CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 708,402	$ 562,804
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	616,201	583,869
Amortization of deferred financing costs	8,664	9,054
Amortization of above/below market lease intangibles	(53)	3,294
Amortization of discounts and premiums on debt	10,137	21,360
Amortization of deferred settlements on derivative instruments	14,650	13,893
Amortization of right-of-use assets	9,966
Impairment		702
Write-off of pursuit costs	4,098	3,125
(Income) loss from investments in unconsolidated entities	(66,906)	2,993
Distributions from unconsolidated entities – return on capital	2,486	1,885
Net (gain) loss on sales of real estate properties	(269,400)	(256,834)
Net (gain) loss on sales of land parcels	(2,077)	(995)
Net (gain) loss on debt extinguishment	3,381	22,110
Compensation paid with Company Common Shares	20,777	22,270
Changes in assets and liabilities:
(Increase) decrease in other assets	(20,871)	(18,550)
Increase (decrease) in accounts payable and accrued expenses	57,822	58,756
Increase (decrease) in accrued interest payable	11,125	11,097
Increase (decrease) in lease liabilities	(1,784)
Increase (decrease) in other liabilities	(15,578)	1,190
Increase (decrease) in security deposits	3,140	2,168
Net cash provided by operating activities	1,094,180	1,044,191
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(1,147,236)	(708,092)
Investment in real estate – development/other	(137,238)	(101,573)
Capital expenditures to real estate	(128,335)	(138,119)
Non-real estate capital additions	(2,139)	(3,155)
Interest capitalized for real estate under development	(4,801)	(4,547)
Proceeds from disposition of real estate, net	692,649	691,526
Investments in unconsolidated entities	(9,073)	(4,860)
Distributions from unconsolidated entities – return of capital	78,262
Purchase of investment securities and other investments	(269)
Net cash provided by (used for) investing activities	(658,180)	(268,820)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(12,025)	(4,355)
Mortgage notes payable, net:
Proceeds	295,713
Lump sum payoffs	(723,021)	(847,939)
Scheduled principal repayments	(4,883)	(4,938)
Notes, net:
Proceeds	1,194,468	497,010
Lump sum payoffs	(450,000)
Line of credit and commercial paper:
Line of credit proceeds	5,850,000	1,635,000
Line of credit repayments	(5,850,000)	(1,635,000)
Commercial paper proceeds	13,341,198	9,624,610
Commercial paper repayments	(13,486,000)	(9,425,000)
Proceeds from (payments on) settlement of derivative instruments	(41,616)	1,638
Proceeds from Employee Share Purchase Plan (ESPP)	2,323	3,074
Proceeds from exercise of EQR options	67,066	6,000
Payment of offering costs	(789)	(27)
Other financing activities, net	(49)	(48)
Contributions – Noncontrolling Interests – Partially Owned Properties	4,594	125
Contributions – Limited Partners		1
Distributions:
OP Units – General Partner	(620,391)	(583,184)
Preference Units	(2,318)	(2,318)
OP Units – Limited Partners	(22,202)	(21,040)
Noncontrolling Interests – Partially Owned Properties	(6,404)	(8,882)
Net cash provided by (used for) financing activities	(467,717)	(787,383)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(31,717)	(12,012)
Cash and cash equivalents and restricted deposits, beginning of period	116,313	100,762
Cash and cash equivalents and restricted deposits, end of period	84,596	88,750
Cash and cash equivalents	28,777	32,995
Restricted deposits	55,819	55,755
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	246,410	268,966
Net cash paid for income and other taxes	918	934
Amortization of deferred financing costs:
Investment in real estate, net	60
Other assets	1,808	1,809
Mortgage notes payable, net	3,529	4,197
Notes, net	3,387	3,048
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	8,017	19,394
Notes, net	2,120	1,966
Amortization of deferred settlements on derivative instruments:
Other liabilities	(9)	(9)
Accumulated other comprehensive income	14,659	13,902
Write-off of pursuit costs:
Investment in real estate, net	4,042	3,079
Other assets	48	13
Accounts payable and accrued expenses	8	33
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	(67,900)	1,973
Other liabilities	994	1,020
Realized/unrealized (gain) loss on derivative instruments:
Other assets	2,002	(24,021)
Notes, net	2,277	(1,491)
Other liabilities	29,486	1,491
Accumulated other comprehensive income	(33,765)	24,021
Investments in unconsolidated entities:
Investments in unconsolidated entities	(6,973)	(3,180)
Other liabilities	(2,100)	(1,680)
Debt financing costs:
Other assets	145
Mortgage notes payable, net	(2,354)
Notes, net	(10,454)	(4,355)
Other liabilities	638
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(491,010)
Other assets	184,116
Lease liabilities	335,096
Other liabilities	(28,202)
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	(3,381)	(22,110)
ERPOP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	708,402	562,804
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	616,201	583,869
Amortization of deferred financing costs	8,664	9,054
Amortization of above/below market lease intangibles	(53)	3,294
Amortization of discounts and premiums on debt	10,137	21,360
Amortization of deferred settlements on derivative instruments	14,650	13,893
Amortization of right-of-use assets	9,966
Impairment		702
Write-off of pursuit costs	4,098	3,125
(Income) loss from investments in unconsolidated entities	(66,906)	2,993
Distributions from unconsolidated entities – return on capital	2,486	1,885
Net (gain) loss on sales of real estate properties	(269,400)	(256,834)
Net (gain) loss on sales of land parcels	(2,077)	(995)
Net (gain) loss on debt extinguishment	3,381	22,110
Compensation paid with Company Common Shares	20,777	22,270
Changes in assets and liabilities:
(Increase) decrease in other assets	(20,871)	(18,550)
Increase (decrease) in accounts payable and accrued expenses	57,822	58,756
Increase (decrease) in accrued interest payable	11,125	11,097
Increase (decrease) in lease liabilities	(1,784)
Increase (decrease) in other liabilities	(15,578)	1,190
Increase (decrease) in security deposits	3,140	2,168
Net cash provided by operating activities	1,094,180	1,044,191
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(1,147,236)	(708,092)
Investment in real estate – development/other	(137,238)	(101,573)
Capital expenditures to real estate	(128,335)	(138,119)
Non-real estate capital additions	(2,139)	(3,155)
Interest capitalized for real estate under development	(4,801)	(4,547)
Proceeds from disposition of real estate, net	692,649	691,526
Investments in unconsolidated entities	(9,073)	(4,860)
Distributions from unconsolidated entities – return of capital	78,262
Purchase of investment securities and other investments	(269)
Net cash provided by (used for) investing activities	(658,180)	(268,820)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(12,025)	(4,355)
Mortgage notes payable, net:
Proceeds	295,713
Lump sum payoffs	(723,021)	(847,939)
Scheduled principal repayments	(4,883)	(4,938)
Notes, net:
Proceeds	1,194,468	497,010
Lump sum payoffs	(450,000)
Line of credit and commercial paper:
Line of credit proceeds	5,850,000	1,635,000
Line of credit repayments	(5,850,000)	(1,635,000)
Commercial paper proceeds	13,341,198	9,624,610
Commercial paper repayments	(13,486,000)	(9,425,000)
Proceeds from (payments on) settlement of derivative instruments	(41,616)	1,638
Proceeds from Employee Share Purchase Plan (ESPP)	2,323	3,074
Proceeds from exercise of EQR options	67,066	6,000
Payment of offering costs	(789)	(27)
Other financing activities, net	(49)	(48)
Contributions – Noncontrolling Interests – Partially Owned Properties	4,594	125
Contributions – Limited Partners		1
Distributions:
OP Units – General Partner	(620,391)	(583,184)
Preference Units	(2,318)	(2,318)
OP Units – Limited Partners	(22,202)	(21,040)
Noncontrolling Interests – Partially Owned Properties	(6,404)	(8,882)
Net cash provided by (used for) financing activities	(467,717)	(787,383)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(31,717)	(12,012)
Cash and cash equivalents and restricted deposits, beginning of period	116,313	100,762
Cash and cash equivalents and restricted deposits, end of period	84,596	88,750
Cash and cash equivalents	28,777	32,995
Restricted deposits	55,819	55,755
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	246,410	268,966
Net cash paid for income and other taxes	918	934
Amortization of deferred financing costs:
Investment in real estate, net	(60)
Other assets	1,808	1,809
Mortgage notes payable, net	3,529	4,197
Notes, net	3,387	3,048
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	8,017	19,394
Notes, net	2,120	1,966
Amortization of deferred settlements on derivative instruments:
Other liabilities	(9)	(9)
Accumulated other comprehensive income	14,659	13,902
Write-off of pursuit costs:
Investment in real estate, net	4,042	3,079
Other assets	48	13
Accounts payable and accrued expenses	8	33
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	(67,900)	1,973
Other liabilities	994	1,020
Realized/unrealized (gain) loss on derivative instruments:
Other assets	2,002	(24,021)
Notes, net	2,277	(1,491)
Other liabilities	29,486	1,491
Accumulated other comprehensive income	(33,765)	24,021
Investments in unconsolidated entities:
Investments in unconsolidated entities	(6,973)	(3,180)
Other liabilities	(2,100)	(1,680)
Debt financing costs:
Other assets	145
Mortgage notes payable, net	(2,354)
Notes, net	(10,454)	(4,355)
Other liabilities	638
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(491,010)
Other assets	184,116
Lease liabilities	335,096
Other liabilities	(28,202)
ERPOP [Member] | Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	$ (3,381)	$ (22,110)