CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 260,482	$ 714,819
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	348,106	330,930
Amortization of deferred financing costs	7,037	8,048
Amortization of discounts and premiums on debt	(3,538)	851
Amortization of deferred settlements on derivative instruments	6,935	1,624
Write-off of pursuit costs	3,565	3,038
Distributions from unconsolidated entities - return on capital	240	42
Net (Gain) On Sale Of Land Parcels	0	(4,217)
Net (gain) on sales of discontinued operations	(204,053)	(682,236)
Loss on debt extinguishment	272	0
Unrealized (gain) loss on derivative instruments	(1)	2,569
Compensation paid with Company Common Shares	16,878	12,389
Changes in assets and liabilities:
(Increase) decrease in deposits - restricted	(1,330)	1,971
(Increase) in other assets	(23,017)	(4,456)
Increase in accounts payable and accrued expenses	35,794	35,165
(Decrease) in accrued interest payable	(5,426)	(6,047)
Increase (decrease) in other liabilities	141,090	(21,980)
Increase in security deposits	2,979	(33)
Net cash provided by operating activities	586,013	392,477
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate - acquisitions	(520,775)	(475,397)
Investment in real estate - development/other	(78,210)	(63,558)
Improvements to real estate	(68,319)	(64,863)
Additions to non-real estate property	(4,700)	(3,987)
Interest capitalized for real estate and unconsolidated entities under development	(10,055)	(3,683)
Proceeds from disposition of real estate, net	333,015	1,194,005
Investments in unconsolidated entities	(5,420)	(412)
(Increase) in deposits on real estate acquisitions and investments, net	(40,539)	(171,152)
Decrease in mortgage deposits	1,553	1,688
Acquisition of Noncontrolling Interests - Partially Owned Properties	(87)	(8,575)
Net cash (used for) provided by investing activities	(393,537)	404,066
CASH FLOWS FROM FINANCING ACTIVITIES:
Loan and bond acquisition costs	(4,283)	(1,466)
Mortgage notes payable:
Proceeds	0	135,230
Restricted cash	214	(11,663)
Scheduled principal repayments	(7,575)	(8,366)
Loss on debt extinguishments	(272)	0
Notes, net:
Lump sum payoffs	(253,858)	(93,096)
Line of Credit Facility:
Proceeds	105,000	0
Repayments	(70,000)	0
Proceeds from exercise of EQR options	31,281	83,534
Payment of offering costs	(1,907)	(2,611)
Other financing activities, net	(33)	(33)
Contributions - Noncontrolling Interests - Partially Owned Properties	2,935	0
Contributions - Limited Partners	5	0
Distributions:
Noncontrolling Interests - Partially Owned Properties	(2,225)	(454)
Net cash (used for) financing activities	(531,812)	(623,187)
Net (decrease) increase in cash and cash equivalents	(339,336)	173,356
Cash and cash equivalents, beginning of period	383,921	431,408
Cash and cash equivalents, end of period	44,585	604,764
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	236,600	242,655
Net cash paid for income and other taxes	454	628
Real estate acquisitions/dispositions/other:
Mortgage loans assumed	106,600	99,131
Valuation Of OP Units Issued	66,606	0
Amortization of discounts and premiums on debt:
Mortgage notes payable	(4,664)	(3,816)
Notes, net	1,126	4,667
Amortization of deferred settlements on derivative instruments:
Other liabilities	(268)	(267)
Accumulated other comprehensive income	7,203	1,891
Unrealized (gain) loss on derivative instruments:
Other assets	4,663	1,975
Mortgage notes payable	(2,589)	(226)
Notes, net	(2,074)	(501)
Other liabilities	8,641	26,440
Accumulated other comprehensive income	(8,642)	(25,119)
Interest capitalized for real estate and unconsolidated entities under development:
Investment in real estate, net	(9,676)	(3,597)
Investments in unconsolidated entities	(379)	(86)
OPERATING PARTNERSHIP
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	260,482	714,819
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	348,106	330,930
Amortization of deferred financing costs	7,037	8,048
Amortization of discounts and premiums on debt	(3,538)	851
Amortization of deferred settlements on derivative instruments	6,935	1,624
Write-off of pursuit costs	3,565	3,038
Distributions from unconsolidated entities - return on capital	240	42
Net (Gain) On Sale Of Land Parcels	0	(4,217)
Net (gain) on sales of discontinued operations	(204,053)	(682,236)
Unrealized (gain) loss on derivative instruments	(1)	2,569
Compensation paid with Company Common Shares	16,878	12,389
Changes in assets and liabilities:
(Increase) decrease in deposits - restricted	(1,330)	1,971
(Increase) in other assets	(23,017)	(4,456)
Increase in accounts payable and accrued expenses	35,794	35,165
(Decrease) in accrued interest payable	(5,426)	(6,047)
Increase (decrease) in other liabilities	141,090	(21,980)
Increase in security deposits	2,979	(33)
Net cash provided by operating activities	586,013	392,477
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate - acquisitions	(520,775)	(475,397)
Investment in real estate - development/other	(78,210)	(63,558)
Improvements to real estate	(68,319)	(64,863)
Additions to non-real estate property	(4,700)	(3,987)
Interest capitalized for real estate and unconsolidated entities under development	(10,055)	(3,683)
Proceeds from disposition of real estate, net	333,015	1,194,005
Investments in unconsolidated entities	(5,420)	(412)
(Increase) in deposits on real estate acquisitions and investments, net	(40,539)	(171,152)
Decrease in mortgage deposits	1,553	1,688
Acquisition of Noncontrolling Interests - Partially Owned Properties	(87)	(8,575)
Net cash (used for) provided by investing activities	(393,537)	404,066
CASH FLOWS FROM FINANCING ACTIVITIES:
Loan and bond acquisition costs	(4,283)	(1,466)
Mortgage notes payable:
Proceeds	0	135,230
Restricted cash	214	(11,663)
Lump sum payoffs	(198,763)	(632,477)
Scheduled principal repayments	(7,575)	(8,366)
Notes, net:
Lump sum payoffs	(253,858)	(93,096)
Line of Credit Facility:
Proceeds	105,000	0
Repayments	(70,000)	0
Proceeds from sale of OP Units	152,058	154,508
Proceeds from EQR's Employee Share Purchase Plan (ESPP)	4,523	3,501
Proceeds from exercise of EQR options	31,281	83,534
Payment of offering costs	(1,907)	(2,611)
Contributions - Noncontrolling Interests - Partially Owned Properties	2,935	0
Contributions - Limited Partners	5	0
Distributions:
OP Units - General Partner	(269,755)	(231,995)
Preference Units	(6,933)	(6,933)
OP Units - Limited Partners	(12,224)	(10,866)
Noncontrolling Interests - Partially Owned Properties	(2,225)	(454)
Net cash (used for) financing activities	(531,812)	(623,187)
Net (decrease) increase in cash and cash equivalents	(339,336)	173,356
Cash and cash equivalents, beginning of period	383,921	431,408
Cash and cash equivalents, end of period	44,585	604,764
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	236,600	242,655
Net cash paid for income and other taxes	454	628
Real estate acquisitions/dispositions/other:
Mortgage loans assumed	106,600	99,131
Amortization of discounts and premiums on debt:
Mortgage notes payable	(4,664)	(3,816)
Notes, net	1,126	4,667
Amortization of deferred settlements on derivative instruments:
Other liabilities	(268)	(267)
Accumulated other comprehensive income	7,203	1,891
Unrealized (gain) loss on derivative instruments:
Other assets	4,663	1,975
Mortgage notes payable	(2,589)	(226)
Notes, net	(2,074)	(501)
Other liabilities	8,641	26,440
Accumulated other comprehensive income	(8,642)	(25,119)
Interest capitalized for real estate and unconsolidated entities under development:
Investment in real estate, net	(9,676)	(3,597)
Investments in unconsolidated entities	(379)	(86)
Other:
Receivable on sale of OP Units	$ 28,457	$ 0