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, 2022			$ 37,280	$ 11,138,706	$ 209,961	$ (2,547)
Balance, beginning of year at Dec. 31, 2022								$ (721)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				4,659	(4,659)
Exercise of EQR share options				11,358
EQR's Employee Share Purchase Plan (ESPP)				2,124
EQR restricted shares				7,945	1
EQR share options				3,125
EQR ESPP discount				398
Net income available to Units - General Partner		$ 349,693		349,693
OP Units - General Partner distributions				(502,070)
Supplemental Executive Retirement Plan (SERP)				148
Acquisition of Noncontrolling Interests – Partially Owned Properties				(900)
Change in market value of Redeemable Limited Partners				(39,123)
Adjustment for Limited Partners ownership in Operating Partnership				6,815	(6,815)
Equity compensation associated with Units - Limited Partners					10,867
Net income available to Units - Limited Partners		11,613			11,613
Units - Limited Partners distributions					(15,640)
Change in carrying value of Redeemable Limited Partners					2,077
Unrealized holding gains (losses) arising during the period	$ 4,054	4,054				4,054
Losses reclassified into earnings from other comprehensive income	2,201	2,201				2,201
Distributions declared per Unit outstanding							$ 1.325
Net income attributable to Noncontrolling Interests	364,933	364,933						2,082
Contributions by Noncontrolling Interests								9
Distributions to Noncontrolling Interests								(3,261)
Acquisitions of Noncontrolling Interests - Partially Owned Properties								(2,837)
Balance, end of period at Jun. 30, 2023			37,280	10,982,878	207,405	3,708
Balance, end of period at Jun. 30, 2023								(4,728)
Balance, beginning of year at Mar. 31, 2023			37,280	11,111,240	211,718	(11,232)
Balance, beginning of year at Mar. 31, 2023								(2,553)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				986	(986)
Exercise of EQR share options				3,246
EQR's Employee Share Purchase Plan (ESPP)				672
EQR restricted shares				4,291	1
EQR share options				1,628
EQR ESPP discount				138
Net income available to Units - General Partner		138,430		138,430
OP Units - General Partner distributions				(251,101)
Supplemental Executive Retirement Plan (SERP)				(343)
Acquisition of Noncontrolling Interests – Partially Owned Properties				(900)
Change in market value of Redeemable Limited Partners				(33,177)
Adjustment for Limited Partners ownership in Operating Partnership				7,768	(7,768)
Equity compensation associated with Units - Limited Partners					6,213
Net income available to Units - Limited Partners		4,554			4,554
Units - Limited Partners distributions					(7,736)
Change in carrying value of Redeemable Limited Partners					1,409
Unrealized holding gains (losses) arising during the period	13,834	13,834				13,834
Losses reclassified into earnings from other comprehensive income	1,106	1,106				1,106
Distributions declared per Unit outstanding							0.6625
Net income attributable to Noncontrolling Interests	144,862	144,862						1,105
Contributions by Noncontrolling Interests								9
Distributions to Noncontrolling Interests								(452)
Acquisitions of Noncontrolling Interests - Partially Owned Properties								(2,837)
Balance, end of period at Jun. 30, 2023			37,280	10,982,878	207,405	3,708
Balance, end of period at Jun. 30, 2023								(4,728)
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	38,500			(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)