CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 3,731,831	$ 190,224
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	172,885	194,521
Amortization of deferred financing costs	5,394	2,589
Amortization of above/below market leases	851	846
Amortization of discounts and premiums on debt	(19,563)	(3,751)
Amortization of deferred settlements on derivative instruments	28,585	4,205
Write-off of pursuit costs	1,448	493
Loss (income) from investments in unconsolidated entities	1,104	(2,963)
Distributions from unconsolidated entities – return on capital	655	516
Net (gain) on sales of investment securities and other investments	(556)	0
Net (gain) on sales of real estate properties	(3,723,479)	(79,951)
Net (gain) loss on sales of land parcels	(11,722)	1
Net (gain) on sales of discontinued operations	(15)	0
Realized/unrealized loss on derivative instruments	0	24
Compensation paid with Company Common Shares	9,967	13,610
Changes in assets and liabilities:
Decrease in deposits – restricted	7,823	290
(Increase) in mortgage deposits	(455)	(456)
Decrease (increase) in other assets	17,175	(4,237)
Increase in accounts payable and accrued expenses	32,964	45,450
(Decrease) in accrued interest payable	(15,817)	(4,870)
(Decrease) in other liabilities	(23,703)	(8,307)
(Decrease) in security deposits	(13,990)	(339)
Net cash provided by operating activities	201,382	347,895
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(160,680)	(6,720)
Investment in real estate – development/other	(150,164)	(146,194)
Capital expenditures to real estate	(33,902)	(38,170)
Non-real estate capital additions	(1,205)	(469)
Interest capitalized for real estate under development	(14,246)	(15,313)
Proceeds from disposition of real estate, net	6,303,904	142,931
Investments in unconsolidated entities	(900)	(2,410)
Distributions from unconsolidated entities – return of capital	336	18,969
Proceeds from sale of investment securities and other investments	1,430	0
(Increase) in deposits on real estate acquisitions and investments, net	(193,533)	(131,787)
Decrease (increase) in mortgage deposits	196	(59)
Net cash provided by (used for) investing activities	5,751,236	(179,222)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(397)	0
Mortgage deposits	(2,150)	(2,059)
Mortgage notes payable, net:
Lump sum payoffs	(482,601)	(121,326)
Scheduled principal repayments	(2,208)	(2,746)
Notes, net:
Lump sum payoffs	(1,500,000)	0
Line of credit and commercial paper:
Line of credit proceeds	246,000	1,997,000
Line of credit repayments	(246,000)	(2,200,000)
Commercial paper proceeds	1,324,784	1,155,228
Commercial paper repayments	(1,712,472)	(814,600)
(Payments on) settlement of derivative instruments	0	(25)
Proceeds from EQR's Employee Share Purchase Plan (ESPP)	982	1,927
Proceeds from exercise of options	20,687	32,213
Redemption of Preference Units	0	(9,820)
Premium on redemption of Preference Units	0	(2,789)
Other financing activities, net	(138)	0
Contributions – Limited Partners	1	1
Distributions:
Noncontrolling Interests – Partially Owned Properties	(26,781)	(2,891)
Net cash (used for) financing activities	(5,626,845)	(159,335)
Net increase in cash and cash equivalents	325,773	9,338
Cash and cash equivalents, beginning of period	42,276	40,080
Cash and cash equivalents, end of period	368,049	49,418
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	220,385	113,113
Net cash paid for income and other taxes	524	718
Real estate acquisitions/dispositions/other:
Mortgage loans assumed	43,400	0
Amortization of deferred financing costs:
Other assets	763	764
Mortgage notes payable, net	1,868	843
Notes, net	2,763	982
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	(21,515)	(4,567)
Notes, net	1,540	618
Line of credit and commercial paper	412	198
Amortization of deferred settlements on derivative instruments:
Other liabilities	(69)	(133)
Accumulated other comprehensive income	28,654	4,338
Write-off of pursuit costs:
Investment in real estate, net	982	434
Other assets	389	59
Accounts payable and accrued expenses	77	0
Loss (income) from investments in unconsolidated entities:
Investments in unconsolidated entities	709	(3,625)
Other liabilities	395	662
Realized/unrealized loss on derivative instruments:
Other assets	(6,878)	(4,963)
Notes, net	6,878	4,842
Other liabilities	2,906	11,933
Unrealized holding (losses) arising during the period	(2,906)	(11,788)
Investments in unconsolidated entities:
Investments in unconsolidated entities	0	(130)
Other liabilities	(900)	(2,280)
Debt financing costs [Abstract]
Payments of Financing Costs	(397)	0
Other:
Foreign currency translation adjustments	(75)	420
ERPOP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	3,731,831	190,224
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	172,885	194,521
Amortization of deferred financing costs	5,394	2,589
Amortization of above/below market leases	851	846
Amortization of discounts and premiums on debt	(19,563)	(3,751)
Amortization of deferred settlements on derivative instruments	28,585	4,205
Write-off of pursuit costs	1,448	493
Loss (income) from investments in unconsolidated entities	1,104	(2,963)
Distributions from unconsolidated entities – return on capital	655	516
Net (gain) on sales of investment securities and other investments	(556)	0
Net (gain) on sales of real estate properties	(3,723,479)	(79,951)
Net (gain) loss on sales of land parcels	(11,722)	1
Net (gain) on sales of discontinued operations	(15)	0
Realized/unrealized loss on derivative instruments	0	24
Compensation paid with Company Common Shares	9,967	13,610
Changes in assets and liabilities:
Decrease in deposits – restricted	7,823	290
(Increase) in mortgage deposits	(455)	(456)
Decrease (increase) in other assets	17,175	(4,237)
Increase in accounts payable and accrued expenses	32,964	45,450
(Decrease) in accrued interest payable	(15,817)	(4,870)
(Decrease) in other liabilities	(23,703)	(8,307)
(Decrease) in security deposits	(13,990)	(339)
Net cash provided by operating activities	201,382	347,895
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(160,680)	(6,720)
Investment in real estate – development/other	(150,164)	(146,194)
Capital expenditures to real estate	(33,902)	(38,170)
Non-real estate capital additions	(1,205)	(469)
Interest capitalized for real estate under development	(14,246)	(15,313)
Proceeds from disposition of real estate, net	6,303,904	142,931
Investments in unconsolidated entities	(900)	(2,410)
Distributions from unconsolidated entities – return of capital	336	18,969
Proceeds from sale of investment securities and other investments	1,430	0
(Increase) in deposits on real estate acquisitions and investments, net	(193,533)	(131,787)
Decrease (increase) in mortgage deposits	196	(59)
Net cash provided by (used for) investing activities	5,751,236	(179,222)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(397)	0
Mortgage deposits	(2,150)	(2,059)
Mortgage notes payable, net:
Lump sum payoffs	(482,601)	(121,326)
Scheduled principal repayments	(2,208)	(2,746)
Notes, net:
Lump sum payoffs	(1,500,000)	0
Line of credit and commercial paper:
Line of credit proceeds	246,000	1,997,000
Line of credit repayments	(246,000)	(2,200,000)
Commercial paper proceeds	1,324,784	1,155,228
Commercial paper repayments	(1,712,472)	(814,600)
(Payments on) settlement of derivative instruments	0	(25)
Proceeds from EQR's Employee Share Purchase Plan (ESPP)	982	1,927
Proceeds from exercise of options	20,687	32,213
Redemption of Preference Units	0	(9,820)
Premium on redemption of Preference Units	0	(2,789)
Other financing activities, net	(138)	0
Contributions – Limited Partners	1	1
Distributions:
OP Units – General Partner	(3,122,652)	(181,408)
Preference Units	(773)	(891)
OP Units – Limited Partners	(123,127)	(7,149)
Noncontrolling Interests – Partially Owned Properties	(26,781)	(2,891)
Net cash (used for) financing activities	(5,626,845)	(159,335)
Net increase in cash and cash equivalents	325,773	9,338
Cash and cash equivalents, beginning of period	42,276	40,080
Cash and cash equivalents, end of period	368,049	49,418
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	220,385	113,113
Net cash paid for income and other taxes	524	718
Real estate acquisitions/dispositions/other:
Mortgage loans assumed	43,400	0
Amortization of deferred financing costs:
Other assets	763	764
Mortgage notes payable, net	1,868	843
Notes, net	2,763	982
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	(21,515)	(4,567)
Notes, net	1,540	618
Line of credit and commercial paper	412	198
Amortization of deferred settlements on derivative instruments:
Other liabilities	(69)	(133)
Accumulated other comprehensive income	28,654	4,338
Write-off of pursuit costs:
Investment in real estate, net	982	434
Other assets	389	59
Loss (income) from investments in unconsolidated entities:
Investments in unconsolidated entities	709	(3,625)
Other liabilities	395	662
Realized/unrealized loss on derivative instruments:
Other assets	(6,878)	(4,963)
Notes, net	6,878	4,842
Other liabilities	2,906	11,933
Unrealized holding (losses) arising during the period	(2,906)	(11,788)
Investments in unconsolidated entities:
Investments in unconsolidated entities	0	(130)
Other liabilities	(900)	(2,280)
Debt financing costs [Abstract]
Payments of Financing Costs	(397)	0
Other:
Foreign currency translation adjustments	(75)	420
Land [Member] | ERPOP [Member]
Write-off of pursuit costs:
Accounts payable and accrued expenses	$ 77	$ 0