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, 2021			$ 37,280	$ 10,951,940	$ 214,094	$ (34,272)
Balance, beginning of year at Dec. 31, 2021								$ 18,166
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				1,484	(1,484)
Exercise of EQR share options				18,928
EQR's Employee Share Purchase Plan (ESPP)				2,378
EQR restricted shares				7,361	1
EQR share options				1,390
EQR ESPP discount				420
Net income available to Units - General Partner		$ 293,321		293,321
OP Units General Partner distributions				(470,424)
Offering costs				(487)
Supplemental Executive Retirement Plan (SERP)				(269)
Acquisition of Noncontrolling Interests – Partially Owned Properties				(27,355)
Change in market value of Redeemable Limited Partners				98,140
Adjustment for Limited Partners ownership in Operating Partnership				6,632	(6,632)
Equity compensation associated with Units - Limited Partners					13,159
Net income available to Units - Limited Partners		10,027			10,027
Units - Limited Partners distributions					(15,488)
Change in carrying value of Redeemable Limited Partners					2,649
Unrealized holding gains (losses) arising during the period	$ (1,259)	(1,259)				(1,259)
Losses reclassified into earnings from other comprehensive income	(4,881)	(4,881)				4,881
Distributions declared per Unit outstanding							$ 1.25
Net income attributable to Noncontrolling Interests	306,476	306,476						1,583
Contributions by Noncontrolling Interests								603
Distributions to Noncontrolling Interests								(17,263)
Acquisitions of Noncontrolling Interests - Partially Owned Properties								(4,823)
Balance, end of period at Jun. 30, 2022			37,280	10,883,459	216,326	(30,650)
Balance, end of period at Jun. 30, 2022								(1,734)
Balance, beginning of year at Mar. 31, 2022			37,280	10,808,434	217,451	(31,847)
Balance, beginning of year at Mar. 31, 2022								3,415
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				1,310	(1,310)
Exercise of EQR share options				4,584
EQR's Employee Share Purchase Plan (ESPP)				1,409
EQR restricted shares				3,750
EQR share options				514
EQR ESPP discount				249
Net income available to Units - General Partner		223,328		223,328
OP Units General Partner distributions				(235,073)
Offering costs				(373)
Supplemental Executive Retirement Plan (SERP)				(106)
Acquisition of Noncontrolling Interests – Partially Owned Properties				(27,355)
Change in market value of Redeemable Limited Partners				97,201
Adjustment for Limited Partners ownership in Operating Partnership				5,587	(5,587)
Equity compensation associated with Units - Limited Partners					5,361
Net income available to Units - Limited Partners		7,633			7,633
Units - Limited Partners distributions					(7,593)
Change in carrying value of Redeemable Limited Partners					371
Unrealized holding gains (losses) arising during the period	(1,259)	(1,259)				(1,259)
Losses reclassified into earnings from other comprehensive income	(2,456)	(2,456)				2,456
Distributions declared per Unit outstanding							0.625
Net income attributable to Noncontrolling Interests	232,678	232,678						944
Contributions by Noncontrolling Interests								157
Distributions to Noncontrolling Interests								(1,427)
Acquisitions of Noncontrolling Interests - Partially Owned Properties								(4,823)
Balance, end of period at Jun. 30, 2022			37,280	10,883,459	216,326	(30,650)
Balance, end of period at Jun. 30, 2022								(1,734)
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)