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				5,048	(5,048)
Exercise of EQR share options				6,480
EQR's Employee Share Purchase Plan (ESPP)				2,449
EQR restricted shares				9,383	2
EQR share options				2,507
EQR ESPP discount				501
OP Units repurchased and retired				(38,474)
Net income available to Units - General Partner		$ 470,924		470,924
OP Units - General Partner distributions				(511,720)
Supplemental Executive Retirement Plan (SERP)				(598)
Change in market value of Redeemable Limited Partners				(39,058)
Adjustment for Limited Partners ownership in Operating Partnership				1,532	(1,532)
Equity compensation associated with Units - Limited Partners					10,236
Net income available to Units - Limited Partners		13,278			13,278
Units - Limited Partners distributions					(15,875)
Change in carrying value of Redeemable Limited Partners					665
Losses reclassified into earnings from other comprehensive income	$ 1,210	1,210				1,210
Distributions declared per Unit outstanding							$ 1.35
Net income attributable to Noncontrolling Interests	488,587	488,587						2,039
Contributions by Noncontrolling Interests								458
Distributions to Noncontrolling Interests								(2,786)
Other								(1,000)
Balance, end of period at Jun. 30, 2024			17,155	10,951,818	204,032	6,914
Balance, end of period at Jun. 30, 2024								(295)
Balance, beginning of year at Mar. 31, 2024			17,155	11,044,203	207,272	6,314
Balance, beginning of year at Mar. 31, 2024								(1,131)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				4,794	(4,794)
Exercise of EQR share options				2,079
EQR's Employee Share Purchase Plan (ESPP)				805
EQR restricted shares				4,887
EQR share options				1,218
EQR ESPP discount				205
Net income available to Units - General Partner		177,128		177,128
OP Units - General Partner distributions				(255,877)
Supplemental Executive Retirement Plan (SERP)				(371)
Change in market value of Redeemable Limited Partners				(30,243)
Adjustment for Limited Partners ownership in Operating Partnership				2,990	(2,990)
Equity compensation associated with Units - Limited Partners					6,149
Net income available to Units - Limited Partners		5,003			5,003
Units - Limited Partners distributions					(7,429)
Change in carrying value of Redeemable Limited Partners					821
Losses reclassified into earnings from other comprehensive income	600	600				600
Distributions declared per Unit outstanding							0.675
Net income attributable to Noncontrolling Interests	183,555	183,555						1,069
Contributions by Noncontrolling Interests								223
Distributions to Noncontrolling Interests								(456)
Balance, end of period at Jun. 30, 2024			17,155	10,951,818	204,032	6,914
Balance, end of period at Jun. 30, 2024								(295)
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				8,773	(8,773)
Exercise of EQR share options				5,357
EQR's Employee Share Purchase Plan (ESPP)				1,413
EQR restricted shares				9,339	4
EQR share options				2,656
EQR ESPP discount				258
Net income available to Units - General Partner		448,237		448,237
OP Units - General Partner distributions				(526,428)
Offering costs				(481)
Supplemental Executive Retirement Plan (SERP)				(740)
Change in market value of Redeemable Limited Partners				19,568
Adjustment for Limited Partners ownership in Operating Partnership				(1,692)	1,692
Equity compensation associated with Units - Limited Partners					10,593
Net income available to Units - Limited Partners		12,328			12,328
Units - Limited Partners distributions					(16,159)
Change in carrying value of Redeemable Limited Partners					1,090
Unrealized holding gains (losses) arising during the period	(3,550)	(3,550)				(3,550)
Losses reclassified into earnings from other comprehensive income	951	951				951
Distributions declared per Unit outstanding							1.385
Net income attributable to Noncontrolling Interests	463,583	463,583						2,307
Distributions to Noncontrolling Interests								(4,052)
Balance, end of period at Jun. 30, 2025			17,155	10,989,451	202,717	1,615
Balance, end of period at Jun. 30, 2025								(2,463)
Balance, beginning of year at Mar. 31, 2025			17,155	11,026,779	207,090	3,396
Balance, beginning of year at Mar. 31, 2025								(2,989)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				4,366	(4,366)
Exercise of EQR share options				997
EQR's Employee Share Purchase Plan (ESPP)				471
EQR restricted shares				4,901
EQR share options				1,377
EQR ESPP discount				64
Net income available to Units - General Partner		192,001		192,001
OP Units - General Partner distributions				(263,133)
Offering costs				(481)
Supplemental Executive Retirement Plan (SERP)				(851)
Change in market value of Redeemable Limited Partners				18,813
Adjustment for Limited Partners ownership in Operating Partnership				4,147	(4,147)
Equity compensation associated with Units - Limited Partners					5,492
Net income available to Units - Limited Partners		5,226			5,226
Units - Limited Partners distributions					(7,559)
Change in carrying value of Redeemable Limited Partners					981
Unrealized holding gains (losses) arising during the period	(2,046)	(2,046)				(2,046)
Losses reclassified into earnings from other comprehensive income	265	265				265
Distributions declared per Unit outstanding							$ 0.6925
Net income attributable to Noncontrolling Interests	$ 198,785	$ 198,785						1,203
Distributions to Noncontrolling Interests								(677)
Balance, end of period at Jun. 30, 2025			$ 17,155	$ 10,989,451	$ 202,717	$ 1,615
Balance, end of period at Jun. 30, 2025								$ (2,463)