CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Total	ERPOP [Member]	PREFERRED SHARES [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				174	(174)
Exercise of EQR share options				14,344
EQR's Employee Share Purchase Plan (ESPP)				969
EQR restricted shares				3,611	1
EQR share options				876
EQR ESPP discount				171
Net income available to Units - General Partner		$ 69,993		69,993
OP Units General Partner distributions				(235,351)
Offering costs				(114)
Supplemental Executive Retirement Plan (SERP)				(163)
Change in market value of Redeemable Limited Partners				939
Adjustment for Limited Partners ownership in Operating Partnership				1,045	(1,045)
Equity compensation associated with Units - Limited Partners					7,798
Net income available to Units - Limited Partners		2,394			2,394
Units - Limited Partners distributions					(7,895)
Change in carrying value of Redeemable Limited Partners					2,278
Losses reclassified into earnings from other comprehensive income	$ (2,425)	(2,425)				2,425
Distributions declared per Unit outstanding							$ 0.625
Net income attributable to Noncontrolling Interests	73,798	73,798						639
Contributions by Noncontrolling Interests								446
Distributions to Noncontrolling Interests								(15,836)
Balance, end of period at Mar. 31, 2022			37,280	10,808,434	217,451	(31,847)
Balance, end of period at Mar. 31, 2022								3,415
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				3,673	(3,673)
Exercise of EQR share options				8,112
EQR's Employee Share Purchase Plan (ESPP)				1,452
EQR restricted shares				3,654
EQR share options				1,497
EQR ESPP discount				260
Net income available to Units - General Partner		211,263		211,263
OP Units General Partner distributions				(250,969)
Supplemental Executive Retirement Plan (SERP)				491
Change in market value of Redeemable Limited Partners				(5,946)
Adjustment for Limited Partners ownership in Operating Partnership				(953)	953
Equity compensation associated with Units - Limited Partners					4,654
Net income available to Units - Limited Partners		7,059			7,059
Units - Limited Partners distributions					(7,904)
Change in carrying value of Redeemable Limited Partners					668
Unrealized holding gains (losses) arising during the period	(9,780)	(9,780)				(9,780)
Losses reclassified into earnings from other comprehensive income	(1,095)	(1,095)				1,095
Distributions declared per Unit outstanding							$ 0.6625
Net income attributable to Noncontrolling Interests	$ 220,071	$ 220,071						977
Distributions to Noncontrolling Interests								(2,809)
Balance, end of period at Mar. 31, 2023			$ 37,280	$ 11,111,240	$ 211,718	$ (11,232)
Balance, end of period at Mar. 31, 2023								$ (2,553)