,600
Gain/(loss) on sale of real estate owned	16,867	$ 1
Joint venture management and other fees	$ 1,965	$ 1,242
Type of revenue	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember
13th and Market Properties LLC | Accounts Payable, Accrued Expenses and Other Liabilities
Joint Ventures
Investment in unconsolidated entities	$ (8,900)		$ (8,900)