CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Total	ERPOP [Member]	Preferred Stock [Member] ERPOP [Member]	GENERAL PARTNER [Member] ERPOP [Member]	LIMITED PARTNERS [Member] ERPOP [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) [Member] ERPOP [Member]	DISTRIBUTIONS [Member] ERPOP [Member]	PARTIALLY OWNED PROPERTIES [Member] ERPOP [Member]
Balance, beginning of year at Dec. 31, 2023			$ 37,280	$ 11,042,844	$ 202,306	$ 5,704
Balance, beginning of year at Dec. 31, 2023								$ 994
Partial redemption			(20,125)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				254	(254)
Exercise of EQR share options				4,401
EQR's Employee Share Purchase Plan (ESPP)				1,644
EQR restricted shares				4,496	2
EQR share options				1,289
EQR ESPP discount				296
OP Units repurchased and retired				(38,474)
Net income available to Units - General Partner		$ 293,796		293,796
OP Units - General Partner distributions				(255,843)
Supplemental Executive Retirement Plan (SERP)				(227)
Change in market value of Redeemable Limited Partners				(8,815)
Adjustment for Limited Partners ownership in Operating Partnership				(1,458)	1,458
Equity compensation associated with Units - Limited Partners					4,087
Net income available to Units - Limited Partners		8,275			8,275
Units - Limited Partners distributions					(8,446)
Change in carrying value of Redeemable Limited Partners					(156)
Unrealized holding gains (losses) arising during the period	$ 0
Losses reclassified into earnings from other comprehensive income	610	610				610
Distributions declared per Unit outstanding							$ 0.675
Net income attributable to Noncontrolling Interests	305,032	305,032						970
Contributions by Noncontrolling Interests								235
Distributions to Noncontrolling Interests								(2,330)
Other								(1,000)
Balance, end of period at Mar. 31, 2024			17,155	11,044,203	207,272	6,314
Balance, end of period at Mar. 31, 2024								(1,131)
Balance, beginning of year at Dec. 31, 2024			17,155	11,023,191	201,942	4,214
Balance, beginning of year at Dec. 31, 2024								(718)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				4,407	(4,407)
Exercise of EQR share options				4,360
EQR's Employee Share Purchase Plan (ESPP)				942
EQR restricted shares				4,438	4
EQR share options				1,279
EQR ESPP discount				194
Net income available to Units - General Partner		256,236		256,236
OP Units - General Partner distributions				(263,295)
Supplemental Executive Retirement Plan (SERP)				111
Change in market value of Redeemable Limited Partners				755
Adjustment for Limited Partners ownership in Operating Partnership				(5,839)	5,839
Equity compensation associated with Units - Limited Partners					5,101
Net income available to Units - Limited Partners		7,102			7,102
Units - Limited Partners distributions					(8,600)
Change in carrying value of Redeemable Limited Partners					109
Unrealized holding gains (losses) arising during the period	(1,504)	(1,504)				(1,504)
Losses reclassified into earnings from other comprehensive income	686	686				686
Distributions declared per Unit outstanding							$ 0.6925
Net income attributable to Noncontrolling Interests	$ 264,798	$ 264,798						1,104
Distributions to Noncontrolling Interests								(3,375)
Balance, end of period at Mar. 31, 2025			$ 17,155	$ 11,026,779	$ 207,090	$ 3,396		$ (2,989)