Erp Operating LTD Partnership 10-Q 7 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 31, 2014
Entity Registrant Name	'EQUITY RESIDENTIAL	'
Entity Central Index Key	'0000906107	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	361,742,672
OPERATING PARTNERSHIP	'	'
Entity Registrant Name	'ERP OPERATING LIMITED PARTNERSHIP	'
Entity Central Index Key	'0000931182	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Non-accelerated Filer	'

CONSOLIDATED_BALANCE_SHEETS_Un

CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investment in real estate	'	'
Land	$6,296,735	$6,192,512
Depreciable property	19,730,737	19,226,047
Projects under development	1,006,992	988,867
Land held for development	306,625	393,522
Real Estate Investment Property, at Cost	27,341,089	26,800,948
Real Estate Investment Property, Accumulated Depreciation	-5,170,438	-4,807,709
Investment in real estate, net	22,170,651	21,993,239
Cash and cash equivalents	76,132	53,534
Investments in unconsolidated entities	142,318	178,526
Deposits - restricted	84,408	103,567
Escrow deposits - mortgage	45,269	42,636
Deferred financing costs, net	63,441	58,486
Other assets	409,183	404,557
Total assets	22,991,402	22,834,545
Liabilities:	'	'
Mortgage notes payable	5,158,091	5,174,166
Notes, net	5,923,952	5,477,088
Lines of credit	0	115,000
Accounts payable and accrued expenses	168,225	118,791
Accrued interest payable	78,389	78,309
Other liabilities	331,662	347,748
Security deposits	74,508	71,592
Distributions payable	187,906	243,511
Total liabilities	11,922,733	11,626,205
Commitments and contingencies	'	'
Redeemable Noncontrolling Interests - Operating Partnership	440,050	363,144
Shareholders' equity:	'	'
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 1,000,000 shares issued and outstanding as of June 30, 2014 and December 31, 2013	50,000	50,000
Common Shares of beneficial interest, $0.01 par value; 1,000,000,000 shares authorized; 361,562,007 shares issued and outstanding as of June 30, 2014 and 360,479,260 shares issued and outstanding as of December 31, 2013	3,616	3,605
Paid in capital	8,527,380	8,561,500
Retained earnings	1,875,732	2,047,258
Accumulated other comprehensive (loss)	-166,990	-155,162
Total shareholders' equity	10,289,738	10,507,201
Noncontrolling Interests:	'	'
Operating Partnership	213,038	211,412
Noncontrolling Interests - Partially Owned Properties	125,843	126,583
Total Noncontrolling Interests	338,881	337,995
Total equity	10,628,619	10,845,196
Total liabilities and equity	$22,991,402	$22,834,545

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Shareholders' equity:	'	'
Preferred Shares of beneficial interest, par value	$0.01	$0.01
Preferred Shares of beneficial interest, shares authorized	100,000,000	100,000,000
Preferred Shares of beneficial interest, shares issued	1,000,000	1,000,000
Preferred Shares of beneficial interest, shares outstanding	1,000,000	1,000,000
Common Shares of beneficial interest, par value	$0.01	$0.01
Common Shares of beneficial interest, shares authorized	1,000,000,000	1,000,000,000
Common Shares of beneficial interest, shares issued	361,562,007	360,479,260
Common Shares of beneficial interest, shares outstanding	361,562,007	360,479,260

CONSOLIDATED_BALANCE_SHEETS_OF

CONSOLIDATED BALANCE SHEETS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investment in real estate	'	'
Land	$6,296,735	$6,192,512
Depreciable property	19,730,737	19,226,047
Projects under development	1,006,992	988,867
Land held for development	306,625	393,522
Real Estate Investment Property, at Cost	27,341,089	26,800,948
Real Estate Investment Property, Accumulated Depreciation	-5,170,438	-4,807,709
Investment in real estate, net	22,170,651	21,993,239
Cash and cash equivalents	76,132	53,534
Investments in unconsolidated entities	142,318	178,526
Deposits - restricted	84,408	103,567
Escrow deposits - mortgage	45,269	42,636
Deferred financing costs, net	63,441	58,486
Other assets	409,183	404,557
Total assets	22,991,402	22,834,545
Liabilities:	'	'
Mortgage notes payable	5,158,091	5,174,166
Notes, net	5,923,952	5,477,088
Lines of credit	0	115,000
Accounts payable and accrued expenses	168,225	118,791
Accrued interest payable	78,389	78,309
Other liabilities	331,662	347,748
Security deposits	74,508	71,592
Distributions payable	187,906	243,511
Total liabilities	11,922,733	11,626,205
Commitments and contingencies	'	'
Partnersb Capital:	'	'
Accumulated other comprehensive (loss)	-166,990	-155,162
Noncontrolling Interests - Partially Owned Properties	125,843	126,583
Total liabilities and equity	22,991,402	22,834,545
OPERATING PARTNERSHIP	'	'
Investment in real estate	'	'
Land	6,296,735	6,192,512
Depreciable property	19,730,737	19,226,047
Projects under development	1,006,992	988,867
Land held for development	306,625	393,522
Real Estate Investment Property, at Cost	27,341,089	26,800,948
Real Estate Investment Property, Accumulated Depreciation	-5,170,438	-4,807,709
Investment in real estate, net	22,170,651	21,993,239
Cash and cash equivalents	76,132	53,534
Investments in unconsolidated entities	142,318	178,526
Deposits - restricted	84,408	103,567
Escrow deposits - mortgage	45,269	42,636
Deferred financing costs, net	63,441	58,486
Other assets	409,183	404,557
Total assets	22,991,402	22,834,545
Liabilities:	'	'
Mortgage notes payable	5,158,091	5,174,166
Notes, net	5,923,952	5,477,088
Lines of credit	0	115,000
Accounts payable and accrued expenses	168,225	118,791
Accrued interest payable	78,389	78,309
Other liabilities	331,662	347,748
Security deposits	74,508	71,592
Distributions payable	187,906	243,511
Total liabilities	11,922,733	11,626,205
Commitments and contingencies	'	'
Redeemable Limited Partners	440,050	363,144
Partnersb Capital:	'	'
Preferred Units, Preferred Partners' Capital Accounts	50,000	50,000
General Partner	10,406,728	10,612,363
Limited Partners	213,038	211,412
Accumulated other comprehensive (loss)	-166,990	-155,162
Total partnersb capital	10,502,776	10,718,613
Noncontrolling Interests - Partially Owned Properties	125,843	126,583
Total capital	10,628,619	10,845,196
Total liabilities and equity	$22,991,402	$22,834,545

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
REVENUES	'	'	'	'
Rental income	$649,766	$614,544	$1,280,491	$1,117,106
Fee and asset management	2,802	2,673	5,519	4,833
Total revenues	652,568	617,217	1,286,010	1,121,939
EXPENSES	'	'	'	'
Property and maintenance	115,388	113,501	240,961	212,030
Real estate taxes and insurance	83,055	76,742	165,149	141,837
Property management	20,555	22,031	42,673	44,520
Fee and asset management	1,378	1,577	3,040	3,223
Depreciation	190,136	323,304	375,303	519,526
General and administrative	13,752	16,085	31,328	32,580
Total expenses	424,264	553,240	858,454	953,716
Operating Income	228,304	63,977	427,556	168,223
Interest and other income	2,032	432	2,637	752
Other expenses	-1,533	-1,631	-2,190	-23,350
Interest:	'	'	'	'
Expense incurred, net	-115,924	-122,950	-228,973	-317,417
Amortization of deferred financing costs	-3,134	-4,353	-5,926	-11,301
Income (loss) before income and other taxes, (loss) from investments in unconsolidated entities, net gain on sales of land parcels, discontinued operations and net gain on sales of real estate properties	109,745	-64,525	193,104	-183,093
Income and other tax (expense) benefit	-646	-428	-886	-833
(Loss) from investments in unconsolidated entities	-7,616	-8,174	-9,025	-54,540
Net gain on sales of land parcels	824	14,616	794	14,616
Income (loss) from continuing operations	102,307	-58,511	183,987	-223,850
Discontinued operations, net	510	395,243	1,562	1,621,616
Income before net gain on sales of real estate properties	102,817	336,732	185,549	1,397,766
Net gain on sales of real estate properties	14,903	0	14,903	0
Net income	117,720	336,732	200,452	1,397,766
Net (income) loss attributable to Noncontrolling Interests:	'	'	'	'
Net (Income) loss Attributable to Noncontrolling Interest	-4,442	-12,788	-7,535	-56,111
Net (income) loss attributable to Noncontrolling Interests b Partially Owned Properties	-588	815	-1,092	790
Net income attributable to controlling interests	112,690	324,759	191,825	1,342,445
Preferred distributions	-1,036	-1,036	-2,072	-2,072
Net income available to Common Shares	$111,654	$323,723	$189,753	$1,340,373
Earnings per share - basic:	'	'	'	'
Income (loss) from continuing operations available to Common Shares	$0.31	($0.16)	$0.52	($0.62)
Net income available to Common Shares	$0.31	$0.90	$0.53	$3.84
Weighted average Common Shares outstanding	360,809	359,653	360,641	348,654
Earnings per share - diluted:	'	'	'	'
Income (loss) from continuing operations available to Common Shares	$0.31	($0.16)	$0.52	($0.62)
Net income available to Common Shares	$0.31	$0.90	$0.52	$3.84
Weighted average Common Shares outstanding	377,118	359,653	376,780	348,654
Distributions declared per Common Share outstanding	$0.50	$0.40	$1	$0.80

CONSOLIDATED_STATEMENTS_OF_OPE1

CONSOLIDATED STATEMENTS OF OPERATIONS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) (USD $)	3 Months Ended		6 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
REVENUES	'	'	'	'
Rental income	$649,766,000	$614,544,000	$1,280,491,000	$1,117,106,000
Fee and asset management	2,802,000	2,673,000	5,519,000	4,833,000
Total revenues	652,568,000	617,217,000	1,286,010,000	1,121,939,000
EXPENSES	'	'	'	'
Property and maintenance	115,388,000	113,501,000	240,961,000	212,030,000
Real estate taxes and insurance	83,055,000	76,742,000	165,149,000	141,837,000
Property management	20,555,000	22,031,000	42,673,000	44,520,000
Fee and asset management	1,378,000	1,577,000	3,040,000	3,223,000
Depreciation	190,136,000	323,304,000	375,303,000	519,526,000
General and administrative	13,752,000	16,085,000	31,328,000	32,580,000
Total expenses	424,264,000	553,240,000	858,454,000	953,716,000
Operating Income	228,304,000	63,977,000	427,556,000	168,223,000
Interest and other income	2,032,000	432,000	2,637,000	752,000
Other expenses	-1,533,000	-1,631,000	-2,190,000	-23,350,000
Interest:	'	'	'	'
Expense incurred, net	-115,924,000	-122,950,000	-228,973,000	-317,417,000
Amortization of deferred financing costs	-3,134,000	-4,353,000	-5,926,000	-11,301,000
Income (loss) before income and other taxes, (loss) from investments in unconsolidated entities, net gain on sales of land parcels, discontinued operations and net gain on sales of real estate properties	109,745,000	-64,525,000	193,104,000	-183,093,000
Income and other tax (expense) benefit	-646,000	-428,000	-886,000	-833,000
(Loss) from investments in unconsolidated entities	-7,616,000	-8,174,000	-9,025,000	-54,540,000
Net gain on sales of land parcels	824,000	14,616,000	794,000	14,616,000
Income (loss) from continuing operations	102,307,000	-58,511,000	183,987,000	-223,850,000
Discontinued operations, net	510,000	395,243,000	1,562,000	1,621,616,000
Income before net gain on sales of real estate properties	102,817,000	336,732,000	185,549,000	1,397,766,000
Net gain on sales of real estate properties	14,903,000	0	14,903,000	0
Net income	117,720,000	336,732,000	200,452,000	1,397,766,000
Net (income) loss attributable to Noncontrolling Interests b Partially Owned Properties	-588,000	815,000	-1,092,000	790,000
Net income attributable to controlling interests	112,690,000	324,759,000	191,825,000	1,342,445,000
Earnings per Unit - basic:	'	'	'	'
Income (loss) from continuing operations available to Units	$0.31	($0.16)	$0.52	($0.62)
Net income available to Units	$0.31	$0.90	$0.53	$3.84
Earnings per Unit - diluted:	'	'	'	'
Income (loss) from continuing operations available to Units	$0.31	($0.16)	$0.52	($0.62)
Net income available to Units	$0.31	$0.90	$0.52	$3.84
OPERATING PARTNERSHIP	'	'	'	'
REVENUES	'	'	'	'
Rental income	649,766,000	614,544,000	1,280,491,000	1,117,106,000
Fee and asset management	2,802,000	2,673,000	5,519,000	4,833,000
Total revenues	652,568,000	617,217,000	1,286,010,000	1,121,939,000
EXPENSES	'	'	'	'
Property and maintenance	115,388,000	113,501,000	240,961,000	212,030,000
Real estate taxes and insurance	83,055,000	76,742,000	165,149,000	141,837,000
Property management	20,555,000	22,031,000	42,673,000	44,520,000
Fee and asset management	1,378,000	1,577,000	3,040,000	3,223,000
Depreciation	190,136,000	323,304,000	375,303,000	519,526,000
General and administrative	13,752,000	16,085,000	31,328,000	32,580,000
Total expenses	424,264,000	553,240,000	858,454,000	953,716,000
Operating Income	228,304,000	63,977,000	427,556,000	168,223,000
Interest and other income	2,032,000	432,000	2,637,000	752,000
Other expenses	-1,533,000	-1,631,000	-2,190,000	-23,350,000
Interest:	'	'	'	'
Expense incurred, net	-115,924,000	-122,950,000	-228,973,000	-317,417,000
Amortization of deferred financing costs	-3,134,000	-4,353,000	-5,926,000	-11,301,000
Income (loss) before income and other taxes, (loss) from investments in unconsolidated entities, net gain on sales of land parcels, discontinued operations and net gain on sales of real estate properties	109,745,000	-64,525,000	193,104,000	-183,093,000
Income and other tax (expense) benefit	-646,000	-428,000	-886,000	-833,000
(Loss) from investments in unconsolidated entities	-7,616,000	-8,174,000	-9,025,000	-54,540,000
Net gain on sales of land parcels	824,000	14,616,000	794,000	14,616,000
Income (loss) from continuing operations	102,307,000	-58,511,000	183,987,000	-223,850,000
Discontinued operations, net	510,000	395,243,000	1,562,000	1,621,616,000
Income before net gain on sales of real estate properties	102,817,000	336,732,000	185,549,000	1,397,766,000
Net gain on sales of real estate properties	14,903,000	0	14,903,000	0
Net income	117,720,000	336,732,000	200,452,000	1,397,766,000
Net (income) loss attributable to Noncontrolling Interests b Partially Owned Properties	-588,000	815,000	-1,092,000	790,000
Net income attributable to controlling interests	117,132,000	337,547,000	199,360,000	1,398,556,000
ALLOCATION OF NET INCOME:	'	'	'	'
Preference Units	1,036,000	1,036,000	2,072,000	2,072,000
General Partner	111,654,000	323,723,000	189,753,000	1,340,373,000
Limited Partners	4,442,000	12,788,000	7,535,000	56,111,000
Net income available to Units	$116,096,000	$336,511,000	$197,288,000	$1,396,484,000
Earnings per Unit - basic:	'	'	'	'
Income (loss) from continuing operations available to Units	$0.31	($0.16)	$0.52	($0.62)
Net income available to Units	$0.31	$0.90	$0.53	$3.84
Weighted average Units outstanding	374,551	373,403	374,377	362,390
Earnings per Unit - diluted:	'	'	'	'
Income (loss) from continuing operations available to Units	$0.31	($0.16)	$0.52	($0.62)
Net income available to Units	$0.31	$0.90	$0.52	$3.84
Weighted average Units outstanding	377,118	373,403	376,780	362,390
Distributions declared per Unit outstanding	$0.50	$0.40	$1	$0.80

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net income	$117,720	$336,732	$200,452	$1,397,766
Other comprehensive (loss) income b derivative instruments:	'	'	'	'
Unrealized holding (losses) gains arising during the period	-9,929	9,523	-21,881	12,337
Losses reclassified into earnings from other comprehensive income	4,206	3,826	8,335	12,098
Other comprehensive income b other instruments:	'	'	'	'
Unrealized holding gains arising during the period	0	501	0	928
Other comprehensive income b foreign currency:	'	'	'	'
Currency translation adjustments arising during the period	1,627	1,814	1,718	941
Other comprehensive (loss) income	-4,096	15,664	-11,828	26,304
Comprehensive income	113,624	352,396	188,624	1,424,070
Comprehensive (income) attributable to Noncontrolling Interests	-4,873	-12,568	-8,175	-56,342
Comprehensive income attributable to controlling interests	$108,751	$339,828	$180,449	$1,367,728

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Comprehensive income:	'	'	'	'
Net income	$117,720	$336,732	$200,452	$1,397,766
Other comprehensive (loss) income b derivative instruments:	'	'	'	'
Unrealized holding (losses) gains arising during the period	-9,929	9,523	-21,881	12,337
Losses reclassified into earnings from other comprehensive income	4,206	3,826	8,335	12,098
Other comprehensive income b other instruments:	'	'	'	'
Unrealized holding gains arising during the period	0	501	0	928
Other comprehensive income b foreign currency:	'	'	'	'
Currency translation adjustments arising during the period	1,627	1,814	1,718	941
Other comprehensive (loss) income	-4,096	15,664	-11,828	26,304
Comprehensive income	113,624	352,396	188,624	1,424,070
Comprehensive (income) loss attributable to Noncontrolling Interests b Partially Owned Properties	-4,873	-12,568	-8,175	-56,342
Comprehensive income attributable to controlling interests	108,751	339,828	180,449	1,367,728
OPERATING PARTNERSHIP	'	'	'	'
Comprehensive income:	'	'	'	'
Net income	117,720	336,732	200,452	1,397,766
Other comprehensive (loss) income b derivative instruments:	'	'	'	'
Unrealized holding (losses) gains arising during the period	-9,929	9,523	-21,881	12,337
Losses reclassified into earnings from other comprehensive income	4,206	3,826	8,335	12,098
Other comprehensive income b other instruments:	'	'	'	'
Unrealized holding gains arising during the period	0	501	0	928
Other comprehensive income b foreign currency:	'	'	'	'
Currency translation adjustments arising during the period	1,627	1,814	1,718	941
Other comprehensive (loss) income	-4,096	15,664	-11,828	26,304
Comprehensive income	113,624	352,396	188,624	1,424,070
Comprehensive (income) loss attributable to Noncontrolling Interests b Partially Owned Properties	-588	815	-1,092	790
Comprehensive income attributable to controlling interests	$113,036	$353,211	$187,532	$1,424,860

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$200,452	$1,397,766
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	375,303	550,488
Amortization of deferred financing costs	5,926	11,529
Amortization of Intangible Assets	1,530	1,216
Amortization of discounts and premiums on debt	-5,876	-23,031
Amortization of deferred settlements on derivative instruments	8,068	11,830
Write-off of pursuit costs	1,492	3,365
Income Loss from Investments in Unconsolidated Entities Adjustment	9,025	54,540
Distributions from unconsolidated entities - return on capital	2,390	588
Net (gain) on sales of land parcels	-794	-14,616
Net (gain) on sales of discontinued operations	-224	-1,588,874
Net (gain) on sales of real estate properties	-14,903	0
Unrealized (gain) loss on derivative instruments	-90	24
Compensation paid with Company Common Shares	21,905	22,089
Changes in assets and liabilities:	'	'
(Increase) in deposits b restricted	-1,820	-12,220
Decrease in mortgage deposits	187	789
(Increase) in other assets	-7,745	-4,695
Increase in accounts payable and accrued expenses	38,951	25,956
Increase (decrease) in accrued interest payable	80	-1,396
(Decrease) in other liabilities	-17,237	-11,449
Increase (decrease) in security deposits	2,916	-6,080
Net cash provided by operating activities	619,536	417,819
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Payments to Acquire Businesses, Net of Cash Acquired	0	-4,000,875
Investment in real estate b acquisitions	-265,466	-108,308
Investment in real estate - development/other	-245,657	-154,576
Improvements to real estate	-76,912	-57,253
Additions to non-real estate property	-1,818	-2,801
Interest capitalized for real estate and unconsolidated entities under development	-25,037	-20,006
Proceeds from disposition of real estate, net	48,359	3,764,000
Investments in unconsolidated entities	-9,554	-53,687
Proceeds From Distributions Received From Unconsolidated Subsidiaries	64,669	0
Decrease in deposits on real estate acquisitions and investments, net	20,979	65,869
Decrease in mortgage deposits	760	5,089
Acquisition of Noncontrolling Interests b Partially Owned Properties	-5,501	0
Net cash (used for) investing activities	-495,178	-562,548
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Loan and bond acquisition costs	-10,881	-18,006
Mortgage Deposits	-3,580	-2,208
Mortgage notes payable:	'	'
Proceeds from Issuance of Long-term Debt	0	683
Lump sum payoffs	-3,064	-697,897
Scheduled principal repayments	-6,000	-6,336
Notes, net:	'	'
Proceeds from Notes Payable	1,194,277	1,245,550
Lump sum payoffs	-750,000	-400,000
Line of Credit Facility:	'	'
Proceeds	3,374,000	8,413,000
Repayments	-3,489,000	-8,413,000
(Payments on) settlement of derivative instruments	-733	-44,013
Proceeds from Employee Stock Purchase Plan	2,218	2,363
Proceeds from exercise of options	25,685	13,885
Payments for Repurchase of Common Stock	-1,777	0
Payment of offering costs	0	-744
Other financing activities, net	-33	-33
Contributions - Noncontrolling Interests - Partially Owned Properties	5,684	6,769
Contributions - Noncontrolling Interests - Operating Partnership	3	5
Distributions:	'	'
Common Shares	-414,843	-393,347
Preferred Shares	-2,072	-1,036
Noncontrolling Interests b Operating Partnership	-16,405	-16,528
Noncontrolling Interests b Partially Owned Properties	-5,239	-4,404
Net cash (used for) financing activities	-101,760	-315,297
Net increase (decrease) in cash and cash equivalents	22,598	-460,026
Cash and cash equivalents, beginning of period	53,534	612,590
Cash and cash equivalents, end of period	76,132	152,564
SUPPLEMENTAL INFORMATION:	'	'
Cash paid for interest, net of amounts capitalized	226,785	319,992
Net cash paid for income and other taxes	843	1,028
AmortizationOfDeferredFinancingCosts [Abstract]	'	'
Amortization Of Deferred Financing Costs Investment In Real Estate Net	0	-1
Amortization Of Deferred Financing Costs Deferred Financing Costs Net	5,926	11,530
Amortization of discounts and premiums on debt:	'	'
Mortgage notes payable	-7,011	-24,083
Notes, net	1,135	1,052
Amortization of deferred settlements on derivative instruments:	'	'
Other liabilities	-267	-268
Losses reclassified into earnings from other comprehensive income	8,335	12,098
Loss From Investments In Unconsolidated Entities [Abstract]	'	'
Income Loss From Equity Method Investments Merger	7,354	49,507
Other Liabilities Loss From Investments in unconsolidated entities	1,671	5,033
Distributions from unconsolidated entities return on capital [Abstract]	'	'
Distributions from unconsolidated entities investments in unconsolidated entities	2,285	588
Distributions from unconsolidated entities other liabilities	105	0
Unrealized (gain) loss on derivative instruments:	'	'
Other assets	10,611	-10,753
Notes, net	1,452	-1,523
Other liabilities	9,728	-37
Unrealized holding (losses) gains arising during the period	-21,881	12,337
Acquisition of Archstone, net of cash acquired [Abstract]	'	'
Acquisition of Archstone Investment in Real Estate Net	39,929	-8,713,217
Acquisition of Archstone Investments in Unconsolidated Entities	-33,993	-214,677
Acquisition of Archstone Deposits Restricted	0	-474
Acquisition of Archstone Escrow Deposits Mortgage	0	-35,898
Acquisition of Archstone Deferred Financing Costs	0	-25,780
Acquisition of Archstone Other Assets	-2,586	-203,008
Acquisition of Archstone Mortgage Notes Payable	0	3,076,876
Acquisition of Archstone Accounts Payable And Accrued Liabilities	-146	17,576
Acqusition of Archstone Interest Payable	0	11,256
Acquisition of Archstone Other Liabilities	-3,204	117,391
Acquisition of Archstone Security Deposits	0	10,949
Acquisition of Archstone Common Shares Issued	0	1,929,868
Acquisition of Archstone Noncontrolling Interests Partially Owned Properties	0	28,263
Interest capitalized for real estate and unconsolidated entities under development:	'	'
Investment in real estate, net	-25,002	-19,195
Investments in unconsolidated entities	-35	-811
Investments in unconsolidated entities [Abstract]	'	'
Investments in unconsolidated entities	-2,354	-4,371
Investments in unconsolidated entities other liabilities	-7,200	-49,316
Other:	'	'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	($1,718)	($941)

CONSOLIDATED_STATEMENTS_OF_CAS1

CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$200,452	$1,397,766
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	375,303	550,488
Amortization of deferred financing costs	5,926	11,529
Amortization of Intangible Assets	1,530	1,216
Amortization of discounts and premiums on debt	-5,876	-23,031
Amortization of deferred settlements on derivative instruments	8,068	11,830
Write-off of pursuit costs	1,492	3,365
Income Loss from Investments in Unconsolidated Entities Adjustment	9,025	54,540
Distributions from unconsolidated entities - return on capital	2,390	588
Net (gain) on sales of discontinued operations	-224	-1,588,874
Net (gain) on sales of real estate properties	-14,903	0
Unrealized (gain) loss on derivative instruments	-90	24
Compensation paid with Company Common Shares	21,905	22,089
Changes in assets and liabilities:	'	'
(Increase) in deposits b restricted	-1,820	-12,220
Decrease in mortgage deposits	187	789
(Increase) in other assets	-7,745	-4,695
Increase in accounts payable and accrued expenses	38,951	25,956
Increase (decrease) in accrued interest payable	80	-1,396
(Decrease) in other liabilities	-17,237	-11,449
Increase (decrease) in security deposits	2,916	-6,080
Net cash provided by operating activities	619,536	417,819
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Payments to Acquire Businesses, Net of Cash Acquired	0	-4,000,875
Investment in real estate - acquisitions	-265,466	-108,308
Investment in real estate - development/other	-245,657	-154,576
Improvements to real estate	-76,912	-57,253
Additions to non-real estate property	-1,818	-2,801
Interest capitalized for real estate and unconsolidated entities under development	-25,037	-20,006
Proceeds from disposition of real estate, net	48,359	3,764,000
Investments in unconsolidated entities	-9,554	-53,687
Proceeds From Distributions Received From Unconsolidated Subsidiaries	64,669	0
Decrease in deposits on real estate acquisitions and investments, net	20,979	65,869
Decrease in mortgage deposits	760	5,089
Acquisition of Noncontrolling Interests b Partially Owned Properties	-5,501	0
Net cash (used for) investing activities	-495,178	-562,548
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Loan and bond acquisition costs	-10,881	-18,006
Mortgage Deposits	-3,580	-2,208
Mortgage notes payable:	'	'
Proceeds from Issuance of Long-term Debt	0	683
Scheduled principal repayments	-6,000	-6,336
Notes, net:	'	'
Proceeds from Notes Payable	1,194,277	1,245,550
Lump sum payoffs	-750,000	-400,000
Line of Credit Facility:	'	'
Proceeds	3,374,000	8,413,000
Repayments	-3,489,000	-8,413,000
(Payments on) settlement of derivative instruments	-733	-44,013
Proceeds from exercise of options	25,685	13,885
Payment of offering costs	0	-744
Other financing activities, net	-33	-33
Contributions - Noncontrolling Interests - Partially Owned Properties	5,684	6,769
Contributions - Noncontrolling Interests - Operating Partnership	3	5
Distributions:	'	'
Noncontrolling Interests b Partially Owned Properties	-5,239	-4,404
Net cash (used for) financing activities	-101,760	-315,297
Net increase (decrease) in cash and cash equivalents	22,598	-460,026
Cash and cash equivalents, beginning of period	53,534	612,590
Cash and cash equivalents, end of period	76,132	152,564
SUPPLEMENTAL INFORMATION:	'	'
Cash paid for interest, net of amounts capitalized	226,785	319,992
Net cash paid for income and other taxes	843	1,028
AmortizationOfDeferredFinancingCosts [Abstract]	'	'
Amortization Of Deferred Financing Costs Investment In Real Estate Net	0	1
Amortization Of Deferred Financing Costs Deferred Financing Costs Net	5,926	11,530
Amortization of discounts and premiums on debt:	'	'
Mortgage notes payable	7,011	24,083
Notes, net	1,135	1,052
Amortization of deferred settlements on derivative instruments:	'	'
Other liabilities	-267	-268
Losses reclassified into earnings from other comprehensive income	8,335	12,098
Loss From Investments In Unconsolidated Entities [Abstract]	'	'
Income Loss From Equity Method Investments Merger	7,354	49,507
Other Liabilities Loss From Investments in unconsolidated entities	1,671	5,033
Distributions from unconsolidated entities return on capital [Abstract]	'	'
Distributions from unconsolidated entities investments in unconsolidated entities	2,285	588
Distributions from unconsolidated entities other liabilities	105	0
Unrealized (gain) loss on derivative instruments:	'	'
Other assets	10,611	-10,753
Notes, net	1,452	-1,523
Other liabilities	9,728	-37
Unrealized holding (losses) gains arising during the period	-21,881	12,337
Acquisition of Archstone, net of cash acquired [Abstract]	'	'
Acquisition of Archstone Investment in Real Estate Net	39,929	-8,713,217
Acquisition of Archstone Investments in Unconsolidated Entities	-33,993	-214,677
Acquisition of Archstone Deposits Restricted	0	-474
Acquisition of Archstone Escrow Deposits Mortgage	0	-35,898
Acquisition of Archstone Deferred Financing Costs	0	-25,780
Acquisition of Archstone Other Assets	-2,586	-203,008
Acquisition of Archstone Mortgage Notes Payable	0	3,076,876
Acquisition of Archstone Accounts Payable And Accrued Liabilities	-146	17,576
Acqusition of Archstone Interest Payable	0	11,256
Acquisition of Archstone Other Liabilities	-3,204	117,391
Acquisition of Archstone Security Deposits	0	10,949
Acquisition of Archstone Common Shares Issued	0	1,929,868
Acquisition of Archstone Noncontrolling Interests Partially Owned Properties	0	28,263
Interest capitalized for real estate and unconsolidated entities under development:	'	'
Investment in real estate, net	-25,002	-19,195
Investments in unconsolidated entities	-35	-811
Investments in unconsolidated entities [Abstract]	'	'
Investments in unconsolidated entities	2,354	4,371
Investments in unconsolidated entities other liabilities	7,200	49,316
Other:	'	'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	-1,718	-941
OPERATING PARTNERSHIP	'	'
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	200,452	1,397,766
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	375,303	550,488
Amortization of deferred financing costs	5,926	11,529
Amortization of Intangible Assets	1,530	1,216
Amortization of discounts and premiums on debt	-5,876	-23,031
Amortization of deferred settlements on derivative instruments	8,068	11,830
Write-off of pursuit costs	1,492	3,365
Income Loss from Investments in Unconsolidated Entities Adjustment	9,025	54,540
Distributions from unconsolidated entities - return on capital	2,390	588
Net (gain) on sales of land parcels	-794	-14,616
Net (gain) on sales of discontinued operations	-224	-1,588,874
Net (gain) on sales of real estate properties	-14,903	0
Unrealized (gain) loss on derivative instruments	-90	24
Compensation paid with Company Common Shares	21,905	22,089
Changes in assets and liabilities:	'	'
(Increase) in deposits b restricted	-1,820	-12,220
Decrease in mortgage deposits	187	789
(Increase) in other assets	-7,745	-4,695
Increase in accounts payable and accrued expenses	38,951	25,956
Increase (decrease) in accrued interest payable	80	-1,396
(Decrease) in other liabilities	-17,237	-11,449
Increase (decrease) in security deposits	2,916	-6,080
Net cash provided by operating activities	619,536	417,819
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Payments to Acquire Businesses, Net of Cash Acquired	0	-4,000,875
Investment in real estate - acquisitions	-265,466	-108,308
Investment in real estate - development/other	-245,657	-154,576
Improvements to real estate	-76,912	-57,253
Additions to non-real estate property	-1,818	-2,801
Interest capitalized for real estate and unconsolidated entities under development	-25,037	-20,006
Proceeds from disposition of real estate, net	48,359	3,764,000
Investments in unconsolidated entities	-9,554	-53,687
Proceeds From Distributions Received From Unconsolidated Subsidiaries	64,669	0
Decrease in deposits on real estate acquisitions and investments, net	20,979	65,869
Decrease in mortgage deposits	760	5,089
Acquisition of Noncontrolling Interests b Partially Owned Properties	-5,501	0
Net cash (used for) investing activities	-495,178	-562,548
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Loan and bond acquisition costs	-10,881	-18,006
Mortgage Deposits	-3,580	-2,208
Mortgage notes payable:	'	'
Proceeds from Issuance of Long-term Debt	0	683
Lump sum payoffs	-3,064	-697,897
Scheduled principal repayments	-6,000	-6,336
Notes, net:	'	'
Proceeds from Notes Payable	1,194,277	1,245,550
Lump sum payoffs	-750,000	-400,000
Line of Credit Facility:	'	'
Proceeds	3,374,000	8,413,000
Repayments	-3,489,000	-8,413,000
(Payments on) settlement of derivative instruments	-733	-44,013
Stock Issued During Period, Value, Employee Stock Purchase Plan	2,218	2,363
Proceeds from exercise of options	25,685	13,885
Payments For Repurchase Of Op Units	-1,777	0
Payment of offering costs	0	-744
Other financing activities, net	-33	-33
Contributions - Noncontrolling Interests - Partially Owned Properties	5,684	6,769
Contributions - Noncontrolling Interests - Operating Partnership	3	5
Distributions:	'	'
OP Units - General Partner	-414,843	-393,347
Preference Units	-2,072	-1,036
OP Units - Limited Partners	-16,405	-16,528
Noncontrolling Interests b Partially Owned Properties	-5,239	-4,404
Net cash (used for) financing activities	-101,760	-315,297
Net increase (decrease) in cash and cash equivalents	22,598	-460,026
Cash and cash equivalents, beginning of period	53,534	612,590
Cash and cash equivalents, end of period	76,132	152,564
SUPPLEMENTAL INFORMATION:	'	'
Cash paid for interest, net of amounts capitalized	226,785	319,992
Net cash paid for income and other taxes	843	1,028
AmortizationOfDeferredFinancingCosts [Abstract]	'	'
Amortization Of Deferred Financing Costs Investment In Real Estate Net	0	-1
Amortization Of Deferred Financing Costs Deferred Financing Costs Net	5,926	11,530
Amortization of discounts and premiums on debt:	'	'
Mortgage notes payable	-7,011	-24,083
Notes, net	1,135	1,052
Amortization of deferred settlements on derivative instruments:	'	'
Other liabilities	-267	-268
Losses reclassified into earnings from other comprehensive income	8,335	12,098
Loss From Investments In Unconsolidated Entities [Abstract]	'	'
Income Loss From Equity Method Investments Merger	7,354	49,507
Other Liabilities Loss From Investments in unconsolidated entities	1,671	5,033
Distributions from unconsolidated entities return on capital [Abstract]	'	'
Distributions from unconsolidated entities investments in unconsolidated entities	2,285	588
Distributions from unconsolidated entities other liabilities	105	0
Unrealized (gain) loss on derivative instruments:	'	'
Other assets	10,611	-10,753
Notes, net	1,452	-1,523
Other liabilities	9,728	-37
Unrealized holding (losses) gains arising during the period	-21,881	12,337
Acquisition of Archstone, net of cash acquired [Abstract]	'	'
Acquisition of Archstone Investment in Real Estate Net	39,929	-8,713,217
Acquisition of Archstone Investments in Unconsolidated Entities	-33,993	-214,677
Acquisition of Archstone Deposits Restricted	0	-474
Acquisition of Archstone Escrow Deposits Mortgage	0	-35,898
Acquisition of Archstone Deferred Financing Costs	0	-25,780
Acquisition of Archstone Other Assets	-2,586	-203,008
Acquisition of Archstone Mortgage Notes Payable	0	3,076,876
Acquisition of Archstone Accounts Payable And Accrued Liabilities	-146	17,576
Acqusition of Archstone Interest Payable	0	11,256
Acquisition of Archstone Other Liabilities	-3,204	117,391
Acquisition of Archstone Security Deposits	0	10,949
Acquisition of Archstone Common Shares Issued	0	1,929,868
Acquisition of Archstone Noncontrolling Interests Partially Owned Properties	0	28,263
Interest capitalized for real estate and unconsolidated entities under development:	'	'
Investment in real estate, net	-25,002	-19,195
Investments in unconsolidated entities	-35	-811
Investments in unconsolidated entities [Abstract]	'	'
Investments in unconsolidated entities	-2,354	-4,371
Investments in unconsolidated entities other liabilities	-7,200	-49,316
Other:	'	'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	($1,718)	($941)

CONSOLIDATED_STATEMENT_OF_CHAN

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Unaudited) (USD $)	Total	PREFERRED SHARES	COMMON SHARES, $0.01 PAR VALUE	Additional Paid-in Capital [Member]	RETAINED EARNINGS	Accumulated Other Comprehensive (Loss)	OPERATING PARTNERSHIP	Partially Owned Properties [Member]
In Thousands, unless otherwise specified
Beginning Balance, Noncontrolling Interest at Dec. 31, 2013	$337,995	'	'	'	'	'	$211,412	$126,583
Beginning Balance, Parent at Dec. 31, 2013	10,507,201	50,000	3,605	8,561,500	2,047,258	-155,162	'	'
Common Share Issuance:	'	'	'	'	'	'	'	'
Conversion of OP Units held by Noncontrolling Interests into OP Units held by General Partner	'	'	1	1,429	'	'	-1,430	'
Exercise of share options	'	'	8	25,677	'	'	'	'
Stock Issued During Period, Value, Employee Stock Purchase Plan	'	'	'	2,218	'	'	'	'
Share-based employee compensation expense:	'	'	'	'	'	'	'	'
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition	'	'	2	6,981	'	'	'	'
Share options	'	'	'	5,330	'	'	'	'
ESPP discount	'	'	'	587	'	'	'	'
Payments for Repurchase of Common Stock	-1,777	'	'	-1,777	'	'	'	'
Supplemental Executive Retirement Plan (SERP)	'	'	'	4,212	'	'	'	'
Acquisition Noncontrolling Interests Partially Owned Properties	'	'	'	-2,308	'	'	'	-2,244
Change in market value	-80,615	'	'	-80,615	'	'	'	'
Adjustment for Noncontrolling Interests ownership in Operating Partnership	'	'	'	4,146	'	'	-4,146	'
Net income attributable to controlling interests	191,825	'	'	'	191,825	'	'	'
Common Share distributions	'	'	'	'	-361,279	'	'	'
Dividends, Preferred Stock, Cash	'	'	'	'	-2,072	'	'	'
Other comprehensive (loss) income b derivative instruments:	'	'	'	'	'	'	'	'
Unrealized holding (losses) arising during the period	-21,881	'	'	'	'	-21,881	'	'
Losses reclassified into earnings from other comprehensive income	-8,335	'	'	'	'	8,335	'	'
Currency translation adjustments arising during the period	1,718	'	'	'	'	1,718	'	'
Issuance of LTIP Units to Noncontrolling Interests	'	'	'	'	'	'	3	'
Equity Compensation associated with Noncontrolling Interests	'	'	'	'	'	'	10,319	'
Net (Income) Attributable to Noncontrolling Interest	7,535	'	'	'	'	'	7,535	1,092
Contributions by Noncontrolling Interests	5,684	'	'	'	'	'	'	5,684
Distributions to Noncontrolling Interests	'	'	'	'	'	'	-14,364	-5,272
Change in carrying value	'	'	'	'	'	'	3,709	'
Ending Balance, Noncontrolling Interest at Jun. 30, 2014	338,881	'	'	'	'	'	213,038	125,843
Ending Balance, Parent at Jun. 30, 2014	$10,289,738	$50,000	$3,616	$8,527,380	$1,875,732	($166,990)	'	'

CONSOLIDATED_STATEMENT_OF_CHAN1

CONSOLIDATED STATEMENT OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) (USD $)	Total	PREFERRED UNITS	General Partner [Member]	Limited Partner [Member]	Accumulated Other Comprehensive (Loss)	Partially Owned Properties [Member]
In Thousands, unless otherwise specified
Balance, beginning of year - Noncontrolling Interest at Dec. 31, 2013	'	'	'	'	'	$126,583
Balance, beginning of year at Dec. 31, 2013	'	50,000	10,612,363	211,412	-155,162	'
OP Unit Issuance:	'	'	'	'	'	'
Conversion of OP Units held by Limited Partners into OP Units held by General Partner	'	'	1,430	-1,430	'	'
Exercise of EQR share options	'	'	25,685	'	'	'
Stock Issued During Period, Value, Employee Stock Purchase Plan	'	'	2,218	'	'	'
Share-based employee compensation expense:	'	'	'	'	'	'
EQR restricted shares	'	'	6,983	'	'	'
EQR share options	'	'	5,330	'	'	'
EQR ESPP discount	'	'	587	'	'	'
Payments For Repurchase Of Op Units	'	'	-1,777	'	'	'
Net income available to Units - General Partner	'	'	189,753	'	'	'
OP Units - General Partner distributions	'	'	-361,279	'	'	'
Supplemental Executive Retirement Plan (SERP)	'	'	4,212	'	'	'
Acquisition Noncontrolling Interests Partially Owned Properties	'	'	-2,308	'	'	-2,244
Change in market value of Redeemable Limited Partners	'	'	-80,615	'	'	'
Adjustment for Limited Partners ownership in Operating Partnership	'	'	4,146	-4,146	'	'
Issuance of LTIP Units to Noncontrolling Interests	'	'	'	3	'	'
Equity compensation associated with Units - Limited Partners	'	'	'	10,319	'	'
Net Income (Loss) Allocated to Limited Partners	'	'	'	7,535	'	'
Net (income) attributable to Noncontrolling Interests b Partially Owned Properties	1,092	'	'	'	'	1,092
Units - Limited Partners distributions	'	'	'	-14,364	'	-5,272
Change in carrying value of Redeemable Limited Partners	'	'	'	3,709	'	'
Other comprehensive (loss) income b derivative instruments:	'	'	'	'	'	'
Unrealized holding (losses) arising during the period	-21,881	'	'	'	-21,881	'
Losses reclassified into earnings from other comprehensive income	-8,335	'	'	'	8,335	'
Currency translation adjustments arising during the period	1,718	'	'	'	1,718	'
Contributions by Noncontrolling Interests	5,684	'	'	'	'	5,684
Balance, end of period - Noncontrolling Interest at Jun. 30, 2014	'	'	'	'	'	125,843
Balance, end of period at Jun. 30, 2014	'	$50,000	$10,406,728	$213,038	($166,990)	'

Business

Business	6 Months Ended
	Jun. 30, 2014
Business [Abstract]	'
Business	'
	1	Business
	Equity Residential (“EQR”), a Maryland real estate investment trust (“REIT”) formed in March 1993, is an S&P 500 company focused on the acquisition, development and management of high quality apartment properties in top United States growth markets. ERP Operating Limited Partnership ("ERPOP"), an Illinois limited partnership, was formed in May 1993 to conduct the multifamily residential property business of Equity Residential. EQR has elected to be taxed as a REIT. References to the "Company," "we," "us" or "our" mean collectively EQR, ERPOP and those entities/subsidiaries owned or controlled by EQR and/or ERPOP. References to the "Operating Partnership" mean collectively ERPOP and those entities/subsidiaries owned or controlled by ERPOP. Unless otherwise indicated, the notes to consolidated financial statements apply to both the Company and the Operating Partnership.
	EQR is the general partner of, and as of June 30, 2014 owned an approximate 96.2% ownership interest in, ERPOP. All of the Company’s property ownership, development and related business operations are conducted through the Operating Partnership and EQR has no material assets or liabilities other than its investment in ERPOP. EQR issues public equity from time to time but does not have any indebtedness as all debt is incurred by the Operating Partnership. The Operating Partnership holds substantially all of the assets of the Company, including the Company’s ownership interests in its joint ventures. The Operating Partnership conducts the operations of the business and is structured as a partnership with no publicly traded equity.
	As of June 30, 2014, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 397 properties located in 12 states and the District of Columbia consisting of 111,491 apartment units. The ownership breakdown includes (table does not include various uncompleted development properties):
			Properties	Apartment
				Units
	Wholly Owned Properties		369	100,210
	Master-Leased Properties – Consolidated		3	853
	Partially Owned Properties – Consolidated		19	3,752
	Partially Owned Properties – Unconsolidated		4	1,669
	Military Housing		2	5,007
			397	111,491

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Summary of Significant Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	2	Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) and certain reclassifications considered necessary for a fair presentation have been included. Certain reclassifications have been made to the prior period financial statements in order to conform to the current year presentation. These reclassifications did not have an impact on net income previously reported. Operating results for the six months ended June 30, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014.
	In preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
	The balance sheets at December 31, 2013 have been derived from the audited financial statements at that date but do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.
	For further information, including definitions of capitalized terms not defined herein, refer to the consolidated financial statements and footnotes thereto included in the Company’s and the Operating Partnership's annual report on Form 10-K for the year ended December 31, 2013.
	Income and Other Taxes
	Due to the structure of EQR as a REIT and the nature of the operations of its operating properties, no provision for federal income taxes has been made at the EQR level. In addition, ERPOP generally is not liable for federal income taxes as the partners recognize their proportionate share of income or loss in their tax returns; therefore no provision for federal income taxes has been made at the ERPOP level. Historically, the Company has generally only incurred certain state and local income, excise and franchise taxes. The Company has elected Taxable REIT Subsidiary (“TRS”) status for certain of its corporate subsidiaries and as a result, these entities will incur both federal and state income taxes on any taxable income of such entities after consideration of any net operating losses.
	Deferred tax assets and liabilities applicable to the TRS are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. These assets and liabilities are measured using enacted tax rates for which the temporary differences are expected to be recovered or settled. The effects of changes in tax rates on deferred tax assets and liabilities are recognized in earnings in the period enacted. The Company’s deferred tax assets are generally the result of tax affected suspended interest deductions, net operating losses, differing depreciable lives on capitalized assets and the timing of expense recognition for certain accrued liabilities. As of June 30, 2014, the Company has recorded a deferred tax asset, which is fully offset by a valuation allowance due to the uncertainty in forecasting future TRS taxable income.
	Other
	The Company is the controlling partner in various consolidated partnerships owning 19 properties and 3,752 apartment units and various completed and uncompleted development properties having a noncontrolling interest book value of $125.8 million at June 30, 2014. The Company is required to make certain disclosures regarding noncontrolling interests in consolidated limited-life subsidiaries. Of the consolidated entities described above, the Company is the controlling partner in limited-life partnerships owning six properties having a noncontrolling interest deficit balance of $10.2 million. These six partnership agreements contain provisions that require the partnerships to be liquidated through the sale of their assets upon reaching a date specified in each respective partnership agreement. The Company, as controlling partner, has an obligation to cause the property owning partnerships to distribute the proceeds of liquidation to the Noncontrolling Interests in these Partially Owned Properties only to the extent that the net proceeds received by the partnerships from the sale of their assets warrant a distribution based on the partnership agreements. As of June 30, 2014, the Company estimates the value of Noncontrolling Interest distributions for these six properties would have been approximately $53.2 million (“Settlement Value”) had the partnerships been liquidated. This Settlement Value is based on estimated third party consideration realized by the partnerships upon disposition of the six Partially Owned Properties and is net of all other assets and liabilities, including yield maintenance on the mortgages encumbering the properties, that would have been due on June 30, 2014 had those mortgages been prepaid. Due to, among other things, the inherent uncertainty in the sale of real estate assets, the amount of any potential distribution to the Noncontrolling Interests in the Company's Partially Owned Properties is subject to change. To the extent that the partnerships' underlying assets are worth less than the underlying liabilities, the Company has no obligation to remit any consideration to the Noncontrolling Interests in these Partially Owned Properties.
	Effective January 1, 2013, companies are required to report, in one place, information about reclassifications out of accumulated other comprehensive income ("AOCI"). Companies are also required to report changes in AOCI balances. For significant items reclassified out of AOCI to net income in their entirety in the same reporting period, reporting is required about the effect of the reclassifications on the respective line items in the statement where net income is presented. For items that are not reclassified to net income in their entirety in the same reporting period, a cross reference to other disclosures currently required under US GAAP is required in the notes. This does not have a material effect on the Company's consolidated results of operations or financial position. See Note 9 for further discussion.
	Effective January 1, 2014, companies are required to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date as the sum of the amount a company agreed to pay on the basis of its arrangement among its co-obligors and any additional amount a company expects to pay on behalf of its co-obligors. Companies are required to disclose the nature and amount of the obligation as well as other information about those obligations. This does not have a material effect on the Company's consolidated results of operations or financial position.
	In April 2014, the Financial Accounting Standards Board (the "FASB") issued new guidance for reporting discontinued operations. Only disposals representing a strategic shift in operations that has a major effect on a company’s operations and financial results will be presented as discontinued operations. Companies will be required to expand their disclosures about discontinued operations to provide more information on the assets, liabilities, income and expenses of the discontinued operations. Companies will also be required to disclose the pre-tax income attributable to a disposal of a significant part of a company that does not qualify for discontinued operations reporting. Application of this guidance is prospective from the date of adoption and early adoption is permitted, but only for disposals (or classifications as held for sale) that have not been reported in financial statements previously issued. The new standard is effective January 1, 2015 but the Company early adopted it as allowed effective January 1, 2014. Adoption of this standard did not have a material effect on the Company's overall consolidated results of operations or financial position. However, adoption will result in substantially fewer of the Company's dispositions meeting the discontinued operations qualifications. See Note 11 for further discussion.
	In May 2014, the FASB issued a comprehensive new revenue recognition standard entitled Revenue from Contracts with Customers that will supersede nearly all existing revenue recognition guidance. The new standard specifically excludes lease contracts. The new standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. Companies will likely need to use more judgment and make more estimates than under current revenue recognition guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration, if any, to include in the transaction price and allocating the transaction price to each separate performance obligation. The new standard will be effective for the Company beginning on January 1, 2017 and early adoption is not permitted. The new standard may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of adoption. The Company has not yet selected a transition method and is currently evaluating the impact of adopting the new standard on its consolidated results of operations and financial position.

Equity_Capital_and_Other_Inter

Equity, Capital and Other Interests	6 Months Ended
	Jun. 30, 2014
Equity, Capital and other Interests [Abstract]	'
Equity Capital And Other Interests [Text Block]	'
	3	Equity, Capital and Other Interests
	Equity and Redeemable Noncontrolling Interests of Equity Residential
	The following tables present the changes in the Company’s issued and outstanding Common Shares and “Units” (which includes OP Units and Long-Term Incentive Plan (“LTIP”) Units) for the six months ended June 30, 2014:
			2014
	Common Shares
	Common Shares outstanding at January 1,		360,479,260
	Common Shares Issued:
	Conversion of OP Units		56,536
	Exercise of share options		851,514
	Employee Share Purchase Plan (ESPP)		47,457
	Restricted share grants, net		170,626
	Common Shares Other:
	Conversion of restricted shares to LTIP Units		(12,146	)
	Repurchased and retired		(31,240	)
	Common Shares outstanding at June 30,		361,562,007
	Units
	Units outstanding at January 1,		14,180,376
	LTIP Units, net		200,840
	Conversion of restricted shares to LTIP Units		12,146
	Conversion of OP Units to Common Shares		(56,536	)
	Units outstanding at June 30,		14,336,826
	Total Common Shares and Units outstanding at June 30,		375,898,833
	Units Ownership Interest in Operating Partnership		3.8	%
	The equity positions of various individuals and entities that contributed their properties to the Operating Partnership in exchange for OP Units, as well as the equity positions of the holders of LTIP Units, are collectively referred to as the “Noncontrolling Interests – Operating Partnership”. Subject to certain exceptions (including the “book-up” requirements of LTIP Units), the Noncontrolling Interests – Operating Partnership may exchange their Units with EQR for Common Shares on a one-for-one basis. The carrying value of the Noncontrolling Interests – Operating Partnership (including redeemable interests) is allocated based on the number of Noncontrolling Interests – Operating Partnership Units in total in proportion to the number of Noncontrolling Interests – Operating Partnership Units in total plus the number of Common Shares. Net income is allocated to the Noncontrolling Interests – Operating Partnership based on the weighted average ownership percentage during the period.
	The Operating Partnership has the right but not the obligation to make a cash payment instead of issuing Common Shares to any and all holders of Noncontrolling Interests – Operating Partnership Units requesting an exchange of their OP Units with EQR. Once the Operating Partnership elects not to redeem the Noncontrolling Interests – Operating Partnership Units for cash, EQR is obligated to deliver Common Shares to the exchanging holder of the Noncontrolling Interests – Operating Partnership Units.
	The Noncontrolling Interests – Operating Partnership Units are classified as either mezzanine equity or permanent equity. If EQR is required, either by contract or securities law, to deliver registered Common Shares, such Noncontrolling Interests – Operating Partnership are differentiated and referred to as “Redeemable Noncontrolling Interests – Operating Partnership”. Instruments that require settlement in registered shares can not be classified in permanent equity as it is not always completely within an issuer’s control to deliver registered shares. Therefore, settlement in cash is assumed and that responsibility for settlement in cash is deemed to fall to the Operating Partnership as the primary source of cash for EQR, resulting in presentation in the mezzanine section of the balance sheet. The Redeemable Noncontrolling Interests – Operating Partnership are adjusted to the greater of carrying value or fair market value based on the Common Share price of EQR at the end of each respective reporting period. EQR has the ability to deliver unregistered Common Shares for the remaining portion of the Noncontrolling Interests – Operating Partnership Units that are classified in permanent equity at June 30, 2014 and December 31, 2013.
	The carrying value of the Redeemable Noncontrolling Interests – Operating Partnership is allocated based on the number of Redeemable Noncontrolling Interests – Operating Partnership Units in proportion to the number of Noncontrolling Interests – Operating Partnership Units in total. Such percentage of the total carrying value of Units which is ascribed to the Redeemable Noncontrolling Interests – Operating Partnership is then adjusted to the greater of carrying value or fair market value as described above. As of June 30, 2014, the Redeemable Noncontrolling Interests – Operating Partnership have a redemption value of approximately $440.1 million, which represents the value of Common Shares that would be issued in exchange with the Redeemable Noncontrolling Interests – Operating Partnership Units.
	The following table presents the changes in the redemption value of the Redeemable Noncontrolling Interests – Operating Partnership for the six months ended June 30, 2014 (amounts in thousands):
			2014
	Balance at January 1,		$	363,144
	Change in market value		80,615
	Change in carrying value		(3,709		)
	Balance at June 30,		$	440,050
	Net proceeds from EQR Common Share and Preferred Share (see definition below) offerings are contributed by EQR to ERPOP. In return for those contributions, EQR receives a number of OP Units in ERPOP equal to the number of Common Shares it has issued in the equity offering (or in the case of a preferred equity offering, a number of preference units in ERPOP equal in number and having the same terms as the Preferred Shares issued in the equity offering). As a result, the net offering proceeds from Common Shares and Preferred Shares are allocated between shareholders’ equity and Noncontrolling Interests – Operating Partnership to account for the change in their respective percentage ownership of the underlying equity of ERPOP.
	The Company’s declaration of trust authorizes it to issue up to 100,000,000 preferred shares of beneficial interest, $0.01 par value per share (the “Preferred Shares”), with specific rights, preferences and other attributes as the Board of Trustees may determine, which may include preferences, powers and rights that are senior to the rights of holders of the Company’s Common Shares.
	The following table presents the Company’s issued and outstanding Preferred Shares as of June 30, 2014 and December 31, 2013:
							Amounts in thousands
			Redemption		Annual		June 30,		December 31,
			Date (1)		Dividend per		2014		2013
					Share (2)
	Preferred Shares of beneficial interest, $0.01 par value;
	100,000,000 shares authorized:
	8.29% Series K Cumulative Redeemable Preferred; liquidation		12/10/26			$4.14	$	50,000	$	50,000
	value $50 per share; 1,000,000 shares issued and outstanding
	at June 30, 2014 and December 31, 2013
							$	50,000	$	50,000
	-1	On or after the redemption date, redeemable preferred shares may be redeemed for cash at the option of the Company, in whole or
	in part, at a redemption price equal to the liquidation price per share, plus accrued and unpaid distributions, if any.
	-2	Dividends on Preferred Shares are payable quarterly.
	Capital and Redeemable Limited Partners of ERP Operating Limited Partnership
	The following tables present the changes in the Operating Partnership’s issued and outstanding Units and in the limited partners’ Units for the six months ended June 30, 2014:
			2014
	General and Limited Partner Units
	General and Limited Partner Units outstanding at January 1,		374,659,636
	Issued to General Partner:
	Exercise of EQR share options		851,514
	EQR’s Employee Share Purchase Plan (ESPP)		47,457
	EQR's restricted share grants, net		170,626
	Issued to Limited Partners:
	LTIP Units, net		200,840
	OP Units Other:
	Repurchased and retired		(31,240	)
	General and Limited Partner Units outstanding at June 30,		375,898,833
Limited Partner Units
Limited Partner Units outstanding at January 1,		14,180,376
Limited Partner LTIP Units, net		200,840
Conversion of EQR restricted shares to LTIP Units		12,146
Conversion of Limited Partner OP Units to EQR Common Shares		(56,536	)
Limited Partner Units outstanding at June 30,		14,336,826
Limited Partner Units Ownership Interest in Operating Partnership		3.8	%
The Limited Partners of the Operating Partnership as of June 30, 2014 include various individuals and entities that contributed their properties to the Operating Partnership in exchange for OP Units, as well as the equity positions of the holders of LTIP Units. Subject to certain exceptions (including the “book-up” requirements of LTIP Units), Limited Partners may exchange their Units with EQR for Common Shares on a one-for-one basis. The carrying value of the Limited Partner Units (including redeemable interests) is allocated based on the number of Limited Partner Units in total in proportion to the number of Limited Partner Units in total plus the number of General Partner Units. Net income is allocated to the Limited Partner Units based on the weighted average ownership percentage during the period.
The Operating Partnership has the right but not the obligation to make a cash payment instead of issuing Common Shares to any and all holders of Limited Partner Units requesting an exchange of their OP Units with EQR. Once the Operating Partnership elects not to redeem the Limited Partner Units for cash, EQR is obligated to deliver Common Shares to the exchanging limited partner.
The Limited Partner Units are classified as either mezzanine equity or permanent equity. If EQR is required, either by contract or securities law, to deliver registered Common Shares, such Limited Partner Units are differentiated and referred to as “Redeemable Limited Partner Units”. Instruments that require settlement in registered shares can not be classified in permanent equity as it is not always completely within an issuer's control to deliver registered shares. Therefore, settlement in cash is assumed and that responsibility for settlement in cash is deemed to fall to the Operating Partnership as the primary source of cash for EQR, resulting in presentation in the mezzanine section of the balance sheet. The Redeemable Limited Partner Units are adjusted to the greater of carrying value or fair market value based on the Common Share price of EQR at the end of each respective reporting period. EQR has the ability to deliver unregistered Common Shares for the remaining portion of the Limited Partner Units that are classified in permanent equity at June 30, 2014 and December 31, 2013.
The carrying value of the Redeemable Limited Partner Units is allocated based on the number of Redeemable Limited Partner Units in proportion to the number of Limited Partner Units in total. Such percentage of the total carrying value of Limited Partner Units which is ascribed to the Redeemable Limited Partner Units is then adjusted to the greater of carrying value or fair market value as described above. As of June 30, 2014, the Redeemable Limited Partner Units have a redemption value of approximately $440.1 million, which represents the value of Common Shares that would be issued in exchange with the Redeemable Limited Partner Units.
The following table presents the changes in the redemption value of the Redeemable Limited Partners for the six months ended June 30, 2014 (amounts in thousands):
		2014
Balance at January 1,		$	363,144
Change in market value		80,615
Change in carrying value		(3,709		)
Balance at June 30,		$	440,050
EQR contributes all net proceeds from its various equity offerings (including proceeds from exercise of options for Common Shares) to ERPOP. In return for those contributions, EQR receives a number of OP Units in ERPOP equal to the number of Common Shares it has issued in the equity offering (or in the case of a preferred equity offering, a number of preference units in ERPOP equal in number and having the same terms as the preferred shares issued in the equity offering).
The following table presents the Operating Partnership’s issued and outstanding “Preference Units” as of June 30, 2014 and December 31, 2013:
						Amounts in thousands
		Redemption		Annual		June 30,		December 31,
		Date (1)		Dividend per		2014		2013
				Unit (2)
Preference Units:
8.29% Series K Cumulative Redeemable Preference Units;		12/10/26			$4.14	$	50,000	$	50,000
liquidation value $50 per unit; 1,000,000 units issued and
outstanding at June 30, 2014 and December 31, 2013
						$	50,000	$	50,000
-1	On or after the redemption date, redeemable preference units may be redeemed for cash at the option of the Operating Partnership, in whole or in part, at a redemption price equal to the liquidation price per unit, plus accrued and unpaid distributions, if any, in conjunction with the concurrent redemption of the corresponding Company Preferred Shares.
-2	Dividends on Preference Units are payable quarterly.
Other
On February 27, 2013, the Company issued 34,468,085 Common Shares to an affiliate of Lehman Brothers Holdings Inc. as partial consideration for the portion of the Archstone Portfolio acquired by the Company (as discussed in Note 4 below). The shares had a total value of $1.9 billion based on the February 27, 2013 closing price of EQR Common Shares of $55.99 per share. Concurrent with this transaction, ERPOP issued 34,468,085 OP Units to EQR. On March 7, 2013, EQR filed a shelf registration statement relating to the resale of these shares by the selling shareholders.
In September 2009, the Company announced the establishment of an At-The-Market (“ATM”) share offering program which would allow EQR to sell Common Shares from time to time into the existing trading market at current market prices as well as through negotiated transactions. Per the terms of ERPOP's partnership agreement, EQR contributes the net proceeds from all equity offerings to the capital of ERPOP in exchange for additional OP Units (on a one-for-one Common Share per OP Unit basis). On July 30, 2013, the Board of Trustees approved an increase to the amount of shares which may be offered under the ATM program to 13.0 million Common Shares and extended the program maturity to July 2016. EQR has not issued any shares under this program since September 14, 2012.
Effective July 30, 2013, the Board of Trustees approved an increase and modification to the Company's share repurchase program to allow for the potential repurchase of up to 13.0 million Common Shares. Considering the repurchase activity for the six months ended June 30, 2014 (see discussion below), EQR has remaining authorization to repurchase an additional 12,968,760 of its shares as of June 30, 2014.
During the six months ended June 30, 2014, EQR repurchased 31,240 of its Common Shares at a price of $56.87 per share for total consideration of approximately $1.8 million. These shares were retired subsequent to the repurchases. Concurrent with these transactions, ERPOP repurchased and retired 31,240 OP Units previously issued to EQR. All of the shares repurchased during the six months ended June 30, 2014 were repurchased from employees at the then current market price to cover the minimum statutory tax withholding obligations related to the vesting of employees’ restricted shares.
During the six months ended June 30, 2014, the Company acquired all of its partners' interests in one consolidated partially owned property consisting of 268 apartment units and one consolidated partially owned land parcel for $5.5 million. In conjunction with these transactions, the Company reduced paid in capital (included in general partner's capital in the Operating Partnership's financial statements) by $2.3 million, Noncontrolling Interests – Partially Owned Properties by $2.2 million and other liabilities by $1.0 million.
See Note 6 for a discussion of the Noncontrolling Interests assumed in conjunction with the acquisition of Archstone.

Real_Estate

Real Estate	6 Months Ended
	Jun. 30, 2014
Real Estate [Abstract]	'
Real Estate Disclosure [Text Block]	'
	4	Real Estate and Lease Intangibles
	The following table summarizes the carrying amounts for the Company’s investment in real estate (at cost) as of June 30, 2014 and December 31, 2013 (amounts in thousands):
			June 30,				December 31,
			2014				2013
	Land		$	6,296,735			$	6,192,512
	Depreciable property:
	Buildings and improvements		17,920,222				17,509,609
	Furniture, fixtures and equipment		1,302,882				1,214,220
	In-Place lease intangibles		507,633				502,218
	Projects under development:
	Land		391,156				353,574
	Construction-in-progress		615,836				635,293
	Land held for development:
	Land		256,536				341,389
	Construction-in-progress		50,089				52,133
	Investment in real estate		27,341,089				26,800,948
	Accumulated depreciation		(5,170,438		)		(4,807,709		)
	Investment in real estate, net		$	22,170,651			$	21,993,239
	The following table summarizes the carrying amounts for the Company's above and below market ground and retail lease intangibles as of June 30, 2014 and December 31, 2013 (amounts in thousands):
	Description		Balance Sheet Location		June 30,				December 31,
					2014				2013
	Assets
	Ground lease intangibles – below market		Other Assets		$	178,251			$	178,251
	Retail lease intangibles – above market		Other Assets		1,260				1,260
	Lease intangible assets				179,511				179,511
	Accumulated amortization				(6,641		)		(4,364		)
	Lease intangible assets, net				$	172,870			$	175,147
	Liabilities
	Ground lease intangibles – above market		Other Liabilities		$	2,400			$	2,400
	Retail lease intangibles – below market		Other Liabilities		5,270				5,500
	Lease intangible liabilities				7,670				7,900
	Accumulated amortization				(1,678		)		(1,161		)
	Lease intangible liabilities, net				$	5,992			$	6,739
	During the six months ended June 30, 2014 and 2013, the Company amortized approximately $2.2 million and $1.4 million, respectively, of above and below market ground lease intangibles which is included (net increase) in property and maintenance expense in the accompanying consolidated statements of operations and comprehensive income and approximately $0.6 million and $0.2 million, respectively, of above and below market retail lease intangibles which is included (net increase) in rental income in the accompanying consolidated statements of operations and comprehensive income. During the quarters ended June 30, 2014 and 2013, the Company amortized approximately $1.1 million and $1.0 million, respectively, of above and below market ground lease intangibles which is included (net increase) in property and maintenance expense in the accompanying consolidated statements of operations and comprehensive income and approximately $0.3 million and $0.1 million, respectively, of above and below market retail lease intangibles which is included (net increase) in rental income in the accompanying consolidated statements of operations and comprehensive income.
	The weighted average amortization period for above and below market ground lease intangibles and retail lease intangibles is 49.8 years and 2.8 years, respectively.
	The following table provides a summary of the aggregate amortization expense for above and below market ground lease intangibles and retail lease intangibles for each of the next five years (amounts in thousands):
			Remaining
			2014				2015				2016			2017			2018			2019
	Ground lease intangibles		$	2,161			$	4,321			$	4,321		$	4,321		$	4,321		$	4,321
	Retail lease intangibles		(469		)		(939		)		(896		)	(540		)	(71		)	(71		)
	Total		$	1,692			$	3,382			$	3,425		$	3,781		$	4,250		$	4,250
	Archstone Acquisition
	On February 27, 2013, the Company, AvalonBay Communities, Inc. (“AVB”) and certain of their respective subsidiaries completed their previously announced acquisition (the “Archstone Acquisition” or the “Archstone Transaction”) from Archstone Enterprise LP (“Enterprise”) (which subsequently changed its name to Jupiter Enterprise LP), an affiliate of Lehman Brothers Holdings Inc. (“Lehman”) and its affiliates, of all of the assets of Enterprise (including interests in various entities affiliated with Enterprise), constituting a portfolio of apartment properties and other assets (the “Archstone Portfolio”).
	The Company acquired assets representing approximately 60% of the Archstone Portfolio which consisted principally of high-quality apartment properties in major markets in the United States. The acquisition allowed the Company to accelerate the completion of its strategic shift into coastal apartment markets. Pursuant to the Archstone Transaction, the Company acquired directly or indirectly, 71 wholly owned, stabilized properties consisting of 20,160 apartment units, one partially owned and consolidated stabilized property consisting of 432 apartment units, one partially owned and unconsolidated stabilized property consisting of 336 apartment units, three consolidated master-leased properties consisting of 853 apartment units, four projects in various stages of construction (two consolidated and two unconsolidated) for 964 apartment units and fourteen land sites for approximately $9.0 billion. During the six months ended June 30, 2013, the Company recorded revenues and net operating income ("NOI") of $204.5 million and $140.0 million, respectively, from the acquired assets. During the quarter ended June 30, 2013, the Company recorded revenues and NOI of $151.9 million and $103.9 million, respectively, from the acquired assets.
	The consideration paid by the Company in connection with the Archstone Acquisition consisted of cash of approximately $4.0 billion (inclusive of $2.0 billion of Archstone secured mortgage principal paid off in conjunction with the closing), 34,468,085 Common Shares (which shares had a total value of $1.9 billion based on the February 27, 2013 closing price of EQR common shares of $55.99 per share) issued to the seller and the assumption of approximately $3.1 billion of mortgage debt (inclusive of a net mark-to-market premium of $127.9 million) and approximately 60% of all of the other assets and liabilities related to the Archstone Portfolio. The cash consideration was funded with proceeds from the issuance of 21,850,000 Common Shares (which shares had a total value of approximately $1.2 billion based on a price of $54.75 per share) in the November/December 2012 public equity offering, asset sales of approximately $4.5 billion that were completed during the year ended December 31, 2013, the Company's $750.0 million unsecured term loan facility (which was subsequently paid off in the second quarter of 2014) and the Company's revolving credit facility.
	The Company owns the building and improvements and leases the land underlying the improvements under long-term ground leases that expire beginning in 2042 and running through 2103 for nine of the operating properties acquired and discussed above. These properties are consolidated and reflected as real estate assets while the ground leases are accounted for as operating leases. The Company also leases the three master-leased properties discussed above to third party operators and earns monthly net rental income.
	The Company accounted for the acquisition under the acquisition method in accordance with Accounting Standards Codification ("ASC") 805, Business Combinations (“ASC 805”), and the accounting for this business combination is complete and final. The following table summarizes the acquisition date fair values of the assets acquired and liabilities assumed, which the Company determined using Level 1, Level 2 and Level 3 inputs (amounts in thousands):
	Land		$	2,239,000
	Depreciable property:
	Buildings and improvements		5,765,538
	Furniture, fixtures and equipment		61,470
	In-Place lease intangibles		304,830
	Projects under development		36,583
	Land held for development		244,097
	Investments in unconsolidated entities		230,608
	Other assets		195,260
	Other liabilities		(108,997		)
	Net assets acquired		$	8,968,389
	The allocation of fair values of the assets acquired and liabilities assumed has changed from the allocation reported in “Note 4 – Real Estate and Lease Intangibles” in the Notes to Consolidated Financial Statements included in Part II of our Annual Report on Form 10-K for the year ended December 31, 2013 filed with the SEC on February 27, 2014. The changes to our valuation assumptions were based on more accurate information concerning the subject assets and liabilities and resulted from information not readily available at the acquisition date, final purchase price settlement with our partner in accordance with the terms of the purchase agreement and reclassification adjustments for presentation. None of these changes had a material impact on our Consolidated Financial Statements. The Company's assessment of the fair values and the allocation of the purchase price to the identified tangible and intangible assets/liabilities at March 31, 2014 was its final and best estimate of fair value. As a result, the Company did not make any changes to its allocation of fair values of the assets acquired and liabilities assumed subsequent to the allocation reported in "Note 4 – Real Estate and Lease Intangibles" in the Notes to Consolidated Financial Statements included in Part I of our Quarterly Report on Form 10-Q for the quarter ended March 31, 2014 filed with the SEC on May 8, 2014.
	The fair values of investment in real estate were determined using internally developed models that were based on market assumptions and comparable sales data as well as external valuations performed by unrelated third parties. The market assumptions used as inputs to the Company’s fair value model include construction costs, leasing assumptions, growth rates, discount rates, terminal capitalization rates and development yields. The Company used data on its existing portfolio of properties and its recent acquisition and development properties, as well as similar market data from third party sources, when available, in determining these inputs (Level 2 and 3). The fair value of Noncontrolling Interests was calculated similar to the investment in real estate described above. The fair value of mortgage debt was calculated using indicative rates, leverage and coverage provided by lenders of similar loans (Level 2). The Common Shares issued to an affiliate of Lehman Brothers Holdings Inc. were valued using the quoted market price of Common Shares (Level 1).
	The following table summarizes the acquisition date fair values of the above and below market ground and retail lease intangibles, which we determined using Level 2 and Level 3 inputs (amounts in thousands):
	Description		Balance Sheet Location		Fair Value
	Ground lease intangibles – below market		Other Assets		$	178,251
Retail lease intangibles – above market		Other Assets		1,260
Ground lease intangibles – above market		Other Liabilities		2,400
Retail lease intangibles – below market		Other Liabilities		8,040
As of June 30, 2014, the Company has incurred cumulative Archstone-related expenses of approximately $100.9 million, of which approximately $13.5 million of this total was financing-related and approximately $87.4 million was merger costs. During the six months ended June 30, 2014, the Company expensed nominal amounts of direct merger costs. During the six months ended June 30, 2013, the Company expensed $19.6 million of direct merger costs primarily related to investment banking and legal/accounting fees, which were included in other expenses in the accompanying consolidated statements of operations and comprehensive income. During the six months ended June 30, 2014 and 2013, the Company also expensed $6.2 million and $53.0 million, respectively, of indirect merger costs primarily related to severance and retention obligations, office leases and German operations/sales that were incurred through our 60% interest in unconsolidated joint ventures with AVB, which were included in (loss) from investments in unconsolidated entities in the accompanying consolidated statements of operations and comprehensive income. Finally, during the six months ended June 30, 2013, the Company also expensed $2.5 million of financing-related costs, which were included in interest expense in the accompanying consolidated statements of operations and comprehensive income.
Unaudited Pro Forma Financial Information
Equity Residential
The following table illustrates the effect on net income, earnings per share – basic and earnings per share – diluted as if the Company had consummated the Archstone Acquisition as of January 1, 2012 (amounts in thousands, except per share amounts):
		Six Months Ended				Quarter Ended
		30-Jun-13				30-Jun-13
Total revenues		$	1,256,088			$	635,078
Income from continuing operations		60,541				96,585
Discontinued operations, net		1,608,374				389,329
Net income		1,668,915				485,914
Net income available to Common Shares		1,601,368				467,237
Earnings per share - basic:
Net income available to Common Shares		$	4.45			$	1.3
Weighted average Common Shares outstanding (1)		359,509				359,653
Earnings per share - diluted:
Net income available to Common Shares		$	4.44			$	1.29
Weighted average Common Shares outstanding (1)		375,722				375,910
-1	Includes an adjustment for Common Shares issued to the public in November/December 2012 and to an affiliate of Lehman Brothers Holdings Inc. in February 2013 as partial consideration for the Archstone Acquisition.
ERP Operating Limited Partnership
The following table illustrates the effect on net income, earnings per Unit – basic and earnings per Unit – diluted as if the Operating Partnership had consummated the Archstone Acquisition as of January 1, 2012 (amounts in thousands, except per Unit amounts):
		Six Months Ended				Quarter Ended
		30-Jun-13				30-Jun-13
Total revenues		$	1,256,088			$	635,078
Income from continuing operations		60,541				96,585
Discontinued operations, net		1,608,374				389,329
Net income		1,668,915				485,914
Net income available to Units		1,668,439				485,693
Earnings per Unit - basic:
Net income available to Units		$	4.45			$	1.3
Weighted average Units outstanding (1)		373,245				373,403
Earnings per Unit - diluted:
Net income available to Units		$	4.44			$	1.29
Weighted average Units outstanding (1)		375,722				375,910
-1	Includes an adjustment for Common Shares issued to the public in November/December 2012 and to an affiliate of Lehman Brothers Holdings Inc. in February 2013 as partial consideration for the Archstone Acquisition. Concurrent with these transactions, ERPOP issued the same number of OP Units to EQR.
For the six months ended June 30, 2013, acquisition costs of $19.6 million and severance/retention and other costs of $50.9 million related to the Archstone Acquisition are not expected to have a continuing impact on the Company's financial results and therefore have been excluded from these pro forma results. The pro forma results also do not include the impact of any synergies or lower borrowing costs that the Company has or may achieve as a result of the acquisition or any strategies that management has or may consider in order to more efficiently manage the Company's operations, nor do they give pro forma effect to any other acquisitions, dispositions or capital markets transactions (excluding the equity offering in November/December 2012 which proceeds were used for the Archstone Acquisition) that the Company completed during the periods presented. These pro forma results are not necessarily indicative of the operating results that would have been obtained had the Archstone Acquisition occurred at the beginning of the periods presented, nor are they necessarily indicative of future operating results.
Other
During the six months ended June 30, 2014, the Company acquired the entire equity interest in the following from unaffiliated parties (purchase price in thousands):
		Properties			Apartment Units			Purchase Price
Rental Properties – Consolidated		3			772			$	249,610
Land Parcels – Consolidated		—			—			15,790
Total		3			772			$	265,400
During the six months ended June 30, 2014, the Company disposed of the following to unaffiliated parties (sales price in thousands):
		Properties			Apartment Units			Sales Price
Rental Properties		1			336			$	40,850
Land Parcel		—			—			8,200
Total		1			336			$	49,050
The Company recognized a net gain on sales of real estate properties of approximately $14.9 million and a net gain on sales of land parcels of approximately $0.8 million on the above sales.

Commitments_to_AcquireDispose_

Commitments to Acquire/Dispose of Real Estate	6 Months Ended
	Jun. 30, 2014
Commitments to Acquire Dispose of Real Estate [Abstract]	'
Commitments To Acquire Dispose Of Real Estate Text Block	'
	5	Commitments to Acquire/Dispose of Real Estate
	In addition to the land parcel that was subsequently acquired as discussed in Note 14, the Company has entered into a separate agreement to acquire the following (purchase price in thousands):
			Properties	Apartment Units	Purchase Price
	Land Parcel		—	—	$	3,300
	Total		—	—	$	3,300
	The Company has entered into separate agreements to dispose of the following (sales price in thousands):
			Properties	Apartment Units	Sales Price
	Rental Properties		6	2,005	$	306,350
	Land Parcel		—	—	54,402
	Total		6	2,005	$	360,752
	The closings of these pending transactions are subject to certain conditions and restrictions, therefore, there can be no assurance that these transactions will be consummated or that the final terms will not differ in material respects from those summarized in the preceding paragraphs.

Investments_in_Partially_Owned

Investments in Partially Owned Entities	6 Months Ended
	Jun. 30, 2014
Investments in Partially Owned Entities [Abstract]	'
Investments in Partially Owned Entities	'
	6	Investments in Partially Owned Entities
	The Company has co-invested in various properties with unrelated third parties which are either consolidated or accounted for under the equity method of accounting (unconsolidated). The following tables and information summarize the Company’s investments in partially owned entities as of June 30, 2014 (amounts in thousands except for project and apartment unit amounts):
		Consolidated									Unconsolidated
		Development Projects									Development Projects
		Held for			Operating			Total			Held for			Completed, Not Stabilized (3)			Operating			Total
		and/or Under									and/or Under
		Development									Development
	Total projects (1)	—			19			19			—			2			2			4
	Total apartment units (1)	—			3,752			3,752			—			945			724			1,669
	Balance sheet information at 6/30/14 (at 100%):
	ASSETS
	Investment in real estate	$	329,668		$	676,848		$	1,006,516		$	55,998		$	233,411		$	108,164		$	397,573
	Accumulated depreciation	—			(183,571		)	(183,571		)	—			(6,693		)	(7,136		)	(13,829		)
	Investment in real estate, net	329,668			493,277			822,945			55,998			226,718			101,028			383,744
	Cash and cash equivalents	4,488			14,125			18,613			454			2,830			1,582			4,866
	Investments in unconsolidated entities	—			53,209			53,209			—			—			—			—
	Deposits – restricted	34,761			250			35,011			—			130			47			177
	Deferred financing costs, net	—			2,318			2,318			53			4			122			179
	Other assets	6,679			26,176			32,855			14			41			1,250			1,305
	Total assets	$	375,596		$	589,355		$	964,951		$	56,519		$	229,723		$	104,029		$	390,271
	LIABILITIES AND EQUITY/CAPITAL
	Mortgage notes payable (2)	$	—		$	360,305		$	360,305		$	21,982		$	145,016		$	63,305		$	230,303
	Accounts payable & accrued expenses	12,313			1,730			14,043			5,095			955			350			6,400
	Accrued interest payable	—			1,265			1,265			43			687			42			772
	Other liabilities	140			1,252			1,392			—			244			1,046			1,290
	Security deposits	—			1,916			1,916			—			279			140			419
	Total liabilities	12,453			366,468			378,921			27,120			147,181			64,883			239,184
	Noncontrolling Interests – Partially Owned	117,677			8,166			125,843			27,858			70,428			23,434			121,720
	Properties/Partners' equity
	Company equity/General and Limited Partners'	245,466			214,721			460,187			1,541			12,114			15,712			29,367
	Capital
	Total equity/capital	363,143			222,887			586,030			29,399			82,542			39,146			151,087
	Total liabilities and equity/capital	$	375,596		$	589,355		$	964,951		$	56,519		$	229,723		$	104,029		$	390,271
		Consolidated									Unconsolidated
		Development Projects									Development Projects
		Held for									Held for						Operating
		and/or Under									and/or Under			Completed, Not Stabilized (3)
		Development			Operating			Total			Development									Total
	Operating information for the six months
	ended 6/30/14 (at 100%):
	Operating revenue	$	—		$	43,110		$	43,110		$	—		$	7,958		$	5,060		$	13,018
	Operating expenses	154			12,825			12,979			132			3,287			1,856			5,275
	Net operating (loss) income	(154		)	30,285			30,131			(132		)	4,671			3,204			7,743
	Depreciation	—			10,768			10,768			—			5,299			2,039			7,338
	General and administrative/other	(3		)	26			23			—			1			122			123
	Operating (loss) income	(151		)	19,491			19,340			(132		)	(629		)	1,043			282
	Interest and other income	—			3			3			—			—			—			—
	Other expenses	(76		)	(32		)	(108		)	—			—			—			—
	Interest:
	Expense incurred, net	—			(7,788		)	(7,788		)	—			(3,864		)	(926		)	(4,790		)
	Amortization of deferred financing costs	—			(177		)	(177		)	—			—			(7		)	(7		)
	(Loss) income before income and other taxes	(227		)	11,497			11,270			(132		)	(4,493		)	110			(4,515		)
	and (loss) from investments in
	unconsolidated entities
	Income and other tax (expense) benefit	—			(45		)	(45		)	—			(7		)	—			(7		)
	(Loss) from investments in unconsolidated	—			(879		)	(879		)	—			—			—			—
	entities
	Net (loss) income	$	(227	)	$	10,573		$	10,346		$	(132	)	$	(4,500	)	$	110		$	(4,522	)
	-1	Project and apartment unit counts exclude all uncompleted development projects until those projects are substantially completed.
	-2	All debt is non-recourse to the Company with the exception of 50% of the current $22.0 million outstanding debt balance on one unconsolidated development project.
	-3	Projects included here are substantially complete. However, they may still require additional exterior and interior work for all units to be available for leasing.
	Note:	The above tables exclude the Company's interests in unconsolidated joint ventures entered into with AVB in connection with the Archstone Transaction. These ventures own certain non-core Archstone assets that are held for sale and succeeded to certain residual Archstone liabilities, such as liability for various employment-related matters as well as responsibility for tax protection arrangements and third-party preferred interests in former Archstone subsidiaries. The preferred interests have an aggregate liquidation value of $76.8 million at June 30, 2014. The ventures are owned 60% by the Company and 40% by AVB.
	The Company is the controlling partner in various consolidated partnership properties and development properties having a noncontrolling interest book value of $125.8 million at June 30, 2014. The Company does not have any VIEs.
Archstone Acquisition
On February 27, 2013, in conjunction with the Archstone Acquisition, the Company acquired interests in several joint ventures. Details of these interests follow by project:
East Palmetto Park – This venture was formed to ultimately develop certain land parcels into a 377 unit apartment building located in Boca Raton, Florida. The Company has a 90% equity interest with an initial basis of $20.2 million. The Company is the managing member, is responsible for constructing the project and its partner does not have substantive kick-out or participating rights. As a result, the entity is required to be consolidated on the Company's balance sheet.
Wisconsin Place – This project contains a mixed-use site located in Chevy Chase, Maryland consisting of residential, retail, office and accessory uses, including underground parking facilities. The Company has a 75% equity interest with an initial basis of $198.5 million in the 432 unit residential component. The Company is the managing member, was responsible for constructing the residential project and its partner does not have substantive kick-out or participating rights. As a result, the entity that owns the residential component of this mixed-use site is required to be consolidated on the Company's balance sheet. Such entity also retains an unconsolidated interest in an entity that owns the land underlying the entire project and owns and operates the parking facility. The initial fair value of this investment is $56.5 million. The Company does not have any ownership interest in the retail and office components.
San Norterra – This venture developed certain land parcels into a 388 unit apartment building located in Phoenix, Arizona and was completed and stabilized during the quarter ended June 30, 2014. The Company has an 85% equity interest with an initial basis of $16.9 million. Total project costs were approximately $52.8 million and construction was partially funded with a construction loan that was guaranteed by the partner and non-recourse to the Company. The loan has a maximum debt commitment of $34.8 million and a current unconsolidated outstanding balance of $33.0 million; the loan bears interest at LIBOR plus 2.00% and matures January 6, 2015. The partner is the managing member and developed the project. The Company does not have substantive kick-out or participating rights. As a result, the entity is unconsolidated and recorded using the equity method of accounting.
Waterton Tenside – This venture was formed to develop and operate a 336 unit apartment property located in Atlanta, Georgia. The Company has a 20% equity interest with an initial basis of $5.1 million. The partner is the managing member and developed the project. The project is encumbered by a non-recourse mortgage loan that has a current outstanding balance of $30.3 million, bears interest at 3.66% and matures December 1, 2018. The Company does not have substantive kick-out or participating rights. As a result, the entity is unconsolidated and recorded using the equity method of accounting.
Parc on Powell (formerly known as 1333 Powell) – This venture is currently developing certain land parcels into a 176 unit apartment building located in Emeryville, California. The Company has a 5% equity interest with an initial obligation of approximately $2.1 million. Total project costs are expected to be approximately $75.0 million and construction is being partially funded with a construction loan. The loan has a maximum debt commitment of $39.5 million and a current unconsolidated outstanding balance of $22.0 million; the loan bears interest at LIBOR plus 2.25% and matures August 14, 2015. The Company has given a repayment guaranty on the construction loan of 50% of the outstanding balance, up to a maximum of $19.7 million, and has given certain construction cost overrun guarantees. The partner is the managing member. The Company does not have substantive kick-out or participating rights. As a result, the entity is unconsolidated and recorded using the equity method of accounting.
On February 27, 2013, in connection with the Archstone Acquisition, subsidiaries of the Company and AVB entered into three limited liability company agreements (collectively, the “Residual JV”). The Residual JV owns certain non-core Archstone assets, such as interests in a six property portfolio of apartment buildings and succeeded to certain residual Archstone liabilities, such as liability for various employment-related matters. The Residual JV is owned 60% by the Company and 40% by AVB and the Company's initial investment was $147.6 million. The Residual JV is managed by a Management Committee consisting of two members from each of the Company and AVB. Both partners have equal participation in the Management Committee and all significant participating rights are shared by both partners. As a result, the Residual JV is unconsolidated and recorded using the equity method of accounting.
During the six months ended June 30, 2014, the Company closed on the sale of its unconsolidated interest in the German portfolio fund and the German management company, representing the sale of the majority of the remaining German real estate assets that were acquired by the Residual JV as part of the Archstone Acquisition. The Company's pro rata share of the proceeds/distributions that have been repatriated to the Residual JV and received by the Company as a result of the German dispositions was approximately $64.7 million during the six months ended June 30, 2014 and $83.6 million cumulatively since the closing of the Archstone Acquisition.
On February 27, 2013, in connection with the Archstone Acquisition, a subsidiary of the Company and AVB entered into a limited liability company agreement (the “Legacy JV”), through which they assumed obligations of Archstone in the form of preferred interests, some of which are governed by tax protection arrangements. During the year ended December 31, 2013, the Company purchased with AVB $65.0 million (of which the Company's 60% share was $39.0 million) of the preferred interests assumed by Legacy JV. At June 30, 2014, the remaining preferred interests have an aggregate liquidation value of $76.8 million, our share of which is included in other liabilities in the accompanying consolidated balance sheets. Obligations of the Legacy JV are borne 60% by the Company and 40% by AVB. The Legacy JV is managed by a Management Committee consisting of two members from each of the Company and AVB. Both partners have equal participation in the Management Committee and all significant participating rights are shared by both partners. As a result, the Legacy JV is unconsolidated and recorded using the equity method of accounting.
Other
In December 2011, the Company and Toll Brothers (NYSE: TOL) jointly acquired a vacant land parcel at 400 Park Avenue South in New York City. The Company's and Toll Brothers' allocated portions of the purchase price were approximately $76.1 million and $57.9 million, respectively. The Company is the managing member and Toll Brothers does not have substantive kick-out or participating rights. Until the core and shell of the building is complete, the building and land will be owned jointly and are required to be consolidated on the Company's balance sheet. Thereafter, the Company will solely own and control the rental portion of the building (floors 2-22) and Toll Brothers will solely own and control the for sale portion of the building (floors 23-40). Once the core and shell are complete, the Toll Brothers' portion of the property will be deconsolidated from the Company's balance sheet. The acquisition was financed through contributions by the Company and Toll Brothers of approximately $102.5 million and $75.7 million, respectively, which included the land purchase noted above, restricted deposits and taxes and fees. As of June 30, 2014, the Company's and Toll Brothers' consolidated contributions to the joint venture were approximately $327.9 million, of which Toll Brothers' noncontrolling interest balance totaled $117.4 million.
The Company admitted an 80% institutional partner to two separate entities/transactions (Nexus Sawgrass in December 2010 and Domain in August 2011), each owning a developable land parcel, in exchange for $40.1 million in cash and retained a 20% equity interest in both of these entities. These projects are now unconsolidated. Details of these projects follow:
•	Nexus Sawgrass – This development project is substantially complete. Total project costs are expected to be approximately $79.0 million and construction was predominantly funded with a long-term, non-recourse secured loan from the partner. The mortgage loan has a maximum debt commitment of $48.7 million and a current unconsolidated outstanding balance of $48.6 million; the loan bears interest at 5.60% and matures January 1, 2021.
•	Domain – This development project is substantially complete. Total project costs are expected to be approximately $155.8 million and construction was predominantly funded with a long-term, non-recourse secured loan from the partner. The mortgage loan has a maximum debt commitment of $98.6 million and a current unconsolidated outstanding balance of $96.4 million; the loan bears interest at 5.75% and matures January 1, 2022.
While the Company is the managing member of both of the joint ventures, was responsible for constructing both of the projects and has given certain construction cost overrun guarantees, the joint venture partner has significant participating rights and has active involvement in and oversight of the ongoing projects. The Company currently has no further funding obligations related to these projects.

Deposits_Restricted

Deposits - Restricted	6 Months Ended
	Jun. 30, 2014
Deposits - Restricted [Abstract]	'
Restricted Cash And Cash Equivalents Disclosure [Text Block]	'
	7	Deposits – Restricted and Escrow Deposits – Mortgage
	The following table presents the Company’s restricted deposits as of June 30, 2014 and December 31, 2013 (amounts in thousands):
			June 30,		December 31,
			2014		2013
	Earnest money on pending acquisitions		$	830	$	4,514
	Restricted deposits on real estate investments		36,476		53,771
	Resident security and utility deposits		46,597		44,777
	Other		505		505
	Totals		$	84,408	$	103,567
	The following table presents the Company’s escrow deposits as of June 30, 2014 and December 31, 2013 (amounts in thousands):
			June 30,		December 31,
			2014		2013
	Real estate taxes and insurance		$	3,500	$	3,687
	Replacement reserves		3,469		4,229
	Mortgage principal reserves/sinking funds		37,448		33,868
	Other		852		852
	Totals		$	45,269	$	42,636

Debt

Debt	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Debt Disclosure [Text Block]	'
	8.    Debt
	EQR does not have any indebtedness as all debt is incurred by the Operating Partnership. EQR guarantees the Operating Partnership’s revolving credit facility up to the maximum amount and for the full term of the facility.
	Mortgage Notes Payable
	As of June 30, 2014, the Company had outstanding mortgage debt of approximately $5.2 billion.
	During the six months ended June 30, 2014, the Company:
	▪	Repaid $9.1 million of mortgage loans.
	As of June 30, 2014, the Company had $700.5 million of secured debt subject to third party credit enhancement.
	As of June 30, 2014, scheduled maturities for the Company’s outstanding mortgage indebtedness were at various dates through May 1, 2061. At June 30, 2014, the interest rate range on the Company’s mortgage debt was 0.03% to 7.25%. During the six months ended June 30, 2014, the weighted average interest rate on the Company’s mortgage debt was 4.23%.
	Notes
	As of June 30, 2014, the Company had outstanding unsecured notes of approximately $5.9 billion.
	During the six months ended June 30, 2014, the Company:
	▪	Repaid its $750.0 million unsecured term loan facility in conjunction with the note issuances discussed below;
	▪	Issued $450.0 million of five-year 2.375% fixed rate public notes, receiving net proceeds of $449.6 million before underwriting fees and other expenses, at an all-in effective interest rate of 2.52% and swapped the notes to a floating interest rate in conjunction with the issuance (see Note 9 for further discussion); and
	▪	Issued $750.0 million of thirty-year 4.50% fixed rate public notes, receiving net proceeds of $744.7 million before underwriting fees, hedge termination costs and other expenses, at an all-in effective interest rate of 4.57% after termination of various forward starting swaps in conjunction with the issuance (see Note 9 for further discussion).
	As of June 30, 2014, scheduled maturities for the Company’s outstanding notes were at various dates through 2044. At June 30, 2014, the interest rate range on the Company’s notes was 2.375% to 7.57%. During the six months ended June 30, 2014, the weighted average interest rate on the Company’s notes was 4.97%.
	Lines of Credit
	On January 11, 2013, the Company replaced its existing $1.75 billion facility with a $2.5 billion unsecured revolving credit facility maturing April 1, 2018. The Company has the ability to increase available borrowings by an additional $500.0 million by adding additional banks to the facility or obtaining the agreement of existing banks to increase their commitments. The interest rate on advances under the facility will generally be LIBOR plus a spread (currently 1.05%) and the Company pays an annual facility fee (currently 15 basis points). Both the spread and the facility fee are dependent on the credit rating of the Company's long-term debt.
	As of June 30, 2014, the amount available on the credit facility was $2.47 billion (net of $34.8 million which was restricted/dedicated to support letters of credit). During the six months ended June 30, 2014, the weighted average interest rate was 0.96%.

Derivative_and_Other_Fair_Valu

Derivative and Other Fair Value Instruments	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Derivatives and Fair Value [Text Block]	'
	9	Derivative and Other Fair Value Instruments
	The valuation of financial instruments requires the Company to make estimates and judgments that affect the fair value of the instruments. The Company, where possible, bases the fair values of its financial instruments, including its derivative instruments, on listed market prices and third party quotes. Where these are not available, the Company bases its estimates on current instruments with similar terms and maturities or on other factors relevant to the financial instruments.
	The carrying values of the Company’s mortgage notes payable and unsecured notes were approximately $5.2 billion and $5.9 billion, respectively, at June 30, 2014. The fair values of the Company’s mortgage notes payable and unsecured notes were approximately $5.2 billion (Level 2) and $6.4 billion (Level 2), respectively, at June 30, 2014. The carrying values of the Company's mortgage notes payable and unsecured debt (including its line of credit) were approximately $5.2 billion and $5.6 billion, respectively, at December 31, 2013. The fair values of the Company’s mortgage notes payable and unsecured debt (including its line of credit) were approximately $5.1 billion (Level 2) and $5.9 billion (Level 2), respectively, at December 31, 2013. The fair values of the Company’s financial instruments (other than mortgage notes payable, unsecured notes, lines of credit and derivative instruments), including cash and cash equivalents and other financial instruments, approximate their carrying or contract values.
	In the normal course of business, the Company is exposed to the effect of interest rate changes. The Company seeks to manage these risks by following established risk management policies and procedures including the use of derivatives to hedge interest rate risk on debt instruments. The Company may also use derivatives to manage its exposure to foreign exchange rates or manage commodity prices in the daily operations of the business.
	The following table summarizes the Company’s consolidated derivative instruments at June 30, 2014 (dollar amounts are in thousands):
			Fair Value				Forward
			Hedges (1)				Starting
							Swaps (2)
	Current Notional Balance		$	450,000			$	100,000
	Lowest Possible Notional		$	450,000			$	100,000
	Highest Possible Notional		$	450,000			$	100,000
	Lowest Interest Rate		2.375		%		3.14		%
	Highest Interest Rate		2.375		%		3.191		%
	Earliest Maturity Date		2019				2025
	Latest Maturity Date		2019				2025
	-1	Fair Value Hedges – Converts outstanding fixed rate unsecured notes ($450.0 million 2.375%notes due July 1, 2019) to a floating interest rate of 90-Day LIBOR plus 0.61%.
	-2	Forward Starting Swaps – Designed to partially fix interest rates in advance of a planned future debt issuance. These swaps have mandatory counterparty terminations in 2016, and are targeted to 2015 issuances.
	A three-level valuation hierarchy exists for disclosure of fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels are defined as follows:
	•	Level 1 – Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets.
	•	Level 2 – Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument.
	•	Level 3 – Inputs to the valuation methodology are unobservable and significant to the fair value measurement.
	The Company’s derivative positions are valued using models developed by the respective counterparty as well as models developed internally by the Company that use as their basis readily observable market parameters (such as forward yield curves and credit default swap data). Employee holdings other than Common Shares within the supplemental executive retirement plan (the “SERP”) are valued using quoted market prices for identical assets and are included in other assets and other liabilities on the consolidated balance sheets. Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners are valued using the quoted market price of Common Shares. The fair values disclosed for mortgage notes payable and unsecured debt (including its line of credit) were calculated using indicative rates provided by lenders of similar loans in the case of mortgage notes payable and the private unsecured debt (including its line of credit) and quoted market prices for each underlying issuance in the case of the public unsecured notes.
	The following tables provide a summary of the fair value measurements for each major category of assets and liabilities measured at fair value on a recurring basis and the location within the accompanying consolidated balance sheets at June 30, 2014 and December 31, 2013, respectively (amounts in thousands):
									Fair Value Measurements at Reporting Date Using
	Description		Balance Sheet		6/30/14				Quoted Prices in			Significant  Other				Significant
			Location						Active Markets for			Observable Inputs				Unobservable Inputs
									Identical Assets/Liabilities			(Level 2)				(Level  3)
									(Level 1)
	Assets
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Fair Value Hedges		Other Assets		$	1,452			$	—		$	1,452			$	—
	Supplemental Executive Retirement Plan		Other Assets		97,543				97,543			—				—
	Total				$	98,995			$	97,543		$	1,452			$	—
	Liabilities
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Forward Starting Swaps		Other Liabilities		$	2,346			$	—		$	2,346			$	—
	Supplemental Executive Retirement Plan		Other Liabilities		97,543				97,543			—				—
	Total				$	99,889			$	97,543		$	2,346			$	—
	Redeemable Noncontrolling Interests –
	Operating Partnership/Redeemable
	Limited Partners		Mezzanine		$	440,050			$	—		$	440,050			$	—
									Fair Value Measurements at Reporting Date Using
	Description		Balance Sheet		12/31/13				Quoted Prices in			Significant  Other				Significant
			Location						Active Markets for			Observable Inputs				Unobservable Inputs
									Identical Assets/Liabilities			(Level 2)				(Level  3)
									(Level 1)
	Assets
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Forward Starting Swaps		Other Assets		$	18,710			$	—		$	18,710			$	—
	Supplemental Executive Retirement Plan		Other Assets		83,845				83,845			—				—
	Total				$	102,555			$	83,845		$	18,710			$	—
	Liabilities
	Supplemental Executive Retirement Plan		Other Liabilities		$	83,845			$	83,845		$	—			$	—
	Total				$	83,845			$	83,845		$	—			$	—
	Redeemable Noncontrolling Interests –
	Operating Partnership/Redeemable
	Limited Partners		Mezzanine		$	363,144			$	—		$	363,144			$	—
	The following tables provide a summary of the effect of fair value hedges on the Company’s accompanying consolidated statements of operations and comprehensive income for the six months ended June 30, 2014 and 2013, respectively (amounts in thousands):
	30-Jun-14		Location of		Amount of				Hedged Item		Income Statement	Amount of
	Type of Fair Value Hedge		Gain/(Loss)		Gain/(Loss)						Location of	Gain/(Loss)
	Recognized in		Recognized in			Hedged Item	Recognized in
	Income on		Income on			Gain/(Loss)	Income
	Derivative		Derivative				on Hedged Item
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Interest Rate Swaps		Interest expense		$	1,452			Fixed rate debt		Interest expense	$	(1,452	)
Total				$	1,452						$	(1,452	)
30-Jun-13		Location of		Amount of				Hedged Item		Income Statement	Amount of
Type of Fair Value Hedge		Gain/(Loss)		Gain/(Loss)						Location of	Gain/(Loss)
		Recognized in		Recognized in						Hedged Item	Recognized in
		Income		Income						Gain/(Loss)	Income
		on Derivative		on Derivative							on Hedged Item
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Interest Rate Swaps		Interest expense		$	(1,524	)		Fixed rate debt		Interest expense	$	1,524
Total				$	(1,524	)					$	1,524
The following tables provide a summary of the effect of cash flow hedges on the Company’s accompanying consolidated statements of operations and comprehensive income for the six months ended June 30, 2014 and 2013, respectively (amounts in thousands):
		Effective Portion									Ineffective Portion
30-Jun-14		Amount of				Location of Gain/		Amount of Gain/			Location of		Amount of Gain/
Type of Cash Flow Hedge		Gain/(Loss)				(Loss)		(Loss)			Gain/(Loss)		(Loss)
		Recognized in OCI				Reclassified from		Reclassified from			Recognized in		Reclassified from
		on Derivative				Accumulated		Accumulated			Income		Accumulated
						OCI into Income		OCI into Income			on Derivative		OCI into Income
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps/Treasury Locks		$	(21,790	)		Interest expense		$	(8,335	)	Interest expense		$	91
Total		$	(21,790	)				$	(8,335	)			$	91
		Effective Portion									Ineffective Portion
30-Jun-13		Amount of				Location of Gain/		Amount of Gain/			Location of		Amount of Gain/
Type of Cash Flow Hedge		Gain/(Loss)				(Loss)		(Loss)			Gain/(Loss)		(Loss)
		Recognized in OCI				Reclassified from		Reclassified from			Recognized in		Reclassified from
		on Derivative				Accumulated		Accumulated			Income		Accumulated
						OCI into Income		OCI into Income			on Derivative		OCI into Income
Derivatives designated as hedging instruments:
Interest Rate Contracts:
Forward Starting Swaps/Treasury Locks		$	12,337			Interest expense		$	(12,098	)	N/A		$	—
Total		$	12,337					$	(12,098	)			$	—
As of June 30, 2014 and December 31, 2013, there were approximately $169.3 million and $155.8 million in deferred losses, net, included in accumulated other comprehensive (loss), respectively, related to derivative instruments. Based on the estimated fair values of the net derivative instruments at June 30, 2014, the Company may recognize an estimated $22.0 million of accumulated other comprehensive (loss) as additional interest expense during the twelve months ending June 30, 2015.
In June 2014, the Company paid a net $2.0 million to settle seven forward starting ten-year swaps in conjunction with the issuance of $750.0 million of thirty-year fixed rate public notes. The ineffective portion of approximately $0.1 million was recorded as a decrease to interest expense and accrued interest of approximately $1.3 million was recorded as an increase to interest expense. The remaining amount of approximately $0.8 million will be deferred as a component of accumulated other comprehensive (loss) and recognized as an increase to interest expense over the first nine years and ten months of the notes.

Earnings_Per_Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share And Earnings Per Unit [Text Block]	'
	10.    Earning Per Share and Earnings Per Unit
	Equity Residential
	The following tables set forth the computation of net income per share – basic and net income per share – diluted for the Company (amounts in thousands except per share amounts):
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	Numerator for net income per share – basic:
	Income (loss) from continuing operations		$	183,987		$	(223,850	)	$	102,307		$	(58,511	)
	Allocation to Noncontrolling Interests – Operating Partnership, net		(7,475		)	9,078			(4,422		)	2,231
	Net gain on sales of real estate properties		14,903			—			14,903			—
	Net (income) loss attributable to Noncontrolling Interests – Partially		(1,092		)	790			(588		)	815
	Owned Properties
	Preferred distributions		(2,072		)	(2,072		)	(1,036		)	(1,036		)
	Income (loss) from continuing operations available to Common Shares,		188,251			(216,054		)	111,164			(56,501		)
	net of Noncontrolling Interests
	Discontinued operations, net of Noncontrolling Interests		1,502			1,556,427			490			380,224
	Numerator for net income per share – basic		$	189,753		$	1,340,373		$	111,654		$	323,723
	Numerator for net income per share – diluted (1):
	Income from continuing operations		$	183,987					$	102,307
	Net gain on sales of real estate properties		14,903						14,903
	Net (income) attributable to Noncontrolling Interests – Partially		(1,092		)				(588		)
	Owned Properties
	Preferred distributions		(2,072		)				(1,036		)
	Income from continuing operations available to Common Shares		195,726						115,586
	Discontinued operations, net		1,562						510
	Numerator for net income per share – diluted (1)		$	197,288		$	1,340,373		$	116,096		$	323,723
	Denominator for net income per share – basic and diluted (1):
	Denominator for net income per share – basic		360,641			348,654			360,809			359,653
	Effect of dilutive securities:
	OP Units		13,736						13,742
	Long-term compensation shares/units		2,403						2,567
	Denominator for net income per share – diluted (1)		376,780			348,654			377,118			359,653
	Net income per share – basic		$	0.53		$	3.84		$	0.31		$	0.9
	Net income per share – diluted		$	0.52		$	3.84		$	0.31		$	0.9
	Net income per share – basic:
	Income (loss) from continuing operations available to Common Shares,		$	0.522		$	(0.620	)	$	0.308		$	(0.157	)
	net of Noncontrolling Interests
	Discontinued operations, net of Noncontrolling Interests		0.004			4.464			0.001			1.057
	Net income per share – basic		$	0.526		$	3.844		$	0.309		$	0.9
	Net income per share – diluted (1):
	Income (loss) from continuing operations available to Common Shares		$	0.52		$	(0.620	)	$	0.307		$	(0.157	)
	Discontinued operations, net		0.004			4.464			0.001			1.057
	Net income per share – diluted		$	0.524		$	3.844		$	0.308		$	0.9
	-1	Potential common shares issuable from the assumed conversion of OP Units and the exercise/vesting of long-term compensation shares/units are automatically anti-dilutive and therefore excluded from the diluted earnings per share calculation as the Company had a loss from continuing operations for the six months and quarter ended June 30, 2013.
	ERP Operating Limited Partnership
	The following tables set forth the computation of net income per Unit – basic and net income per Unit – diluted for the Operating Partnership (amounts in thousands except per Unit amounts):
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	Numerator for net income per Unit – basic and diluted (1):
	Income (loss) from continuing operations		$	183,987		$	(223,850	)	$	102,307		$	(58,511	)
	Net gain on sales of real estate properties		14,903			—			14,903			—
	Net (income) loss attributable to Noncontrolling Interests – Partially		(1,092		)	790			(588		)	815
	Owned Properties
	Allocation to Preference Units		(2,072		)	(2,072		)	(1,036		)	(1,036		)
	Income (loss) from continuing operations available to Units		195,726			(225,132		)	115,586			(58,732		)
	Discontinued operations, net		1,562			1,621,616			510			395,243
	Numerator for net income per Unit – basic and diluted (1)		$	197,288		$	1,396,484		$	116,096		$	336,511
	Denominator for net income per Unit – basic and diluted (1):
	Denominator for net income per Unit - basic		374,377			362,390			374,551			373,403
	Effect of dilutive securities:
	Dilution for Units issuable upon assumed exercise/vesting of the		2,403						2,567
	Company’s long-term compensation shares/units
	Denominator for net income per Unit – diluted (1)		376,780			362,390			377,118			373,403
	Net income per Unit – basic		$	0.53		$	3.84		$	0.31		$	0.9
Net income per Unit – diluted		$	0.52		$	3.84		$	0.31		$	0.9
Net income per Unit – basic:
Income (loss) from continuing operations available to Units		$	0.522		$	(0.620	)	$	0.308		$	(0.157	)
Discontinued operations, net		0.004			4.464			0.001			1.057
Net income per Unit – basic		$	0.526		$	3.844		$	0.309		$	0.9
Net income per Unit – diluted (1):
Income (loss) from continuing operations available to Units		$	0.52		$	(0.620	)	$	0.307		$	(0.157	)
Discontinued operations, net		0.004			4.464			0.001			1.057
Net income per Unit – diluted		$	0.524		$	3.844		$	0.308		$	0.9
-1	Potential Units issuable from the assumed exercise/vesting of the Company's long-term compensation shares/units are automatically anti-dilutive and therefore excluded from the diluted earnings per Unit calculation as the Operating Partnership had a loss from continuing operations for the six months and quarter ended June 30, 2013.

Discontinued_Operations

Discontinued Operations	6 Months Ended
	Jun. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	11	Discontinued Operations
	The Company has presented separately as discontinued operations in all periods the results of operations for all consolidated assets disposed of and all properties held for sale, if any, for properties sold in 2013 and prior years. The amounts included in discontinued operations for the six months and quarter ended June 30, 2014 represent trailing activity for properties sold in 2013 and prior years. None of the properties sold during the six months and quarter ended June 30, 2014 met the new criteria for reporting discontinued operations. See Note 2 for further discussion.
	The components of discontinued operations are outlined below and include the results of operations for the respective periods that the Company owned such assets for properties sold in 2013 and prior years during the six months and quarters ended June 30, 2014 and 2013 (amounts in thousands).
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	REVENUES
	Rental income		$	1,275		$	107,956		$	252		$	26,174
	Total revenues		1,275			107,956			252			26,174
	EXPENSES (1)
	Property and maintenance		(41		)	31,449			(89		)	11,025
	Real estate taxes and insurance		(6		)	10,867			(19		)	2,273
	Property management		—			1			—			—
	Depreciation		—			30,962			—			7,146
	General and administrative		51			73			46			65
	Total expenses		4			73,352			(62		)	20,509
	Discontinued operating income		1,271			34,604			314			5,665
	Interest and other income		80			90			45			38
	Other expenses		—			(3		)	—			(1		)
	Interest (2):
	Expense incurred, net		—			(1,258		)	—			(6		)
	Amortization of deferred financing costs		—			(228		)	—			—
	Income and other tax (expense) benefit		(13		)	(463		)	(2		)	(405		)
	Discontinued operations		1,338			32,742			357			5,291
	Net gain on sales of discontinued operations		224			1,588,874			153			389,952
	Discontinued operations, net		$	1,562		$	1,621,616		$	510		$	395,243
	-1	Includes expenses paid in the current period for properties sold in prior periods related to the Company’s period of ownership.
	-2	Includes only interest expense specific to secured mortgage notes payable for properties sold.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies [Abstract]	'
Commitments and Contingencies	'
	12	Commitments and Contingencies
	The Company, as an owner of real estate, is subject to various Federal, state and local environmental laws. Compliance by the Company with existing laws has not had a material adverse effect on the Company. However, the Company cannot predict the impact of new or changed laws or regulations on its current properties or on properties that it may acquire in the future.
	The Company is party to a housing discrimination lawsuit brought by a non-profit civil rights organization in April 2006 in the U.S. District Court for the District of Maryland. The suit alleges that the Company designed and built approximately 300 of its properties in violation of the accessibility requirements of the Fair Housing Act and Americans With Disabilities Act. The suit seeks actual and punitive damages, injunctive relief (including modification of non-compliant properties), costs and attorneys' fees. The Company believes it has a number of viable defenses, including that a majority of the named properties were completed before the operative dates of the statutes in question and/or were not designed or built by the Company. Accordingly, the Company is defending the suit vigorously. Due to the pendency of the Company’s defenses and the uncertainty of many other critical factual and legal issues, it is not possible to determine or predict the outcome of the suit or a possible loss or a range of loss, and no amounts have been accrued at June 30, 2014. While no assurances can be given, the Company does not believe that the suit, if adversely determined, would have a material adverse effect on the Company.
	The Company does not believe there is any other litigation pending or threatened against it that, individually or in the aggregate, may reasonably be expected to have a material adverse effect on the Company.
	As of June 30, 2014, the Company has 12 consolidated projects (including Prism at Park Avenue South in New York City which the Company is jointly developing with Toll Brothers that is discussed below) totaling 3,871 apartment units in various stages of development with commitments to fund of approximately $1.0 billion and estimated completion dates ranging through September 30, 2016, as well as other completed development projects that are in various stages of lease up or are stabilized. Some of the projects are being developed solely by the Company, while others are being co-developed with various third party development partners. The development venture agreements with these partners are primarily deal-specific, with differing terms regarding profit-sharing, equity contributions, returns on investment, buy-sell agreements and other customary provisions. The Company is the "general" or "managing" partner of the development ventures.
	As of June 30, 2014, the Company has one unconsolidated project totaling 176 apartment units under development with an estimated completion date of December 31, 2014, as well as other completed development projects that are in various stages of lease up or are stabilized. These projects are all being co-developed with various third party development partners. The development venture agreements with these partners are primarily deal-specific, with differing terms regarding profit-sharing, equity contributions, returns on investment, buy-sell agreements and other customary provisions. The Company currently has no further funding obligations for Domain, Nexus Sawgrass and San Norterra. While the Company is the managing member of the Domain and Nexus Sawgrass joint ventures, was responsible for constructing both projects and has given certain construction cost overrun guarantees, the joint venture partner has significant participating rights and has active involvement in and oversight of the ongoing projects. The Domain and Nexus Sawgrass buy-sell arrangements contain provisions that provide the right, but not the obligation, for the Company to acquire the partner’s interests or sell its interests at any time following the occurrence of certain pre-defined events (including at stabilization) described in the development venture agreements. The respective partner for San Norterra and Parc on Powell (formerly known as 1333 Powell) is the “general” or “managing” partner of the development venture and the Company does not have substantive kick-out or participating rights. The Company has given a repayment guaranty on the construction loan for Parc on Powell of 50% of the outstanding balance, up to a maximum of $19.7 million, and has given certain construction cost overrun guarantees.
	In December 2011, the Company and Toll Brothers (NYSE: TOL) jointly acquired a vacant land parcel at 400 Park Avenue South in New York City. The Company's and Toll Brothers' allocated portions of the purchase price were approximately $76.1 million and $57.9 million, respectively. The Company is the managing member and Toll Brothers does not have substantive kick-out or participating rights. Until the core and shell of the building is complete, the building and land will be owned jointly and are required to be consolidated on the Company's balance sheet. Thereafter, the Company will solely own and control the rental portion of the building (floors 2-22) and Toll Brothers will solely own and control the for sale portion of the building (floors 23-40). Once the core and shell are complete, the Toll Brothers' portion of the property will be deconsolidated from the Company's balance sheet. The acquisition was financed through contributions by the Company and Toll Brothers of approximately $102.5 million and $75.7 million, respectively, which included the land purchase noted above, restricted deposits and taxes and fees. As of June 30, 2014, the Company's and Toll Brothers' consolidated contributions to the joint venture were approximately $327.9 million, of which Toll Brothers' noncontrolling interest balance totaled $117.4 million.

Reportable_Segments

Reportable Segments	6 Months Ended
	Jun. 30, 2014
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]	'
Segment Reporting Disclosure [Text Block]	'
	13	Reportable Segments
	Operating segments are defined as components of an enterprise that engage in business activities from which they may earn revenues and incur expenses and about which discrete financial information is available that is evaluated regularly by the chief operating decision maker. The chief operating decision maker decides how resources are allocated and assesses performance on a recurring basis at least quarterly.
	The Company’s primary business is the acquisition, development and management of multifamily residential properties, which includes the generation of rental and other related income through the leasing of apartment units to residents. The chief operating decision maker evaluates the Company's operating performance geographically by market and both on a same store and non-same store basis. The Company’s operating segments located in its core markets represent its reportable segments (with the aggregation of Los Angeles, Orange County and San Diego into the Southern California reportable segment). The Company's operating segments located in its non-core markets that are not material have also been aggregated in the tables presented below.
	The Company’s fee and asset management and development (including its partially owned properties) activities are other business activities that do not constitute an operating segment and as such, have been aggregated in the "Other" category in the tables presented below.
	All revenues are from external customers and there is no customer who contributed 10% or more of the Company’s total revenues during the six months and quarters ended June 30, 2014 and 2013, respectively.
	The primary financial measure for the Company’s rental real estate segment is net operating income (“NOI”), which represents rental income less: 1) property and maintenance expense; 2) real estate taxes and insurance expense; and 3) property management expense (all as reflected in the accompanying consolidated statements of operations and comprehensive income). The Company believes that NOI is helpful to investors as a supplemental measure of its operating performance because it is a direct measure of the actual operating results of the Company’s apartment communities. Current year NOI is compared to prior year NOI and current year budgeted NOI as a measure of financial performance. The following tables present NOI for each segment from our rental real estate specific to continuing operations for the six months and quarters ended June 30, 2014 and 2013, respectively, as well as total assets and capital expenditures at June 30, 2014 (amounts in thousands):
			Six Months Ended June 30, 2014									Six Months Ended June 30, 2013
			Rental Income			Operating Expenses			NOI			Rental Income			Operating Expenses			NOI
	Same store (1)
	Boston		$	125,024		$	41,414		$	83,610		$	120,455		$	39,651		$	80,804
	Denver		54,123			15,098			39,025			50,494			14,987			35,507
	New York		225,407			88,102			137,305			217,297			83,745			133,552
	San Francisco		165,343			52,960			112,383			152,459			54,109			98,350
	Seattle		76,702			25,805			50,897			71,548			24,553			46,995
	South Florida		97,893			36,404			61,489			93,289			35,417			57,872
	Southern California		207,272			69,450			137,822			198,366			69,149			129,217
	Washington DC		222,135			72,499			149,636			223,807			71,049			152,758
	Non-core		65,607			24,495			41,112			63,715			23,931			39,784
	Total same store		1,239,506			426,227			813,279			1,191,430			416,591			774,839
	Non-same store/other (2) (3)
	Boston		1,817			413			1,404			1,154			255			899
	Seattle		4,444			1,779			2,665			1,303			374			929
	South Florida		2,041			1,301			740			24			146			(122		)
	Southern California		15,623			7,452			8,171			5,397			2,593			2,804
	Washington DC		10,840			3,857			6,983			5,320			1,862			3,458
	Other (3)		6,220			7,754			(1,534		)	4,901			13,295			(8,394		)
	Total non-same store/other		40,985			22,556			18,429			18,099			18,525			(426		)
	Archstone pre-ownership (4)		—			—			—			(92,423		)	(36,729		)	(55,694		)
	Total		$	1,280,491		$	448,783		$	831,708		$	1,117,106		$	398,387		$	718,719
	-1	Same store primarily includes all properties acquired or completed and stabilized prior to January 1, 2013, less properties subsequently sold, which represented 100,648 apartment units. Also includes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-2	Non-same store primarily includes properties acquired after January 1, 2013, plus any properties in lease-up and not stabilized as of January 1, 2013, but excludes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-3	Other includes development, other corporate operations and operations prior to sale for properties sold in 2014 that do not meet the new discontinued operations criteria.
	-4	Represents pro forma Archstone pre-ownership results for the period January 1, 2013 to February 27, 2013 that is included in 2013 same store results.
			Quarter Ended June 30, 2014									Quarter Ended June 30, 2013
			Rental Income			Operating Expenses			NOI			Rental Income			Operating Expenses			NOI
	Same store (1)
	Boston		$	63,117		$	19,259		$	43,858		$	61,401		$	19,444		$	41,957
	Denver		27,511			7,648			19,863			25,524			7,770			17,754
	New York		114,221			41,898			72,323			109,299			40,634			68,665
	San Francisco		84,082			26,305			57,777			77,514			25,955			51,559
	Seattle		38,977			13,037			25,940			36,176			12,316			23,860
	South Florida		49,456			18,220			31,236			47,051			17,774			29,277
	Southern California		104,608			34,811			69,797			100,156			34,275			65,881
	Washington DC		111,739			35,102			76,637			112,815			35,165			77,650
	Non-core		33,035			11,806			21,229			32,110			11,880			20,230
	Total same store		626,746			208,086			418,660			602,046			205,213			396,833
	Non-same store/other (2) (3)
	Boston		790			202			588			898			201			697
	Seattle		2,756			1,042			1,714			1,271			373			898
	South Florida		1,241			760			481			14			68			(54		)
	Southern California		8,446			4,261			4,185			4,106			1,976			2,130
	Washington DC		5,906			1,954			3,952			3,512			1,209			2,303
	Other (3)		3,881			2,693			1,188			2,697			3,234			(537		)
	Total non-same store/other		23,020			10,912			12,108			12,498			7,061			5,437
	Total		$	649,766		$	218,998		$	430,768		$	614,544		$	212,274		$	402,270
	-1	Same store primarily includes all properties acquired or completed and stabilized prior to April 1, 2013, less properties subsequently sold, which represented 100,648 apartment units. Also includes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-2	Non-same store primarily includes properties acquired after April 1, 2013, plus any properties in lease-up and not stabilized as of April 1, 2013, but excludes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-3	Other includes development, other corporate operations and operations prior to sale for properties sold in 2014 that do not meet the new discontinued operations criteria.
			Six Months Ended June 30, 2014
			Total Assets			Capital Expenditures
	Same store (1)
	Boston		$	1,953,627		$	8,814
	Denver		530,832			1,904
New York		4,720,592			8,202
San Francisco		2,753,902			12,704
Seattle		1,046,051			5,264
South Florida		1,170,295			7,600
Southern California		2,978,750			11,953
Washington DC		4,270,418			14,834
Non-core		605,225			3,123
Total same store		20,029,692			74,398
Non-same store/other (2) (3)
Boston		48,830			630
Seattle		226,604			281
South Florida		70,896			16
Southern California		511,343			645
Washington DC		306,594			852
Other (3)		1,797,443			90
Total non-same store/other		2,961,710			2,514
Total		$	22,991,402		$	76,912
-1	Same store primarily includes all properties acquired or completed and stabilized prior to January 1, 2013, less properties subsequently sold, which represented 100,648 apartment units. Also includes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
-2	Non-same store primarily includes properties acquired after January 1, 2013, plus any properties in lease-up and not stabilized as of January 1, 2013, but excludes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
-3	Other includes development, other corporate operations and capital expenditures for properties sold.
Note: Markets/Metro Areas aggregated in the above Southern California and Non-core segments are as follows:
(a) Southern California – Los Angeles, Orange County and San Diego.
(b) Non-core – Inland Empire, CA, New England (excluding Boston), Orlando and Phoenix.
The following table presents a reconciliation of NOI from our rental real estate specific to continuing operations for the six months and quarters ended June 30, 2014 and 2013, respectively (amounts in thousands):
		Six Months Ended June 30,						Quarter Ended June 30,
		2014			2013			2014			2013
Rental income		$	1,280,491		$	1,117,106		$	649,766		$	614,544
Property and maintenance expense		(240,961		)	(212,030		)	(115,388		)	(113,501		)
Real estate taxes and insurance expense		(165,149		)	(141,837		)	(83,055		)	(76,742		)
Property management expense		(42,673		)	(44,520		)	(20,555		)	(22,031		)
Total operating expenses		(448,783		)	(398,387		)	(218,998		)	(212,274		)
Net operating income		$	831,708		$	718,719		$	430,768		$	402,270

Subsequent_EventsOther

Subsequent Events/Other	6 Months Ended
	Jun. 30, 2014
Subsequent Events Other [Abstract]	'
Subsequent Events/Other	'
	14	Subsequent Events/Other
	Subsequent Events
	Subsequent to June 30, 2014, the Company:
	•	Acquired one land parcel for $13.0 million;
	•	Repaid $60.7 million in mortgage loans; and
	•	Closed on the sale of its unconsolidated interest in the remaining Residual JV wholly-owned German real estate assets that were acquired as part of the Archstone Acquisition. With this sale, all German real estate assets have now been sold.
	Other
	During the six months ended June 30, 2014 and 2013, the Company incurred charges of $0.1 million and $0.1 million, respectively, related to property acquisition costs, such as survey, title and legal fees, on the acquisition of operating properties (excluding the Archstone Transaction) and $1.5 million and $3.4 million, respectively, related to the write-off of various pursuit and out-of-pocket costs for terminated acquisition, disposition and development transactions. These costs, totaling $1.6 million and $3.5 million, respectively, are included in other expenses in the accompanying consolidated statements of operations and comprehensive income. See Note 4 for details on the property acquisition costs related to the Archstone Transaction.
	During the six months ended June 30, 2014, the Company received $2.3 million for the settlement of various litigation/insurance claims, which are included in interest and other income in the accompanying consolidated statements of operations and comprehensive income.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Summary of Significant Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) and certain reclassifications considered necessary for a fair presentation have been included. Certain reclassifications have been made to the prior period financial statements in order to conform to the current year presentation. These reclassifications did not have an impact on net income previously reported. Operating results for the six months ended June 30, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014.
	In preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
	The balance sheets at December 31, 2013 have been derived from the audited financial statements at that date but do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.
	For further information, including definitions of capitalized terms not defined herein, refer to the consolidated financial statements and footnotes thereto included in the Company’s and the Operating Partnership's annual report on Form 10-K for the year ended December 31, 2013.
Income and Other Taxes	'
	Income and Other Taxes
	Due to the structure of EQR as a REIT and the nature of the operations of its operating properties, no provision for federal income taxes has been made at the EQR level. In addition, ERPOP generally is not liable for federal income taxes as the partners recognize their proportionate share of income or loss in their tax returns; therefore no provision for federal income taxes has been made at the ERPOP level. Historically, the Company has generally only incurred certain state and local income, excise and franchise taxes. The Company has elected Taxable REIT Subsidiary (“TRS”) status for certain of its corporate subsidiaries and as a result, these entities will incur both federal and state income taxes on any taxable income of such entities after consideration of any net operating losses.
	Deferred tax assets and liabilities applicable to the TRS are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. These assets and liabilities are measured using enacted tax rates for which the temporary differences are expected to be recovered or settled. The effects of changes in tax rates on deferred tax assets and liabilities are recognized in earnings in the period enacted. The Company’s deferred tax assets are generally the result of tax affected suspended interest deductions, net operating losses, differing depreciable lives on capitalized assets and the timing of expense recognition for certain accrued liabilities. As of June 30, 2014, the Company has recorded a deferred tax asset, which is fully offset by a valuation allowance due to the uncertainty in forecasting future TRS taxable income.
Other	'
	Other
	The Company is the controlling partner in various consolidated partnerships owning 19 properties and 3,752 apartment units and various completed and uncompleted development properties having a noncontrolling interest book value of $125.8 million at June 30, 2014. The Company is required to make certain disclosures regarding noncontrolling interests in consolidated limited-life subsidiaries. Of the consolidated entities described above, the Company is the controlling partner in limited-life partnerships owning six properties having a noncontrolling interest deficit balance of $10.2 million. These six partnership agreements contain provisions that require the partnerships to be liquidated through the sale of their assets upon reaching a date specified in each respective partnership agreement. The Company, as controlling partner, has an obligation to cause the property owning partnerships to distribute the proceeds of liquidation to the Noncontrolling Interests in these Partially Owned Properties only to the extent that the net proceeds received by the partnerships from the sale of their assets warrant a distribution based on the partnership agreements. As of June 30, 2014, the Company estimates the value of Noncontrolling Interest distributions for these six properties would have been approximately $53.2 million (“Settlement Value”) had the partnerships been liquidated. This Settlement Value is based on estimated third party consideration realized by the partnerships upon disposition of the six Partially Owned Properties and is net of all other assets and liabilities, including yield maintenance on the mortgages encumbering the properties, that would have been due on June 30, 2014 had those mortgages been prepaid. Due to, among other things, the inherent uncertainty in the sale of real estate assets, the amount of any potential distribution to the Noncontrolling Interests in the Company's Partially Owned Properties is subject to change. To the extent that the partnerships' underlying assets are worth less than the underlying liabilities, the Company has no obligation to remit any consideration to the Noncontrolling Interests in these Partially Owned Properties.
	Effective January 1, 2013, companies are required to report, in one place, information about reclassifications out of accumulated other comprehensive income ("AOCI"). Companies are also required to report changes in AOCI balances. For significant items reclassified out of AOCI to net income in their entirety in the same reporting period, reporting is required about the effect of the reclassifications on the respective line items in the statement where net income is presented. For items that are not reclassified to net income in their entirety in the same reporting period, a cross reference to other disclosures currently required under US GAAP is required in the notes. This does not have a material effect on the Company's consolidated results of operations or financial position. See Note 9 for further discussion.
	Effective January 1, 2014, companies are required to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date as the sum of the amount a company agreed to pay on the basis of its arrangement among its co-obligors and any additional amount a company expects to pay on behalf of its co-obligors. Companies are required to disclose the nature and amount of the obligation as well as other information about those obligations. This does not have a material effect on the Company's consolidated results of operations or financial position.
	In April 2014, the Financial Accounting Standards Board (the "FASB") issued new guidance for reporting discontinued operations. Only disposals representing a strategic shift in operations that has a major effect on a company’s operations and financial results will be presented as discontinued operations. Companies will be required to expand their disclosures about discontinued operations to provide more information on the assets, liabilities, income and expenses of the discontinued operations. Companies will also be required to disclose the pre-tax income attributable to a disposal of a significant part of a company that does not qualify for discontinued operations reporting. Application of this guidance is prospective from the date of adoption and early adoption is permitted, but only for disposals (or classifications as held for sale) that have not been reported in financial statements previously issued. The new standard is effective January 1, 2015 but the Company early adopted it as allowed effective January 1, 2014. Adoption of this standard did not have a material effect on the Company's overall consolidated results of operations or financial position. However, adoption will result in substantially fewer of the Company's dispositions meeting the discontinued operations qualifications. See Note 11 for further discussion.
	In May 2014, the FASB issued a comprehensive new revenue recognition standard entitled Revenue from Contracts with Customers that will supersede nearly all existing revenue recognition guidance. The new standard specifically excludes lease contracts. The new standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. Companies will likely need to use more judgment and make more estimates than under current revenue recognition guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration, if any, to include in the transaction price and allocating the transaction price to each separate performance obligation. The new standard will be effective for the Company beginning on January 1, 2017 and early adoption is not permitted. The new standard may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of adoption. The Company has not yet selected a transition method and is currently evaluating the impact of adopting the new standard on its consolidated results of operations and financial position.

Business_Tables

Business (Tables)	6 Months Ended
	Jun. 30, 2014
Business [Abstract]	'
Schedule of Real Estate Properties	'
	The ownership breakdown includes (table does not include various uncompleted development properties):
		Properties	Apartment
			Units
	Wholly Owned Properties	369	100,210
	Master-Leased Properties – Consolidated	3	853
	Partially Owned Properties – Consolidated	19	3,752
	Partially Owned Properties – Unconsolidated	4	1,669
	Military Housing	2	5,007
		397	111,491

Equity_Capital_and_Other_Inter1

Equity, Capital and Other Interests (Tables)	6 Months Ended
	Jun. 30, 2014
Redeemable Noncontrolling Interest [Table Text Block]	'
	The following table presents the changes in the redemption value of the Redeemable Noncontrolling Interests – Operating Partnership for the six months ended June 30, 2014 (amounts in thousands):
			2014
	Balance at January 1,		$	363,144
	Change in market value		80,615
	Change in carrying value		(3,709		)
	Balance at June 30,		$	440,050
Common shares and units rollforward	'
	The following tables present the changes in the Company’s issued and outstanding Common Shares and “Units” (which includes OP Units and Long-Term Incentive Plan (“LTIP”) Units) for the six months ended June 30, 2014:
			2014
	Common Shares
	Common Shares outstanding at January 1,		360,479,260
	Common Shares Issued:
	Conversion of OP Units		56,536
	Exercise of share options		851,514
	Employee Share Purchase Plan (ESPP)		47,457
	Restricted share grants, net		170,626
	Common Shares Other:
	Conversion of restricted shares to LTIP Units		(12,146	)
	Repurchased and retired		(31,240	)
	Common Shares outstanding at June 30,		361,562,007
	Units
	Units outstanding at January 1,		14,180,376
	LTIP Units, net		200,840
	Conversion of restricted shares to LTIP Units		12,146
	Conversion of OP Units to Common Shares		(56,536	)
	Units outstanding at June 30,		14,336,826
	Total Common Shares and Units outstanding at June 30,		375,898,833
	Units Ownership Interest in Operating Partnership		3.8	%
Schedule Of Preferred Stock [Table Text Block]	'
	The following table presents the Company’s issued and outstanding Preferred Shares as of June 30, 2014 and December 31, 2013:
							Amounts in thousands
			Redemption		Annual		June 30,		December 31,
			Date (1)		Dividend per		2014		2013
					Share (2)
	Preferred Shares of beneficial interest, $0.01 par value;
	100,000,000 shares authorized:
	8.29% Series K Cumulative Redeemable Preferred; liquidation		12/10/26			$4.14	$	50,000	$	50,000
	value $50 per share; 1,000,000 shares issued and outstanding
	at June 30, 2014 and December 31, 2013
							$	50,000	$	50,000
	-1	On or after the redemption date, redeemable preferred shares may be redeemed for cash at the option of the Company, in whole or
	in part, at a redemption price equal to the liquidation price per share, plus accrued and unpaid distributions, if any.
	-2	Dividends on Preferred Shares are payable quarterly.
Limited Partner [Member]	'
Redeemable Noncontrolling Interest [Table Text Block]	'
	The following table presents the changes in the redemption value of the Redeemable Limited Partners for the six months ended June 30, 2014 (amounts in thousands):
			2014
	Balance at January 1,		$	363,144
	Change in market value		80,615
	Change in carrying value		(3,709		)
	Balance at June 30,		$	440,050
Common shares and units rollforward	'
	The following tables present the changes in the Operating Partnership’s issued and outstanding Units and in the limited partners’ Units for the six months ended June 30, 2014:
			2014
	General and Limited Partner Units
	General and Limited Partner Units outstanding at January 1,		374,659,636
	Issued to General Partner:
	Exercise of EQR share options		851,514
	EQR’s Employee Share Purchase Plan (ESPP)		47,457
	EQR's restricted share grants, net		170,626
	Issued to Limited Partners:
	LTIP Units, net		200,840
	OP Units Other:
	Repurchased and retired		(31,240	)
	General and Limited Partner Units outstanding at June 30,		375,898,833
	Limited Partner Units
	Limited Partner Units outstanding at January 1,		14,180,376
	Limited Partner LTIP Units, net		200,840
	Conversion of EQR restricted shares to LTIP Units		12,146
	Conversion of Limited Partner OP Units to EQR Common Shares		(56,536	)
	Limited Partner Units outstanding at June 30,		14,336,826
	Limited Partner Units Ownership Interest in Operating Partnership		3.8	%
Schedule Of Preferred Stock [Table Text Block]	'
	The following table presents the Operating Partnership’s issued and outstanding “Preference Units” as of June 30, 2014 and December 31, 2013:
							Amounts in thousands
			Redemption		Annual		June 30,		December 31,
			Date (1)		Dividend per		2014		2013
					Unit (2)
	Preference Units:
	8.29% Series K Cumulative Redeemable Preference Units;		12/10/26			$4.14	$	50,000	$	50,000
	liquidation value $50 per unit; 1,000,000 units issued and
	outstanding at June 30, 2014 and December 31, 2013
							$	50,000	$	50,000
	-1	On or after the redemption date, redeemable preference units may be redeemed for cash at the option of the Operating Partnership, in whole or in part, at a redemption price equal to the liquidation price per unit, plus accrued and unpaid distributions, if any, in conjunction with the concurrent redemption of the corresponding Company Preferred Shares.
	-2	Dividends on Preference Units are payable quarterly.

Real_Estate_Tables

Real Estate (Tables)	6 Months Ended
	Jun. 30, 2014
Real Estate [Abstract]	'
Schedule of Real Estate Investments And Accumlated Depreciation [Table Text Block}	'
	The following table summarizes the carrying amounts for the Company’s investment in real estate (at cost) as of June 30, 2014 and December 31, 2013 (amounts in thousands):
			June 30,				December 31,
			2014				2013
	Land		$	6,296,735			$	6,192,512
	Depreciable property:
	Buildings and improvements		17,920,222				17,509,609
	Furniture, fixtures and equipment		1,302,882				1,214,220
	In-Place lease intangibles		507,633				502,218
	Projects under development:
	Land		391,156				353,574
	Construction-in-progress		615,836				635,293
	Land held for development:
	Land		256,536				341,389
	Construction-in-progress		50,089				52,133
	Investment in real estate		27,341,089				26,800,948
	Accumulated depreciation		(5,170,438		)		(4,807,709		)
	Investment in real estate, net		$	22,170,651			$	21,993,239
Schedule of Finite-Lived Intangible Assets [Table Text Block]	'
	The following table summarizes the carrying amounts for the Company's above and below market ground and retail lease intangibles as of June 30, 2014 and December 31, 2013 (amounts in thousands):
	Description		Balance Sheet Location		June 30,				December 31,
					2014				2013
	Assets
	Ground lease intangibles – below market		Other Assets		$	178,251			$	178,251
	Retail lease intangibles – above market		Other Assets		1,260				1,260
	Lease intangible assets				179,511				179,511
	Accumulated amortization				(6,641		)		(4,364		)
	Lease intangible assets, net				$	172,870			$	175,147
	Liabilities
	Ground lease intangibles – above market		Other Liabilities		$	2,400			$	2,400
	Retail lease intangibles – below market		Other Liabilities		5,270				5,500
	Lease intangible liabilities				7,670				7,900
	Accumulated amortization				(1,678		)		(1,161		)
	Lease intangible liabilities, net				$	5,992			$	6,739
Schedule of Expected Amortization Expense [Table Text Block]	'
	The following table provides a summary of the aggregate amortization expense for above and below market ground lease intangibles and retail lease intangibles for each of the next five years (amounts in thousands):
			Remaining
			2014				2015				2016			2017			2018			2019
	Ground lease intangibles		$	2,161			$	4,321			$	4,321		$	4,321		$	4,321		$	4,321
	Retail lease intangibles		(469		)		(939		)		(896		)	(540		)	(71		)	(71		)
	Total		$	1,692			$	3,382			$	3,425		$	3,781		$	4,250		$	4,250
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	'
	The following table summarizes the acquisition date fair values of the assets acquired and liabilities assumed, which the Company determined using Level 1, Level 2 and Level 3 inputs (amounts in thousands):
	Land		$	2,239,000
	Depreciable property:
	Buildings and improvements		5,765,538
	Furniture, fixtures and equipment		61,470
	In-Place lease intangibles		304,830
	Projects under development		36,583
	Land held for development		244,097
	Investments in unconsolidated entities		230,608
	Other assets		195,260
	Other liabilities		(108,997		)
	Net assets acquired		$	8,968,389
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Text Block]	'
	The following table summarizes the acquisition date fair values of the above and below market ground and retail lease intangibles, which we determined using Level 2 and Level 3 inputs (amounts in thousands):
	Description		Balance Sheet Location		Fair Value
	Ground lease intangibles – below market		Other Assets		$	178,251
	Retail lease intangibles – above market		Other Assets		1,260
	Ground lease intangibles – above market		Other Liabilities		2,400
	Retail lease intangibles – below market		Other Liabilities		8,040
Acquired Properties Table Text Block	'
	During the six months ended June 30, 2014, the Company disposed of the following to unaffiliated parties (sales price in thousands):
			Properties			Apartment Units			Sales Price
	Rental Properties		1			336			$	40,850
	Land Parcel		—			—			8,200
	Total		1			336			$	49,050
	During the six months ended June 30, 2014, the Company acquired the entire equity interest in the following from unaffiliated parties (purchase price in thousands):
			Properties			Apartment Units			Purchase Price
	Rental Properties – Consolidated		3			772			$	249,610
	Land Parcels – Consolidated		—			—			15,790
	Total		3			772			$	265,400
Statement [Line Items]	'
Business Acquisition, Pro Forma Information [Table Text Block]	'
	The following table illustrates the effect on net income, earnings per share – basic and earnings per share – diluted as if the Company had consummated the Archstone Acquisition as of January 1, 2012 (amounts in thousands, except per share amounts):
			Six Months Ended				Quarter Ended
			30-Jun-13				30-Jun-13
	Total revenues		$	1,256,088			$	635,078
	Income from continuing operations		60,541				96,585
	Discontinued operations, net		1,608,374				389,329
	Net income		1,668,915				485,914
	Net income available to Common Shares		1,601,368				467,237
	Earnings per share - basic:
	Net income available to Common Shares		$	4.45			$	1.3
	Weighted average Common Shares outstanding (1)		359,509				359,653
	Earnings per share - diluted:
	Net income available to Common Shares		$	4.44			$	1.29
	Weighted average Common Shares outstanding (1)		375,722				375,910
	-1	Includes an adjustment for Common Shares issued to the public in November/December 2012 and to an affiliate of Lehman Brothers Holdings Inc. in February 2013 as partial consideration for the Archstone Acquisition.
Limited Partner [Member]	'
Statement [Line Items]	'
Business Acquisition, Pro Forma Information [Table Text Block]	'
	The following table illustrates the effect on net income, earnings per Unit – basic and earnings per Unit – diluted as if the Operating Partnership had consummated the Archstone Acquisition as of January 1, 2012 (amounts in thousands, except per Unit amounts):
			Six Months Ended				Quarter Ended
			30-Jun-13				30-Jun-13
	Total revenues		$	1,256,088			$	635,078
	Income from continuing operations		60,541				96,585
	Discontinued operations, net		1,608,374				389,329
	Net income		1,668,915				485,914
	Net income available to Units		1,668,439				485,693
	Earnings per Unit - basic:
	Net income available to Units		$	4.45			$	1.3
	Weighted average Units outstanding (1)		373,245				373,403
	Earnings per Unit - diluted:
	Net income available to Units		$	4.44			$	1.29
	Weighted average Units outstanding (1)		375,722				375,910
	-1	Includes an adjustment for Common Shares issued to the public in November/December 2012 and to an affiliate of Lehman Brothers Holdings Inc. in February 2013 as partial consideration for the Archstone Acquisition. Concurrent with these transactions, ERPOP issued the same number of OP Units to EQR.

Commitments_to_AcquireDispose_1

Commitments to Acquire/Dispose of Real Estate (Tables)	6 Months Ended
	Jun. 30, 2014
Commitments to Acquire Dispose of Real Estate [Abstract]	'
Real Estate to be Acquired Table Text Block	'
	he Company has entered into a separate agreement to acquire the following (purchase price in thousands):
		Properties	Apartment Units	Purchase Price
	Land Parcel	—	—	$	3,300
	Total	—	—	$	3,300
Real Estate To Be Disposed Of Text Block	'
	The Company has entered into separate agreements to dispose of the following (sales price in thousands):
		Properties	Apartment Units	Sales Price
	Rental Properties	6	2,005	$	306,350
	Land Parcel	—	—	54,402
	Total	6	2,005	$	360,752

Investments_in_Partially_Owned1

Investments in Partially Owned Entities (Tables)	6 Months Ended
	Jun. 30, 2014
Investments in Partially Owned Entities [Abstract]	'
Partially Owned Property Balance Sheet Schedule [Table Text Block]	'
	The following tables and information summarize the Company’s investments in partially owned entities as of June 30, 2014 (amounts in thousands except for project and apartment unit amounts):
		Consolidated									Unconsolidated
		Development Projects									Development Projects
		Held for			Operating			Total			Held for			Completed, Not Stabilized (3)			Operating			Total
		and/or Under									and/or Under
		Development									Development
	Total projects (1)	—			19			19			—			2			2			4
	Total apartment units (1)	—			3,752			3,752			—			945			724			1,669
	Balance sheet information at 6/30/14 (at 100%):
	ASSETS
	Investment in real estate	$	329,668		$	676,848		$	1,006,516		$	55,998		$	233,411		$	108,164		$	397,573
	Accumulated depreciation	—			(183,571		)	(183,571		)	—			(6,693		)	(7,136		)	(13,829		)
	Investment in real estate, net	329,668			493,277			822,945			55,998			226,718			101,028			383,744
	Cash and cash equivalents	4,488			14,125			18,613			454			2,830			1,582			4,866
	Investments in unconsolidated entities	—			53,209			53,209			—			—			—			—
	Deposits – restricted	34,761			250			35,011			—			130			47			177
	Deferred financing costs, net	—			2,318			2,318			53			4			122			179
	Other assets	6,679			26,176			32,855			14			41			1,250			1,305
	Total assets	$	375,596		$	589,355		$	964,951		$	56,519		$	229,723		$	104,029		$	390,271
	LIABILITIES AND EQUITY/CAPITAL
	Mortgage notes payable (2)	$	—		$	360,305		$	360,305		$	21,982		$	145,016		$	63,305		$	230,303
	Accounts payable & accrued expenses	12,313			1,730			14,043			5,095			955			350			6,400
	Accrued interest payable	—			1,265			1,265			43			687			42			772
	Other liabilities	140			1,252			1,392			—			244			1,046			1,290
	Security deposits	—			1,916			1,916			—			279			140			419
	Total liabilities	12,453			366,468			378,921			27,120			147,181			64,883			239,184
	Noncontrolling Interests – Partially Owned	117,677			8,166			125,843			27,858			70,428			23,434			121,720
	Properties/Partners' equity
	Company equity/General and Limited Partners'	245,466			214,721			460,187			1,541			12,114			15,712			29,367
	Capital
	Total equity/capital	363,143			222,887			586,030			29,399			82,542			39,146			151,087
	Total liabilities and equity/capital	$	375,596		$	589,355		$	964,951		$	56,519		$	229,723		$	104,029		$	390,271
Partially Owned Property Income Statement Schedule [Table Text Block]	'
		Consolidated									Unconsolidated
		Development Projects									Development Projects
		Held for									Held for						Operating
		and/or Under									and/or Under			Completed, Not Stabilized (3)
		Development			Operating			Total			Development									Total
	Operating information for the six months
	ended 6/30/14 (at 100%):
	Operating revenue	$	—		$	43,110		$	43,110		$	—		$	7,958		$	5,060		$	13,018
	Operating expenses	154			12,825			12,979			132			3,287			1,856			5,275
	Net operating (loss) income	(154		)	30,285			30,131			(132		)	4,671			3,204			7,743
	Depreciation	—			10,768			10,768			—			5,299			2,039			7,338
	General and administrative/other	(3		)	26			23			—			1			122			123
	Operating (loss) income	(151		)	19,491			19,340			(132		)	(629		)	1,043			282
	Interest and other income	—			3			3			—			—			—			—
	Other expenses	(76		)	(32		)	(108		)	—			—			—			—
	Interest:
	Expense incurred, net	—			(7,788		)	(7,788		)	—			(3,864		)	(926		)	(4,790		)
	Amortization of deferred financing costs	—			(177		)	(177		)	—			—			(7		)	(7		)
	(Loss) income before income and other taxes	(227		)	11,497			11,270			(132		)	(4,493		)	110			(4,515		)
	and (loss) from investments in
	unconsolidated entities
	Income and other tax (expense) benefit	—			(45		)	(45		)	—			(7		)	—			(7		)
	(Loss) from investments in unconsolidated	—			(879		)	(879		)	—			—			—			—
	entities
	Net (loss) income	$	(227	)	$	10,573		$	10,346		$	(132	)	$	(4,500	)	$	110		$	(4,522	)
	-1	Project and apartment unit counts exclude all uncompleted development projects until those projects are substantially completed.
	-2	All debt is non-recourse to the Company with the exception of 50% of the current $22.0 million outstanding debt balance on one unconsolidated development project.
	-3	Projects included here are substantially complete. However, they may still require additional exterior and interior work for all units to be available for leasing.
	Note:	The above tables exclude the Company's interests in unconsolidated joint ventures entered into with AVB in connection with the Archstone Transaction. These ventures own certain non-core Archstone assets that are held for sale and succeeded to certain residual Archstone liabilities, such as liability for various employment-related matters as well as responsibility for tax protection arrangements and third-party preferred interests in former Archstone subsidiaries. The preferred interests have an aggregate liquidation value of $76.8 million at June 30, 2014. The ventures are owned 60% by the Company and 40% by AVB.

Deposits_Restricted_Tables

Deposits - Restricted (Tables)	6 Months Ended
	Jun. 30, 2014
Deposits - Restricted [Abstract]	'
Schedule of Restricted Cash and Cash Equivalents [Table Text Block]	'
	The following table presents the Company’s restricted deposits as of June 30, 2014 and December 31, 2013 (amounts in thousands):
		June 30,		December 31,
		2014		2013
	Earnest money on pending acquisitions	$	830	$	4,514
	Restricted deposits on real estate investments	36,476		53,771
	Resident security and utility deposits	46,597		44,777
	Other	505		505
	Totals	$	84,408	$	103,567
Escrow Deposits [Text Block]	'
	The following table presents the Company’s escrow deposits as of June 30, 2014 and December 31, 2013 (amounts in thousands):
		June 30,		December 31,
		2014		2013
	Real estate taxes and insurance	$	3,500	$	3,687
	Replacement reserves	3,469		4,229
	Mortgage principal reserves/sinking funds	37,448		33,868
	Other	852		852
	Totals	$	45,269	$	42,636

Derivative_and_Other_Fair_Valu1

Derivative and Other Fair Value Instruments (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Derivative Instrument Table	'
	The following table summarizes the Company’s consolidated derivative instruments at June 30, 2014 (dollar amounts are in thousands):
			Fair Value				Forward
			Hedges (1)				Starting
							Swaps (2)
	Current Notional Balance		$	450,000			$	100,000
	Lowest Possible Notional		$	450,000			$	100,000
	Highest Possible Notional		$	450,000			$	100,000
	Lowest Interest Rate		2.375		%		3.14		%
	Highest Interest Rate		2.375		%		3.191		%
	Earliest Maturity Date		2019				2025
	Latest Maturity Date		2019				2025
	-1	Fair Value Hedges – Converts outstanding fixed rate unsecured notes ($450.0 million 2.375%notes due July 1, 2019) to a floating interest rate of 90-Day LIBOR plus 0.61%.
	-2	Forward Starting Swaps – Designed to partially fix interest rates in advance of a planned future debt issuance. These swaps have mandatory counterparty terminations in 2016, and are targeted to 2015 issuances.
Schedule of Location and Amount of Financial Instruments on Balanace Sheet	'
	The following tables provide a summary of the fair value measurements for each major category of assets and liabilities measured at fair value on a recurring basis and the location within the accompanying consolidated balance sheets at June 30, 2014 and December 31, 2013, respectively (amounts in thousands):
									Fair Value Measurements at Reporting Date Using
	Description		Balance Sheet		6/30/14				Quoted Prices in			Significant  Other				Significant
			Location						Active Markets for			Observable Inputs				Unobservable Inputs
									Identical Assets/Liabilities			(Level 2)				(Level  3)
									(Level 1)
	Assets
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Fair Value Hedges		Other Assets		$	1,452			$	—		$	1,452			$	—
	Supplemental Executive Retirement Plan		Other Assets		97,543				97,543			—				—
	Total				$	98,995			$	97,543		$	1,452			$	—
	Liabilities
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Forward Starting Swaps		Other Liabilities		$	2,346			$	—		$	2,346			$	—
	Supplemental Executive Retirement Plan		Other Liabilities		97,543				97,543			—				—
	Total				$	99,889			$	97,543		$	2,346			$	—
	Redeemable Noncontrolling Interests –
	Operating Partnership/Redeemable
	Limited Partners		Mezzanine		$	440,050			$	—		$	440,050			$	—
									Fair Value Measurements at Reporting Date Using
	Description		Balance Sheet		12/31/13				Quoted Prices in			Significant  Other				Significant
			Location						Active Markets for			Observable Inputs				Unobservable Inputs
									Identical Assets/Liabilities			(Level 2)				(Level  3)
									(Level 1)
	Assets
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Forward Starting Swaps		Other Assets		$	18,710			$	—		$	18,710			$	—
	Supplemental Executive Retirement Plan		Other Assets		83,845				83,845			—				—
	Total				$	102,555			$	83,845		$	18,710			$	—
	Liabilities
	Supplemental Executive Retirement Plan		Other Liabilities		$	83,845			$	83,845		$	—			$	—
	Total				$	83,845			$	83,845		$	—			$	—
	Redeemable Noncontrolling Interests –
	Operating Partnership/Redeemable
	Limited Partners		Mezzanine		$	363,144			$	—		$	363,144			$	—
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	'
	The following tables provide a summary of the effect of fair value hedges on the Company’s accompanying consolidated statements of operations and comprehensive income for the six months ended June 30, 2014 and 2013, respectively (amounts in thousands):
	30-Jun-14		Location of		Amount of				Hedged Item		Income Statement	Amount of
	Type of Fair Value Hedge		Gain/(Loss)		Gain/(Loss)						Location of	Gain/(Loss)
			Recognized in		Recognized in						Hedged Item	Recognized in
			Income on		Income on						Gain/(Loss)	Income
			Derivative		Derivative							on Hedged Item
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Interest Rate Swaps		Interest expense		$	1,452			Fixed rate debt		Interest expense	$	(1,452	)
	Total				$	1,452						$	(1,452	)
	30-Jun-13		Location of		Amount of				Hedged Item		Income Statement	Amount of
	Type of Fair Value Hedge		Gain/(Loss)		Gain/(Loss)						Location of	Gain/(Loss)
			Recognized in		Recognized in						Hedged Item	Recognized in
			Income		Income						Gain/(Loss)	Income
			on Derivative		on Derivative							on Hedged Item
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Interest Rate Swaps		Interest expense		$	(1,524	)		Fixed rate debt		Interest expense	$	1,524
	Total				$	(1,524	)					$	1,524
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	'
	The following tables provide a summary of the effect of cash flow hedges on the Company’s accompanying consolidated statements of operations and comprehensive income for the six months ended June 30, 2014 and 2013, respectively (amounts in thousands):
			Effective Portion									Ineffective Portion
	30-Jun-14		Amount of				Location of Gain/		Amount of Gain/			Location of		Amount of Gain/
	Type of Cash Flow Hedge		Gain/(Loss)				(Loss)		(Loss)			Gain/(Loss)		(Loss)
			Recognized in OCI				Reclassified from		Reclassified from			Recognized in		Reclassified from
			on Derivative				Accumulated		Accumulated			Income		Accumulated
							OCI into Income		OCI into Income			on Derivative		OCI into Income
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Forward Starting Swaps/Treasury Locks		$	(21,790	)		Interest expense		$	(8,335	)	Interest expense		$	91
	Total		$	(21,790	)				$	(8,335	)			$	91
			Effective Portion									Ineffective Portion
	30-Jun-13		Amount of				Location of Gain/		Amount of Gain/			Location of		Amount of Gain/
	Type of Cash Flow Hedge		Gain/(Loss)				(Loss)		(Loss)			Gain/(Loss)		(Loss)
			Recognized in OCI				Reclassified from		Reclassified from			Recognized in		Reclassified from
			on Derivative				Accumulated		Accumulated			Income		Accumulated
							OCI into Income		OCI into Income			on Derivative		OCI into Income
	Derivatives designated as hedging instruments:
	Interest Rate Contracts:
	Forward Starting Swaps/Treasury Locks		$	12,337			Interest expense		$	(12,098	)	N/A		$	—
	Total		$	12,337					$	(12,098	)			$	—

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2014
Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block]	'
	The following tables set forth the computation of net income per share – basic and net income per share – diluted for the Company (amounts in thousands except per share amounts):
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	Numerator for net income per share – basic:
	Income (loss) from continuing operations		$	183,987		$	(223,850	)	$	102,307		$	(58,511	)
	Allocation to Noncontrolling Interests – Operating Partnership, net		(7,475		)	9,078			(4,422		)	2,231
	Net gain on sales of real estate properties		14,903			—			14,903			—
	Net (income) loss attributable to Noncontrolling Interests – Partially		(1,092		)	790			(588		)	815
	Owned Properties
	Preferred distributions		(2,072		)	(2,072		)	(1,036		)	(1,036		)
	Income (loss) from continuing operations available to Common Shares,		188,251			(216,054		)	111,164			(56,501		)
	net of Noncontrolling Interests
	Discontinued operations, net of Noncontrolling Interests		1,502			1,556,427			490			380,224
	Numerator for net income per share – basic		$	189,753		$	1,340,373		$	111,654		$	323,723
	Numerator for net income per share – diluted (1):
	Income from continuing operations		$	183,987					$	102,307
	Net gain on sales of real estate properties		14,903						14,903
	Net (income) attributable to Noncontrolling Interests – Partially		(1,092		)				(588		)
	Owned Properties
	Preferred distributions		(2,072		)				(1,036		)
	Income from continuing operations available to Common Shares		195,726						115,586
	Discontinued operations, net		1,562						510
	Numerator for net income per share – diluted (1)		$	197,288		$	1,340,373		$	116,096		$	323,723
	Denominator for net income per share – basic and diluted (1):
	Denominator for net income per share – basic		360,641			348,654			360,809			359,653
	Effect of dilutive securities:
	OP Units		13,736						13,742
	Long-term compensation shares/units		2,403						2,567
	Denominator for net income per share – diluted (1)		376,780			348,654			377,118			359,653
	Net income per share – basic		$	0.53		$	3.84		$	0.31		$	0.9
	Net income per share – diluted		$	0.52		$	3.84		$	0.31		$	0.9
	Net income per share – basic:
	Income (loss) from continuing operations available to Common Shares,		$	0.522		$	(0.620	)	$	0.308		$	(0.157	)
	net of Noncontrolling Interests
	Discontinued operations, net of Noncontrolling Interests		0.004			4.464			0.001			1.057
	Net income per share – basic		$	0.526		$	3.844		$	0.309		$	0.9
	Net income per share – diluted (1):
	Income (loss) from continuing operations available to Common Shares		$	0.52		$	(0.620	)	$	0.307		$	(0.157	)
	Discontinued operations, net		0.004			4.464			0.001			1.057
	Net income per share – diluted		$	0.524		$	3.844		$	0.308		$	0.9
	-1	Potential common shares issuable from the assumed conversion of OP Units and the exercise/vesting of long-term compensation shares/units are automatically anti-dilutive and therefore excluded from the diluted earnings per share calculation as the Company had a loss from continuing operations for the six months and quarter ended June 30, 2013.
Operating Partnership [Member]	'
Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block]	'
	The following tables set forth the computation of net income per Unit – basic and net income per Unit – diluted for the Operating Partnership (amounts in thousands except per Unit amounts):
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	Numerator for net income per Unit – basic and diluted (1):
	Income (loss) from continuing operations		$	183,987		$	(223,850	)	$	102,307		$	(58,511	)
	Net gain on sales of real estate properties		14,903			—			14,903			—
	Net (income) loss attributable to Noncontrolling Interests – Partially		(1,092		)	790			(588		)	815
	Owned Properties
	Allocation to Preference Units		(2,072		)	(2,072		)	(1,036		)	(1,036		)
	Income (loss) from continuing operations available to Units		195,726			(225,132		)	115,586			(58,732		)
	Discontinued operations, net		1,562			1,621,616			510			395,243
	Numerator for net income per Unit – basic and diluted (1)		$	197,288		$	1,396,484		$	116,096		$	336,511
	Denominator for net income per Unit – basic and diluted (1):
	Denominator for net income per Unit - basic		374,377			362,390			374,551			373,403
	Effect of dilutive securities:
	Dilution for Units issuable upon assumed exercise/vesting of the		2,403						2,567
	Company’s long-term compensation shares/units
	Denominator for net income per Unit – diluted (1)		376,780			362,390			377,118			373,403
	Net income per Unit – basic		$	0.53		$	3.84		$	0.31		$	0.9
	Net income per Unit – diluted		$	0.52		$	3.84		$	0.31		$	0.9
	Net income per Unit – basic:
	Income (loss) from continuing operations available to Units		$	0.522		$	(0.620	)	$	0.308		$	(0.157	)
	Discontinued operations, net		0.004			4.464			0.001			1.057
	Net income per Unit – basic		$	0.526		$	3.844		$	0.309		$	0.9
	Net income per Unit – diluted (1):
	Income (loss) from continuing operations available to Units		$	0.52		$	(0.620	)	$	0.307		$	(0.157	)
	Discontinued operations, net		0.004			4.464			0.001			1.057
	Net income per Unit – diluted		$	0.524		$	3.844		$	0.308		$	0.9
	-1	Potential Units issuable from the assumed exercise/vesting of the Company's long-term compensation shares/units are automatically anti-dilutive and therefore excluded from the diluted earnings per Unit calculation as the Operating Partnership had a loss from continuing operations for the six months and quarter ended June 30, 2013.

Discontinued_Operations_Tables

Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Components of discontinued operations	'
	The components of discontinued operations are outlined below and include the results of operations for the respective periods that the Company owned such assets for properties sold in 2013 and prior years during the six months and quarters ended June 30, 2014 and 2013 (amounts in thousands).
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	REVENUES
	Rental income		$	1,275		$	107,956		$	252		$	26,174
	Total revenues		1,275			107,956			252			26,174
	EXPENSES (1)
	Property and maintenance		(41		)	31,449			(89		)	11,025
	Real estate taxes and insurance		(6		)	10,867			(19		)	2,273
	Property management		—			1			—			—
	Depreciation		—			30,962			—			7,146
	General and administrative		51			73			46			65
	Total expenses		4			73,352			(62		)	20,509
	Discontinued operating income		1,271			34,604			314			5,665
	Interest and other income		80			90			45			38
	Other expenses		—			(3		)	—			(1		)
	Interest (2):
	Expense incurred, net		—			(1,258		)	—			(6		)
	Amortization of deferred financing costs		—			(228		)	—			—
	Income and other tax (expense) benefit		(13		)	(463		)	(2		)	(405		)
	Discontinued operations		1,338			32,742			357			5,291
	Net gain on sales of discontinued operations		224			1,588,874			153			389,952
	Discontinued operations, net		$	1,562		$	1,621,616		$	510		$	395,243
	-1	Includes expenses paid in the current period for properties sold in prior periods related to the Company’s period of ownership.
	-2	Includes only interest expense specific to secured mortgage notes payable for properties sold.

Reportable_Segments_Tables

Reportable Segments (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]	'
Reportable Segments Schedule	'
	The following tables present NOI for each segment from our rental real estate specific to continuing operations for the six months and quarters ended June 30, 2014 and 2013, respectively, as well as total assets and capital expenditures at June 30, 2014 (amounts in thousands):
			Six Months Ended June 30, 2014									Six Months Ended June 30, 2013
			Rental Income			Operating Expenses			NOI			Rental Income			Operating Expenses			NOI
	Same store (1)
	Boston		$	125,024		$	41,414		$	83,610		$	120,455		$	39,651		$	80,804
	Denver		54,123			15,098			39,025			50,494			14,987			35,507
	New York		225,407			88,102			137,305			217,297			83,745			133,552
	San Francisco		165,343			52,960			112,383			152,459			54,109			98,350
	Seattle		76,702			25,805			50,897			71,548			24,553			46,995
	South Florida		97,893			36,404			61,489			93,289			35,417			57,872
	Southern California		207,272			69,450			137,822			198,366			69,149			129,217
	Washington DC		222,135			72,499			149,636			223,807			71,049			152,758
	Non-core		65,607			24,495			41,112			63,715			23,931			39,784
	Total same store		1,239,506			426,227			813,279			1,191,430			416,591			774,839
	Non-same store/other (2) (3)
	Boston		1,817			413			1,404			1,154			255			899
	Seattle		4,444			1,779			2,665			1,303			374			929
	South Florida		2,041			1,301			740			24			146			(122		)
	Southern California		15,623			7,452			8,171			5,397			2,593			2,804
	Washington DC		10,840			3,857			6,983			5,320			1,862			3,458
	Other (3)		6,220			7,754			(1,534		)	4,901			13,295			(8,394		)
	Total non-same store/other		40,985			22,556			18,429			18,099			18,525			(426		)
	Archstone pre-ownership (4)		—			—			—			(92,423		)	(36,729		)	(55,694		)
	Total		$	1,280,491		$	448,783		$	831,708		$	1,117,106		$	398,387		$	718,719
	-1	Same store primarily includes all properties acquired or completed and stabilized prior to January 1, 2013, less properties subsequently sold, which represented 100,648 apartment units. Also includes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-2	Non-same store primarily includes properties acquired after January 1, 2013, plus any properties in lease-up and not stabilized as of January 1, 2013, but excludes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-3	Other includes development, other corporate operations and operations prior to sale for properties sold in 2014 that do not meet the new discontinued operations criteria.
	-4	Represents pro forma Archstone pre-ownership results for the period January 1, 2013 to February 27, 2013 that is included in 2013 same store results.
			Quarter Ended June 30, 2014									Quarter Ended June 30, 2013
			Rental Income			Operating Expenses			NOI			Rental Income			Operating Expenses			NOI
	Same store (1)
	Boston		$	63,117		$	19,259		$	43,858		$	61,401		$	19,444		$	41,957
	Denver		27,511			7,648			19,863			25,524			7,770			17,754
	New York		114,221			41,898			72,323			109,299			40,634			68,665
	San Francisco		84,082			26,305			57,777			77,514			25,955			51,559
	Seattle		38,977			13,037			25,940			36,176			12,316			23,860
	South Florida		49,456			18,220			31,236			47,051			17,774			29,277
	Southern California		104,608			34,811			69,797			100,156			34,275			65,881
	Washington DC		111,739			35,102			76,637			112,815			35,165			77,650
	Non-core		33,035			11,806			21,229			32,110			11,880			20,230
	Total same store		626,746			208,086			418,660			602,046			205,213			396,833
	Non-same store/other (2) (3)
	Boston		790			202			588			898			201			697
	Seattle		2,756			1,042			1,714			1,271			373			898
	South Florida		1,241			760			481			14			68			(54		)
	Southern California		8,446			4,261			4,185			4,106			1,976			2,130
	Washington DC		5,906			1,954			3,952			3,512			1,209			2,303
	Other (3)		3,881			2,693			1,188			2,697			3,234			(537		)
	Total non-same store/other		23,020			10,912			12,108			12,498			7,061			5,437
	Total		$	649,766		$	218,998		$	430,768		$	614,544		$	212,274		$	402,270
	-1	Same store primarily includes all properties acquired or completed and stabilized prior to April 1, 2013, less properties subsequently sold, which represented 100,648 apartment units. Also includes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-2	Non-same store primarily includes properties acquired after April 1, 2013, plus any properties in lease-up and not stabilized as of April 1, 2013, but excludes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
	-3	Other includes development, other corporate operations and operations prior to sale for properties sold in 2014 that do not meet the new discontinued operations criteria.
			Six Months Ended June 30, 2014
			Total Assets			Capital Expenditures
	Same store (1)
	Boston		$	1,953,627		$	8,814
	Denver		530,832			1,904
	New York		4,720,592			8,202
	San Francisco		2,753,902			12,704
	Seattle		1,046,051			5,264
	South Florida		1,170,295			7,600
	Southern California		2,978,750			11,953
Washington DC		4,270,418			14,834
Non-core		605,225			3,123
Total same store		20,029,692			74,398
Non-same store/other (2) (3)
Boston		48,830			630
Seattle		226,604			281
South Florida		70,896			16
Southern California		511,343			645
Washington DC		306,594			852
Other (3)		1,797,443			90
Total non-same store/other		2,961,710			2,514
Total		$	22,991,402		$	76,912
-1	Same store primarily includes all properties acquired or completed and stabilized prior to January 1, 2013, less properties subsequently sold, which represented 100,648 apartment units. Also includes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
-2	Non-same store primarily includes properties acquired after January 1, 2013, plus any properties in lease-up and not stabilized as of January 1, 2013, but excludes 18,465 stabilized apartment units acquired in the Archstone Acquisition that are owned and managed by the Company.
-3	Other includes development, other corporate operations and capital expenditures for properties sold.
Reconciliation of NOI	'
	The following table presents a reconciliation of NOI from our rental real estate specific to continuing operations for the six months and quarters ended June 30, 2014 and 2013, respectively (amounts in thousands):
			Six Months Ended June 30,						Quarter Ended June 30,
			2014			2013			2014			2013
	Rental income		$	1,280,491		$	1,117,106		$	649,766		$	614,544
	Property and maintenance expense		(240,961		)	(212,030		)	(115,388		)	(113,501		)
	Real estate taxes and insurance expense		(165,149		)	(141,837		)	(83,055		)	(76,742		)
	Property management expense		(42,673		)	(44,520		)	(20,555		)	(22,031		)
	Total operating expenses		(448,783		)	(398,387		)	(218,998		)	(212,274		)
	Net operating income		$	831,708		$	718,719		$	430,768		$	402,270

Business_Details

Business (Details)	Jun. 30, 2014
Noncontrolling Interest, Ownership Percentage by Parent	96.20%
Number of Real Estate Properties	397
Number of States in which Entity Operates	12
Number of Units in Real Estate Property	111,491
Consolidated Entities [Member]	'
Number of Real Estate Properties	369
Number of Units in Real Estate Property	100,210
Master-Leased Properties [Member]	'
Number of Real Estate Properties	3
Number of Units in Real Estate Property	853
Consolidated Properties [Member]	'
Number of Real Estate Properties	19
Number of Units in Real Estate Property	3,752
Unconsolidated Properties [Member]	'
Number of Real Estate Properties	4
Number of Units in Real Estate Property	1,669
Military Housing [Member]	'
Number of Real Estate Properties	2
Number of Units in Real Estate Property	5,007

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Number of Real Estate Properties	397	'
Number of Units in Real Estate Property	111,491	'
Noncontrolling Interests - Partially Owned Properties	$125,843,000	$126,583,000
Noncontrolling Interest Balance Limited Life Partnerships	-10,200,000	'
Noncontrolling Interests Settlement Value	$53,200,000	'
Consolidated Properties [Member]	'	'
Number of Real Estate Properties	19	'
Number of Units in Real Estate Property	3,752	'
Limited Life Partnership Properties [Member]	'	'
Number of Real Estate Properties	6	'

Equity_Capital_and_Other_Inter2

Equity, Capital and Other Interests EQR Common Shares (Details)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Common Shares of beneficial interest, shares outstanding	361,562,007	360,479,260
Common Shares Issued:	'	'
Conversion of OP Units	56,536	'
Exercise of share options	851,514	'
Employee Share Purchase Plan (ESPP)	47,457	'
Restricted Share Grants Net	170,626	'
Conversion Of Restricted Shares To Ltip Units Shares	-12,146	'
Stock Repurchased And Retired	-31,240	'
Units	'	'
Common Shares And Units Outstanding	375,898,833	'
Units Ownership Interest in Operating Partnership	3.80%	'
Limited Partner [Member]	'	'
Limited Partners' Capital Account, Units Outstanding	14,336,826	14,180,376
Common Shares Issued:	'	'
Conversion of OP Units	-56,536	'
Conversion Of Restricted Shares To Ltip Units Shares	12,146	'
Units	'	'
Issuance Of LTIPs	200,840	'

Equity_Capital_and_Other_Inter3

Equity, Capital and Other Interests Redeemable (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Redeemable Noncontrolling Interests - Operating Partnership	$440,050	$363,144
Change in market value	80,615	'
Change in carrying value	-3,709	'
Limited Partners Change In Redemption Value	80,615	'
Limited Partners Change In Carrying Value	($3,709)	'

Equity_Capital_and_Other_Inter4

Equity, Capital and Other Interests Preferred (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock, Par or Stated Value Per Share	$0.01	$0.01
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 1,000,000 shares issued and outstanding as of June 30, 2014 and December 31, 2013	$50,000	$50,000
Series K Preferred Stock [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock Preference Units Issued	1,000,000	1,000,000
Preferred Stock Preference Units Outstanding	1,000,000	1,000,000
Preferred Stock Preference Units Redemption Price Per Share Unit	$50	$50
Preferred Stock Preference Units Dividend Rate Percentage	8.29%	8.29%
Preferred Stocks Preference Units Redemption Date	10-Dec-26	'
Annual Dividend Per Preferred Share Preference Unit	$4.14	'
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 1,000,000 shares issued and outstanding as of June 30, 2014 and December 31, 2013	50,000	50,000
Preferred Units, Preferred Partners' Capital Accounts	$50,000	$50,000

Equity_Capital_and_Other_Inter5

Equity, Capital and Other Interests ERP Units (Details)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Capital Unit [Line Items]	'	'
Common Shares And Units Outstanding	375,898,833	'
Exercise of EQR share options	851,514	'
EQR's Employee Share Purchase Plan (ESPP)	47,457	'
Restricted Share Grants Net	170,626	'
OP Units repurchased and retired	31,240	'
Conversion Of Restricted Shares To Ltip Units Shares	-12,146	'
Shares Issued During Period Shares Conversion Of Units To Common Shares	56,536	'
Units Ownership Interest in Operating Partnership	3.80%	'
Limited Partner [Member]	'	'
Capital Unit [Line Items]	'	'
Limited Partners' Capital Account, Units Outstanding	14,336,826	14,180,376
Issuance Of LTIPs	200,840	'
Conversion Of Restricted Shares To Ltip Units Shares	12,146	'
Shares Issued During Period Shares Conversion Of Units To Common Shares	-56,536	'
Limited Partner [Member]	'	'
Capital Unit [Line Items]	'	'
Limited Partners' Capital Account, Units Outstanding	14,336,826	14,180,376
Issuance Of LTIPs	200,840	'
Conversion Of Restricted Shares To Ltip Units Shares	12,146	'
Shares Issued During Period Shares Conversion Of Units To Common Shares	-56,536	'
General And Limited Partner [Member]	'	'
Capital Unit [Line Items]	'	'
Common Shares And Units Outstanding	375,898,833	374,659,636
Exercise of EQR share options	851,514	'
EQR's Employee Share Purchase Plan (ESPP)	47,457	'
Restricted Share Grants Net	170,626	'
Issuance Of LTIPs	200,840	'
OP Units repurchased and retired	-31,240	'

Equity_Capital_and_Other_Inter6

Equity, Capital and Other Interests Text (Details) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Jun. 30, 2014
Additional Common Shares Authorized	'	13,000,000
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	'	13,000,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	'	12,968,760
Stock Repurchased And Retired	'	-31,240
Treasury Stock Acquired, Average Cost Per Share	'	56.87
Value Of Stock Repurchased And Retired	'	1,800,000
OP Units repurchased and retired	'	31,240
Number of Units in Real Estate Property	'	111,491
Payments to Acquire Interest in Subsidiaries and Affiliates	'	5,500,000
Increase To Reduction Of Paid In Capital	'	2,300,000
Reduction In Partially Owned Properties	'	2,200,000
Reduction In Other Liabilities	'	1,000,000
Archstone Transaction [Member]	'	'
Issuance of Common Shares	34,468,085	'
Stock Issued During Period, Value, New Issues	$1,900,000,000	'
Average Price Per Common Share Issued	$55.99	'
Units Issued During Period New Issues	'	34,468,085
Enclave at Wellington [Domain]	'	'
Number of Units in Real Estate Property	'	268

Real_Estate_Details

Real Estate (Details) (USD $)

3 Months Ended

6 Months Ended

16 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

16 Months Ended

3 Months Ended

6 Months Ended

16 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

Jun. 30, 2013

Mar. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Mar. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Mar. 31, 2013

Jun. 30, 2013

Jun. 30, 2014

Mar. 31, 2013

Mar. 31, 2013

Jun. 30, 2013

Mar. 31, 2013

Jun. 30, 2013

Jun. 30, 2014

Mar. 31, 2013

Jun. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Mar. 31, 2013

Jun. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Mar. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Retail Site [Member]

Retail Site [Member]

Retail Site [Member]

Retail Site [Member]

Assets [Member]

Assets [Member]

Assets [Member]

Liability [Member]

Liability [Member]

Liability [Member]

Consolidated Properties [Member]

Ground Lease [Member]

Ground Lease [Member]

Ground Lease [Member]

Ground Lease [Member]

Archstone [Member]

Archstone [Member]

Archstone [Member]

Building and Building Improvements [Member]

Furniture and Fixtures [Member]

Archstone Transaction [Member]

Archstone Transaction [Member]

Archstone Transaction [Member]

Archstone Transaction [Member]

Unconsolidated Properties [Member]

Investment Banking and Legal/Accounting Fees [Member]

Projects under development [Member]

Projects under development [Member]

Land held for development [Member]

Land held for development [Member]

Archstone Transaction [Member]

OPERATING PARTNERSHIP

OPERATING PARTNERSHIP

Public Offering [Member]

Term Loan [Member]

Consolidated Rental Properties [Member]

Consolidated Rental Properties [Member]

Land [Member]

Land

'

'

$6,296,735,000

'

$6,296,735,000

$6,192,512,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

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'

'

'

'

'

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'

'

'

'

'

'

'

Property, Plant and Equipment, Gross [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment Building and Building Improvements

'

'

17,920,222,000

'

17,920,222,000

17,509,609,000

'

'

'

'

'

'

'

'

'

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'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixtures and Equipment, Gross

'

'

1,302,882,000

'

1,302,882,000

1,214,220,000

'

'

'

'

'

'

'

'

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'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Asset, Acquired-in-Place Leases

'

'

507,633,000

'

507,633,000

502,218,000

'

'

'

'

'

'

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'

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Land Under Development

'

'

'

'

'

'

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'

'

'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

391,156,000

353,574,000

'

'

'

'

'

'

'

'

'

'

Projects under development

'

'

1,006,992,000

'

1,006,992,000

988,867,000

'

'

'

'

'

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'

'

615,836,000

635,293,000

50,089,000

52,133,000

'

'

'

'

'

'

'

'

Land held for development

'

'

306,625,000

'

306,625,000

393,522,000

'

'

'

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'

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'

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'

'

'

'

'

'

'

'

'

256,536,000

341,389,000

'

'

'

'

'

'

'

'

Real Estate Investment Property, at Cost

'

'

27,341,089,000

'

27,341,089,000

26,800,948,000

'

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'

'

'

'

Real Estate Investment Property, Accumulated Depreciation

'

'

-5,170,438,000

'

-5,170,438,000

-4,807,709,000

'

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'

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'

'

'

'

'

'

'

Investment in real estate, net

'

'

22,170,651,000

'

22,170,651,000

21,993,239,000

'

'

'

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'

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'

'

'

Below Market Lease, Gross

'

'

'

'

'

'

'

'

'

'

178,251,000

178,251,000

178,251,000

5,270,000

5,500,000

8,040,000

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Asset, Off-market Lease, Favorable, Gross

'

1,260,000

1,260,000

'

1,260,000

1,260,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Gross

'

'

179,511,000

'

179,511,000

179,511,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of Intangible Assets

'

'

-6,641,000

'

-6,641,000

-4,364,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease Intangible Assets, Net

'

'

172,870,000

'

172,870,000

175,147,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Off-market Lease, Unfavorable

'

'

'

'

'

'

'

'

'

'

'

'

'

2,400,000

2,400,000

2,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease Intangible Liabilities

'

'

7,670,000

'

7,670,000

7,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization Of Intangible Liabilities

'

'

-1,678,000

'

-1,678,000

-1,161,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease Intangible Liabilities, net

'

'

5,992,000

'

5,992,000

6,739,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of Intangible Assets

'

'

1,530,000

1,216,000

'

'

300,000

100,000

600,000

200,000

'

'

'

'

'

'

'

1,100,000

1,000,000

2,200,000

1,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Ground Lease Amortization Period

'

'

49.8

'

49.8

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Retail Lease Amortization Period

'

'

2.8

'

2.8

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year

'

'

1,692,000

'

1,692,000

'

-469,000

'

-469,000

'

'

'

'

'

'

'

'

2,161,000

'

2,161,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months

'

'

3,382,000

'

3,382,000

'

-939,000

'

-939,000

'

'

'

'

'

'

'

'

4,321,000

'

4,321,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Amortization Expense, Year Two

'

'

3,425,000

'

3,425,000

'

-896,000

'

-896,000

'

'

'

'

'

'

'

'

4,321,000

'

4,321,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Amortization Expense, Year Three

'

'

3,781,000

'

3,781,000

'

-540,000

'

-540,000

'

'

'

'

'

'

'

'

4,321,000

'

4,321,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Amortization Expense, Year Four

'

'

4,250,000

'

4,250,000

'

-71,000

'

-71,000

'

'

'

'

'

'

'

'

4,321,000

'

4,321,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Amortization Expense, Year Five

'

'

4,250,000

'

4,250,000

'

-71,000

'

-71,000

'

'

'

'

'

'

'

'

4,321,000

'

4,321,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Properties acquired

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

71

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

Property Units Acquired

'

'

772

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,160

'

'

'

'

772

'

'

Partially Owned Properties Acquired Properties

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partially Owned Units Acquired Units

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

432

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partially Owned Unconsolidated Properties Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partially Owned Unconsolidated Units Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

336

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Master Leased Properties Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Master Leased Units Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

853

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Uncompleted Development Properties Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

4

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

Uncompleted Development Units Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

964

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Land parcels acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,968,389,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

151,900,000

'

204,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

103,900,000

'

140,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments to Acquire Businesses, Net of Cash Acquired

'

'

0

4,000,875,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Mortgage notes payable

'

'

5,158,091,000

'

5,158,091,000

5,174,166,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Common Shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

21,850,000

'

'

'

'

Stock Issued During Period, Value, New Issues

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,200,000,000

'

'

'

'

Average Price Per Common Share Issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$54.75

'

'

'

'

Noncash or Part Noncash Acquisition, Debt Assumed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Mark-to-Market Debt Premiums

'

127,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds From Sale Of Property

'

'

49,050,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

40,850,000

4,500,000,000

8,200,000

Term Loan Principal Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

750,000,000

'

'

'

Number of Properties Subject to Ground Leases

'

9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Real Estate Properties

'

'

397

'

397

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Purchase Price Allocation, Land

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,239,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,765,538,000

61,470,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

304,830,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination Purchase Price Allocation Projects Under Development

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

36,583,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination Purchase Price Allocation Land Held for Development

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

244,097,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination Purchase Price Allocation Investments in Unconsolidated Entities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

230,608,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Purchase Price Allocation, Other Assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

195,260,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Purchase Price Allocation, Other Liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-108,997,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Acquisition Related Costs

'

'

100,000

100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments of Financing Costs

'

'

10,881,000

18,006,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,500,000

13,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments for Merger Related Costs

'

'

'

19,600,000

87,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

19,600,000

'

'

'

'

'

'

'

'

'

'

'

'

Income Loss From Equity Method Investments Merger Expenses

'

'

6,200,000

53,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Pro Forma Revenue

635,078,000

'

'

1,256,088,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

635,078,000

1,256,088,000

'

'

'

'

'

Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax

96,585,000

'

'

60,541,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

96,585,000

60,541,000

'

'

'

'

'

Business Acquisition, Proforma Income Loss From Discontinued Operations Net Of Tax

389,329,000

'

'

1,608,374,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

389,329,000

1,608,374,000

'

'

'

'

'

Business Acquisition, Pro Forma Net Income (Loss)

485,914,000

'

'

1,668,915,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

485,914,000

1,668,915,000

'

'

'

'

'

Business Acquisition, Proforma Net Income Available to Common Shares

467,237,000

'

'

1,601,368,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Proforma Net Income Available to Units

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

485,693,000

1,668,439,000

'

'

'

'

'

Business Acquisition, Pro Forma Earnings Per Share, Basic

$1.30

'

'

$4.45

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.30

$4.45

'

'

'

'

'

Business Acquisition, Pro Forma Earnings Per Share, Diluted

$1.29

'

'

$4.44

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.29

$4.44

'

'

'

'

'

Business Acquisition, Proforma Weighted Average Common Shares Basic

359,653,000

'

'

359,509,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Proforma Weighted Average Number Of Shares Diluted

375,910,000

'

'

375,722,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Proforma Weighted Average Limited Partnership And General Partnership Units Outstanding Basic

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

373,403,000

373,245,000

'

'

'

'

'

Business Acquisition, Proforma Weighted Average Number Of Limited Partnership And General Partnership Unit Outstanding Diluted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

375,910,000

375,722,000

'

'

'

'

'

Severance Costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$50,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Real_Estate_Details_2

Real Estate (Details 2) (USD $)

3 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Consolidated Rental Properties [Member]

Consolidated Rental Properties [Member]

Land [Member]

Ground Lease [Member]

Ground Lease [Member]

Ground Lease [Member]

Ground Lease [Member]

Retail Site [Member]

Retail Site [Member]

Retail Site [Member]

Retail Site [Member]

Amortization of Intangible Assets

'

'

$1,530,000

$1,216,000

'

'

'

$1,100,000

$1,000,000

$2,200,000

$1,400,000

$300,000

$100,000

$600,000

$200,000

Income Loss From Equity Method Investments Merger Expenses

'

'

6,200,000

53,000,000

'

'

'

'

'

'

'

'

'

'

'

Properties acquired

'

'

3

'

3

'

'

'

'

'

'

'

'

'

'

Property Units Acquired

'

'

772

'

772

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets

265,400,000

'

265,400,000

'

249,610,000

'

15,790,000

'

'

'

'

'

'

'

'

Disposed Properties

'

'

1

'

1

'

'

'

'

'

'

'

'

'

'

Disposed Units

'

'

336

'

336

'

'

'

'

'

'

'

'

'

'

Proceeds From Sale Of Property

'

'

49,050,000

'

40,850,000

4,500,000,000

8,200,000

'

'

'

'

'

'

'

'

Net gain on sales of real estate properties

14,903,000

0

14,903,000

0

'

'

'

'

'

'

'

'

'

'

'

Net gain on sales of land parcels

$824,000

$14,616,000

$794,000

$14,616,000

'

'

'

'

'

'

'

'

'

'

'

Commitments_to_AcquireDispose_2

Commitments to Acquire/Dispose of Real Estate (Details) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Commitments to Acquire Real Estate	'
Properties Acquired-Total	0
Rental Units Acquired - Total	0
Purchase Price - Total	$3,300
Commitments to Dispose of Real Estate	'
Properties Disposed - Total	6
Rental Units Disposed-Total	2,005
Sales Price For Commitments To Dispose	360,752
Rental Properties Disposed of [Member]	'
Commitments to Dispose of Real Estate	'
Properties Disposed - Total	6
Rental Units Disposed-Total	2,005
Sales Price For Commitments To Dispose	306,350
Land [Member]	'
Commitments to Dispose of Real Estate	'
Sales Price For Commitments To Dispose	54,402
Land [Member]	'
Commitments to Acquire Real Estate	'
Purchase Price - Total	$3,300

Investments_in_Partially_Owned2

Investments in Partially Owned Entities (Details) (USD $)

3 Months Ended

6 Months Ended

6 Months Ended

16 Months Ended

6 Months Ended

6 Months Ended

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Mar. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

San Norterra [Domain]

Consolidated Development Projects Held for and or Under Development [Member]

Consolidated Operating [Domain]

Consolidated Total [Domain]

Unconsolidated Development Projects Held for and or Under Development [Domain]

Unconsolidated Completed, Not Stabilized [Domain]

Unconsolidated Operating [Domain]

Unconsolidated Total [Domain]

Parc on Powell (formerly 1333 Powell) [Domain]

Archstone Transaction [Member]

Archstone Transaction [Member]

Residual JV [Domain]

East Palmetto Park [Domain]

Wisconsin Place [Domain]

San Norterra [Domain]

Waterton Tenside [Domain]

Parc on Powell (formerly 1333 Powell) [Domain]

Joint Venture Partner [Member]

Company's Portion [Member]

Nexus Sawgrass [Member]

Domain [Member]

London Interbank Offered Rate (LIBOR) [Member]

London Interbank Offered Rate (LIBOR) [Member]

San Norterra [Domain]

Parc on Powell (formerly 1333 Powell) [Domain]

Investments In Partially Owned Entities (Textuals) [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liquidation Value Preferred Interests

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$76,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Percentage of Voting Interests Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

60.00%

'

90.00%

75.00%

'

'

'

'

'

'

'

'

'

Joint Venture Partner Ownership Percentage

80.00%

'

80.00%

'

'

'

'

'

'

'

'

'

'

'

'

40.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Partially Owned Consolidated Units to be Developed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

377

'

'

'

'

'

'

'

'

'

'

Initial Basis of Real Estate, Consolidated

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,200,000

198,500,000

'

'

'

'

'

'

'

'

'

Equity Method Investment, Ownership Percentage

20.00%

'

20.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

85.00%

20.00%

5.00%

'

'

'

'

'

'

Initial Basis of Real Estate, Unconsolidated

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16,900,000

5,100,000

2,100,000

'

'

'

'

'

'

Project Cost

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

52,800,000

'

75,000,000

'

'

79,000,000

155,800,000

'

'

Maximum Debt Commitment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

34,800,000

'

39,500,000

'

'

48,700,000

98,600,000

'

'

Debt Instrument, Description of Variable Rate Basis

'

'

'

'

'

'

'LIBOR plus 2.00%

'

'

'

'

'

'

'

'LIBOR plus 2.25%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Basis Spread on Variable Rate

'

'

1.05%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.00%

2.25%

Debt Instrument, Maturity Date

'

'

1-May-61

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6-Jan-15

1-Dec-18

14-Aug-15

'

'

1-Jan-21

1-Jan-22

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.66%

'

'

'

5.60%

5.75%

'

'

Partially Owned Unconsolidated Units To Be Developed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

176

'

'

'

'

'

'

Guarantor Obligations, Maximum Exposure

'

'

'

'

'

'

'

'

'

'

'

'

'

'

19,700,000

'

'

'

'

'

'

'

19,700,000

'

'

'

'

'

'

Proceeds From Distributions Received From Unconsolidated Subsidiaries

'

'

64,669,000

0

'

'

'

'

'

'

'

'

'

'

'

83,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred Interests

'

'

65,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

39,000,000

'

'

'

'

Land purchase price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

57,900,000

76,100,000

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets

265,400,000

'

265,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

75,700,000

102,500,000

'

'

'

'

Investment in Joint Venture

327,900,000

'

327,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Joint Ventures

2

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partners Payments To Acquire Equity Method Investments

'

'

40,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partially Owned Property Balance Sheet Schedule

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Real Estate Properties

397

'

397

'

'

'

'

0

19

19

0

2

2

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Units in Real Estate Property

111,491

'

111,491

'

'

'

'

0

3,752

3,752

0

945

724

1,669

'

'

'

'

'

432

388

336

'

'

'

'

'

'

'

ASSETS

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Real Estate Investment Property, at Cost

27,341,089,000

'

27,341,089,000

'

26,800,948,000

'

'

329,668,000

676,848,000

1,006,516,000

55,998,000

233,411,000

108,164,000

397,573,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Real Estate Investment Property, Accumulated Depreciation

-5,170,438,000

'

-5,170,438,000

'

-4,807,709,000

'

'

0

-183,571,000

-183,571,000

0

-6,693,000

-7,136,000

-13,829,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment in real estate, net

22,170,651,000

'

22,170,651,000

'

21,993,239,000

'

'

329,668,000

493,277,000

822,945,000

55,998,000

226,718,000

101,028,000

383,744,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and Cash Equivalents, at Carrying Value

76,132,000

152,564,000

76,132,000

152,564,000

53,534,000

612,590,000

'

4,488,000

14,125,000

18,613,000

454,000

2,830,000

1,582,000

4,866,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures

142,318,000

'

142,318,000

'

178,526,000

'

'

0

53,209,000

53,209,000

0

0

0

0

'

'

'

147,600,000

'

56,500,000

'

'

'

'

'

'

'

'

'

Restricted Cash and Cash Equivalents

84,408,000

'

84,408,000

'

103,567,000

'

'

34,761,000

250,000

35,011,000

0

130,000

47,000

177,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred Finance Costs, Net

63,441,000

'

63,441,000

'

58,486,000

'

'

0

2,318,000

2,318,000

53,000

4,000

122,000

179,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Assets

409,183,000

'

409,183,000

'

404,557,000

'

'

6,679,000

26,176,000

32,855,000

14,000

41,000

1,250,000

1,305,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total assets

22,991,402,000

'

22,991,402,000

'

22,834,545,000

'

'

375,596,000

589,355,000

964,951,000

56,519,000

229,723,000

104,029,000

390,271,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

LIABILITIES AND EQUITY

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Secured Debt

5,158,091,000

'

5,158,091,000

'

5,174,166,000

'

'

0

360,305,000

360,305,000

21,982,000

145,016,000

63,305,000

230,303,000

'

'

'

'

'

'

33,000,000

30,300,000

22,000,000

'

'

48,600,000

96,400,000

'

'

Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable

168,225,000

'

168,225,000

'

118,791,000

'

'

12,313,000

1,730,000

14,043,000

5,095,000

955,000

350,000

6,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest Payable

78,389,000

'

78,389,000

'

78,309,000

'

'

0

1,265,000

1,265,000

43,000

687,000

42,000

772,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Liabilities

331,662,000

'

331,662,000

'

347,748,000

'

'

140,000

1,252,000

1,392,000

0

244,000

1,046,000

1,290,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Security Deposit Liability

74,508,000

'

74,508,000

'

71,592,000

'

'

0

1,916,000

1,916,000

0

279,000

140,000

419,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total liabilities

11,922,733,000

'

11,922,733,000

'

11,626,205,000

'

'

12,453,000

366,468,000

378,921,000

27,120,000

147,181,000

64,883,000

239,184,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interests Partially Owned Properties

125,843,000

'

125,843,000

'

126,583,000

'

'

117,677,000

8,166,000

125,843,000

27,858,000

70,428,000

23,434,000

121,720,000

'

'

'

'

'

'

'

'

'

117,400,000

'

'

'

'

'

Parent Equity Interest

'

'

'

'

'

'

'

245,466,000

214,721,000

460,187,000

1,541,000

12,114,000

15,712,000

29,367,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Equity Interest

'

'

'

'

'

'

'

363,143,000

222,887,000

586,030,000

29,399,000

82,542,000

39,146,000

151,087,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total liabilities and equity

22,991,402,000

'

22,991,402,000

'

22,834,545,000

'

'

375,596,000

589,355,000

964,951,000

56,519,000

229,723,000

104,029,000

390,271,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partially Owned Property Income Statement Schedule

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating revenue

652,568,000

617,217,000

1,286,010,000

1,121,939,000

'

'

'

0

43,110,000

43,110,000

0

7,958,000

5,060,000

13,018,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating Expenses

'

'

'

'

'

'

'

154,000

12,825,000

12,979,000

132,000

3,287,000

1,856,000

5,275,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross Profit

'

'

'

'

'

'

'

-154,000

30,285,000

30,131,000

-132,000

4,671,000

3,204,000

7,743,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Depreciation

190,136,000

323,304,000

375,303,000

519,526,000

'

'

'

0

10,768,000

10,768,000

0

5,299,000

2,039,000

7,338,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

General and Administrative Expense

13,752,000

16,085,000

31,328,000

32,580,000

'

'

'

-3,000

26,000

23,000

0

1,000

122,000

123,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating Income

228,304,000

63,977,000

427,556,000

168,223,000

'

'

'

-151,000

19,491,000

19,340,000

-132,000

-629,000

1,043,000

282,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest and Other Income

2,032,000

432,000

2,637,000

752,000

'

'

'

0

3,000

3,000

0

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Nonoperating Income (Expense)

'

'

'

'

'

'

'

-76,000

-32,000

-108,000

0

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest Expense, Debt

115,924,000

122,950,000

228,973,000

317,417,000

'

'

'

0

-7,788,000

-7,788,000

0

-3,864,000

-926,000

-4,790,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of Financing Costs

-3,134,000

-4,353,000

-5,926,000

-11,301,000

'

'

'

0

-177,000

-177,000

0

0

-7,000

-7,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income (loss) before income and other taxes, (loss) from investments in unconsolidated entities, net gain on sales of land parcels, discontinued operations and net gain on sales of real estate properties

109,745,000

-64,525,000

193,104,000

-183,093,000

'

'

'

-227,000

11,497,000

11,270,000

-132,000

-4,493,000

110,000

-4,515,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income and other tax (expense) benefit

-646,000

-428,000

-886,000

-833,000

'

'

'

0

-45,000

-45,000

0

-7,000

0

-7,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

(Loss) from investments in unconsolidated entities

-7,616,000

-8,174,000

-9,025,000

-54,540,000

'

'

'

0

-879,000

-879,000

0

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

$117,720,000

$336,732,000

$200,452,000

$1,397,766,000

'

'

'

($227,000)

$10,573,000

$10,346,000

($132,000)

($4,500,000)

$110,000

($4,522,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deposits_Restricted_Details

Deposits - Restricted (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Earnest Money On Pending Acquisitions	$830	$4,514
Restricted deposits on real estate investments	36,476	53,771
Resident security and utility deposits	46,597	44,777
Other Restricted Cash	505	505
Restricted Cash and Cash Equivalents	84,408	103,567
Escrow deposits for real estate taxes and insurance	3,500	3,687
Replacement Reserve Escrow	3,469	4,229
Principal fund reserves/sinking funds	37,448	33,868
Escrow deposits - other	852	852
Escrow Deposits For Mortgage And Replacement Reserves	$45,269	$42,636

Debt_Mortgage_Notes_Payable_De

Debt Mortgage Notes Payable (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]	'	'
Mortgage notes payable	$5,158,091,000	$5,174,166,000
Repayments Of Long-term Debt	9,100,000	'
Debt Instrument, Maturity Date	1-May-61	'
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	0.03%	'
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum	7.25%	'
Weighted Average Mortgage Debt Interest Rate	4.23%	'
Credit enhanced debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Mortgage notes payable	$700,500,000	'

Debt_Notes_Details

Debt Notes (Details) (USD $)	6 Months Ended			6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014
			Term Loan [Member]	2.375% Notes [Member]	4.50% Notes [Member]	Unsecured Debt [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'
Notes, net	$5,923,952,000	$5,477,088,000	'	'	'	'
Term Loan Principal Amount	'	'	750,000,000	'	'	'
Proceeds from Issuance of Unsecured Debt	'	'	'	450,000,000	750,000,000	'
Debt Instrument, Interest Rate, Stated Percentage	'	'	'	2.38%	4.50%	'
Proceeds from Debt, Net of Issuance Costs	'	'	'	$449,600,000	$744,700,000	'
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Maximum	'	'	'	2.52%	4.57%	'
Debt Instrument, Maturity Date Range, End	31-Dec-44	'	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	0.03%	'	'	'	'	2.38%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum	7.25%	'	'	'	'	7.57%
Weighted Average Interest Rate	4.97%	'	'	'	'	'

Debt_Lines_of_Credit_Details

Debt Lines of Credit (Details) (USD $)	6 Months Ended
	Jun. 30, 2014
Line of Credit Facility [Line Items]	'
Debt Instrument, Maturity Date	1-May-61
500.0 million ability to increase	$500,000,000
Debt Instrument, Basis Spread on Variable Rate	1.05%
A 250 billion LOC [Member] [Domain]	'
Line of Credit Facility [Line Items]	'
Unsecured revolving credit facility	2,500,000,000
Debt Instrument, Maturity Date	1-Apr-18
Remaining borrowing capacity	2,470,000,000
Amount restricted/dedicated to support letters of credit	34,800,000
Weighted Average Interest Rate Revolving Credit Facility	0.96%
A 175 billion LOC [Member]	'
Line of Credit Facility [Line Items]	'
Unsecured revolving credit facility	$1,750,000,000
London Interbank Offered Rate (LIBOR) [Member]	'
Line of Credit Facility [Line Items]	'
Line Of Credit Facility Commitment Fee	15.00%
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member]	'
Line of Credit Facility [Line Items]	'
Debt Instrument, Description of Variable Rate Basis	'LIBOR plus 1.05%

Derivative_and_Other_Fair_Valu2

Derivative and Other Fair Value Instruments (Details) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Fair Value Hedging maturity date 2019 [Member]	'
Derivative [Line Items]	'
Current Notional Balance	$450,000
Lowest Possible Notional	450,000
Highest Possible Notional	450,000
Lowest Interest Rate	2.38%
Highest Interest Rate	2.38%
Forward Starting Swaps Fair Value Hedging maturity date 2025 [Member]	'
Derivative [Line Items]	'
Current Notional Balance	100,000
Lowest Possible Notional	100,000
Highest Possible Notional	$100,000
Lowest Interest Rate	3.14%
Highest Interest Rate	3.19%

Derivative_and_Other_Fair_Valu3

Derivative and Other Fair Value Instruments (Details 1) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Derivative asset, fair value	$1,452	$18,710
Other Assets, Fair Value Disclosure	97,543	83,845
Assets, Fair Value Disclosure	98,995	102,555
Derivative liability, fair value	2,346	'
Other Liabilities, Fair Value Disclosure	97,543	83,845
Liabilities, Fair Value Disclosure	99,889	83,845
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	440,050	363,144
Fair Value, Inputs, Level 1 [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative asset, fair value	0	0
Other Assets, Fair Value Disclosure	97,543	83,845
Assets, Fair Value Disclosure	97,543	83,845
Derivative liability, fair value	0	'
Other Liabilities, Fair Value Disclosure	97,543	83,845
Liabilities, Fair Value Disclosure	97,543	83,845
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative asset, fair value	1,452	18,710
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	1,452	18,710
Derivative liability, fair value	2,346	'
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	2,346	0
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	440,050	363,144
Fair Value, Inputs, Level 3 [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative asset, fair value	0	0
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Derivative liability, fair value	0	'
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	0	0
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	$0	$0

Derivative_and_Other_Fair_Valu4

Derivative and Other Fair Value Instruments (Details 3) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Increase (Decrease) in Fair Value of Interest Rate Fair Value Hedging Instruments	$1,452	($1,524)
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	-1,452	1,524
Effective Portion - Amount of Gain/ (Loss) Recognized in OCI on Derivative	-21,790	12,337
Effective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	-8,335	-12,098
Ineffective Portion - Amount of Gain/ (Loss) Reclassifed from Accumulated OCI into Income	91	0
Interest Rate Swap [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Increase (Decrease) in Fair Value of Interest Rate Fair Value Hedging Instruments	1,452	-1,524
Derivative, Description of Hedged Item	'Fixed rate debt	'Fixed rate debt
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	-1,452	1,524
Forward Starting Swaps/Treasury Locks [Member]	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Effective Portion - Amount of Gain/ (Loss) Recognized in OCI on Derivative	-21,790	12,337
Effective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	-8,335	-12,098
Ineffective Portion - Amount of Gain/ (Loss) Reclassifed from Accumulated OCI into Income	$91	$0

Derivative_and_Other_Fair_Valu5

Derivative and Other Fair Value Instruments (Details Textuals) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Derivative [Line Items]	'	'
Mortgage notes payable	$5,158,091,000	$5,174,166,000
Notes, net	5,923,952,000	5,477,088,000
Debt Instrument, Fair Value Disclosure	5,200,000,000	5,100,000,000
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	-169,300,000	-155,800,000
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	22,000,000	'
Payments for (Proceeds from) Hedge, Investing Activities	2,000,000	'
Debt Instrument, Face Amount	750,000,000	'
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	100,000	'
Interest Expense	1,300,000	'
ChargesHedgeTerminationActivities	800,000	'
Total Note Payable and Long-Term Line of Credit [Member]	'	'
Derivative [Line Items]	'	'
Notes, net	5,900,000,000	5,600,000,000
Debt Instrument, Fair Value Disclosure	6,400,000,000	5,900,000,000
Fair Value Hedging maturity date 2019 [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Variable Interest Rate	0.61%	'
London Interbank Offered Rate (LIBOR) [Member] | Fair Value Hedging maturity date 2019 [Member]	'	'
Derivative [Line Items]	'	'
Debt Instrument, Description of Variable Rate Basis	'LIBOR plus 0.61%	'
2.375% Notes [Member]	'	'
Derivative [Line Items]	'	'
Proceeds from Issuance of Unsecured Debt	$450,000,000	'
Debt Instrument, Interest Rate, Stated Percentage	2.38%	'
Maturity Date	1-Jul-19	'

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$102,307	($58,511)	$183,987	($223,850)
Income (Loss) Attributable to Noncontrolling Interest	-4,422	2,231	-7,475	9,078
Net gain on sales of real estate properties	14,903	0	14,903	0
Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties	-588	815	-1,092	790
Dividends, Preferred Stock	-1,036	-1,036	-2,072	-2,072
Income (Loss) from Continuing Operations Attributable to Parent	111,164	-56,501	188,251	-216,054
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	490	380,224	1,502	1,556,427
Net Income Loss Available To Common Stockholder Basic	111,654	323,723	189,753	1,340,373
Income From Continuing Operations Available To Common Shares	115,586	'	195,726	'
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	510	395,243	1,562	1,621,616
Net Income (Loss) Available to Common Stockholders, Diluted	116,096	323,723	197,288	1,340,373
Weighted Average Number of Shares Outstanding, Basic	360,809	359,653	360,641	348,654
Dilutive Op Units	13,742	'	13,736	'
Dilutive Securities Options	2,567	'	2,403	'
Weighted Average Number of Shares Outstanding, Diluted	377,118	359,653	376,780	348,654
Earnings Per Share, Basic	$0.31	$0.90	$0.53	$3.84
Earnings Per Share, Diluted	$0.31	$0.90	$0.52	$3.84
Income (loss) from continuing operations available to Common Shares	$0.31	($0.16)	$0.52	($0.62)
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$0.00	$1.06	$0.00	$4.46
Income (loss) from continuing operations available to Common Shares	$0.31	($0.16)	$0.52	($0.62)
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share	$0.00	$1.06	$0.00	$4.46
OPERATING PARTNERSHIP	'	'	'	'
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	102,307	-58,511	183,987	-223,850
Net gain on sales of real estate properties	14,903	0	14,903	0
Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties	-588	815	-1,092	790
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	510	395,243	1,562	1,621,616
Dilutive Securities Options	2,567	'	2,403	'
Earnings Per Share, Basic	$0.31	$0.90	$0.53	$3.84
Earnings Per Share, Diluted	$0.31	$0.90	$0.52	$3.84
Income (loss) from continuing operations available to Common Shares	$0.31	($0.16)	$0.52	($0.62)
Income (loss) from continuing operations available to Common Shares	$0.31	($0.16)	$0.52	($0.62)
Dividend preference units	-1,036	-1,036	-2,072	-2,072
Income (Loss) From Continuing Operations Available To Units	115,586	-58,732	195,726	-225,132
Net Income loss available to Op unitholders basic diluted numerator	$116,096	$336,511	$197,288	$1,396,484
Weighted Average Limited Partnership and General Partnership Units Outstanding, Basic	374,551	373,403	374,377	362,390
Weighted Average Number Of Limited Partnership And General Partnership Unit Outstanding Diluted	377,118	373,403	376,780	362,390
Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Limited Partnership and General Partnership Unit, Basic	$0.00	$1.06	$0.00	$4.46
Income Loss From Discontinued Operations Net Of Tax Per Outstanding Limited Partnership And General Partnership Diluted	$0.00	$1.06	$0.00	$4.46

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
REVENUES	'		'		'		'
Disposal Group Including Discontinued Operation Rental Income	$252		$26,174		$1,275		$107,956
Disposal Group, Including Discontinued Operation, Revenue	252		26,174		1,275		107,956
EXPENSES (1)	'		'		'		'
Disposal Group Including Discontinued Operation Property And Maintenance	-89	[1]	11,025	[1]	-41	[1]	31,449	[1]
Disposal Group Including Discontinued Operation Real Estate Taxes And Insurance	-19	[1]	2,273	[1]	-6	[1]	10,867	[1]
Disposal Group Including Discontinued Operations Property Management	0		0	[1]	0		1	[1]
Disposal Group Including Discontinued Operation Depreciation	0	[1]	7,146	[1]	0	[1]	30,962	[1]
Disposal Group Including Discontinued Operation General And Administrative	46	[1]	65	[1]	51	[1]	73	[1]
Disposal Group, Including Discontinued Operation, Operating Expense	-62	[1]	20,509	[1]	4	[1]	73,352	[1]
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	314		5,665		1,271		34,604
Disposal Group Including Discontinued Operation Interest And Other Income	45		38		80		90
Disposal Group Including Discontinued Operation Other Expenses	0		-1		0		-3
Interest (2)	'		'		'		'
Expense Incurred, Net	0	[2]	-6	[2]	0	[2]	-1,258	[2]
Disposal Group Including Discontinued Operation Amortization Of Deferred Financing Costs	0	[2]	0	[2]	0	[2]	-228	[2]
Discontinued Operation, Tax Effect of Discontinued Operation	-2		-405		-13		-463
Income Loss From Discontinued Operations	357		5,291		1,338		32,742
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	153		389,952		224		1,588,874
Discontinued operations, net	$510		$395,243		$1,562		$1,621,616
[1]	Includes expenses paid in the current period for properties sold in prior periods related to the Companybs period of ownership.
[2]	Includes only interest expense specific to secured mortgage notes payable for properties sold.

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
300 properties designed and built in violation of accessibility requirements	300	'
Projects in various stages of development	12	'
Units in various stages of development	3,871	'
Consolidated Project Under Development Commitment Fund	$1,000,000,000	'
Various stages of development with estimated completion dates ranging through September 30, 2016	30-Sep-16	'
Number Of Apartments Units Under Development Unconsolidated Projects	176	'
Estimated completion period of project	31-Dec-14	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	265,400,000	'
Investment in Joint Venture	327,900,000	'
Noncontrolling Interests - Partially Owned Properties	125,843,000	126,583,000
Company's Portion [Member]	'	'
Land purchase price	76,100,000	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	102,500,000	'
Joint Venture Partner [Member]	'	'
Land purchase price	57,900,000	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	75,700,000	'
Noncontrolling Interests - Partially Owned Properties	117,400,000	'
Unconsolidated Development Projects Held for and or Under Development [Domain]	'	'
Number Of Unconsolidated Projects	1	'
Parc on Powell (formerly 1333 Powell) [Domain]	'	'
Guarantor Obligations, Maximum Exposure	$19,700,000	'

Reportable_Segments_Details

Reportable Segments (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Rental income:	'	'	'	'	'
Same store	$626,746	$602,046	$1,239,506	$1,191,430	'
Segment Reporting Segment Non Same Store Rental Income	23,020	12,498	40,985	18,099	'
Segment Reporting Information Revenues	649,766	614,544	1,280,491	1,117,106	'
Operating expenses:	'	'	'	'	'
Same store	208,086	205,213	426,227	416,591	'
Segment Reporting Segment Non Same Store Operating Expenses	10,912	7,061	22,556	18,525	'
Segment Reporting Segment Operating Expenses	218,998	212,274	448,783	398,387	'
NOI:	'	'	'	'	'
Same store	418,660	396,833	813,279	774,839	'
Segment Reporting Information Non Same Store Net Operating Income	12,108	5,437	18,429	-426	'
Segment Reporting Information Net Operating Income	430,768	402,270	831,708	718,719	'
Assets	22,991,402	'	22,991,402	'	22,834,545
Payments to Acquire Other Property, Plant, and Equipment	'	'	76,912	'	'
Reportable Segments (Textuals) [Abstract]	'	'	'	'	'
Units in same store properties	'	'	100,648	'	'
Rental income	649,766	614,544	1,280,491	1,117,106	'
Property Repairs and Maintenance	-115,388	-113,501	-240,961	-212,030	'
Real Estate Taxes and Insurance	-83,055	-76,742	-165,149	-141,837	'
Property management	-20,555	-22,031	-42,673	-44,520	'
Total Operating Expenses	-218,998	-212,274	-448,783	-398,387	'
Archstone [Member]	'	'	'	'	'
Reportable Segments (Textuals) [Abstract]	'	'	'	'	'
Units in same store properties	'	'	18,465	'	'
Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	20,029,692	'	20,029,692	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	74,398	'	'
Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	2,961,710	'	2,961,710	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	2,514	'	'
Boston [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	63,117	61,401	125,024	120,455	'
Segment Reporting Segment Non Same Store Rental Income	790	898	1,817	1,154	'
Operating expenses:	'	'	'	'	'
Same store	19,259	19,444	41,414	39,651	'
Segment Reporting Segment Non Same Store Operating Expenses	202	201	413	255	'
NOI:	'	'	'	'	'
Same store	43,858	41,957	83,610	80,804	'
Segment Reporting Information Non Same Store Net Operating Income	588	697	1,404	899	'
Boston [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	1,953,627	'	1,953,627	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	8,814	'	'
Boston [Domain] | Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	48,830	'	48,830	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	630	'	'
Denver [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	27,511	25,524	54,123	50,494	'
Operating expenses:	'	'	'	'	'
Same store	7,648	7,770	15,098	14,987	'
NOI:	'	'	'	'	'
Same store	19,863	17,754	39,025	35,507	'
Denver [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	530,832	'	530,832	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	1,904	'	'
New York [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	114,221	109,299	225,407	217,297	'
Operating expenses:	'	'	'	'	'
Same store	41,898	40,634	88,102	83,745	'
NOI:	'	'	'	'	'
Same store	72,323	68,665	137,305	133,552	'
New York [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	4,720,592	'	4,720,592	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	8,202	'	'
San Francisco [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	84,082	77,514	165,343	152,459	'
Operating expenses:	'	'	'	'	'
Same store	26,305	25,955	52,960	54,109	'
NOI:	'	'	'	'	'
Same store	57,777	51,559	112,383	98,350	'
San Francisco [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	2,753,902	'	2,753,902	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	12,704	'	'
Seattle [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	38,977	36,176	76,702	71,548	'
Segment Reporting Segment Non Same Store Rental Income	2,756	1,271	4,444	1,303	'
Operating expenses:	'	'	'	'	'
Same store	13,037	12,316	25,805	24,553	'
Segment Reporting Segment Non Same Store Operating Expenses	1,042	373	1,779	374	'
NOI:	'	'	'	'	'
Same store	25,940	23,860	50,897	46,995	'
Segment Reporting Information Non Same Store Net Operating Income	1,714	898	2,665	929	'
Seattle [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	1,046,051	'	1,046,051	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	5,264	'	'
Seattle [Domain] | Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	226,604	'	226,604	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	281	'	'
South Florida [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	49,456	47,051	97,893	93,289	'
Segment Reporting Segment Non Same Store Rental Income	1,241	14	2,041	24	'
Operating expenses:	'	'	'	'	'
Same store	18,220	17,774	36,404	35,417	'
Segment Reporting Segment Non Same Store Operating Expenses	760	68	1,301	146	'
NOI:	'	'	'	'	'
Same store	31,236	29,277	61,489	57,872	'
Segment Reporting Information Non Same Store Net Operating Income	481	-54	740	-122	'
South Florida [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	1,170,295	'	1,170,295	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	7,600	'	'
South Florida [Domain] | Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	70,896	'	70,896	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	16	'	'
Southern California [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	104,608	100,156	207,272	198,366	'
Segment Reporting Segment Non Same Store Rental Income	8,446	4,106	15,623	5,397	'
Operating expenses:	'	'	'	'	'
Same store	34,811	34,275	69,450	69,149	'
Segment Reporting Segment Non Same Store Operating Expenses	4,261	1,976	7,452	2,593	'
NOI:	'	'	'	'	'
Same store	69,797	65,881	137,822	129,217	'
Segment Reporting Information Non Same Store Net Operating Income	4,185	2,130	8,171	2,804	'
Southern California [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	2,978,750	'	2,978,750	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	11,953	'	'
Southern California [Domain] | Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	511,343	'	511,343	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	645	'	'
Washington DC [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	111,739	112,815	222,135	223,807	'
Segment Reporting Segment Non Same Store Rental Income	5,906	3,512	10,840	5,320	'
Operating expenses:	'	'	'	'	'
Same store	35,102	35,165	72,499	71,049	'
Segment Reporting Segment Non Same Store Operating Expenses	1,954	1,209	3,857	1,862	'
NOI:	'	'	'	'	'
Same store	76,637	77,650	149,636	152,758	'
Segment Reporting Information Non Same Store Net Operating Income	3,952	2,303	6,983	3,458	'
Washington DC [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	4,270,418	'	4,270,418	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	14,834	'	'
Washington DC [Domain] | Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	306,594	'	306,594	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	852	'	'
Non-Core [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	33,035	32,110	65,607	63,715	'
Operating expenses:	'	'	'	'	'
Same store	11,806	11,880	24,495	23,931	'
NOI:	'	'	'	'	'
Same store	21,229	20,230	41,112	39,784	'
Non-Core [Domain] | Same Store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	605,225	'	605,225	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	3,123	'	'
Archstone pre-ownership [Member]	'	'	'	'	'
Rental income:	'	'	'	'	'
Same store	'	'	0	-92,423	'
Operating expenses:	'	'	'	'	'
Same store	'	'	0	-36,729	'
NOI:	'	'	'	'	'
Same store	'	'	0	-55,694	'
Other [Domain]	'	'	'	'	'
Rental income:	'	'	'	'	'
Segment Reporting Segment Non Same Store Rental Income	3,881	2,697	6,220	4,901	'
Operating expenses:	'	'	'	'	'
Segment Reporting Segment Non Same Store Operating Expenses	2,693	3,234	7,754	13,295	'
NOI:	'	'	'	'	'
Segment Reporting Information Non Same Store Net Operating Income	1,188	-537	-1,534	-8,394	'
Other [Domain] | Non-same store [Domain]	'	'	'	'	'
NOI:	'	'	'	'	'
Assets	1,797,443	'	1,797,443	'	'
Payments to Acquire Other Property, Plant, and Equipment	'	'	$90	'	'

Subsequent_EventsOther_Details

Subsequent Events/Other (Details) (USD $)	6 Months Ended		1 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jul. 31, 2014
			Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'
Land parcels acquired	'	'	1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$265,400,000	'	$13,000,000
Repayments Of Long-term Debt	9,100,000	'	60,700,000
Business Combination, Acquisition Related Costs	100,000	100,000	'
Write-off of pursuit costs	1,492,000	3,365,000	'
Other Expenses	1,600,000	3,500,000	'
Litigation Settlement, Amount	$2,300,000	'	'