JOINT VENTURES AND PARTNERSHIPS - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	$ 9,113,339	$ 9,312,337
Investments, at fair value	886,492	917,483
Cash and cash equivalents	1,222	1,326	$ 2,922	$ 1,193
Other assets	231,308	197,493
Total assets	10,605,674	10,897,586
Accounts payable and accrued liabilities	142,102	115,105
Total liabilities	6,456,911	6,436,691
Total equity	3,288,797	3,443,540	3,991,354	$ 4,098,295
Financial information relating to unconsolidated joint ventures operations
Total revenues	1,712,317	1,671,842	1,627,501
Property operating expenses	304,971	292,572	273,736
Real estate depreciation and amortization	654,121	676,068	676,419
Gain/(loss) on sale of real estate owned	242,913	16,867	351,193
Operating income/(loss)	553,606	284,569	635,008
Interest expense	(196,619)	(195,712)	(180,866)
Other income/(loss)	19,175	(12,336)	17,759
Net income/(loss)	403,715	95,877	474,488
UDR/MetLife
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	1,137,830	1,174,695
Cash and cash equivalents	28,596	12,528
Other assets	9,464	20,774
Total assets	1,175,890	1,207,997
Third party debt, net	844,681	845,963
Accounts payable and accrued liabilities	18,431	19,393
Total liabilities	863,112	865,356
Total equity	312,778	342,641
Financial information relating to unconsolidated joint ventures operations
Total revenues	146,406	141,014	139,073
Property operating expenses	61,914	64,329	58,298
Real estate depreciation and amortization	53,340	53,543	54,895
Operating income/(loss)	31,152	23,142	25,880
Interest expense	(33,607)	(33,491)	(32,720)
Net income/(loss)	(2,455)	(10,349)	(6,840)
UDR/LaSalle
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	764,229	567,474
Cash and cash equivalents	10,308	5,688
Other assets	7,704	1,334
Total assets	782,241	574,496
Third party debt, net	297,714	45,246
Accounts payable and accrued liabilities	6,887	5,150
Total liabilities	304,601	50,396
Total equity	477,640	524,100
Financial information relating to unconsolidated joint ventures operations
Total revenues	51,870	49,063	20,514
Property operating expenses	18,566	17,657	6,896
Real estate depreciation and amortization	38,744	45,375	21,182
Operating income/(loss)	(5,440)	(13,969)	(7,564)
Interest expense	(3,994)	(2,698)	(126)
Net income/(loss)	(9,434)	(16,667)	(7,690)
Debt and Preferred Equity Program and Other Investments
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	1,678,536	1,372,206
Investments, at fair value	489,468	372,478
Cash and cash equivalents	39,273	29,716
Other assets	117,650	125,236
Total assets	2,324,927	1,899,636
Third party debt, net	1,353,686	1,168,926
Accounts payable and accrued liabilities	155,143	133,962
Total liabilities	1,508,829	1,302,888
Total equity	816,098	596,748
Financial information relating to unconsolidated joint ventures operations
Total revenues	178,221	131,876	109,753
Property operating expenses	92,172	69,737	54,442
Real estate depreciation and amortization	69,530	51,633	43,407
Operating income/(loss)	16,519	10,506	11,904
Interest expense	(103,620)	(74,268)	(53,385)
Net unrealized/realized gain/(loss) on held investments	70,039	84,835	23,403
Other income/(loss)	3,718	(3,840)	537
Net income/(loss)	(13,344)	17,233	(17,541)
Unconsolidated Joint Ventures and Partnerships
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	3,580,595	3,114,375
Investments, at fair value	489,468	372,478
Cash and cash equivalents	78,177	47,932
Other assets	134,818	147,344
Total assets	4,283,058	3,682,129
Third party debt, net	2,496,081	2,060,135
Accounts payable and accrued liabilities	180,461	158,505
Total liabilities	2,676,542	2,218,640
Total equity	1,606,516	1,463,489
Financial information relating to unconsolidated joint ventures operations
Total revenues	376,497	321,953	269,340
Property operating expenses	172,652	151,723	119,636
Real estate depreciation and amortization	161,614	150,551	119,484
Operating income/(loss)	42,231	19,679	30,220
Interest expense	(141,221)	(110,457)	(86,231)
Net unrealized/realized gain/(loss) on held investments	70,039	84,835	23,403
Other income/(loss)	3,718	(3,840)	537
Net income/(loss)	$ (25,233)	$ (9,783)	$ (32,071)