Equity Residential (EQR) 10-Q 2 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 27, 2018
Document And Entity Information [Line Items]
Entity Registrant Name	EQUITY RESIDENTIAL
Entity Central Index Key	906,107
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	EQR
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		368,281,975
ERPOP [Member]
Document And Entity Information [Line Items]
Entity Registrant Name	ERP OPERATING LIMITED PARTNERSHIP
Entity Central Index Key	931,182
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investment in real estate
Land	$ 5,986,329	$ 5,996,024
Depreciable property	19,946,606	19,768,362
Projects under development	145,564	163,547
Land held for development	86,098	98,963
Investment in real estate	26,164,597	26,026,896
Accumulated depreciation	(6,338,043)	(6,040,378)
Investment in real estate, net	19,826,554	19,986,518
Cash and cash equivalents	34,507	50,647
Investments in unconsolidated entities	58,124	58,254
Restricted deposits	54,370	50,115
Other assets	433,027	425,065
Total assets	20,406,582	20,570,599
Liabilities:
Mortgage notes payable, net	2,894,325	3,618,722
Notes, net	5,532,637	5,038,812
Line of credit and commercial paper	345,807	299,757
Accounts payable and accrued expenses	146,415	114,766
Accrued interest payable	63,341	58,035
Other liabilities	344,159	341,852
Security deposits	66,800	65,009
Distributions payable	206,829	192,828
Total liabilities	9,600,313	9,729,781
Commitments and contingencies
Redeemable Noncontrolling Interests – Operating Partnership	366,483	366,955
Shareholders’ equity:
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017	37,280	37,280
Common Shares of beneficial interest, $0.01 par value; 1,000,000,000 shares authorized; 368,278,336 shares issued and outstanding as of June 30, 2018 and 368,018,082 shares issued and outstanding as of December 31, 2017	3,683	3,680
Paid in capital	8,905,184	8,886,586
Retained earnings	1,329,600	1,403,530
Accumulated other comprehensive income (loss)	(67,310)	(88,612)
Total shareholders’ equity	10,208,437	10,242,464
Noncontrolling Interests:
Operating Partnership	232,995	226,691
Partially Owned Properties	(1,646)	4,708
Total Noncontrolling Interests	231,349	231,399
Total equity	10,439,786	10,473,863
Total liabilities and equity/capital	$ 20,406,582	$ 20,570,599

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock, Shares Issued	745,600	745,600
Preferred Stock, Shares Outstanding	745,600	745,600
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Issued	368,278,336	368,018,082
Common Stock, Shares, Outstanding	368,278,336	368,018,082

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
REVENUES
Rental income	$ 639,620	$ 612,299	$ 1,272,451	$ 1,216,219
Total revenues	639,808	612,480	1,272,824	1,216,580
EXPENSES
Property and maintenance	103,744	99,316	211,946	201,924
Real estate taxes and insurance	89,482	87,503	181,396	169,231
General and administrative	12,502	13,626	28,780	27,799
Depreciation	192,942	179,896	389,251	358,864
Total expenses	422,154	401,930	858,301	801,659
Operating income	217,654	210,550	414,523	414,921
Interest and other income	1,116	1,162	6,996	1,763
Other expenses	(3,769)	(1,042)	(7,210)	(2,132)
Interest:
Expense incurred, net	(94,131)	(91,224)	(210,235)	(197,434)
Amortization of deferred financing costs	(2,099)	(2,087)	(5,778)	(4,383)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	118,771	117,359	198,296	212,735
Income and other tax (expense) benefit	(274)	(220)	(487)	(482)
Income (loss) from investments in unconsolidated entities	(1,031)	(682)	(2,008)	(1,755)
Net gain (loss) on sales of real estate properties	(51)	87,726	142,162	124,433
Net gain (loss) on sales of land parcels	995	(23)	995	19,170
Net income	118,410	204,160	338,958	354,101
Net (income) loss attributable to Noncontrolling Interests:
Operating Partnership	(4,299)	(7,354)	(12,358)	(12,765)
Partially Owned Properties	(509)	(765)	(1,189)	(1,553)
Net income attributable to controlling interests	113,602	196,041	325,411	339,783
Preferred distributions	(772)	(773)	(1,545)	(1,546)
Net income available to Common Shares	$ 112,830	$ 195,268	$ 323,866	$ 338,237
Earnings per share – basic:
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Weighted average Common Shares outstanding	367,930	366,820	367,865	366,713
Earnings per share – diluted:
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Weighted average Common Shares outstanding	383,423	382,692	383,224	382,505
Distributions declared per Common Share outstanding	$ 0.54	$ 0.50375	$ 1.08	$ 1.0075
Fee and asset management
REVENUES
Fee and asset management	$ 188	$ 181	$ 373	$ 361
Property management
EXPENSES
Property and maintenance	$ 23,484	$ 21,589	$ 46,928	$ 43,841

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Comprehensive income:
Net income	$ 118,410	$ 204,160	$ 338,958	$ 354,101
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	5,908	3,507	11,995	3,507
Losses reclassified into earnings from other comprehensive income	4,516	4,668	9,307	9,251
Other comprehensive income (loss)	10,424	8,175	21,302	12,758
Comprehensive income	128,834	212,335	360,260	366,859
Comprehensive (income) attributable to Noncontrolling Interests	(5,190)	(8,416)	(14,329)	(14,782)
Comprehensive income attributable to controlling interests	$ 123,644	$ 203,919	$ 345,931	$ 352,077

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 338,958	$ 354,101
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	389,251	358,864
Amortization of deferred financing costs	5,778	4,383
Amortization of above/below market lease intangibles	2,196	1,717
Amortization of discounts and premiums on debt	3,263	1,391
Amortization of deferred settlements on derivative instruments	9,302	9,246
Write-off of pursuit costs	2,066	1,546
(Income) loss from investments in unconsolidated entities	2,008	1,755
Distributions from unconsolidated entities – return on capital	1,188	1,345
Net (gain) loss on sales of real estate properties	(142,162)	(124,433)
Net (gain) loss on sales of land parcels	(995)	(19,170)
Net (gain) loss on debt extinguishment	22,110	12,258
Compensation paid with Company Common Shares	17,032	15,027
Changes in assets and liabilities:
(Increase) decrease in other assets	417	(39,845)
Increase (decrease) in accounts payable and accrued expenses	25,396	24,503
Increase (decrease) in accrued interest payable	5,306	(12,123)
Increase (decrease) in other liabilities	2,549	(32,476)
Increase (decrease) in security deposits	1,791	1,024
Net cash provided by operating activities	685,454	559,113
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(200,546)	(57,066)
Investment in real estate – development/other	(76,635)	(175,887)
Capital expenditures to real estate	(85,987)	(89,297)
Non-real estate capital additions	(2,145)	(654)
Interest capitalized for real estate under development	(2,937)	(16,626)
Proceeds from disposition of real estate, net	287,173	297,298
Investments in unconsolidated entities	(3,099)	(2,488)
Distributions from unconsolidated entities – return of capital		113
Net cash provided by (used for) investing activities	(84,176)	(44,607)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,354)	(2)
Mortgage notes payable, net:
Lump sum payoffs	(725,639)	(370,420)
Scheduled principal repayments	(3,273)	(6,971)
Notes, net:
Proceeds	497,010
Lump sum payoffs		(394,077)
Line of credit and commercial paper:
Line of credit proceeds	415,000	890,000
Line of credit repayments	(415,000)	(625,000)
Commercial paper proceeds	4,766,050	2,610,863
Commercial paper repayments	(4,720,000)	(2,131,500)
Proceeds from (payments on) settlement of derivative instruments	1,638
Proceeds from Employee Share Purchase Plan (ESPP)	2,181	2,111
Proceeds from exercise of options	2,617	8,143
Payment of offering costs	(27)	(36)
Other financing activities, net	(48)	(40)
Contributions – Noncontrolling Interests – Partially Owned Properties	125	125
Contributions – Noncontrolling Interests – Operating Partnership	1
Distributions:
Common Shares	(384,315)	(369,244)
Preferred Shares	(1,545)	(2,318)
Noncontrolling Interests – Operating Partnership	(13,854)	(13,913)
Noncontrolling Interests – Partially Owned Properties	(7,620)	(5,944)
Net cash provided by (used for) financing activities	(613,163)	(420,481)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(11,885)	94,025
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	88,877	313,113
Cash and cash equivalents	34,507	37,719
Restricted deposits	54,370	275,394
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	188,913	197,336
Net cash paid for income and other taxes	644	624
Amortization of deferred financing costs:
Other assets	1,206	1,206
Mortgage notes payable, net	2,552	1,378
Notes, net	2,020	1,799
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	1,963	195
Notes, net	1,300	1,196
Amortization of deferred settlements on derivative instruments:
Other liabilities	(5)	(5)
Accumulated other comprehensive income	9,307	9,251
Write-off of pursuit costs:
Investment in real estate, net	2,042	1,505
Other assets	10	21
Accounts payable and accrued expenses	14	20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,321	1,025
Other liabilities	687	730
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(13,226)	(2,877)
Notes, net	(2,151)	(630)
Other liabilities	3,382
Accumulated other comprehensive income	11,995	3,507
Investments in unconsolidated entities:
Investments in unconsolidated entities	(2,379)	(1,588)
Other liabilities	(720)	(900)
Debt financing costs:
Notes, net	(4,354)	(2)
Proceeds from (payments on) settlement of derivative instruments:
Other assets	1,638
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	$ (22,110)	$ (12,258)

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Unaudited) - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	PREFERRED SHARES	COMMON SHARES, $0.01 PAR VALUE	PAID IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	OPERATING PARTNERSHIP	PARTIALLY OWNED PROPERTIES
Balance, beginning of year at Dec. 31, 2017	$ 10,242,464	$ 37,280	$ 3,680	$ 8,886,586	$ 1,403,530	$ (88,612)
Balance, beginning of year at Dec. 31, 2017	231,399						$ 226,691	$ 4,708
COMMON SHARES, $0.01 PAR VALUE
Conversion of OP Units into Common Shares				331			(331)
Exercise of share options			1	2,616
Employee Share Purchase Plan (ESPP)			1	2,180
Share-based employee compensation expense:
Restricted shares			1	5,162
Share options				8,536
ESPP discount				400
Offering costs				(27)
Supplemental Executive Retirement Plan (SERP)				(538)
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	172			(172)
Adjustment for Noncontrolling Interests ownership in Operating Partnership				110			(110)
PAID IN CAPITAL
Conversion of OP Units into Common Shares				331			(331)
Exercise of share options			1	2,616
Employee Share Purchase Plan (ESPP)			1	2,180
RETAINED EARNINGS
Net income attributable to controlling interests	325,411				325,411
Common Share distributions					(397,796)
Preferred Share distributions					(1,545)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	11,995					11,995
Losses reclassified into earnings from other comprehensive income	(9,307)					9,307
NONCONTROLLING INTERESTS
Issuance of restricted units to Noncontrolling Interests							1
Conversion of OP Units into Common Shares				331			(331)
Equity compensation associated with Noncontrolling Interests							8,116
Net income	338,958
Distributions to Noncontrolling Interests							(14,374)	(7,668)
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	(644)						644
Adjustment for Noncontrolling Interests ownership in Operating Partnership				110			(110)
Net income attributable to Noncontrolling Interests	12,358						12,358	1,189
PARTIALLY OWNED PROPERTIES
Net income	338,958
Distributions to Noncontrolling Interests							(14,374)	(7,668)
Net income attributable to Noncontrolling Interests	12,358						12,358	1,189
Contributions by Noncontrolling Interests								125
Balance, end of period at Jun. 30, 2018	10,208,437	$ 37,280	$ 3,683	$ 8,905,184	$ 1,329,600	$ (67,310)
Balance, end of period at Jun. 30, 2018	$ 231,349						$ 232,995	$ (1,646)

CONSOLIDATED BALANCE SHEETS OF

CONSOLIDATED BALANCE SHEETS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investment in real estate
Land	$ 5,986,329	$ 5,996,024
Depreciable property	19,946,606	19,768,362
Projects under development	145,564	163,547
Land held for development	86,098	98,963
Investment in real estate	26,164,597	26,026,896
Accumulated depreciation	(6,338,043)	(6,040,378)
Investment in real estate, net	19,826,554	19,986,518
Cash and cash equivalents	34,507	50,647
Investments in unconsolidated entities	58,124	58,254
Restricted deposits	54,370	50,115
Other assets	433,027	425,065
Total assets	20,406,582	20,570,599
Liabilities:
Mortgage notes payable, net	2,894,325	3,618,722
Notes, net	5,532,637	5,038,812
Line of credit and commercial paper	345,807	299,757
Accounts payable and accrued expenses	146,415	114,766
Accrued interest payable	63,341	58,035
Other liabilities	344,159	341,852
Security deposits	66,800	65,009
Distributions payable	206,829	192,828
Total liabilities	9,600,313	9,729,781
Commitments and contingencies
Partners’ Capital:
Accumulated other comprehensive income (loss)	(67,310)	(88,612)
Noncontrolling Interests – Partially Owned Properties	(1,646)	4,708
Total liabilities and equity/capital	20,406,582	20,570,599
ERPOP [Member]
Investment in real estate
Land	5,986,329	5,996,024
Depreciable property	19,946,606	19,768,362
Projects under development	145,564	163,547
Land held for development	86,098	98,963
Investment in real estate	26,164,597	26,026,896
Accumulated depreciation	(6,338,043)	(6,040,378)
Investment in real estate, net	19,826,554	19,986,518
Cash and cash equivalents	34,507	50,647
Investments in unconsolidated entities	58,124	58,254
Restricted deposits	54,370	50,115
Other assets	433,027	425,065
Total assets	20,406,582	20,570,599
Liabilities:
Mortgage notes payable, net	2,894,325	3,618,722
Notes, net	5,532,637	5,038,812
Line of credit and commercial paper	345,807	299,757
Accounts payable and accrued expenses	146,415	114,766
Accrued interest payable	63,341	58,035
Other liabilities	344,159	341,852
Security deposits	66,800	65,009
Distributions payable	206,829	192,828
Total liabilities	9,600,313	9,729,781
Commitments and contingencies
Redeemable Limited Partners	366,483	366,955
Partners’ Capital:
Preference Units	37,280	37,280
General Partner	10,238,467	10,293,796
Limited Partners	232,995	226,691
Accumulated other comprehensive income (loss)	(67,310)	(88,612)
Total partners’ capital	10,441,432	10,469,155
Noncontrolling Interests – Partially Owned Properties	(1,646)	4,708
Total capital	10,439,786	10,473,863
Total liabilities and equity/capital	$ 20,406,582	$ 20,570,599

CONSOLIDATED STATEMENTS OF OPE9

CONSOLIDATED STATEMENTS OF OPERATIONS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
REVENUES
Rental income	$ 639,620	$ 612,299	$ 1,272,451	$ 1,216,219
Total revenues	639,808	612,480	1,272,824	1,216,580
EXPENSES
Property and maintenance	103,744	99,316	211,946	201,924
Real estate taxes and insurance	89,482	87,503	181,396	169,231
General and administrative	12,502	13,626	28,780	27,799
Depreciation	192,942	179,896	389,251	358,864
Total expenses	422,154	401,930	858,301	801,659
Operating income	217,654	210,550	414,523	414,921
Interest and other income	1,116	1,162	6,996	1,763
Other expenses	(3,769)	(1,042)	(7,210)	(2,132)
Interest:
Expense incurred, net	(94,131)	(91,224)	(210,235)	(197,434)
Amortization of deferred financing costs	(2,099)	(2,087)	(5,778)	(4,383)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	118,771	117,359	198,296	212,735
Income and other tax (expense) benefit	(274)	(220)	(487)	(482)
Income (loss) from investments in unconsolidated entities	(1,031)	(682)	(2,008)	(1,755)
Net gain (loss) on sales of real estate properties	(51)	87,726	142,162	124,433
Net gain (loss) on sales of land parcels	995	(23)	995	19,170
Net income	118,410	204,160	338,958	354,101
Partially Owned Properties	(509)	(765)	(1,189)	(1,553)
Net income attributable to controlling interests	$ 113,602	$ 196,041	$ 325,411	$ 339,783
Earnings per Unit – basic:
Net income available to Units	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Earnings per Unit – diluted:
Net income available to Units	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Weighted average Units outstanding	383,423	382,692	383,224	382,505
Fee and asset management
REVENUES
Fee and asset management	$ 188	$ 181	$ 373	$ 361
Property management
EXPENSES
Property and maintenance	23,484	21,589	46,928	43,841
ERPOP [Member]
REVENUES
Rental income	639,620	612,299	1,272,451	1,216,219
Total revenues	639,808	612,480	1,272,824	1,216,580
EXPENSES
Property and maintenance	103,744	99,316	211,946	201,924
Real estate taxes and insurance	89,482	87,503	181,396	169,231
General and administrative	12,502	13,626	28,780	27,799
Depreciation	192,942	179,896	389,251	358,864
Total expenses	422,154	401,930	858,301	801,659
Operating income	217,654	210,550	414,523	414,921
Interest and other income	1,116	1,162	6,996	1,763
Other expenses	(3,769)	(1,042)	(7,210)	(2,132)
Interest:
Expense incurred, net	(94,131)	(91,224)	(210,235)	(197,434)
Amortization of deferred financing costs	(2,099)	(2,087)	(5,778)	(4,383)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	118,771	117,359	198,296	212,735
Income and other tax (expense) benefit	(274)	(220)	(487)	(482)
Income (loss) from investments in unconsolidated entities	(1,031)	(682)	(2,008)	(1,755)
Net gain (loss) on sales of real estate properties	(51)	87,726	142,162	124,433
Net gain (loss) on sales of land parcels	995	(23)	995	19,170
Net income	118,410	204,160	338,958	354,101
Partially Owned Properties	(509)	(765)	(1,189)	(1,553)
Net income attributable to controlling interests	117,901	203,395	337,769	352,548
ALLOCATION OF NET INCOME:
Preference Units	772	773	1,545	1,546
General Partner	112,830	195,268	323,866	338,237
Limited Partners	4,299	7,354	12,358	12,765
Net income available to Units	$ 117,129	$ 202,622	$ 336,224	$ 351,002
Earnings per Unit – basic:
Net income available to Units	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Weighted average Units outstanding	380,795	379,733	380,729	379,619
Earnings per Unit – diluted:
Net income available to Units	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Weighted average Units outstanding	383,423	382,692	383,224	382,505
Distributions declared per Unit outstanding	$ 0.54	$ 0.50375	$ 1.08	$ 1.0075
ERPOP [Member] | Fee and asset management
REVENUES
Fee and asset management	$ 188	$ 181	$ 373	$ 361
ERPOP [Member] | Property management
EXPENSES
Property and maintenance	$ 23,484	$ 21,589	$ 46,928	$ 43,841

CONSOLIDATED STATEMENTS OF CO10

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Comprehensive income:
Net income	$ 118,410	$ 204,160	$ 338,958	$ 354,101
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	5,908	3,507	11,995	3,507
Losses reclassified into earnings from other comprehensive income	4,516	4,668	9,307	9,251
Other comprehensive income (loss)	10,424	8,175	21,302	12,758
Comprehensive income	128,834	212,335	360,260	366,859
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(5,190)	(8,416)	(14,329)	(14,782)
Comprehensive income attributable to controlling interests	123,644	203,919	345,931	352,077
ERPOP [Member]
Comprehensive income:
Net income	118,410	204,160	338,958	354,101
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	5,908	3,507	11,995	3,507
Losses reclassified into earnings from other comprehensive income	4,516	4,668	9,307	9,251
Other comprehensive income (loss)	10,424	8,175	21,302	12,758
Comprehensive income	128,834	212,335	360,260	366,859
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(509)	(765)	(1,189)	(1,553)
Comprehensive income attributable to controlling interests	$ 128,325	$ 211,570	$ 359,071	$ 365,306

CONSOLIDATED STATEMENTS OF CA11

CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 338,958	$ 354,101
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	389,251	358,864
Amortization of deferred financing costs	5,778	4,383
Amortization of above/below market lease intangibles	2,196	1,717
Amortization of discounts and premiums on debt	3,263	1,391
Amortization of deferred settlements on derivative instruments	9,302	9,246
Write-off of pursuit costs	2,066	1,546
(Income) loss from investments in unconsolidated entities	2,008	1,755
Distributions from unconsolidated entities – return on capital	1,188	1,345
Net (gain) loss on sales of real estate properties	(142,162)	(124,433)
Net (gain) loss on sales of land parcels	(995)	(19,170)
Net (gain) loss on debt extinguishment	22,110	12,258
Compensation paid with Company Common Shares	17,032	15,027
Changes in assets and liabilities:
(Increase) decrease in other assets	417	(39,845)
Increase (decrease) in accounts payable and accrued expenses	25,396	24,503
Increase (decrease) in accrued interest payable	5,306	(12,123)
Increase (decrease) in other liabilities	2,549	(32,476)
Increase (decrease) in security deposits	1,791	1,024
Net cash provided by operating activities	685,454	559,113
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(200,546)	(57,066)
Investment in real estate – development/other	(76,635)	(175,887)
Capital expenditures to real estate	(85,987)	(89,297)
Non-real estate capital additions	(2,145)	(654)
Interest capitalized for real estate under development	(2,937)	(16,626)
Proceeds from disposition of real estate, net	287,173	297,298
Investments in unconsolidated entities	(3,099)	(2,488)
Distributions from unconsolidated entities – return of capital		113
Net cash provided by (used for) investing activities	(84,176)	(44,607)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,354)	(2)
Mortgage notes payable, net:
Lump sum payoffs	(725,639)	(370,420)
Scheduled principal repayments	(3,273)	(6,971)
Notes, net:
Proceeds	497,010
Lump sum payoffs		(394,077)
Line of credit and commercial paper:
Line of credit proceeds	415,000	890,000
Line of credit repayments	(415,000)	(625,000)
Commercial paper proceeds	4,766,050	2,610,863
Commercial paper repayments	(4,720,000)	(2,131,500)
Proceeds from (payments on) settlement of derivative instruments	1,638
Proceeds from Employee Share Purchase Plan (ESPP)	2,181	2,111
Proceeds from exercise of EQR options	2,617	8,143
Payment of offering costs	(27)	(36)
Other financing activities, net	(48)	(40)
Contributions – Noncontrolling Interests – Partially Owned Properties	125	125
Contributions – Limited Partners	1
Distributions:
OP Units – General Partner	(384,315)	(369,244)
Preference Units	(1,545)	(2,318)
OP Units – Limited Partners	(13,854)	(13,913)
Noncontrolling Interests – Partially Owned Properties	(7,620)	(5,944)
Net cash provided by (used for) financing activities	(613,163)	(420,481)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(11,885)	94,025
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	88,877	313,113
Cash and cash equivalents	34,507	37,719
Restricted deposits	54,370	275,394
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	188,913	197,336
Net cash paid for income and other taxes	644	624
Amortization of deferred financing costs:
Other assets	1,206	1,206
Mortgage notes payable, net	2,552	1,378
Notes, net	2,020	1,799
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	1,963	195
Notes, net	1,300	1,196
Amortization of deferred settlements on derivative instruments:
Other liabilities	(5)	(5)
Accumulated other comprehensive income	9,307	9,251
Write-off of pursuit costs:
Investment in real estate, net	2,042	1,505
Other assets	10	21
Accounts payable and accrued expenses	14	20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,321	1,025
Other liabilities	687	730
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(13,226)	(2,877)
Notes, net	(2,151)	(630)
Other liabilities	3,382
Accumulated other comprehensive income	11,995	3,507
Investments in unconsolidated entities:
Investments in unconsolidated entities	(2,379)	(1,588)
Other liabilities	(720)	(900)
Debt financing costs:
Notes, net	(4,354)	(2)
Proceeds from (payments on) settlement of derivative instruments:
Other assets	1,638
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	(22,110)	(12,258)
ERPOP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	338,958	354,101
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	389,251	358,864
Amortization of deferred financing costs	5,778	4,383
Amortization of above/below market lease intangibles	2,196	1,717
Amortization of discounts and premiums on debt	3,263	1,391
Amortization of deferred settlements on derivative instruments	9,302	9,246
Write-off of pursuit costs	2,066	1,546
(Income) loss from investments in unconsolidated entities	2,008	1,755
Distributions from unconsolidated entities – return on capital	1,188	1,345
Net (gain) loss on sales of real estate properties	(142,162)	(124,433)
Net (gain) loss on sales of land parcels	(995)	(19,170)
Net (gain) loss on debt extinguishment	22,110	12,258
Compensation paid with Company Common Shares	17,032	15,027
Changes in assets and liabilities:
(Increase) decrease in other assets	417	(39,845)
Increase (decrease) in accounts payable and accrued expenses	25,396	24,503
Increase (decrease) in accrued interest payable	5,306	(12,123)
Increase (decrease) in other liabilities	2,549	(32,476)
Increase (decrease) in security deposits	1,791	1,024
Net cash provided by operating activities	685,454	559,113
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(200,546)	(57,066)
Investment in real estate – development/other	(76,635)	(175,887)
Capital expenditures to real estate	(85,987)	(89,297)
Non-real estate capital additions	(2,145)	(654)
Interest capitalized for real estate under development	(2,937)	(16,626)
Proceeds from disposition of real estate, net	287,173	297,298
Investments in unconsolidated entities	(3,099)	(2,488)
Distributions from unconsolidated entities – return of capital		113
Net cash provided by (used for) investing activities	(84,176)	(44,607)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,354)	(2)
Mortgage notes payable, net:
Lump sum payoffs	(725,639)	(370,420)
Scheduled principal repayments	(3,273)	(6,971)
Notes, net:
Proceeds	497,010
Lump sum payoffs		(394,077)
Line of credit and commercial paper:
Line of credit proceeds	415,000	890,000
Line of credit repayments	(415,000)	(625,000)
Commercial paper proceeds	4,766,050	2,610,863
Commercial paper repayments	(4,720,000)	(2,131,500)
Proceeds from (payments on) settlement of derivative instruments	1,638
Proceeds from Employee Share Purchase Plan (ESPP)	2,181	2,111
Proceeds from exercise of EQR options	2,617	8,143
Payment of offering costs	(27)	(36)
Other financing activities, net	(48)	(40)
Contributions – Noncontrolling Interests – Partially Owned Properties	125	125
Contributions – Limited Partners	1
Distributions:
OP Units – General Partner	(384,315)	(369,244)
Preference Units	(1,545)	(2,318)
OP Units – Limited Partners	(13,854)	(13,913)
Noncontrolling Interests – Partially Owned Properties	(7,620)	(5,944)
Net cash provided by (used for) financing activities	(613,163)	(420,481)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(11,885)	94,025
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	88,877	313,113
Cash and cash equivalents	34,507	37,719
Restricted deposits	54,370	275,394
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	188,913	197,336
Net cash paid for income and other taxes	644	624
Amortization of deferred financing costs:
Other assets	1,206	1,206
Mortgage notes payable, net	2,552	1,378
Notes, net	2,020	1,799
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	1,963	195
Notes, net	1,300	1,196
Amortization of deferred settlements on derivative instruments:
Other liabilities	(5)	(5)
Accumulated other comprehensive income	9,307	9,251
Write-off of pursuit costs:
Investment in real estate, net	2,042	1,505
Other assets	10	21
Accounts payable and accrued expenses	14	20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,321	1,025
Other liabilities	687	730
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(13,226)	(2,877)
Notes, net	(2,151)	(630)
Other liabilities	3,382
Accumulated other comprehensive income	11,995	3,507
Investments in unconsolidated entities:
Investments in unconsolidated entities	(2,379)	(1,588)
Other liabilities	(720)	(900)
Debt financing costs:
Notes, net	(4,354)	(2)
Proceeds from (payments on) settlement of derivative instruments:
Other assets	1,638
ERPOP [Member] | Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	$ (22,110)	$ (12,258)

CONSOLIDATED STATEMENT OF CHA12

CONSOLIDATED STATEMENT OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	ERPOP [Member]	PREFERRED SHARESERPOP [Member]	General Partner [Member]ERPOP [Member]	Limited Partner [Member]ERPOP [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)ERPOP [Member]	PARTIALLY OWNED PROPERTIES [Member]ERPOP [Member]
Balance, beginning of year at Dec. 31, 2017			$ 37,280	$ 10,293,796	$ 226,691	$ (88,612)
Balance, beginning of year at Dec. 31, 2017							$ 4,708
OP Unit Issuance:
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				331	(331)
Exercise of EQR share options				2,617
EQR's Employee Share Purchase Plan (ESPP)				2,181
Share-based employee compensation expense:
EQR restricted shares				5,163
EQR share options				8,536
EQR ESPP discount				400
Net income available to Units General Partner		$ 323,866		323,866
OP Units General Partner distributions				(397,796)
Offering costs				(27)
Supplemental Executive Retirement Plan (SERP)				(538)
Change in market value of Redeemable Limited Partners				(172)
Adjustment for Limited Partners ownership in Operating Partnership				110	(110)
LIMITED PARTNERS
Issuance of restricted units to Limited Partners					1
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				331	(331)
Equity compensation associated with Units Limited Partners					8,116
Net income available to Units Limited Partners		12,358			12,358
Units Limited Partners distributions					(14,374)
Change in carrying value of Redeemable Limited Partners					644
Adjustment for Limited Partners ownership in Operating Partnership				110	(110)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	$ 11,995	11,995				11,995
Losses reclassified into earnings from other comprehensive income	(9,307)	(9,307)				9,307
NONCONTROLLING INTERESTS PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	$ 338,958	$ 338,958					1,189
Contributions by Noncontrolling Interests							125
Distributions to Noncontrolling Interests							(7,668)
Balance, end of period at Jun. 30, 2018			$ 37,280	$ 10,238,467	$ 232,995	$ (67,310)
Balance, end of period at Jun. 30, 2018							$ (1,646)

Business

Business	6 Months Ended
	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business	1. Business Equity Residential (“EQR”) is an S&P 500 company focused on the acquisition, development and management of rental apartment properties primarily in urban and high-density suburban coastal gateway markets. ERP Operating Limited Partnership (“ERPOP”) is focused on conducting the multifamily residential property business of Equity Residential. EQR is a Maryland real estate investment trust (“REIT”) formed in March 1993 and ERPOP is an Illinois limited partnership formed in May 1993. ERPOP. ERPOP. EQR is the general partner of, and as of June 30, 2018 owned an approximate 96.3% ownership interest in, ERPOP. All of the Company’s property ownership, development and related business operations are conducted through the Operating Partnership ERPOP. ERPOP, As of June 30, 2018, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 304 properties located in 10 states and the District of Columbia consisting of 78,645 apartment units. The ownership breakdown includes (table does not include various uncompleted development properties): Properties Apartment Units Wholly Owned Properties 284 74,003 Master-Leased Properties – Consolidated 1 162 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 304 78,645 Note: Effective February 1, 2018 and April 2, 2018, the Company took over management of two of its Master-Leased properties containing 94 apartment units and 597 apartment units located in Boston and Los Angeles, respectively.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
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, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. 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, 2017 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, 2017. 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 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 were 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. In December 2017, the President signed into law H.R. 1, informally titled the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act is not expected to have a material impact on our REIT or subsidiary entities, our ability to continue to qualify as a REIT or on our results of operations. However, the complete impact of the Tax Act is not yet fully known and there can be no assurances that it will have a neutral or favorable impact. Recently Issued Accounting Pronouncements In • Lessors – Leases will be accounted for using an approach that is substantially equivalent to existing guidance for operating, sales-type and financing leases, but aligned with the new revenue recognition standard. Lessors will be required to allocate lease payments to separate lease and non-lease components of each lease agreement, with the non-lease components evaluated under the new revenue recognition standard. • Lessees – Leases will be accounted for using a dual approach, classifying leases as either operating or finance based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized on a straight-line basis over the term of the lease (for operating leases) or based on an effective interest method (for finance leases). A lessee is also required to record a right-of-use asset and a lease liability on its balance sheet for all leases with a term of greater than 12 months regardless of their classification as operating or finance leases. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. The new standard will be effective for the Company beginning on January 1, 2019, with early adoption permitted, though the Company currently anticipates adopting the new standard on the effective date. The new standard must be adopted using a modified retrospective method, which requires application of the new guidance at the beginning of the earliest comparative period presented and provides for certain practical expedients, which the Company currently anticipates electing. The Company anticipates that its residential and retail/commercial leases where it is the lessor will continue to be accounted for as operating leases under the new standard. Therefore, the Company does not currently anticipate significant changes in the accounting for its lease revenues. The Company is also the lessee under various corporate office and ground leases, which it will be required to recognize as right of use assets and related lease liabilities on its consolidated balance sheets upon adoption. The Company currently anticipates that its corporate office leases where it is the lessee will continue to be accounted for as operating leases under the new standard. Based on its anticipated election of the practical expedients, the Company would not be required to reassess the classification of existing ground leases and therefore these leases would continue to be accounted for as operating leases. However, in the event we modify existing ground leases and/or enter into new ground leases after adoption of the new standard, such leases will likely be classified as finance leases. The Company will continue to evaluate the impact of adopting the new leases standard on its consolidated results of operations and financial position. In July 2018, the FASB issued an amendment to the new leases standard, which includes a practical expedient that provides lessors an option not to separate lease and non-lease components when certain criteria are met and instead account for those components as a single component under the new leases standard. The amendment also provides a transition option that permits the application of the new guidance as of the adoption date rather than to all periods presented. The Company anticipates electing the practical expedient to account for both its lease and non-lease components as a single component under the leases standard and electing the new transition option. In June 2016, the FASB In August 2017, the FASB issued a final standard which makes changes to the hedge accounting model to enable entities to better portray their risk management activities in the financial statements. The new standard expands an entity’s ability to hedge nonfinancial and financial risk components, reduces complexity in fair value hedges of interest rate risk and eases certain documentation and assessment requirements. The new standard also eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of any hedging instrument to be presented in the same income statement line as the hedged instrument. The new standard will be effective for the Company beginning on January 1, 2019 and early adoption is permitted. The Company is currently evaluating the impact of adopting the new standard on its consolidated results of operations and financial position. Recently Adopted Accounting Pronouncements In FASB Revenue from Contracts with Customers any, For the remaining approximately 6% of rental income that is subject to the new revenue recognition standard, the Company’s disaggregated revenue streams are disclosed in the table below for the six months and quarter ended June 30, 2018. These revenue streams have the same timing and pattern of revenue recognition across our reportable segments, with consistent allocations between the leasing and revenue recognition standards. The revenue streams and percentages are comparable with the percentage of rental income for the six months and quarter ended June 30, 2017. The following table presents the disaggregation of revenue streams of our rental income for the six months and quarter ended June 30, 2018 (amounts in thousands): Six Months Ended June 30, 2018 Quarter Ended June 30, 2018 Revenue Stream Applicable Standard Amount of Rental Income Percentage of Rental Income Amount of Rental Income Percentage of Rental Income Leasing revenue Leases $ 1,192,789 93.8 % $ 599,976 93.8 % Utility recoveries (“RUBS”) Revenue Recognition 30,935 2.4 % 15,560 2.4 % Parking revenue Revenue Recognition 14,064 1.1 % 6,267 1.0 % Other revenue Revenue Recognition 34,663 2.7 % 17,817 2.8 % Rental income $ 1,272,451 100.0 % $ 639,620 100.0 % Additionally, as part of the new revenue recognition standard, the FASB issued amendments related to partial sales of real estate (see further discussion below). Adoption of the new partial sales standard did not result in a change of accounting for the Company related to its disposition process. We concluded that the Company’s typical dispositions will continue to meet the criteria for sale and associated profit recognition under both new standards. In FASB In FASB • Cash payments related to debt prepayments or extinguishment costs are to be classified within financing • The portion of the cash payment made to settle a zero-coupon bond or a bond with an insignificant cash coupon attributable to accreted interest related to a debt discount is to be classified as a cash outflow within operating activities, and the portion attributable to the principal is to be classified within financing • Insurance settlement proceeds are to be classified based on the nature of the • Companies must elect to classify distributions received from equity method investees using either a cumulative earnings approach or a look-through approach and the election must be disclosed; • Restricted Total The While overall cash flows did not change, there are changes between cash flow classifications due primarily to the debt prepayment penalties that the Company has incurred in the comparative period. As of June 30, 2017, the following cash flows were reclassified (amounts in thousands): Six Months Ended June 30, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 3,359 $ (1,968 ) $ 1,391 Net (gain) loss on debt extinguishment $ — $ 12,258 $ 12,258 (Increase) decrease in deposits - restricted $ 310 $ (310 ) $ — (Increase) decrease in mortgage deposits $ 900 $ (900 ) $ — Net cash provided by operating activities $ 550,033 $ 9,080 $ 559,113 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ (177,742 ) $ 177,742 $ — (Increase) decrease in mortgage deposits $ (4,108 ) $ 4,108 $ — Net cash provided by (used for) investing activities $ (226,457 ) $ 181,850 $ (44,607 ) Cash Flows from Financing Activities: Mortgage deposits $ 47,127 $ (47,127 ) $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (12,258 ) $ (12,258 ) Line of credit and commercial paper: Commercial paper proceeds $ 2,608,895 $ 1,968 $ 2,610,863 Net cash (used for) financing activities $ (363,064 ) $ (57,417 ) $ (420,481 ) Cash and cash equivalents, beginning of period $ 77,207 (adjustments for restricted deposits, beginning of period) $ 141,881 Cash and cash equivalents and restricted deposits, beginning of period $ 219,088 Cash and cash equivalents, end of period $ 37,719 (adjustments for restricted deposits, end of period) $ 275,394 Cash and cash equivalents and restricted deposits, end of period $ 313,113 In FASB In FASB clarifies the accounting treatment for partial sales of nonfinancial assets (i.e. real estate). The standard clarifies that partial sales transactions include contributions of nonfinancial assets to a joint venture or other noncontrolled investee. Companies must recognize a full gain or loss on transfers of nonfinancial assets to equity method investees. The standard requires companies to derecognize distinct nonfinancial assets or distinct in substance nonfinancial assets in partial sale transactions when it does not have a controlling financial interest in the legal entity that holds the asset and transfers control of the asset. Once the distinct nonfinancial asset is transferred, the company is required to measure any non-controlling interest it receives or retains at fair value and recognize a full gain or loss on the transaction. If a company transfers ownership interests in a consolidated subsidiary and continues to maintain a controlling financial interest, the company does not derecognize the assets or liabilities, and accounts for the transaction as an equity transaction and no gain or loss is recognized. The Company has not had a partial sale of nonfinancial assets in the current or comparative periods, therefore the adoption of this standard did not have a material impact on its consolidated results of operations and financial position. Other The Company is the controlling partner in various consolidated partnerships owning 17 properties consisting of 3,535 apartment units having a noncontrolling interest deficit balance of $1.6 million at June 30, 2018. 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 four properties having a noncontrolling interest deficit balance of $8.7 million. These four 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, 2018, the Company estimates the value of Noncontrolling Interest distributions for these four properties would have been approximately $66.8 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 four 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 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

Equity, Capital and Other Inter

Equity, Capital and Other Interests	6 Months Ended
	Jun. 30, 2018
Equity Capital And Other Interests [Abstract]
Equity, Capital and Other Interests	3. Equity, Capital and Other 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 restricted units) for the six months ended June 30, 2018: 2018 Common Shares Common Shares outstanding at January 1, 368,018,082 Common Shares Issued: Conversion of OP Units 11,494 Exercise of share options 80,875 Employee Share Purchase Plan (ESPP) 44,858 Restricted share grants, net 123,027 Common Shares outstanding at June 30, 368,278,336 Units Units outstanding at January 1, 13,768,438 Restricted unit grants, net 267,074 Conversion of OP Units to Common Shares (11,494 ) Units outstanding at June 30, 14,024,018 Total Common Shares and Units outstanding at June 30, 382,302,354 Units Ownership Interest in Operating Partnership 3.7 % 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 restricted units, are collectively referred to as the “Noncontrolling Interests – Operating Partnership”. Subject to certain exceptions (including the “book-up” requirements of restricted 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 law, Instruments that require settlement in registered shares cannot 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, 2018 and December 31, 2017. The The 2018 Balance at January 1, $ 366,955 Change in market value 172 Change in carrying value (644 ) Balance at June 30, $ 366,483 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 The Amounts in thousands Annual Call Dividend Per June 30, December 31, Date (1) Share (2) 2018 2017 Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized: 8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call 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, 2018: 2018 General and Limited Partner Units General and Limited Partner Units outstanding at January 1, 381,786,520 Issued to General Partner: Exercise of EQR share options 80,875 EQR’s Employee Share Purchase Plan (ESPP) 44,858 EQR’s restricted share grants, net 123,027 Issued to Limited Partners: Restricted unit grants, net 267,074 General and Limited Partner Units outstanding at June 30, 382,302,354 Limited Partner Units Limited Partner Units outstanding at January 1, 13,768,438 Limited Partner restricted unit grants, net 267,074 Conversion of Limited Partner OP Units to EQR Common Shares (11,494 ) Limited Partner Units outstanding at June 30, 14,024,018 Limited Partner Units Ownership Interest in Operating Partnership 3.7 % The Limited Partners of the Operating Partnership as of June 30, 2018 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 restricted units. Subject to certain exceptions (including the “book-up” requirements of restricted 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 cannot 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, 2018 and . The carrying value of the Redeemable Limited Partner Units is allocated based on the number of Redeemable Limited Partner The following table presents the changes in the redemption value of the Redeemable Limited Partners for the six months ended June 30, 2018 (amounts in thousands): 2018 Balance at January 1, $ 366,955 Change in market value 172 Change in carrying value (644 ) Balance at June 30, $ 366,483 EQR contributes all net proceeds from its various equity offerings (including proceeds from exercise of options for Common ERPOP. The December 31, 2017 Amounts in thousands Annual Call Dividend Per June 30, December 31, Date (1) Unit (2) 2018 2017 Preference Units: 8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 745,600 units issued and outstanding as of June 30, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call 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 In September 2009, the Company announced the establishment of an At-The-Market (“ATM”) The Company may repurchase up to 13.0 million Common Shares under its share repurchase program. No shares were repurchased during the six months ended June 30, 2018. As of June 30, 2018, EQR has remaining authorization to repurchase up to 13.0 million of its shares under the repurchase program.

Real Estate and Lease Intangibl

Real Estate and Lease Intangibles	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Real Estate and Lease Intangibles	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, 2018 and December 31, 2017 (amounts in thousands): June 30, 2018 December 31, 2017 Land $ 5,986,329 $ 5,996,024 Depreciable property: Buildings and improvements 17,852,269 17,743,042 Furniture, fixtures and equipment 1,615,089 1,548,961 In-Place lease intangibles 479,248 476,359 Projects under development: Land 39,437 43,226 Construction-in-progress 106,127 120,321 Land held for development: Land 61,038 62,538 Construction-in-progress 25,060 36,425 Investment in real estate 26,164,597 26,026,896 Accumulated depreciation (6,338,043 ) (6,040,378 ) Investment in real estate, net $ 19,826,554 $ 19,986,518 The following table summarizes the carrying amounts for the Company’s above and below market ground and retail lease intangibles as of June 30, 2018 and December 31, 2017 (amounts in thousands): Description Balance Sheet Location June 30, 2018 December 31, 2017 Assets Ground lease intangibles – below market Other Assets $ 191,918 $ 191,918 Retail lease intangibles – above market Other Assets 1,260 1,260 Lease intangible assets 193,178 193,178 Accumulated amortization (24,691 ) (22,434 ) Lease intangible assets, net $ 168,487 $ 170,744 Liabilities Ground lease intangibles – above market Other Liabilities $ 2,400 $ 2,400 Retail lease intangibles – below market Other Liabilities 5,270 5,270 Lease intangible liabilities 7,670 7,670 Accumulated amortization (5,204 ) (5,143 ) Lease intangible liabilities, net $ 2,466 $ 2,527 The following table provides a summary of the effect of the amortization for above and below market ground and retail lease intangibles on Six Months Ended June 30, Quarter Ended June 30, Description Income Statement Location 2018 2017 2018 2017 Ground lease intangible amortization Property and Maintenance $ (2,232 ) $ (2,161 ) $ (1,116 ) $ (1,081 ) Retail lease intangible amortization Rental Income 36 444 18 220 Total amortization of above/below market lease intangibles $ (2,196 ) $ (1,717 ) $ (1,098 ) $ (861 ) The following table provides a summary of the aggregate amortization for above and below market ground and retail lease intangibles for each of the next five years (amounts in thousands): Remaining 2018 2019 2020 2021 2022 2023 Ground lease intangibles $ (2,231 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) Retail lease intangibles 35 71 71 71 27 19 Total $ (2,196 ) $ (4,392 ) $ (4,392 ) $ (4,392 ) $ (4,436 ) $ (4,444 ) During the six months ended June 30, 2018, 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 (1) 2 357 $ 199,700 Total 2 357 $ 199,700 (1) Purchase price includes an allocation of approximately $49.1 million to land and $151.4 million to depreciable property (inclusive of capitalized closing costs). During the six months ended June 30, 2018 , the Company disposed of the following to unaffiliated parties (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 4 786 $ 290,020 Land Parcels (one) — — 2,700 Total 4 786 $ 292,720 The Company recognized a net gain on sales of real estate properties of approximately $142.2 million and a net gain on sales of land parcels of approximately $1.0 million on the above sales.

Commitments to Acquire_Dispose

Commitments to Acquire/Dispose of Real Estate	6 Months Ended
	Jun. 30, 2018
Commitments To Acquire Dispose Of Real Estate [Abstract]
Commitments to Acquire/Dispose of Real Estate	5. Commitments to Acquire/Dispose of Real The Company has entered into a separate agreement to acquire the following (purchase price in thousands): Properties Apartment Units Purchase Price Rental Properties – Consolidated 1 372 $ 135,500 Total 1 372 $ 135,500 The Company has entered into a separate agreement to dispose of the following (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 1 506 $ 416,100 Total 1 506 $ 416,100 The closing 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 above.

Investments in Partially Owned

Investments in Partially Owned Entities	6 Months Ended
	Jun. 30, 2018
Investments In Partially Owned Entities [Abstract]
Investments in Partially Owned Entities	6. Investments in Partially Owned The Consolidated Variable Interest Entities (“VIEs”) In accordance with accounting standards for consolidation of VIEs, the Company consolidates ERPOP on EQR’s financial statements. As the sole general partner of ERPOP, EQR has exclusive control of ERPOP’s day-to-day management. The limited partners are not able to exercise substantive kick-out or participating rights. As a result, ERPOP qualifies as a VIE. EQR has a controlling financial interest in ERPOP and, thus, is ERPOP’s primary beneficiary. EQR has the power to direct the activities of ERPOP that most significantly impact ERPOP’s economic performance as well as the obligation to absorb losses or the right to receive benefits from ERPOP that could potentially be significant to ERPOP. The Company has various equity interests in certain joint ventures owning 17 properties containing 3,535 apartment units. The Company is the general partner or managing member of these joint ventures and is responsible for managing the operations and affairs of the joint ventures as well as making all decisions regarding the businesses of the joint ventures. The limited partners or non-managing members are not able to exercise substantive kick-out or participating rights. As a result, the joint ventures qualify as VIEs. The Company has a controlling financial interest in the VIEs and, thus, is the VIEs’ primary beneficiary. The Company has both the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance as well as the obligation to absorb losses or the right to receive benefits from the VIEs that could potentially be significant to the VIEs. As a result, the joint ventures are required to be consolidated on the Company’s financial statements. The consolidated assets and liabilities related to the joint ventures were approximately $717.5 million and $313.4 million, respectively, at June 30, 2018 and approximately $518.9 million and $307.0 million, respectively, at December 31, 2017. Investments in Unconsolidated Entities The following table and information summarizes the Company’s investments in unconsolidated entities, which are accounted for under the equity method of accounting as the requirements for consolidation are not met, as of June 30, 2018 and December 31, 2017 (amounts in thousands except for ownership percentage): June 30, 2018 December 31, 2017 Ownership Percentage Investments in Unconsolidated Entities: Wisconsin Place Developer (VIE) (1) $ 43,456 $ 44,451 33.3% Operating Properties (Non-VIE) (2) 11,378 12,367 20.0% Other 3,290 1,436 Varies Investments in Unconsolidated Entities $ 58,124 $ 58,254 (1) Represents an unconsolidated interest in an entity that owns the land underlying one of the consolidated joint venture properties noted above and owns and operates a related parking facility. The joint venture, as a limited partner, does not have substantive kick-out or participating rights in the entity. As a result, the entity qualifies as a VIE. The joint venture does not have a controlling financial interest in the VIE and is not the VIE’s primary beneficiary. The joint venture does not have the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance or the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. As a result, the entity that owns the land and owns and operates the parking facility is unconsolidated and recorded using the equity method of accounting. (2) Includes two joint ventures under separate agreements with the same partner totaling 945 apartment units.

Restricted Deposits

Restricted Deposits	6 Months Ended
	Jun. 30, 2018
Deposits Restricted [Abstract]
Restricted Deposits	7. Restricted Deposits The following table presents the Company’s restricted deposits as of June 30, 2018 and December 31, 2017 (amounts in thousands): June 30, 2018 December 31, 2017 Mortgage escrow deposits: Real estate taxes and insurance $ 1,171 $ 845 Replacement reserves 7,698 8,347 Mortgage principal reserves/sinking funds 6,544 3,167 Other 852 852 Mortgage escrow deposits 16,265 13,211 Restricted cash: Earnest money on pending acquisitions 750 750 Restricted deposits on real estate investments 712 58 Resident security and utility deposits 35,097 35,183 Other 1,546 913 Restricted cash 38,105 36,904 Restricted deposits $ 54,370 $ 50,115

Debt

Debt	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Debt	8. Debt EQR Mortgage Notes Payable As of June 30, 2018, the Company had outstanding mortgage debt of approximately $2.9 billion. During the six months ended June 30, 2018, the Company: • Repaid $550.0 million of 6.08% mortgage debt held in a Fannie Mae loan pool maturing in 2020 and incurred a prepayment penalty of approximately $22.1 million; • Repaid $43.7 million of conventional fixed-rate mortgage loans maturing in 2018; • Repaid $131.9 million of various tax-exempt mortgage bonds maturing in 2028 through 2042; and • Repaid $3.3 million of scheduled principal repayments on various mortgage debt. The Company recorded $1.6 million of write-offs of unamortized deferred financing costs during the six months ended June 30, 2018 as additional interest expense related to debt extinguishment of mortgages. The Company also recorded $0.2 million of write-offs of net unamortized premiums during the six months ended June 30, 2018 as a reduction of interest expense related to debt extinguishment of mortgages. As of June 30, 2018, the Company had $563.4 million of secured debt subject to third party credit enhancement. As Notes As of June 30, 2018, the Company had outstanding unsecured notes of approximately $5.5 billion. During the six months ended June 30, 2018, the Company issued $500.0 million of ten-year 3.50% unsecured notes, receiving net proceeds of approximately $497.0 million before underwriting fees, hedge termination costs and other expenses, at an all-in effective interest rate of 3.61%. As June 30, 2018 The Company’s unsecured public debt contains certain financial and operating covenants including, among other things, maintenance of certain financial ratios. The Company was in compliance with its unsecured public debt covenants for the six months ended June 30, 2018. Line of Credit and Commercial Paper On November 3, 2016, the Company replaced its existing $2.5 billion facility with a $2.0 billion unsecured revolving credit facility maturing January 10, 2022. The Company has the ability to increase available borrowings by an additional $750.0 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 0.825%), or based on bids received from the lending group, and the Company pays an annual facility fee (currently 12.5 basis points). Both the spread and the facility fee are dependent on the credit rating of the Company’s long term debt. On As 30 Other On April 24, 2017, the Company executed a new letter of credit facility with a third party financial institution which is not backed by or collateralized by borrowings on the Company’s unsecured revolving credit facility. As of June 30, 2018, there was $9.0 million in letters of credit outstanding on this facility.

Derivative and Other Fair Value

Derivative and Other Fair Value Instruments	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Derivative and Other Fair Value Instruments	9. Derivative and Other Fair Value 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. 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 commodity prices in the daily operations of the business. A • 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 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 commercial paper and line of credit, if applicable) 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 commercial paper and line of credit, if applicable) and quoted market prices for each underlying issuance in the case of the public unsecured notes. The fair values of the Company’s financial instruments (other than mortgage notes payable, unsecured notes, commercial paper, line of credit and derivative instruments), including cash and cash equivalents and other financial instruments, approximate their carrying or contract value. The June 30, 2018 December 31, 2017 Carrying Value Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Mortgage notes payable, net $ 2,894,325 $ 2,823,402 $ 3,618,722 $ 3,615,384 Unsecured debt, net 5,878,444 5,911,615 5,338,569 5,619,744 Total debt, net $ 8,772,769 $ 8,735,017 $ 8,957,291 $ 9,235,128 The June 30, 2018 Fair Value Hedges (1) Forward Starting Swaps (2) Current Notional Balance $ 450,000 $ 800,000 Lowest Interest Rate 2.375 % 2.1478 % Highest Interest Rate 2.375 % 3.1163 % Earliest Maturity Date 2019 2028 Latest Maturity Date 2019 2029 (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 planned future debt issuances. Of the $800.0 million notional balance, $300.0 million of these swaps have mandatory counterparty terminations in 2019 and are targeted for certain 2018 debt issuances while $500.0 million of these swaps have mandatory counterparty terminations in 2020 and are targeted for certain 2019 debt issuances. The Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 6/30/2018 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps Other Assets $ 16,731 $ — $ 16,731 $ — Supplemental Executive Retirement Plan Other Assets 140,432 140,432 — — Total $ 157,163 $ 140,432 $ 16,731 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 3,748 $ — $ 3,748 $ — Forward Starting Swaps Other Liabilities 1,231 — 1,231 — Supplemental Executive Retirement Plan Other Liabilities 140,432 140,432 — — Total $ 145,411 $ 140,432 $ 4,979 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 366,483 $ — $ 366,483 $ — Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 12/31/2017 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Staring Swaps Other Assets $ 5,143 $ — $ 5,143 $ — Supplemental Executive Retirement Plan Other Assets 140,159 140,159 — — Total $ 145,302 $ 140,159 $ 5,143 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 1,597 $ — $ 1,597 $ — Supplemental Executive Retirement Plan Other Liabilities 140,159 140,159 — — Total $ 141,756 $ 140,159 $ 1,597 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 366,955 $ — $ 366,955 $ — The June 30, 2018 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (2,151 ) Fixed rate debt Interest expense $ 2,151 Total $ (2,151 ) $ 2,151 June 30, 2017 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (630 ) Fixed rate debt Interest expense $ 630 Total $ (630 ) $ 630 The Effective Portion Ineffective Portion June 30, 2018 Type of Cash Flow Hedge Amount of Gain/(Loss) Recognized in OCI on Derivative Location of Gain/(Loss) Reclassified from Accumulated OCI into Income Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ 11,995 Interest expense $ (9,307 ) N/A $ — Total $ 11,995 $ (9,307 ) $ — Effective Portion Ineffective Portion June 30, 2017 Type of Cash Flow Hedge Amount of Gain/(Loss) Recognized in OCI on Derivative Location of Gain/(Loss) Reclassified from Accumulated OCI into Income Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ 3,507 Interest expense $ (9,251 ) N/A $ — Total $ 3,507 $ (9,251 ) $ — As June 30, 2018 December 31, 2017 June 30, 2018 In February 2018, the Company received approximately $1.6 million to settle two forward starting swaps in conjunction with the issuance of $500.0 million of ten-year unsecured public notes. The entire $1.6 million was initially deferred as a component of accumulated other comprehensive income (loss) and will be recognized as a decrease to interest expense over the ten-year term of the notes.

Earning Per Share and Earnings

Earning Per Share and Earnings Per Unit	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Earning Per Share And Earnings Per Unit	10. Earning Per Share and Earnings Per Equity Residential The Six Months Ended June 30, Quarter Ended June 30, 2018 2017 2018 2017 Numerator for net income per share – basic: Net income $ 338,958 $ 354,101 $ 118,410 $ 204,160 Allocation to Noncontrolling Interests – Operating Partnership (12,358 ) (12,765 ) (4,299 ) (7,354 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,189 ) (1,553 ) (509 ) (765 ) Preferred distributions (1,545 ) (1,546 ) (772 ) (773 ) Numerator for net income per share – basic $ 323,866 $ 338,237 $ 112,830 $ 195,268 Numerator for net income per share – diluted: Net income $ 338,958 $ 354,101 $ 118,410 $ 204,160 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,189 ) (1,553 ) (509 ) (765 ) Preferred distributions (1,545 ) (1,546 ) (772 ) (773 ) Numerator for net income per share – diluted $ 336,224 $ 351,002 $ 117,129 $ 202,622 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 367,865 366,713 367,930 366,820 Effect of dilutive securities: OP Units 12,864 12,906 12,865 12,913 Long-term compensation shares/units 2,495 2,886 2,628 2,959 Denominator for net income per share – diluted 383,224 382,505 383,423 382,692 Net income per share – basic $ 0.88 $ 0.92 $ 0.31 $ 0.53 Net income per share – diluted $ 0.88 $ 0.92 $ 0.31 $ 0.53 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, 2018 2017 2018 2017 Numerator for net income per Unit – basic and diluted: Net income $ 338,958 $ 354,101 $ 118,410 $ 204,160 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,189 ) (1,553 ) (509 ) (765 ) Allocation to Preference Units (1,545 ) (1,546 ) (772 ) (773 ) Numerator for net income per Unit – basic and diluted $ 336,224 $ 351,002 $ 117,129 $ 202,622 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 380,729 379,619 380,795 379,733 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,495 2,886 2,628 2,959 Denominator for net income per Unit – diluted 383,224 382,505 383,423 382,692 Net income per Unit – basic $ 0.88 $ 0.92 $ 0.31 $ 0.53 Net income per Unit – diluted $ 0.88 $ 0.92 $ 0.31 $ 0.53

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. 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. As of June 30, 2018, the Company does have environmental reserves totaling approximately $5.2 million related to three of its properties. The The Company does not believe there is any 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, 2018, the Company has four wholly owned projects totaling 912 apartment units in various stages of development with remaining commitments to fund of approximately $466.0 million and estimated completion dates ranging through September 30, 2021, as well as other completed development projects that are in various stages of lease-up or are stabilized. As

Reportable Segments

Reportable Segments	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Reportable Segments	12. Reportable 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 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 same store operating segments located primarily in its coastal gateway markets represent its reportable segments. The Company’s operating segments located in its other markets (Phoenix) that are not material have also been included in the tables presented below. The Company’s fee and asset management and development 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 The primary financial measure for the Company’s rental real estate segment is net operating income (“NOI”), which represents The Six Months Ended June 30, Quarter Ended June 30, 2018 2017 2018 2017 Rental income $ 1,272,451 $ 1,216,219 $ 639,620 $ 612,299 Property and maintenance expense (211,946 ) (201,924 ) (103,744 ) (99,316 ) Real estate taxes and insurance expense (181,396 ) (169,231 ) (89,482 ) (87,503 ) Total operating expenses (393,342 ) (371,155 ) (193,226 ) (186,819 ) Net operating income $ 879,109 $ 845,064 $ 446,394 $ 425,480 The following tables present NOI for each segment from our rental real estate for the six months and quarters ended June 30, 2018 and 2017, Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 205,103 $ 58,892 $ 146,211 $ 198,557 $ 56,960 $ 141,597 Orange County 45,331 11,090 34,241 43,654 10,838 32,816 San Diego 45,425 11,751 33,674 43,620 11,535 32,085 Subtotal - Southern California 295,859 81,733 214,126 285,831 79,333 206,498 San Francisco 219,400 52,854 166,546 213,516 54,018 159,498 Washington D.C. 215,843 66,899 148,944 213,546 64,572 148,974 New York 240,124 94,505 145,619 239,367 88,938 150,429 Boston 113,511 31,593 81,918 110,989 30,145 80,844 Seattle 97,642 27,799 69,843 94,020 26,407 67,613 Other Markets 969 341 628 924 340 584 Total same store 1,183,348 355,724 827,624 1,158,193 343,753 814,440 Non-same store/other (2) (3) Non-same store 83,193 29,862 53,331 34,439 12,533 21,906 Other (3) 5,910 7,756 (1,846 ) 23,587 14,869 8,718 Total non-same store/other 89,103 37,618 51,485 58,026 27,402 30,624 Totals $ 1,272,451 $ 393,342 $ 879,109 $ 1,216,219 $ 371,155 $ 845,064 (1) For the six months ended June 30, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,210 apartment (2) For the six months ended June 30, 2018 and 2017, non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Quarter Ended June 30, 2018 Quarter Ended June 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 102,619 $ 29,032 $ 73,587 $ 99,921 $ 28,309 $ 71,612 Orange County 22,829 5,564 17,265 21,998 5,376 16,622 San Diego 22,932 5,788 17,144 21,897 5,736 16,161 Subtotal - Southern California 148,380 40,384 107,996 143,816 39,421 104,395 San Francisco 115,332 27,581 87,751 111,835 28,466 83,369 Washington D.C. 108,689 33,237 75,452 107,103 32,241 74,862 New York 120,498 46,680 73,818 120,005 43,499 76,506 Boston 57,217 15,511 41,706 55,943 14,941 41,002 Seattle 49,031 14,111 34,920 47,594 13,392 34,202 Other Markets 481 175 306 461 144 317 Total same store 599,628 177,679 421,949 586,757 172,104 414,653 Non-same store/other (2) (3) Non-same store 39,427 13,154 26,273 13,850 5,193 8,657 Other (3) 565 2,393 (1,828 ) 11,692 9,522 2,170 Total non-same store/other 39,992 15,547 24,445 25,542 14,715 10,827 Totals $ 639,620 $ 193,226 $ 446,394 $ 612,299 $ 186,819 $ 425,480 (1) For the quarters ended June 30, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to April 1, 2017, less properties subsequently sold, which represented 72,629 apartment (2) For the quarters ended June 30, 2018 and 2017, non-same store primarily includes properties acquired after April 1, 2017, plus any properties in lease-up and not stabilized as of April 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Six Months Ended June 30, 2018 Total Assets Capital Expenditures Same store (1) Los Angeles $ 2,649,731 $ 13,220 Orange County 323,604 4,017 San Diego 413,701 2,481 Subtotal - Southern California 3,387,036 19,718 San Francisco 3,004,183 21,259 Washington D.C. 3,742,083 14,137 New York 4,404,182 12,092 Boston 1,609,747 9,451 Seattle 1,296,447 6,900 Other Markets 12,795 102 Total same store 17,456,473 83,659 Non-same store/other (2) (3) Non-same store 2,414,779 2,210 Other (3) 535,330 118 Total non-same store/other 2,950,109 2,328 Totals $ 20,406,582 $ 85,987 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,210 apartment (2) Non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and capital expenditures for properties

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent There have been no material subsequent events occurring since June 30, 2018.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
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, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. 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, 2017 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, 2017.
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 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 were 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. In December 2017, the President signed into law H.R. 1, informally titled the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act is not expected to have a material impact on our REIT or subsidiary entities, our ability to continue to qualify as a REIT or on our results of operations. However, the complete impact of the Tax Act is not yet fully known and there can be no assurances that it will have a neutral or favorable impact.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In • Lessors – Leases will be accounted for using an approach that is substantially equivalent to existing guidance for operating, sales-type and financing leases, but aligned with the new revenue recognition standard. Lessors will be required to allocate lease payments to separate lease and non-lease components of each lease agreement, with the non-lease components evaluated under the new revenue recognition standard. • Lessees – Leases will be accounted for using a dual approach, classifying leases as either operating or finance based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized on a straight-line basis over the term of the lease (for operating leases) or based on an effective interest method (for finance leases). A lessee is also required to record a right-of-use asset and a lease liability on its balance sheet for all leases with a term of greater than 12 months regardless of their classification as operating or finance leases. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. The new standard will be effective for the Company beginning on January 1, 2019, with early adoption permitted, though the Company currently anticipates adopting the new standard on the effective date. The new standard must be adopted using a modified retrospective method, which requires application of the new guidance at the beginning of the earliest comparative period presented and provides for certain practical expedients, which the Company currently anticipates electing. The Company anticipates that its residential and retail/commercial leases where it is the lessor will continue to be accounted for as operating leases under the new standard. Therefore, the Company does not currently anticipate significant changes in the accounting for its lease revenues. The Company is also the lessee under various corporate office and ground leases, which it will be required to recognize as right of use assets and related lease liabilities on its consolidated balance sheets upon adoption. The Company currently anticipates that its corporate office leases where it is the lessee will continue to be accounted for as operating leases under the new standard. Based on its anticipated election of the practical expedients, the Company would not be required to reassess the classification of existing ground leases and therefore these leases would continue to be accounted for as operating leases. However, in the event we modify existing ground leases and/or enter into new ground leases after adoption of the new standard, such leases will likely be classified as finance leases. The Company will continue to evaluate the impact of adopting the new leases standard on its consolidated results of operations and financial position. In July 2018, the FASB issued an amendment to the new leases standard, which includes a practical expedient that provides lessors an option not to separate lease and non-lease components when certain criteria are met and instead account for those components as a single component under the new leases standard. The amendment also provides a transition option that permits the application of the new guidance as of the adoption date rather than to all periods presented. The Company anticipates electing the practical expedient to account for both its lease and non-lease components as a single component under the leases standard and electing the new transition option. In June 2016, the FASB In August 2017, the FASB issued a final standard which makes changes to the hedge accounting model to enable entities to better portray their risk management activities in the financial statements. The new standard expands an entity’s ability to hedge nonfinancial and financial risk components, reduces complexity in fair value hedges of interest rate risk and eases certain documentation and assessment requirements. The new standard also eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of any hedging instrument to be presented in the same income statement line as the hedged instrument. The new standard will be effective for the Company beginning on January 1, 2019 and early adoption is permitted. The Company is currently evaluating the impact of adopting the new standard on its consolidated results of operations and financial position. Recently Adopted Accounting Pronouncements In FASB Revenue from Contracts with Customers any, For the remaining approximately 6% of rental income that is subject to the new revenue recognition standard, the Company’s disaggregated revenue streams are disclosed in the table below for the six months and quarter ended June 30, 2018. These revenue streams have the same timing and pattern of revenue recognition across our reportable segments, with consistent allocations between the leasing and revenue recognition standards. The revenue streams and percentages are comparable with the percentage of rental income for the six months and quarter ended June 30, 2017. The following table presents the disaggregation of revenue streams of our rental income for the six months and quarter ended June 30, 2018 (amounts in thousands): Six Months Ended June 30, 2018 Quarter Ended June 30, 2018 Revenue Stream Applicable Standard Amount of Rental Income Percentage of Rental Income Amount of Rental Income Percentage of Rental Income Leasing revenue Leases $ 1,192,789 93.8 % $ 599,976 93.8 % Utility recoveries (“RUBS”) Revenue Recognition 30,935 2.4 % 15,560 2.4 % Parking revenue Revenue Recognition 14,064 1.1 % 6,267 1.0 % Other revenue Revenue Recognition 34,663 2.7 % 17,817 2.8 % Rental income $ 1,272,451 100.0 % $ 639,620 100.0 % Additionally, as part of the new revenue recognition standard, the FASB issued amendments related to partial sales of real estate (see further discussion below). Adoption of the new partial sales standard did not result in a change of accounting for the Company related to its disposition process. We concluded that the Company’s typical dispositions will continue to meet the criteria for sale and associated profit recognition under both new standards. In FASB In FASB • Cash payments related to debt prepayments or extinguishment costs are to be classified within financing • The portion of the cash payment made to settle a zero-coupon bond or a bond with an insignificant cash coupon attributable to accreted interest related to a debt discount is to be classified as a cash outflow within operating activities, and the portion attributable to the principal is to be classified within financing • Insurance settlement proceeds are to be classified based on the nature of the • Companies must elect to classify distributions received from equity method investees using either a cumulative earnings approach or a look-through approach and the election must be disclosed; • Restricted Total The While overall cash flows did not change, there are changes between cash flow classifications due primarily to the debt prepayment penalties that the Company has incurred in the comparative period. As of June 30, 2017, the following cash flows were reclassified (amounts in thousands): Six Months Ended June 30, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 3,359 $ (1,968 ) $ 1,391 Net (gain) loss on debt extinguishment $ — $ 12,258 $ 12,258 (Increase) decrease in deposits - restricted $ 310 $ (310 ) $ — (Increase) decrease in mortgage deposits $ 900 $ (900 ) $ — Net cash provided by operating activities $ 550,033 $ 9,080 $ 559,113 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ (177,742 ) $ 177,742 $ — (Increase) decrease in mortgage deposits $ (4,108 ) $ 4,108 $ — Net cash provided by (used for) investing activities $ (226,457 ) $ 181,850 $ (44,607 ) Cash Flows from Financing Activities: Mortgage deposits $ 47,127 $ (47,127 ) $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (12,258 ) $ (12,258 ) Line of credit and commercial paper: Commercial paper proceeds $ 2,608,895 $ 1,968 $ 2,610,863 Net cash (used for) financing activities $ (363,064 ) $ (57,417 ) $ (420,481 ) Cash and cash equivalents, beginning of period $ 77,207 (adjustments for restricted deposits, beginning of period) $ 141,881 Cash and cash equivalents and restricted deposits, beginning of period $ 219,088 Cash and cash equivalents, end of period $ 37,719 (adjustments for restricted deposits, end of period) $ 275,394 Cash and cash equivalents and restricted deposits, end of period $ 313,113 In FASB In FASB clarifies the accounting treatment for partial sales of nonfinancial assets (i.e. real estate). The standard clarifies that partial sales transactions include contributions of nonfinancial assets to a joint venture or other noncontrolled investee. Companies must recognize a full gain or loss on transfers of nonfinancial assets to equity method investees. The standard requires companies to derecognize distinct nonfinancial assets or distinct in substance nonfinancial assets in partial sale transactions when it does not have a controlling financial interest in the legal entity that holds the asset and transfers control of the asset. Once the distinct nonfinancial asset is transferred, the company is required to measure any non-controlling interest it receives or retains at fair value and recognize a full gain or loss on the transaction. If a company transfers ownership interests in a consolidated subsidiary and continues to maintain a controlling financial interest, the company does not derecognize the assets or liabilities, and accounts for the transaction as an equity transaction and no gain or loss is recognized. The Company has not had a partial sale of nonfinancial assets in the current or comparative periods, therefore the adoption of this standard did not have a material impact on its consolidated results of operations and financial position.
Other	Other The Company is the controlling partner in various consolidated partnerships owning 17 properties consisting of 3,535 apartment units having a noncontrolling interest deficit balance of $1.6 million at June 30, 2018. 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 four properties having a noncontrolling interest deficit balance of $8.7 million. These four 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, 2018, the Company estimates the value of Noncontrolling Interest distributions for these four properties would have been approximately $66.8 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 four 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 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

Business (Tables)

Business (Tables)	6 Months Ended
	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Ownership Breakdown	The ownership breakdown includes (table does not include various uncompleted development properties): Properties Apartment Units Wholly Owned Properties 284 74,003 Master-Leased Properties – Consolidated 1 162 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 304 78,645 Note: Effective February 1, 2018 and April 2, 2018, the Company took over management of two of its Master-Leased properties containing 94 apartment units and 597 apartment units located in Boston and Los Angeles, respectively.

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2018
Summary Of Significant Accounting Policies [Abstract]
Schedule of Disaggregation of Revenue Streams of Rental Income and Percentage of Rental Income	The following table presents the disaggregation of revenue streams of our rental income for the six months and quarter ended June 30, 2018 (amounts in thousands): Six Months Ended June 30, 2018 Quarter Ended June 30, 2018 Revenue Stream Applicable Standard Amount of Rental Income Percentage of Rental Income Amount of Rental Income Percentage of Rental Income Leasing revenue Leases $ 1,192,789 93.8 % $ 599,976 93.8 % Utility recoveries (“RUBS”) Revenue Recognition 30,935 2.4 % 15,560 2.4 % Parking revenue Revenue Recognition 14,064 1.1 % 6,267 1.0 % Other revenue Revenue Recognition 34,663 2.7 % 17,817 2.8 % Rental income $ 1,272,451 100.0 % $ 639,620 100.0 %
Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties	While overall cash flows did not change, there are changes between cash flow classifications due primarily to the debt prepayment penalties that the Company has incurred in the comparative period. As of June 30, 2017, the following cash flows were reclassified (amounts in thousands): Six Months Ended June 30, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 3,359 $ (1,968 ) $ 1,391 Net (gain) loss on debt extinguishment $ — $ 12,258 $ 12,258 (Increase) decrease in deposits - restricted $ 310 $ (310 ) $ — (Increase) decrease in mortgage deposits $ 900 $ (900 ) $ — Net cash provided by operating activities $ 550,033 $ 9,080 $ 559,113 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ (177,742 ) $ 177,742 $ — (Increase) decrease in mortgage deposits $ (4,108 ) $ 4,108 $ — Net cash provided by (used for) investing activities $ (226,457 ) $ 181,850 $ (44,607 ) Cash Flows from Financing Activities: Mortgage deposits $ 47,127 $ (47,127 ) $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (12,258 ) $ (12,258 ) Line of credit and commercial paper: Commercial paper proceeds $ 2,608,895 $ 1,968 $ 2,610,863 Net cash (used for) financing activities $ (363,064 ) $ (57,417 ) $ (420,481 ) Cash and cash equivalents, beginning of period $ 77,207 (adjustments for restricted deposits, beginning of period) $ 141,881 Cash and cash equivalents and restricted deposits, beginning of period $ 219,088 Cash and cash equivalents, end of period $ 37,719 (adjustments for restricted deposits, end of period) $ 275,394 Cash and cash equivalents and restricted deposits, end of period $ 313,113

Equity, Capital and Other Int29

Equity, Capital and Other Interests (Tables)	6 Months Ended
	Jun. 30, 2018
Changes in Issued and Outstanding Common Shares and Units	The following tables present the changes in the Company’s issued and outstanding Common Shares and “Units” (which includes OP Units and restricted units) for the six months ended June 30, 2018: 2018 Common Shares Common Shares outstanding at January 1, 368,018,082 Common Shares Issued: Conversion of OP Units 11,494 Exercise of share options 80,875 Employee Share Purchase Plan (ESPP) 44,858 Restricted share grants, net 123,027 Common Shares outstanding at June 30, 368,278,336 Units Units outstanding at January 1, 13,768,438 Restricted unit grants, net 267,074 Conversion of OP Units to Common Shares (11,494 ) Units outstanding at June 30, 14,024,018 Total Common Shares and Units outstanding at June 30, 382,302,354 Units Ownership Interest in Operating Partnership 3.7 %
Changes in Redemption Value of Redeemable Noncontrolling Interests and Limited Partners Interest	The 2018 Balance at January 1, $ 366,955 Change in market value 172 Change in carrying value (644 ) Balance at June 30, $ 366,483
Issued and Outstanding Preferred Shares and Preference Units	The Amounts in thousands Annual Call Dividend Per June 30, December 31, Date (1) Share (2) 2018 2017 Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized: 8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call 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.
ERPOP [Member]
Changes in Issued and Outstanding Common Shares and Units	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, 2018: 2018 General and Limited Partner Units General and Limited Partner Units outstanding at January 1, 381,786,520 Issued to General Partner: Exercise of EQR share options 80,875 EQR’s Employee Share Purchase Plan (ESPP) 44,858 EQR’s restricted share grants, net 123,027 Issued to Limited Partners: Restricted unit grants, net 267,074 General and Limited Partner Units outstanding at June 30, 382,302,354 Limited Partner Units Limited Partner Units outstanding at January 1, 13,768,438 Limited Partner restricted unit grants, net 267,074 Conversion of Limited Partner OP Units to EQR Common Shares (11,494 ) Limited Partner Units outstanding at June 30, 14,024,018 Limited Partner Units Ownership Interest in Operating Partnership 3.7 %
Changes in Redemption Value of Redeemable Noncontrolling Interests and Limited Partners Interest	The following table presents the changes in the redemption value of the Redeemable Limited Partners for the six months ended June 30, 2018 (amounts in thousands): 2018 Balance at January 1, $ 366,955 Change in market value 172 Change in carrying value (644 ) Balance at June 30, $ 366,483
Issued and Outstanding Preferred Shares and Preference Units	The December 31, 2017 Amounts in thousands Annual Call Dividend Per June 30, December 31, Date (1) Unit (2) 2018 2017 Preference Units: 8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 745,600 units issued and outstanding as of June 30, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call 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 and Lease Intangi30

Real Estate and Lease Intangibles (Tables)	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Summary of Carrying Amounts of Investment in Real Estate	The following table summarizes the carrying amounts for the Company’s investment in real estate (at cost) as of June 30, 2018 and December 31, 2017 (amounts in thousands): June 30, 2018 December 31, 2017 Land $ 5,986,329 $ 5,996,024 Depreciable property: Buildings and improvements 17,852,269 17,743,042 Furniture, fixtures and equipment 1,615,089 1,548,961 In-Place lease intangibles 479,248 476,359 Projects under development: Land 39,437 43,226 Construction-in-progress 106,127 120,321 Land held for development: Land 61,038 62,538 Construction-in-progress 25,060 36,425 Investment in real estate 26,164,597 26,026,896 Accumulated depreciation (6,338,043 ) (6,040,378 ) Investment in real estate, net $ 19,826,554 $ 19,986,518
Summary of Carrying Amounts of Above and Below Market Ground And Retail Lease Intangibles	The following table summarizes the carrying amounts for the Company’s above and below market ground and retail lease intangibles as of June 30, 2018 and December 31, 2017 (amounts in thousands): Description Balance Sheet Location June 30, 2018 December 31, 2017 Assets Ground lease intangibles – below market Other Assets $ 191,918 $ 191,918 Retail lease intangibles – above market Other Assets 1,260 1,260 Lease intangible assets 193,178 193,178 Accumulated amortization (24,691 ) (22,434 ) Lease intangible assets, net $ 168,487 $ 170,744 Liabilities Ground lease intangibles – above market Other Liabilities $ 2,400 $ 2,400 Retail lease intangibles – below market Other Liabilities 5,270 5,270 Lease intangible liabilities 7,670 7,670 Accumulated amortization (5,204 ) (5,143 ) Lease intangible liabilities, net $ 2,466 $ 2,527
Summary of the Effect of the Amortization for Above and Below Market Ground and Retail Lease Intangibles	The following table provides a summary of the effect of the amortization for above and below market ground and retail lease intangibles on Six Months Ended June 30, Quarter Ended June 30, Description Income Statement Location 2018 2017 2018 2017 Ground lease intangible amortization Property and Maintenance $ (2,232 ) $ (2,161 ) $ (1,116 ) $ (1,081 ) Retail lease intangible amortization Rental Income 36 444 18 220 Total amortization of above/below market lease intangibles $ (2,196 ) $ (1,717 ) $ (1,098 ) $ (861 )
Summary of Aggregate Amortization for Above and Below Market Ground And Retail Lease Intangibles	The following table provides a summary of the aggregate amortization for above and below market ground and retail lease intangibles for each of the next five years (amounts in thousands): Remaining 2018 2019 2020 2021 2022 2023 Ground lease intangibles $ (2,231 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) Retail lease intangibles 35 71 71 71 27 19 Total $ (2,196 ) $ (4,392 ) $ (4,392 ) $ (4,392 ) $ (4,436 ) $ (4,444 )
Acquired Properties From Unaffiliated Parties	During the six months ended June 30, 2018, 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 (1) 2 357 $ 199,700 Total 2 357 $ 199,700 (1) Purchase price includes an allocation of approximately $49.1 million to land and $151.4 million to depreciable property (inclusive of capitalized closing costs).
Disposed Properties to Unaffiliated Parties	During the six months ended June 30, 2018 , the Company disposed of the following to unaffiliated parties (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 4 786 $ 290,020 Land Parcels (one) — — 2,700 Total 4 786 $ 292,720

Commitments To Acquire_Dispos31

Commitments To Acquire/Dispose of Real Estate (Tables)	6 Months Ended
	Jun. 30, 2018
Commitments To Acquire Dispose Of Real Estate [Abstract]
Separate Agreement to Acquire	The Company has entered into a separate agreement to acquire the following (purchase price in thousands): Properties Apartment Units Purchase Price Rental Properties – Consolidated 1 372 $ 135,500 Total 1 372 $ 135,500
Separate Agreements to Dispose of	The Company has entered into a separate agreement to dispose of the following (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 1 506 $ 416,100 Total 1 506 $ 416,100

Investments in Partially Owne32

Investments in Partially Owned Entities (Tables)	6 Months Ended
	Jun. 30, 2018
Investments In Partially Owned Entities [Abstract]
Summary of Companys Investment in Unconsolidated Entities	The following table and information summarizes the Company’s investments in unconsolidated entities, which are accounted for under the equity method of accounting as the requirements for consolidation are not met, as of June 30, 2018 and December 31, 2017 (amounts in thousands except for ownership percentage): June 30, 2018 December 31, 2017 Ownership Percentage Investments in Unconsolidated Entities: Wisconsin Place Developer (VIE) (1) $ 43,456 $ 44,451 33.3% Operating Properties (Non-VIE) (2) 11,378 12,367 20.0% Other 3,290 1,436 Varies Investments in Unconsolidated Entities $ 58,124 $ 58,254 (1) Represents an unconsolidated interest in an entity that owns the land underlying one of the consolidated joint venture properties noted above and owns and operates a related parking facility. The joint venture, as a limited partner, does not have substantive kick-out or participating rights in the entity. As a result, the entity qualifies as a VIE. The joint venture does not have a controlling financial interest in the VIE and is not the VIE’s primary beneficiary. The joint venture does not have the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance or the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. As a result, the entity that owns the land and owns and operates the parking facility is unconsolidated and recorded using the equity method of accounting. (2) Includes two joint ventures under separate agreements with the same partner totaling 945 apartment units.

Restricted Deposits (Tables)

Restricted Deposits (Tables)	6 Months Ended
	Jun. 30, 2018
Deposits Restricted [Abstract]
Restricted Deposits	The following table presents the Company’s restricted deposits as of June 30, 2018 and December 31, 2017 (amounts in thousands): June 30, 2018 December 31, 2017 Mortgage escrow deposits: Real estate taxes and insurance $ 1,171 $ 845 Replacement reserves 7,698 8,347 Mortgage principal reserves/sinking funds 6,544 3,167 Other 852 852 Mortgage escrow deposits 16,265 13,211 Restricted cash: Earnest money on pending acquisitions 750 750 Restricted deposits on real estate investments 712 58 Resident security and utility deposits 35,097 35,183 Other 1,546 913 Restricted cash 38,105 36,904 Restricted deposits $ 54,370 $ 50,115

Derivative and Other Fair Val34

Derivative and Other Fair Value Instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Summary of Carrying and Fair Values of Financial Instruments	The June 30, 2018 December 31, 2017 Carrying Value Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Mortgage notes payable, net $ 2,894,325 $ 2,823,402 $ 3,618,722 $ 3,615,384 Unsecured debt, net 5,878,444 5,911,615 5,338,569 5,619,744 Total debt, net $ 8,772,769 $ 8,735,017 $ 8,957,291 $ 9,235,128
Summary of Consolidated Derivative Instruments	The June 30, 2018 Fair Value Hedges (1) Forward Starting Swaps (2) Current Notional Balance $ 450,000 $ 800,000 Lowest Interest Rate 2.375 % 2.1478 % Highest Interest Rate 2.375 % 3.1163 % Earliest Maturity Date 2019 2028 Latest Maturity Date 2019 2029 (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 planned future debt issuances. Of the $800.0 million notional balance, $300.0 million of these swaps have mandatory counterparty terminations in 2019 and are targeted for certain 2018 debt issuances while $500.0 million of these swaps have mandatory counterparty terminations in 2020 and are targeted for certain 2019 debt issuances.
Summary of Fair Value Measurements for Each Major Category of Assets and Liabilities Measured at Fair Value on Recurring Basis	The Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 6/30/2018 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps Other Assets $ 16,731 $ — $ 16,731 $ — Supplemental Executive Retirement Plan Other Assets 140,432 140,432 — — Total $ 157,163 $ 140,432 $ 16,731 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 3,748 $ — $ 3,748 $ — Forward Starting Swaps Other Liabilities 1,231 — 1,231 — Supplemental Executive Retirement Plan Other Liabilities 140,432 140,432 — — Total $ 145,411 $ 140,432 $ 4,979 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 366,483 $ — $ 366,483 $ — Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 12/31/2017 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Staring Swaps Other Assets $ 5,143 $ — $ 5,143 $ — Supplemental Executive Retirement Plan Other Assets 140,159 140,159 — — Total $ 145,302 $ 140,159 $ 5,143 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 1,597 $ — $ 1,597 $ — Supplemental Executive Retirement Plan Other Liabilities 140,159 140,159 — — Total $ 141,756 $ 140,159 $ 1,597 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 366,955 $ — $ 366,955 $ —
Summary of Effect of Fair Value Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The June 30, 2018 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (2,151 ) Fixed rate debt Interest expense $ 2,151 Total $ (2,151 ) $ 2,151 June 30, 2017 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (630 ) Fixed rate debt Interest expense $ 630 Total $ (630 ) $ 630
Summary of Effect of Cash Flow Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The Effective Portion Ineffective Portion June 30, 2018 Type of Cash Flow Hedge Amount of Gain/(Loss) Recognized in OCI on Derivative Location of Gain/(Loss) Reclassified from Accumulated OCI into Income Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ 11,995 Interest expense $ (9,307 ) N/A $ — Total $ 11,995 $ (9,307 ) $ — Effective Portion Ineffective Portion June 30, 2017 Type of Cash Flow Hedge Amount of Gain/(Loss) Recognized in OCI on Derivative Location of Gain/(Loss) Reclassified from Accumulated OCI into Income Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ 3,507 Interest expense $ (9,251 ) N/A $ — Total $ 3,507 $ (9,251 ) $ —

Earning Per Share and Earning35

Earning Per Share and Earnings Per Unit (Tables)	6 Months Ended
	Jun. 30, 2018
Schedule of Calculation of Numerator and Denominator in Earning Per Share and Earnings Per Unit	The Six Months Ended June 30, Quarter Ended June 30, 2018 2017 2018 2017 Numerator for net income per share – basic: Net income $ 338,958 $ 354,101 $ 118,410 $ 204,160 Allocation to Noncontrolling Interests – Operating Partnership (12,358 ) (12,765 ) (4,299 ) (7,354 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,189 ) (1,553 ) (509 ) (765 ) Preferred distributions (1,545 ) (1,546 ) (772 ) (773 ) Numerator for net income per share – basic $ 323,866 $ 338,237 $ 112,830 $ 195,268 Numerator for net income per share – diluted: Net income $ 338,958 $ 354,101 $ 118,410 $ 204,160 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,189 ) (1,553 ) (509 ) (765 ) Preferred distributions (1,545 ) (1,546 ) (772 ) (773 ) Numerator for net income per share – diluted $ 336,224 $ 351,002 $ 117,129 $ 202,622 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 367,865 366,713 367,930 366,820 Effect of dilutive securities: OP Units 12,864 12,906 12,865 12,913 Long-term compensation shares/units 2,495 2,886 2,628 2,959 Denominator for net income per share – diluted 383,224 382,505 383,423 382,692 Net income per share – basic $ 0.88 $ 0.92 $ 0.31 $ 0.53 Net income per share – diluted $ 0.88 $ 0.92 $ 0.31 $ 0.53
ERPOP [Member]
Schedule of Calculation of Numerator and Denominator in Earning Per Share and Earnings Per Unit	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, 2018 2017 2018 2017 Numerator for net income per Unit – basic and diluted: Net income $ 338,958 $ 354,101 $ 118,410 $ 204,160 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,189 ) (1,553 ) (509 ) (765 ) Allocation to Preference Units (1,545 ) (1,546 ) (772 ) (773 ) Numerator for net income per Unit – basic and diluted $ 336,224 $ 351,002 $ 117,129 $ 202,622 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 380,729 379,619 380,795 379,733 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,495 2,886 2,628 2,959 Denominator for net income per Unit – diluted 383,224 382,505 383,423 382,692 Net income per Unit – basic $ 0.88 $ 0.92 $ 0.31 $ 0.53 Net income per Unit – diluted $ 0.88 $ 0.92 $ 0.31 $ 0.53

Reportable Segments (Tables)

Reportable Segments (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Schedule of Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations	The Six Months Ended June 30, Quarter Ended June 30, 2018 2017 2018 2017 Rental income $ 1,272,451 $ 1,216,219 $ 639,620 $ 612,299 Property and maintenance expense (211,946 ) (201,924 ) (103,744 ) (99,316 ) Real estate taxes and insurance expense (181,396 ) (169,231 ) (89,482 ) (87,503 ) Total operating expenses (393,342 ) (371,155 ) (193,226 ) (186,819 ) Net operating income $ 879,109 $ 845,064 $ 446,394 $ 425,480
Schedule of NOI for Each Segment from Rental Real Estate Specific to Continuing Operations	The following tables present NOI for each segment from our rental real estate for the six months and quarters ended June 30, 2018 and 2017, Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 205,103 $ 58,892 $ 146,211 $ 198,557 $ 56,960 $ 141,597 Orange County 45,331 11,090 34,241 43,654 10,838 32,816 San Diego 45,425 11,751 33,674 43,620 11,535 32,085 Subtotal - Southern California 295,859 81,733 214,126 285,831 79,333 206,498 San Francisco 219,400 52,854 166,546 213,516 54,018 159,498 Washington D.C. 215,843 66,899 148,944 213,546 64,572 148,974 New York 240,124 94,505 145,619 239,367 88,938 150,429 Boston 113,511 31,593 81,918 110,989 30,145 80,844 Seattle 97,642 27,799 69,843 94,020 26,407 67,613 Other Markets 969 341 628 924 340 584 Total same store 1,183,348 355,724 827,624 1,158,193 343,753 814,440 Non-same store/other (2) (3) Non-same store 83,193 29,862 53,331 34,439 12,533 21,906 Other (3) 5,910 7,756 (1,846 ) 23,587 14,869 8,718 Total non-same store/other 89,103 37,618 51,485 58,026 27,402 30,624 Totals $ 1,272,451 $ 393,342 $ 879,109 $ 1,216,219 $ 371,155 $ 845,064 (1) For the six months ended June 30, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,210 apartment (2) For the six months ended June 30, 2018 and 2017, non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Quarter Ended June 30, 2018 Quarter Ended June 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 102,619 $ 29,032 $ 73,587 $ 99,921 $ 28,309 $ 71,612 Orange County 22,829 5,564 17,265 21,998 5,376 16,622 San Diego 22,932 5,788 17,144 21,897 5,736 16,161 Subtotal - Southern California 148,380 40,384 107,996 143,816 39,421 104,395 San Francisco 115,332 27,581 87,751 111,835 28,466 83,369 Washington D.C. 108,689 33,237 75,452 107,103 32,241 74,862 New York 120,498 46,680 73,818 120,005 43,499 76,506 Boston 57,217 15,511 41,706 55,943 14,941 41,002 Seattle 49,031 14,111 34,920 47,594 13,392 34,202 Other Markets 481 175 306 461 144 317 Total same store 599,628 177,679 421,949 586,757 172,104 414,653 Non-same store/other (2) (3) Non-same store 39,427 13,154 26,273 13,850 5,193 8,657 Other (3) 565 2,393 (1,828 ) 11,692 9,522 2,170 Total non-same store/other 39,992 15,547 24,445 25,542 14,715 10,827 Totals $ 639,620 $ 193,226 $ 446,394 $ 612,299 $ 186,819 $ 425,480 (1) For the quarters ended June 30, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to April 1, 2017, less properties subsequently sold, which represented 72,629 apartment (2) For the quarters ended June 30, 2018 and 2017, non-same store primarily includes properties acquired after April 1, 2017, plus any properties in lease-up and not stabilized as of April 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Six Months Ended June 30, 2018 Total Assets Capital Expenditures Same store (1) Los Angeles $ 2,649,731 $ 13,220 Orange County 323,604 4,017 San Diego 413,701 2,481 Subtotal - Southern California 3,387,036 19,718 San Francisco 3,004,183 21,259 Washington D.C. 3,742,083 14,137 New York 4,404,182 12,092 Boston 1,609,747 9,451 Seattle 1,296,447 6,900 Other Markets 12,795 102 Total same store 17,456,473 83,659 Non-same store/other (2) (3) Non-same store 2,414,779 2,210 Other (3) 535,330 118 Total non-same store/other 2,950,109 2,328 Totals $ 20,406,582 $ 85,987 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,210 apartment (2) Non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and capital expenditures for properties

Business - Additional Informati

Business - Additional Information (Details)	Jun. 30, 2018StatePropertyApartmentUnit	Apr. 02, 2018ApartmentUnit	Feb. 01, 2018ApartmentUnit
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of states in which entity operates | State	10
Properties | Property	304
Apartment units	78,645
Master-Leased Properties – Consolidated
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Properties | Property	1
Apartment units	162
Master-Leased Properties – Consolidated | Boston
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of self managed apartments			94
Master-Leased Properties – Consolidated | Los Angeles
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of self managed apartments		597
ERPOP [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Noncontrolling interest, ownership percentage by parent	96.30%

Business - Ownership Breakdown

Business - Ownership Breakdown (Details)	Jun. 30, 2018PropertyApartmentUnit
Property/Unit schedule
Properties | Property	304
Apartment Units | ApartmentUnit	78,645
Wholly Owned Properties
Property/Unit schedule
Properties | Property	284
Apartment Units | ApartmentUnit	74,003
Master-Leased Properties – Consolidated
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	162
Partially Owned Properties – Consolidated
Property/Unit schedule
Properties | Property	17
Apartment Units | ApartmentUnit	3,535
Partially Owned Properties – Unconsolidated
Property/Unit schedule
Properties | Property	2
Apartment Units | ApartmentUnit	945

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2017USD ($)	Jun. 30, 2018USD ($)PropertyApartmentUnit	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)PropertyApartmentUnit	Jun. 30, 2017USD ($)
Provision for income tax		$ 274,000	$ 220,000	$ 487,000	$ 482,000
Percentage of rental income excluded from accounting standard adoption				94.00%
Percentage of total revenue subject to revenue recognition standard				6.00%
Properties | Property		304		304
Apartment Units | ApartmentUnit		78,645		78,645
Noncontrolling interests equity (deficit) partially owned properties		$ 1,600,000		$ 1,600,000
Partially Owned Properties – Consolidated
Properties | Property		17		17
Apartment Units | ApartmentUnit		3,535		3,535
Limited Life Partnership Properties [Member]
Properties | Property		4		4
Noncontrolling interests equity (deficit) partially owned properties		$ 8,700,000		$ 8,700,000
Noncontrolling interests settlement value		$ 66,800,000		66,800,000
Adjustments for New Accounting Principle, Early Adoption
Gain (loss) on equity transaction	$ 0
Federal [Member]
Provision for income tax				$ 0

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Schedule of Disaggregation of Revenue Streams of Rental Income and Percentage of Rental Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Amount of rental income	$ 639,620	$ 612,299	$ 1,272,451	$ 1,216,219
Percentage of rental income	100.00%		100.00%
Amount of rental income	$ 599,976		$ 1,192,789
Leasing Revenue [Member}
Percentage of rental income	93.80%		93.80%
Utility Recoveries [Member]
Amount of rental income	$ 15,560		$ 30,935
Percentage of rental income	2.40%		2.40%
Parking Revenue [Member]
Amount of rental income	$ 6,267		$ 14,064
Percentage of rental income	1.00%		1.10%
Other Revenue [Member]
Amount of rental income	$ 17,817		$ 34,663
Percentage of rental income	2.80%		2.70%

Summary of Significant Accoun41

Summary of Significant Accounting Policies - Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt	$ 3,263	$ 1,391
Net (gain) loss on debt extinguishment	22,110	12,258
Net cash provided by operating activities	685,454	559,113
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash provided by (used for) investing activities	(84,176)	(44,607)
CASH FLOWS FROM FINANCING ACTIVITIES:
Commercial paper proceeds	4,766,050	2,610,863
Net cash (used for) financing activities	(613,163)	(420,481)
Cash and cash equivalents, beginning of period	50,647
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents, end of period	34,507	37,719
Cash and cash equivalents and restricted deposits, end of period	88,877	313,113
Scenario, Previously Reported [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		3,359
(Increase) decrease in deposits - restricted		310
(Increase) decrease in mortgage deposits		900
Net cash provided by operating activities		550,033
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		(177,742)
(Increase) decrease in mortgage deposits		(4,108)
Net cash provided by (used for) investing activities		(226,457)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		47,127
Commercial paper proceeds		2,608,895
Net cash (used for) financing activities		(363,064)
Cash and cash equivalents, beginning of period		77,207
Cash and cash equivalents, end of period		37,719
Reclassification Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		(1,968)
Net (gain) loss on debt extinguishment		12,258
(Increase) decrease in deposits - restricted		(310)
(Increase) decrease in mortgage deposits		(900)
Net cash provided by operating activities		9,080
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		177,742
(Increase) decrease in mortgage deposits		4,108
Net cash provided by (used for) investing activities		181,850
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		(47,127)
Commercial paper proceeds		1,968
Net cash (used for) financing activities		(57,417)
(adjustments for restricted deposits, beginning of period)		141,881
(adjustments for restricted deposits, end of period)		275,394
Mortgage Notes Payable, Net [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment	$ (22,110)	(12,258)
Mortgage Notes Payable, Net [Member] | Reclassification Adjustments [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment		$ (12,258)

Equity, Capital and Other Int42

Equity, Capital and Other Interests - Changes in Issued and Outstanding Common Shares and Units (Details)	6 Months Ended
	Jun. 30, 2018shares
Equity Capital And Other Interests [Abstract]
Common Stock, Shares, Outstanding	368,018,082
Common Shares Issued:
Conversion of OP Units	11,494
Exercise of share options	80,875
Employee Share Purchase Plan (ESPP)	44,858
Restricted share grants, net	123,027
Common Stock, Shares, Outstanding	368,278,336
Units
Total Units Outstanding	13,768,438
Restricted unit grants, net	267,074
Conversion of OP Units to Common Shares	(11,494)
Total Units Outstanding	14,024,018
Common Shares And Units Outstanding	382,302,354
Units Ownership Interest in Operating Partnership	3.70%

Equity, Capital and Other Int43

Equity, Capital and Other Interests - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Redeemable noncontrolling interests - operating partnership	$ 366,483	$ 366,955
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, par or stated value per share	$ 0.01	$ 0.01
ERPOP [Member]
Class Of Stock [Line Items]
Redeemable Limited Partners	$ 366,483	$ 366,955

Equity, Capital and Other Int44

Equity, Capital and Other Interests - Changes in Redemption Value of Redeemable Noncontrolling Interests - Operating Partnership (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Equity Capital And Other Interests [Abstract]
Redeemable Noncontrolling Interests - Operating Partnership	$ 366,955
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	172
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	(644)
Redeemable Noncontrolling Interests - Operating Partnership	$ 366,483

Equity, Capital and Other Int45

Equity, Capital and Other Interests - Issued and Outstanding Preferred Shares and Preference Units (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017	$ 37,280	$ 37,280
ERPOP [Member]
Class Of Stock [Line Items]
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017	$ 37,280	37,280
Preferred Stock
Class Of Stock [Line Items]
Preferred Stocks Preference Units Call Date	Dec. 10, 2026
Annual Dividend Per Preferred Share Preference Unit	$ 4.145
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017	$ 37,280	37,280
Preferred Stock | ERPOP [Member]
Class Of Stock [Line Items]
Preferred Stocks Preference Units Call Date	Dec. 10, 2026
Annual Dividend Per Preferred Share Preference Unit	$ 4.145
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2018 and December 31, 2017	$ 37,280	$ 37,280

Equity, Capital and Other Int46

Equity, Capital and Other Interests - Issued and Outstanding Preferred Shares and Preference Units (Parenthetical) (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Preference Units Issued	745,600	745,600
Preferred Stock Preference Units Outstanding	745,600	745,600
Preferred Stock Preference Units Redemption Price Per Share	$ 50	$ 50
Preferred Stock Preference Units Dividend Rate Percentage	8.29%	8.29%
Preferred Stock | ERPOP [Member]
Class Of Stock [Line Items]
Preferred Stock Preference Units Issued	745,600	745,600
Preferred Stock Preference Units Outstanding	745,600	745,600
Preferred Stock Preference Units Redemption Price Per Share	$ 50	$ 50
Preferred Stock Preference Units Dividend Rate Percentage	8.29%	8.29%

Equity, Capital and Other Int47

Equity, Capital and Other Interests - Changes in Operating Partnership's Issued and Outstanding Units (Details)	6 Months Ended
	Jun. 30, 2018shares
General and Limited Partner Units
Exercise of share options	80,875
Employee Share Purchase Plan (ESPP)	44,858
Restricted share grants, net	123,027
Restricted unit grants, net	267,074
Common Shares And Units Outstanding	382,302,354
LIMITED PARTNERS
Total Units Outstanding	13,768,438
Restricted unit grants, net	267,074
Conversion of Limited Partner OP Units to EQR Common Shares	(11,494)
Total Units Outstanding	14,024,018
Units Ownership Interest in Operating Partnership	3.70%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	381,786,520
Exercise of share options	80,875
Employee Share Purchase Plan (ESPP)	44,858
Restricted share grants, net	123,027
Restricted unit grants, net	267,074
Common Shares And Units Outstanding	382,302,354
LIMITED PARTNERS
Total Units Outstanding	13,768,438
Restricted unit grants, net	267,074
Conversion of Limited Partner OP Units to EQR Common Shares	(11,494)
Total Units Outstanding	14,024,018
Units Ownership Interest in Operating Partnership	3.70%

Equity, Capital and Other Int48

Equity, Capital and Other Interests - Changes in Redemption Value of Redeemable Limited Partners Interest (Details) - ERPOP [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Redeemable Limited Partners	$ 366,955
Limited Partners Change In Redemption Value	172
Limited Partners Change In Carrying Value	(644)
Redeemable Limited Partners	$ 366,483

Equity, Capital and Other Int49

Equity, Capital and Other Interests - Other - Additional Information (Details)	6 Months Ended
	Jun. 30, 2018shares
Equity Capital And Other Interests [Abstract]
Additional common shares authorized	13,000,000
Stock repurchase program, number of shares authorized to be repurchased	13,000,000
Stock repurchased and retired during period, shares	0

Real Estate and Lease Intangi50

Real Estate and Lease Intangibles - Summary of Carrying Amounts of Investment in Real Estate (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Land	$ 5,986,329	$ 5,996,024
Depreciable property:
Buildings and improvements	17,852,269	17,743,042
Furniture, fixtures and equipment	1,615,089	1,548,961
In-Place lease intangibles	479,248	476,359
Projects under development:
Construction-in-progress	145,564	163,547
Land held for development:
Land	86,098	98,963
Construction-in-progress	145,564	163,547
Investment in real estate	26,164,597	26,026,896
Accumulated depreciation	(6,338,043)	(6,040,378)
Investment in real estate, net	19,826,554	19,986,518
Projects under development [Member]
Projects under development:
Land	39,437	43,226
Construction-in-progress	106,127	120,321
Land held for development:
Construction-in-progress	106,127	120,321
Land held for development [Member]
Projects under development:
Construction-in-progress	25,060	36,425
Land held for development:
Land	61,038	62,538
Construction-in-progress	$ 25,060	$ 36,425

Real Estate and Lease Intangi51

Real Estate and Lease Intangibles - Summary of Carrying Amounts of Above and Below Market Ground And Retail Lease Intangibles (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Assets [Member]
Lease intangible assets	$ 193,178	$ 193,178
Finite-Lived Intangible Assets, Accumulated Amortization	(24,691)	(22,434)
Lease intangible assets, net	168,487	170,744
Other Assets [Member] | Ground Lease [Member]
Finite-Lived Intangible Asset, Off-market Lease, Favorable, Gross	191,918	191,918
Other Assets [Member] | Retail Lease [Member]
Finite-Lived Intangible Asset, Off-market Lease, Favorable, Gross	1,260	1,260
Other Liabilities [Member]
Lease Intangible Liabilities	7,670	7,670
Finite Lived Intangible Liabilities Accumulated Amortization	(5,204)	(5,143)
Lease intangible liabilities, net	2,466	2,527
Other Liabilities [Member] | Ground Lease [Member]
Finite-Lived Intangible Liabilities, Off-market Lease, Unfavorable, Gross	2,400	2,400
Other Liabilities [Member] | Retail Lease [Member]
Finite-Lived Intangible Liabilities, Off-market Lease, Unfavorable, Gross	$ 5,270	$ 5,270

Real Estate and Lease Intangi52

Real Estate and Lease Intangibles - Summary of the Effect of the Amortization for Above and Below Market Ground and Retail Lease Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Total amortization of above/below market lease intangibles	$ (1,098)	$ (861)	$ (2,196)	$ (1,717)
Ground Lease [Member] | Property and Maintenance [Member]
Total amortization of above/below market lease intangibles	(1,116)	(1,081)	(2,232)	(2,161)
Retail Lease [Member] | Rental Income [Member]
Total amortization of above/below market lease intangibles	$ 18	$ 220	$ 36	$ 444

Real Estate and Lease Intangi53

Real Estate and Lease Intangibles - Summary of Aggregate Amortization for Above and Below Market Ground And Retail Lease Intangibles (Details) $ in Thousands	Jun. 30, 2018USD ($)
Finite-lived intangible assets, amortization expense, remainder of fiscal year 2018	$ (2,196)
Finite-Lived Intangible Assets, Amortization Expense, Year 2019	(4,392)
Finite-lived intangible assets, amortization expense, year 2020	(4,392)
Finite-lived intangible assets, amortization expense, year 2021	(4,392)
Finite-lived intangible assets, amortization expense, year 2022	(4,436)
Finite-lived intangible assets, amortization expense, year 2023	(4,444)
Ground Lease [Member]
Finite-lived intangible assets, amortization expense, remainder of fiscal year 2018	(2,231)
Finite-Lived Intangible Assets, Amortization Expense, Year 2019	(4,463)
Finite-lived intangible assets, amortization expense, year 2020	(4,463)
Finite-lived intangible assets, amortization expense, year 2021	(4,463)
Finite-lived intangible assets, amortization expense, year 2022	(4,463)
Finite-lived intangible assets, amortization expense, year 2023	(4,463)
Retail Lease [Member]
Finite lived intangible assets amortization income, reminder of fiscal year 2018	35
Finite-lived intangible assets; amortization income, year 2019	71
Finite-lived intangible assets; amortization income, year 2020	71
Finite-lived intangible assets; amortization income, year 2021	71
Finite-lived intangible assets; amortization income, year 2022	27
Finite-lived intangible assets; amortization income, year 2023	$ 19

Real Estate and Lease Intangi54

Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)PropertyApartmentUnit
Properties acquired | Property	2
Property Units acquired | ApartmentUnit	357
Purchase Price	$ 199,700
Properties disposed | Property	4
Property Units disposed | ApartmentUnit	786
Sales Price	$ 292,720
Rental Properties - Consolidated [Member]
Properties acquired | Property	2
Property Units acquired | ApartmentUnit	357
Purchase Price	$ 199,700
Properties disposed | Property	4
Property Units disposed | ApartmentUnit	786
Sales Price	$ 290,020
Land [Member]
Purchase Price	49,100
Sales Price	$ 2,700

Real Estate and Lease Intangi55

Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Parenthetical) (Details) $ in Thousands	Jun. 30, 2018USD ($)
Purchase Price	$ 199,700
Land [Member]
Purchase Price	49,100
Depreciable Property [Member]
Purchase Price	$ 151,400

Real Estate and Lease Intangi56

Real Estate and Lease Intangibles - Acquisitions and Dispositions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Real Estate [Abstract]
Net gain on sales of real estate properties	$ (51)	$ 87,726	$ 142,162	$ 124,433
Net gain on sales of land parcels	$ 995	$ (23)	$ 995	$ 19,170

Commitments to Acquire_Dispos57

Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Acquire (Details) - Subsequent Event [Member] $ in Thousands	Aug. 02, 2018USD ($)PropertyApartmentUnit
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	372
Purchase Price | $	$ 135,500
Rental Properties Disposed [Member]
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	372
Purchase Price | $	$ 135,500

Commitments to Acquire_Dispos58

Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Dispose of (Details) - Subsequent Event [Member] $ in Thousands	Aug. 02, 2018USD ($)PropertyApartmentUnit
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	506
Sales Price | $	$ 416,100
Rental Properties Disposed [Member]
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	506
Sales Price | $	$ 416,100

Investments in Partially Owne59

Investments in Partially Owned Entities - Consolidated Variable Interest Entities ("VIEs") - Additional Information (Details) $ in Thousands	Jun. 30, 2018USD ($)PropertyApartmentUnit	Dec. 31, 2017USD ($)
Variable Interest Entity [Line Items]
Properties | Property	304
Apartment units | ApartmentUnit	78,645
Total assets	$ 20,406,582	$ 20,570,599
Total liabilities	$ 9,600,313	9,729,781
Consolidated VIE [Member]
Variable Interest Entity [Line Items]
Properties | Property	17
Apartment units | ApartmentUnit	3,535
Total assets	$ 717,500	518,900
Total liabilities	$ 313,400	$ 307,000

Investments in Partially Owne60

Investments in Partially Owned Entities - Summary of Companys Investment in Unconsolidated Entities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 58,124	$ 58,254
Operating Property [Member] | Unconsolidated Non-VIE [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 11,378	12,367
Ownership Percentage	20.00%
Other [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 3,290	1,436
Consolidated VIE [Member] | Wisconsin Place Developer [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 43,456	$ 44,451
Ownership Percentage	33.30%

Investments in Partially Owne61

Investments in Partially Owned Entities - Summary of Companys Investment in Unconsolidated Entities (Parenthetical) (Details)	6 Months Ended
	Jun. 30, 2018ApartmentUnitJointVenture
Variable Interest Entity [Line Items]
Apartment units	78,645
Operating Property [Member] | Unconsolidated Non-VIE [Member]
Variable Interest Entity [Line Items]
Apartment units	945
Number of joint ventures under agreements | JointVenture	2

Restricted Deposits - Restricte

Restricted Deposits - Restricted Deposits (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Mortgage escrow deposits:
Real estate taxes and insurance	$ 1,171	$ 845
Replacement reserves	7,698	8,347
Mortgage principal reserves/sinking funds	6,544	3,167
Other	852	852
Mortgage escrow deposits	16,265	13,211
Restricted cash:
Earnest money on pending acquisitions	750	750
Restricted deposits on real estate investments	712	58
Resident security and utility deposits	35,097	35,183
Other	1,546	913
Restricted cash	38,105	36,904
Restricted deposits	$ 54,370	$ 50,115	$ 275,394

Debt - Mortgage Notes Payable -

Debt - Mortgage Notes Payable - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Mortgage notes payable	$ 2,894,325	$ 3,618,722
Debt instrument, maturity date	Jan. 10, 2022
Mortgages [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 3,300
Write off of deferred debt issuance cost	1,600
Write off unamortized (premium) discount	$ (200)
Debt instrument, maturity date	May 28, 2061
Weighted average interest rate	4.22%
Mortgages [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.10%
Mortgages [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	6.90%
Conventional Mortgage Loan [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 43,700
Debt instrument, maturity year	2,018
Bonds [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 131,900
Debt instrument maturity year, start	2,028
Debt instrument maturity year, end	2,042
Credit enhanced debt [Member]
Debt Instrument [Line Items]
Mortgage notes payable	$ 563,400
Fannie Mae Pool 3 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 550,000
Debt instrument, interest rate, stated percentage	6.08%
Debt instrument, maturity year	2,020
Prepayment penalty charges	$ 22,100

Debt - Notes - Additional Infor

Debt - Notes - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unsecured notes	$ 5,532,637	$ 5,038,812
Debt instrument, maturity date	Jan. 10, 2022
3.50% Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of unsecured debt	$ 500,000
Debt instrument, interest rate, stated percentage	3.50%
Proceeds from debt, net of issuance costs	$ 497,000
Debt instrument, interest rate, effective percentage	3.61%
Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Aug. 1, 2047
Weighted average interest rate	4.27%
Notes Payable, Other Payables [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	2.375%
Notes Payable, Other Payables [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	7.57%

Debt - Line of Credit and Comme

Debt - Line of Credit and Commercial Paper - Additional Information (Details) - USD ($)	Nov. 03, 2016	Jun. 30, 2018	Nov. 02, 2016	Feb. 02, 2015
Line of Credit Facility [Line Items]
Debt instrument, maturity date		Jan. 10, 2022
Commercial Paper [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility				$ 500,000,000
Commercial paper, net		$ 345,800,000
commercial paper principal outstanding		347,000,000
Unamortized discount		$ 1,200,000
Weighted average interest rate		2.16%
Commercial paper weighted average days outstanding		48 days
Commercial paper principal outstanding		$ 347,000,000
Unsecured Revolving Credit Facility
Line of Credit Facility [Line Items]
Unsecured revolving credit facility	$ 2,000,000,000		$ 2,500,000,000
Ability to increase LOC facility	$ 750,000,000
Debt instrument, basis spread on variable rate	0.825%
Percentage points of line of credit facility commitment fee		0.125%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Weighted average interest rate		2.29%
Remaining borrowing capacity		$ 1,650,000,000
Amount restricted/dedicated to support letters of credit		$ 6,700,000

Debt - Other - Additional Infor

Debt - Other - Additional Information (Details) $ in Millions	Jun. 30, 2018USD ($)
Debt Disclosure [Abstract]
Letters of credit outstanding	$ 9

Derivative and Other Fair Val67

Derivative and Other Fair Value Instruments - Summary of Carrying and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	$ 8,772,769	$ 8,957,291
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	8,735,017	9,235,128
Mortgage Notes Payable, Net [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	2,894,325	3,618,722
Mortgage Notes Payable, Net [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	2,823,402	3,615,384
Unsecured Debt [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	5,878,444	5,338,569
Unsecured Debt [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	$ 5,911,615	$ 5,619,744

Derivative and Other Fair Val68

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Details)	6 Months Ended
	Jun. 30, 2018USD ($)
Fair Value Hedges [Member]
Derivative [Line Items]
Current Notional Balance	$ 450,000,000
Earliest Maturity Date	2,019
Latest Maturity Date	2,019
Fair Value Hedges [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.375%
Fair Value Hedges [Member] | Maximum [Member]
Derivative [Line Items]
Interest Rate	2.375%
Forward Starting Swaps [Member]
Derivative [Line Items]
Current Notional Balance	$ 800,000,000
Earliest Maturity Date	2,028
Latest Maturity Date	2,029
Forward Starting Swaps [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.1478%
Forward Starting Swaps [Member] | Maximum [Member]
Derivative [Line Items]
Interest Rate	3.1163%

Derivative and Other Fair Val69

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Parenthetical) (Details)	6 Months Ended
	Jun. 30, 2018USD ($)
Derivative [Line Items]
Debt instrument, maturity date	Jan. 10, 2022
Forward Starting Swaps [Member]
Derivative [Line Items]
Current Notional Balance	$ 800,000,000
Forward Starting Swaps Mandatory Counterparty Terminations in 2019 [Member]
Derivative [Line Items]
Current Notional Balance	300,000,000
Forward Starting Swaps Mandatory Counterparty Terminations in 2020 [Member]
Derivative [Line Items]
Current Notional Balance	500,000,000
2.375% Notes [Member]
Derivative [Line Items]
Proceeds from issuance of unsecured debt	$ 450,000,000
Debt instrument, interest rate, stated percentage	2.375%
Debt instrument, maturity date	Jul. 1, 2019
2.375% Notes [Member] | London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Debt instrument, basis spread on variable rate	0.61%
Debt instrument, description of variable rate basis	90-Day LIBOR

Derivative and Other Fair Val70

Derivative and Other Fair Value Instruments - Summary of Fair Value Measurements for Each Major Category of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	$ 140,432	$ 140,159
Assets, Fair Value Disclosure	157,163	145,302
Other Liabilities, Fair Value Disclosure	140,432	140,159
Liabilities, Fair Value Disclosure	145,411	141,756
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	366,483	366,955
Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3,748	1,597
Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	16,731	5,143
Other Liabilities, Forward Starting Swaps	1,231
Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	140,432	140,159
Assets, Fair Value Disclosure	140,432	140,159
Other Liabilities, Fair Value Disclosure	140,432	140,159
Liabilities, Fair Value Disclosure	140,432	140,159
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Fair Value, Inputs, Level 1 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Other Liabilities, Forward Starting Swaps	0
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	16,731	5,143
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	4,979	1,597
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	366,483	366,955
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3,748	1,597
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	16,731	5,143
Other Liabilities, Forward Starting Swaps	1,231
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	0	0
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	0	0
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Fair Value, Inputs, Level 3 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	$ 0
Other Liabilities, Forward Starting Swaps	$ 0

Derivative and Other Fair Val71

Derivative and Other Fair Value Instruments - Summary of Effect of Fair Value Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ (2,151)	$ (630)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	2,151	630
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	(2,151)	(630)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	$ 2,151	$ 630

Derivative and Other Fair Val72

Derivative and Other Fair Value Instruments - Summary of Effect of Cash Flow Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	$ 11,995	$ 3,507
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(9,307)	(9,251)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	0	0
Forward Starting Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	11,995	3,507
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(9,307)	(9,251)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	$ 0	$ 0

Derivative and Other Fair Val73

Derivative and Other Fair Value Instruments - Additional Information (Details) $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended
	Feb. 28, 2018USD ($)DerivativeInstrument	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Derivative [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)		$ 67.3	$ 88.6
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net		$ 19.9
Forward Starting Swaps [Member]
Derivative [Line Items]
Proceeds from settlement of derivative instruments	$ 1.6
Forward starting swaps settled | DerivativeInstrument	2
Public notes, face value	$ 500
Debt instrument, term	10 years

Earning Per Share and Earning74

Earning Per Share and Earnings Per Unit - Computation of Net Income per Share Basic and Net Income per Share Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 118,410	$ 204,160	$ 338,958	$ 354,101
Allocation to Noncontrolling Interests – Operating Partnership	(4,299)	(7,354)	(12,358)	(12,765)
Partially Owned Properties	(509)	(765)	(1,189)	(1,553)
Preferred distributions	(772)	(773)	(1,545)	(1,546)
Net income available to Common Shares	112,830	195,268	323,866	338,237
Numerator for net income per share – diluted	$ 117,129	$ 202,622	$ 336,224	$ 351,002
Weighted average Common Shares outstanding	367,930	366,820	367,865	366,713
Dilutive Op Units	12,865	12,913	12,864	12,906
Dilutive Securities Options	2,628	2,959	2,495	2,886
Weighted average Common Shares outstanding	383,423	382,692	383,224	382,505
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92

Earning Per Share and Earning75

Earning Per Share and Earnings Per Unit - Computation of Net Income per Unit Basic and Net Income per Unit Diluted for Operating Partnership (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income	$ 118,410	$ 204,160	$ 338,958	$ 354,101
Partially Owned Properties	$ (509)	$ (765)	$ (1,189)	$ (1,553)
Dilutive Securities Options	2,628	2,959	2,495	2,886
Weighted average Common Shares outstanding	383,423	382,692	383,224	382,505
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92
ERPOP [Member]
Net income	$ 118,410	$ 204,160	$ 338,958	$ 354,101
Partially Owned Properties	(509)	(765)	(1,189)	(1,553)
Allocation to Preference Units	(772)	(773)	(1,545)	(1,546)
Numerator for net income per Unit – basic and diluted	$ 117,129	$ 202,622	$ 336,224	$ 351,002
Denominator for net income per Unit – basic	380,795	379,733	380,729	379,619
Dilutive Securities Options	2,628	2,959	2,495	2,886
Weighted average Common Shares outstanding	383,423	382,692	383,224	382,505
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92
Net income available to Common Shares	$ 0.31	$ 0.53	$ 0.88	$ 0.92

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	6 Months Ended
	Jun. 30, 2018USD ($)PropertyApartmentUnit
Accrual for environmental loss contingencies	$ 5,200,000
Number of properties with environmental reserves | Property	3
Littigation amount total payout	$ 900,000
Litigation reserve oustanding amount	$ 0
Projects in various stages of development | Property	4
Units in various stages of development | ApartmentUnit	912
Consolidated project under development commitment fund	$ 466,000,000
Various stages of development with estimated completion dates ranging through September 30, 2021	Sep. 30, 2021
Partially Owned Properties – Unconsolidated
Number of unconsolidated projects | Property	2

Reportable Segments - Additiona

Reportable Segments - Additional Information (Details) - Customer	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]
Number of customer contributed 10% or more of total revenue	0	0

Reportable Segments - Reconcili

Reportable Segments - Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	$ 639,620	$ 612,299	$ 1,272,451	$ 1,216,219
Property and maintenance expense	(103,744)	(99,316)	(211,946)	(201,924)
Real estate taxes and insurance expense	(89,482)	(87,503)	(181,396)	(169,231)
Operating income	217,654	210,550	414,523	414,921
Same Store, Non-same Store and Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	639,620	612,299	1,272,451	1,216,219
Property and maintenance expense	(103,744)	(99,316)	(211,946)	(201,924)
Real estate taxes and insurance expense	(89,482)	(87,503)	(181,396)	(169,231)
Total operating expenses	(193,226)	(186,819)	(393,342)	(371,155)
Operating income	$ 446,394	$ 425,480	$ 879,109	$ 845,064

Reportable Segments - NOI for E

Reportable Segments - NOI for Each Segment from Our Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Rental income	$ 639,620	$ 612,299	$ 1,272,451	$ 1,216,219
Operating income	217,654	210,550	414,523	414,921
Total Assets	20,406,582		20,406,582		$ 20,570,599
Capital Expenditures			85,987
Same store
Segment Reporting Information [Line Items]
Rental income	599,628	586,757	1,183,348	1,158,193
Operating expenses	177,679	172,104	355,724	343,753
Operating income	421,949	414,653	827,624	814,440
Total Assets	17,456,473		17,456,473
Capital Expenditures			83,659
Non-same store/other
Segment Reporting Information [Line Items]
Rental income	39,992	25,542	89,103	58,026
Operating expenses	15,547	14,715	37,618	27,402
Operating income	24,445	10,827	51,485	30,624
Total Assets	2,950,109		2,950,109
Capital Expenditures			2,328
Same Store, Non-same Store and Other
Segment Reporting Information [Line Items]
Rental income	639,620	612,299	1,272,451	1,216,219
Operating expenses	193,226	186,819	393,342	371,155
Operating income	446,394	425,480	879,109	845,064
Other markets | Same store
Segment Reporting Information [Line Items]
Rental income	481	461	969	924
Operating expenses	175	144	341	340
Operating income	306	317	628	584
Total Assets	12,795		12,795
Capital Expenditures			102
Los Angeles | Same store
Segment Reporting Information [Line Items]
Rental income	102,619	99,921	205,103	198,557
Operating expenses	29,032	28,309	58,892	56,960
Operating income	73,587	71,612	146,211	141,597
Total Assets	2,649,731		2,649,731
Capital Expenditures			13,220
Orange County | Same store
Segment Reporting Information [Line Items]
Rental income	22,829	21,998	45,331	43,654
Operating expenses	5,564	5,376	11,090	10,838
Operating income	17,265	16,622	34,241	32,816
Total Assets	323,604		323,604
Capital Expenditures			4,017
San Diego | Same store
Segment Reporting Information [Line Items]
Rental income	22,932	21,897	45,425	43,620
Operating expenses	5,788	5,736	11,751	11,535
Operating income	17,144	16,161	33,674	32,085
Total Assets	413,701		413,701
Capital Expenditures			2,481
Subtotal - Southern California | Same store
Segment Reporting Information [Line Items]
Rental income	148,380	143,816	295,859	285,831
Operating expenses	40,384	39,421	81,733	79,333
Operating income	107,996	104,395	214,126	206,498
Total Assets	3,387,036		3,387,036
Capital Expenditures			19,718
San Francisco | Same store
Segment Reporting Information [Line Items]
Rental income	115,332	111,835	219,400	213,516
Operating expenses	27,581	28,466	52,854	54,018
Operating income	87,751	83,369	166,546	159,498
Total Assets	3,004,183		3,004,183
Capital Expenditures			21,259
Washington DC | Same store
Segment Reporting Information [Line Items]
Rental income	108,689	107,103	215,843	213,546
Operating expenses	33,237	32,241	66,899	64,572
Operating income	75,452	74,862	148,944	148,974
Total Assets	3,742,083		3,742,083
Capital Expenditures			14,137
New York | Same store
Segment Reporting Information [Line Items]
Rental income	120,498	120,005	240,124	239,367
Operating expenses	46,680	43,499	94,505	88,938
Operating income	73,818	76,506	145,619	150,429
Total Assets	4,404,182		4,404,182
Capital Expenditures			12,092
Boston | Same store
Segment Reporting Information [Line Items]
Rental income	57,217	55,943	113,511	110,989
Operating expenses	15,511	14,941	31,593	30,145
Operating income	41,706	41,002	81,918	80,844
Total Assets	1,609,747		1,609,747
Capital Expenditures			9,451
Seattle | Same store
Segment Reporting Information [Line Items]
Rental income	49,031	47,594	97,642	94,020
Operating expenses	14,111	13,392	27,799	26,407
Operating income	34,920	34,202	69,843	67,613
Total Assets	1,296,447		1,296,447
Capital Expenditures			6,900
Non-same store | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	39,427	13,850	83,193	34,439
Operating expenses	13,154	5,193	29,862	12,533
Operating income	26,273	8,657	53,331	21,906
Total Assets	2,414,779		2,414,779
Capital Expenditures			2,210
Other [Member] | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	565	11,692	5,910	23,587
Operating expenses	2,393	9,522	7,756	14,869
Operating income	(1,828)	$ 2,170	(1,846)	$ 8,718
Total Assets	$ 535,330		535,330
Capital Expenditures			$ 118

Reportable Segments - NOI for80

Reportable Segments - NOI for Each Segment from Our Rental Real Estate Specific to Continuing Operations (Parenthetical) (Details) - Property	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]
Units in same store properties	72,629	72,629	72,210	72,210