CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 220,071	$ 73,798
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	215,830	229,961
Amortization of deferred financing costs	1,979	2,077
Amortization of discounts and premiums on debt	868	1,358
Amortization of deferred settlements on derivative instruments	1,092	2,422
Amortization of right-of-use assets	3,150	3,046
Write-off of pursuit costs	1,332	1,463
(Income) loss from investments in unconsolidated entities	1,382	1,261
Distributions from unconsolidated entities – return on capital	151	79
Net (gain) loss on sales of real estate properties	(100,209)	102
Realized (gain) loss on sale of investment securities	87	(2,066)
Compensation paid with Company Common Shares	9,044	9,203
Changes in assets and liabilities:
(Increase) decrease in other assets	26,257	30,174
Increase (decrease) in accounts payable and accrued expenses	45,357	54,553
Increase (decrease) in accrued interest payable	(16,534)	(12,634)
Increase (decrease) in lease liabilities	(334)	(902)
Increase (decrease) in other liabilities	(16,032)	(27,213)
Increase (decrease) in security deposits	(212)	1,374
Net cash provided by operating activities	393,279	368,056
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions		(113,046)
Investment in real estate – development/other	(16,786)	(24,255)
Capital expenditures to real estate	(55,392)	(35,285)
Non-real estate capital additions	(600)	(971)
Interest capitalized for real estate and unconsolidated entities under development	(3,393)	(1,017)
Proceeds from disposition of real estate, net	133,916
Investments in unconsolidated entities - development/other	(14,480)	(24,897)
Distributions from unconsolidated entities – return of capital	6	9
Purchase of investment securities and other investments		(1,009)
Proceeds from sale of investment securities	452	3,434
Net cash provided by (used for) investing activities	43,723	(197,037)
Mortgage notes payable, net:
Proceeds	14,090	2,689
Scheduled principal repayments	(40)	(1,933)
Line of credit and commercial paper:
Commercial paper proceeds	1,323,145	1,424,086
Commercial paper repayments	(1,453,100)	(1,609,121)
Finance ground lease principal payments	(665)	(140)
Proceeds from Employee Share Purchase Plan (ESPP)	1,452	969
Proceeds from exercise of EQR options	8,112	14,344
Payment of offering costs		(114)
Contributions – Noncontrolling Interests – Partially Owned Properties		446
Contributions – Limited Partners		1
Distributions:
OP Units – General Partner	(236,561)	(226,639)
Preference Units	(1,544)	(772)
OP Units – Limited Partners	(7,380)	(7,535)
Noncontrolling Interests – Partially Owned Properties	(2,598)	(15,836)
Net cash provided by (used for) financing activities	(355,089)	(419,555)
Net increase (decrease) in cash and cash equivalents and restricted deposits	81,913	(248,536)
Cash and cash equivalents and restricted deposits, beginning of period	137,172	360,236
Cash and cash equivalents and restricted deposits, end of period	219,085	111,700
Cash and cash equivalents	133,460	41,140
Restricted deposits	85,625	70,560
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	79,693	81,391
Net cash paid (received) for income and other taxes	348	350
Amortization of deferred financing costs:
Investment in real estate, net	(127)	(127)
Other assets	697	585
Mortgage notes payable, net	449	557
Notes, net	960	1,062
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	306	685
Notes, net	562	673
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	1,095	2,425
Write-off of pursuit costs:
Investment in real estate, net	225	375
Investments in unconsolidated entities	649	1,070
Other assets	458	18
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,071	946
Other liabilities	311	315
Realized/unrealized (gain) loss on derivative instruments:
Other assets	7,410
Other liabilities	2,370
Accumulated other comprehensive income	(9,780)
Interest capitalized for real estate and unconsolidated entities under development:
Investment in real estate, net	(1,422)	(307)
Investments in unconsolidated entities	1,971	710
Investments in unconsolidated entities - development/other:
Investments in unconsolidated entities	(13,700)	(24,897)
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(7,105)
Lease liabilities	7,105
Non-cash share distribution and other transfers from unconsolidated entities:
Investments in unconsolidated entities	539	859
Other assets	(539)	(859)
ERPOP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	220,071	73,798
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	215,830	229,961
Amortization of deferred financing costs	1,979	2,077
Amortization of discounts and premiums on debt	868	1,358
Amortization of deferred settlements on derivative instruments	1,092	2,422
Amortization of right-of-use assets	3,150	3,046
Write-off of pursuit costs	1,332	1,463
(Income) loss from investments in unconsolidated entities	1,382	1,261
Distributions from unconsolidated entities – return on capital	151	79
Net (gain) loss on sales of real estate properties	(100,209)	102
Realized (gain) loss on sale of investment securities	(87)	(2,066)
Compensation paid with Company Common Shares	9,044	9,203
Changes in assets and liabilities:
(Increase) decrease in other assets	26,257	30,174
Increase (decrease) in accounts payable and accrued expenses	45,357	54,553
Increase (decrease) in accrued interest payable	(16,534)	(12,634)
Increase (decrease) in lease liabilities	(334)	(902)
Increase (decrease) in other liabilities	(16,032)	(27,213)
Increase (decrease) in security deposits	(212)	1,374
Net cash provided by operating activities	393,279	368,056
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions		(113,046)
Investment in real estate – development/other	(16,786)	(24,255)
Capital expenditures to real estate	(55,392)	(35,285)
Non-real estate capital additions	(600)	(971)
Interest capitalized for real estate and unconsolidated entities under development	(3,393)	(1,017)
Proceeds from disposition of real estate, net	133,916
Investments in unconsolidated entities - development/other	(14,480)	(24,897)
Distributions from unconsolidated entities – return of capital	6	9
Purchase of investment securities and other investments		(1,009)
Proceeds from sale of investment securities	452	3,434
Net cash provided by (used for) investing activities	43,723	(197,037)
Mortgage notes payable, net:
Proceeds	14,090	2,689
Scheduled principal repayments	(40)	(1,933)
Line of credit and commercial paper:
Commercial paper proceeds	1,323,145	1,424,086
Commercial paper repayments	(1,453,100)	(1,609,121)
Finance ground lease principal payments	(665)	(140)
Proceeds from Employee Share Purchase Plan (ESPP)	1,452	969
Proceeds from exercise of EQR options	8,112	14,344
Payment of offering costs		(114)
Contributions – Noncontrolling Interests – Partially Owned Properties		446
Contributions – Limited Partners		1
Distributions:
OP Units – General Partner	(236,561)	(226,639)
Preference Units	(1,544)	(772)
OP Units – Limited Partners	(7,380)	(7,535)
Noncontrolling Interests – Partially Owned Properties	(2,598)	(15,836)
Net cash provided by (used for) financing activities	(355,089)	(419,555)
Net increase (decrease) in cash and cash equivalents and restricted deposits	81,913	(248,536)
Cash and cash equivalents and restricted deposits, beginning of period	137,172	360,236
Cash and cash equivalents and restricted deposits, end of period	219,085	111,700
Cash and cash equivalents	133,460	41,140
Restricted deposits	85,625	70,560
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	79,693	81,391
Net cash paid (received) for income and other taxes	348	350
Amortization of deferred financing costs:
Investment in real estate, net	(127)	(127)
Other assets	697	585
Mortgage notes payable, net	449	557
Notes, net	562	673
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	306	685
Notes, net	960	1,062
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	1,095	2,425
Write-off of pursuit costs:
Investment in real estate, net	225	375
Investments in unconsolidated entities	649	1,070
Other assets	458	18
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,071	946
Other liabilities	311	315
Realized/unrealized (gain) loss on derivative instruments:
Other assets	7,410
Other liabilities	2,370
Accumulated other comprehensive income	(9,780)
Interest capitalized for real estate and unconsolidated entities under development:
Investment in real estate, net	(1,422)	(307)
Investments in unconsolidated entities	(1,971)	(710)
Investments in unconsolidated entities - development/other:
Investments in unconsolidated entities	(13,700)	(24,897)
Other liabilities	(780)
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(7,105)
Lease liabilities	7,105
Non-cash share distribution and other transfers from unconsolidated entities:
Investments in unconsolidated entities	539	859
Other assets	$ (539)	$ (859)