COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	Jun. 30, 2020 USD ($) community	Dec. 31, 2019 USD ($)
Real estate properties
Number of communities owned (in communities) | community	148
Costs Incurred to Date	$ 179,523
UDR's Remaining Commitment	$ 191,239
King of Prussia
Real estate properties
Contractual purchase price commitment		$ 14,800
Deposit on purchase		$ 800
Wholly owned - under development
Real estate properties
Number of communities owned (in communities) | community	3
Costs Incurred to Date	$ 131,788
UDR's Remaining Commitment	$ 146,712
Wholly owned - redevelopment
Real estate properties
Number of communities owned (in communities) | community	2
Costs Incurred to Date	$ 18,978
UDR's Remaining Commitment	$ 10,272
Preferred Equity Investments
Real estate properties
Number of communities owned (in communities) | community	1
Costs Incurred to Date	$ 8,872
UDR's Remaining Commitment	11,380
Other investments
Real estate properties
Costs Incurred to Date	19,885
UDR's Remaining Commitment	$ 22,875