Equity Residential (EQR) 10-Q 30 Oct 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 26, 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	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	EQR
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		368,440,623
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	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Land	$ 5,866,457	$ 5,996,024
Depreciable property	20,336,747	19,768,362
Projects under development	134,961	163,547
Land held for development	87,335	98,963
Investment in real estate	26,425,500	26,026,896
Accumulated depreciation	(6,494,770)	(6,040,378)
Investment in real estate, net	19,930,730	19,986,518
Investments in unconsolidated entities	57,576	58,254
Cash and cash equivalents	32,995	50,647
Restricted deposits	55,755	50,115
Other assets	465,094	425,065
Total assets	20,542,150	20,570,599
Liabilities:
Mortgage notes payable, net	2,789,436	3,618,722
Notes, net	5,534,990	5,038,812
Line of credit and commercial paper	499,367	299,757
Accounts payable and accrued expenses	182,446	114,766
Accrued interest payable	69,132	58,035
Other liabilities	344,373	341,852
Security deposits	67,177	65,009
Distributions payable	206,899	192,828
Total liabilities	9,693,820	9,729,781
Commitments and contingencies
Redeemable Noncontrolling Interests – Operating Partnership	381,239	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 September 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; 368,409,586 shares issued and outstanding as of September 30, 2018 and 368,018,082 shares issued and outstanding as of December 31, 2017	3,684	3,680
Paid in capital	8,900,324	8,886,586
Retained earnings	1,344,825	1,403,530
Accumulated other comprehensive income (loss)	(50,689)	(88,612)
Total shareholders’ equity	10,235,424	10,242,464
Noncontrolling Interests:
Operating Partnership	233,825	226,691
Partially Owned Properties	(2,158)	4,708
Total Noncontrolling Interests	231,667	231,399
Total equity	10,467,091	10,473,863
Total liabilities and equity/capital	$ 20,542,150	$ 20,570,599

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Sep. 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	368,409,586	368,018,082
Common Stock, Shares, Outstanding	368,409,586	368,018,082

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
REVENUES
Rental income	$ 652,677	$ 623,951	$ 1,925,128	$ 1,840,170
Total revenues	652,867	624,122	1,925,691	1,840,702
EXPENSES
Property and maintenance	110,541	104,721	322,487	306,645
Real estate taxes and insurance	87,388	84,087	268,784	253,318
Property management	22,247	20,861	69,175	64,702
General and administrative	12,640	12,567	41,420	40,366
Depreciation	194,618	184,100	583,869	542,964
Impairment	702		702
Total expenses	428,136	406,336	1,286,437	1,207,995
Operating income	224,731	217,786	639,254	632,707
Interest and other income	7,864	3,945	14,860	5,708
Other expenses	(7,661)	(1,028)	(14,871)	(3,160)
Interest:
Expense incurred, net	(111,219)	(91,145)	(321,454)	(288,579)
Amortization of deferred financing costs	(3,276)	(2,064)	(9,054)	(6,447)
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	110,439	127,494	308,735	340,229
Income and other tax (expense) benefit	(280)	(228)	(767)	(710)
Income (loss) from investments in unconsolidated entities	(985)	(398)	(2,993)	(2,153)
Net gain (loss) on sales of real estate properties	114,672	17,328	256,834	141,761
Net gain (loss) on sales of land parcels			995	19,170
Net income	223,846	144,196	562,804	498,297
Net (income) loss attributable to Noncontrolling Interests:
Operating Partnership	(8,159)	(5,166)	(20,517)	(17,931)
Partially Owned Properties	(750)	(801)	(1,939)	(2,354)
Net income attributable to controlling interests	214,937	138,229	540,348	478,012
Preferred distributions	(773)	(772)	(2,318)	(2,318)
Net income available to Common Shares	$ 214,164	$ 137,457	$ 538,030	$ 475,694
Earnings per share – basic:
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.30
Weighted average Common Shares outstanding	368,028	366,996	367,920	366,809
Earnings per share – diluted:
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.29
Weighted average Common Shares outstanding	383,884	382,945	383,433	382,640
Distributions declared per Common Share outstanding	$ 0.54	$ 0.50375	$ 1.62	$ 1.51125
Fee and asset management
REVENUES
Fee and asset management	$ 190	$ 171	$ 563	$ 532

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Comprehensive income:
Net income	$ 223,846	$ 144,196	$ 562,804	$ 498,297
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	12,026	1,709	24,021	5,216
Losses reclassified into earnings from other comprehensive income	4,595	4,768	13,902	14,019
Other comprehensive income (loss)	16,621	6,477	37,923	19,235
Comprehensive income	240,467	150,673	600,727	517,532
Comprehensive (income) attributable to Noncontrolling Interests	(9,519)	(6,201)	(23,848)	(20,983)
Comprehensive income attributable to controlling interests	$ 230,948	$ 144,472	$ 576,879	$ 496,549

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 562,804	$ 498,297
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	583,869	542,964
Amortization of deferred financing costs	9,054	6,447
Amortization of above/below market lease intangibles	3,294	2,729
Amortization of discounts and premiums on debt	21,360	2,018
Amortization of deferred settlements on derivative instruments	13,893	14,010
Impairment	702
Write-off of pursuit costs	3,125	2,329
(Income) loss from investments in unconsolidated entities	2,993	2,153
Distributions from unconsolidated entities – return on capital	1,885	2,031
Net (gain) loss on sales of real estate properties	(256,834)	(141,761)
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	22,270	19,999
Changes in assets and liabilities:
(Increase) decrease in other assets	(18,550)	(23,024)
Increase (decrease) in accounts payable and accrued expenses	58,756	62,635
Increase (decrease) in accrued interest payable	11,097	11,865
Increase (decrease) in other liabilities	1,190	(28,250)
Increase (decrease) in security deposits	2,168	2,606
Net cash provided by operating activities	1,044,191	970,136
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(708,092)	(466,395)
Investment in real estate – development/other	(101,573)	(227,187)
Capital expenditures to real estate	(138,119)	(143,258)
Non-real estate capital additions	(3,155)	(776)
Interest capitalized for real estate under development	(4,547)	(23,164)
Proceeds from disposition of real estate, net	691,526	350,000
Investments in unconsolidated entities	(4,860)	(5,324)
Distributions from unconsolidated entities – return of capital		329
Net cash provided by (used for) investing activities	(268,820)	(515,775)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,355)	(6,272)
Mortgage notes payable, net:
Lump sum payoffs	(847,939)	(493,420)
Scheduled principal repayments	(4,938)	(8,771)
Notes, net:
Proceeds	497,010	692,466
Lump sum payoffs		(394,077)
Line of credit and commercial paper:
Line of credit proceeds	1,635,000	1,845,000
Line of credit repayments	(1,635,000)	(1,845,000)
Commercial paper proceeds	9,624,610	3,891,596
Commercial paper repayments	(9,425,000)	(3,681,750)
Proceeds from (payments on) settlement of derivative instruments	1,638	1,296
Proceeds from Employee Share Purchase Plan (ESPP)	3,074	2,963
Proceeds from exercise of options	6,000	12,967
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	(583,184)	(554,267)
Preferred Shares	(2,318)	(2,318)
Noncontrolling Interests – Operating Partnership	(21,040)	(20,604)
Noncontrolling Interests – Partially Owned Properties	(8,882)	(6,873)
Net cash provided by (used for) financing activities	(787,383)	(579,273)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(12,012)	(124,912)
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	88,750	94,176
Cash and cash equivalents	32,995	46,565
Restricted deposits	55,755	47,611
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	268,966	257,805
Net cash paid for income and other taxes	934	964
Amortization of deferred financing costs:
Other assets	1,809	1,810
Mortgage notes payable, net	4,197	1,943
Notes, net	3,048	2,694
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	19,394	247
Notes, net	1,966	1,771
Amortization of deferred settlements on derivative instruments:
Other liabilities	(9)	(9)
Accumulated other comprehensive income	13,902	14,019
Write-off of pursuit costs:
Investment in real estate, net	3,079	2,292
Other assets	13	17
Accounts payable and accrued expenses	33	20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,973	1,076
Other liabilities	1,020	1,077
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(24,021)	(3,803)
Notes, net	(1,491)	(1,413)
Other liabilities	1,491
Accumulated other comprehensive income	24,021	5,216
Investments in unconsolidated entities:
Investments in unconsolidated entities	(3,180)	(2,324)
Other liabilities	(1,680)	(3,000)
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) - 9 months ended Sep. 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				356			(356)
Exercise of share options			2	5,998
Employee Share Purchase Plan (ESPP)			1	3,073
Share-based employee compensation expense:
Restricted shares			1	6,803
Share options				9,206
ESPP discount				604
Offering costs				(27)
Supplemental Executive Retirement Plan (SERP)				(533)
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	14,361			(14,361)
Adjustment for Noncontrolling Interests ownership in Operating Partnership				2,619			(2,619)
PAID IN CAPITAL
Conversion of OP Units into Common Shares				356			(356)
Exercise of share options			2	5,998
Employee Share Purchase Plan (ESPP)			1	3,073
RETAINED EARNINGS
Net income attributable to controlling interests	540,348				540,348
Common Share distributions					(596,735)
Preferred Share distributions					(2,318)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	24,021					24,021
Losses reclassified into earnings from other comprehensive income	(13,902)					13,902
NONCONTROLLING INTERESTS
Issuance of restricted units to Noncontrolling Interests							1
Conversion of OP Units into Common Shares				356			(356)
Equity compensation associated with Noncontrolling Interests							11,074
Net income	562,804
Distributions to Noncontrolling Interests							(21,560)	(8,930)
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	(77)						77
Adjustment for Noncontrolling Interests ownership in Operating Partnership				2,619			(2,619)
Net income attributable to Noncontrolling Interests	20,517						20,517	1,939
PARTIALLY OWNED PROPERTIES
Net income	562,804
Distributions to Noncontrolling Interests							(21,560)	(8,930)
Net income attributable to Noncontrolling Interests	20,517						20,517	1,939
Contributions by Noncontrolling Interests								125
Balance, end of period at Sep. 30, 2018	10,235,424	$ 37,280	$ 3,684	$ 8,900,324	$ 1,344,825	$ (50,689)
Balance, end of period at Sep. 30, 2018	$ 231,667						$ 233,825	$ (2,158)

CONSOLIDATED BALANCE SHEETS OF

CONSOLIDATED BALANCE SHEETS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Land	$ 5,866,457	$ 5,996,024
Depreciable property	20,336,747	19,768,362
Projects under development	134,961	163,547
Land held for development	87,335	98,963
Investment in real estate	26,425,500	26,026,896
Accumulated depreciation	(6,494,770)	(6,040,378)
Investment in real estate, net	19,930,730	19,986,518
Investments in unconsolidated entities	57,576	58,254
Cash and cash equivalents	32,995	50,647
Restricted deposits	55,755	50,115
Other assets	465,094	425,065
Total assets	20,542,150	20,570,599
Liabilities:
Mortgage notes payable, net	2,789,436	3,618,722
Notes, net	5,534,990	5,038,812
Line of credit and commercial paper	499,367	299,757
Accounts payable and accrued expenses	182,446	114,766
Accrued interest payable	69,132	58,035
Other liabilities	344,373	341,852
Security deposits	67,177	65,009
Distributions payable	206,899	192,828
Total liabilities	9,693,820	9,729,781
Commitments and contingencies
Partners’ Capital:
Accumulated other comprehensive income (loss)	(50,689)	(88,612)
Noncontrolling Interests – Partially Owned Properties	(2,158)	4,708
Total liabilities and equity/capital	20,542,150	20,570,599
ERPOP [Member]
ASSETS
Land	5,866,457	5,996,024
Depreciable property	20,336,747	19,768,362
Projects under development	134,961	163,547
Land held for development	87,335	98,963
Investment in real estate	26,425,500	26,026,896
Accumulated depreciation	(6,494,770)	(6,040,378)
Investment in real estate, net	19,930,730	19,986,518
Investments in unconsolidated entities	57,576	58,254
Cash and cash equivalents	32,995	50,647
Restricted deposits	55,755	50,115
Other assets	465,094	425,065
Total assets	20,542,150	20,570,599
Liabilities:
Mortgage notes payable, net	2,789,436	3,618,722
Notes, net	5,534,990	5,038,812
Line of credit and commercial paper	499,367	299,757
Accounts payable and accrued expenses	182,446	114,766
Accrued interest payable	69,132	58,035
Other liabilities	344,373	341,852
Security deposits	67,177	65,009
Distributions payable	206,899	192,828
Total liabilities	9,693,820	9,729,781
Commitments and contingencies
Redeemable Limited Partners	381,239	366,955
Partners’ Capital:
Preference Units	37,280	37,280
General Partner	10,248,833	10,293,796
Limited Partners	233,825	226,691
Accumulated other comprehensive income (loss)	(50,689)	(88,612)
Total partners’ capital	10,469,249	10,469,155
Noncontrolling Interests – Partially Owned Properties	(2,158)	4,708
Total capital	10,467,091	10,473,863
Total liabilities and equity/capital	$ 20,542,150	$ 20,570,599

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
REVENUES
Rental income	$ 652,677	$ 623,951	$ 1,925,128	$ 1,840,170
Total revenues	652,867	624,122	1,925,691	1,840,702
EXPENSES
Property and maintenance	110,541	104,721	322,487	306,645
Real estate taxes and insurance	87,388	84,087	268,784	253,318
Property management	22,247	20,861	69,175	64,702
General and administrative	12,640	12,567	41,420	40,366
Depreciation	194,618	184,100	583,869	542,964
Impairment	702		702
Total expenses	428,136	406,336	1,286,437	1,207,995
Operating income	224,731	217,786	639,254	632,707
Interest and other income	7,864	3,945	14,860	5,708
Other expenses	(7,661)	(1,028)	(14,871)	(3,160)
Interest:
Expense incurred, net	(111,219)	(91,145)	(321,454)	(288,579)
Amortization of deferred financing costs	(3,276)	(2,064)	(9,054)	(6,447)
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	110,439	127,494	308,735	340,229
Income and other tax (expense) benefit	(280)	(228)	(767)	(710)
Income (loss) from investments in unconsolidated entities	(985)	(398)	(2,993)	(2,153)
Net gain (loss) on sales of real estate properties	114,672	17,328	256,834	141,761
Net gain (loss) on sales of land parcels			995	19,170
Net income	223,846	144,196	562,804	498,297
Partially Owned Properties	(750)	(801)	(1,939)	(2,354)
Net income attributable to controlling interests	$ 214,937	$ 138,229	$ 540,348	$ 478,012
Earnings per Unit – basic:
Net income available to Units	$ 0.58	$ 0.37	$ 1.46	$ 1.30
Earnings per Unit – diluted:
Net income available to Units	$ 0.58	$ 0.37	$ 1.46	$ 1.29
Weighted average Units outstanding	383,884	382,945	383,433	382,640
Fee and asset management
REVENUES
Fee and asset management	$ 190	$ 171	$ 563	$ 532
ERPOP [Member]
REVENUES
Rental income	652,677	623,951	1,925,128	1,840,170
Total revenues	652,867	624,122	1,925,691	1,840,702
EXPENSES
Property and maintenance	110,541	104,721	322,487	306,645
Real estate taxes and insurance	87,388	84,087	268,784	253,318
Property management	22,247	20,861	69,175	64,702
General and administrative	12,640	12,567	41,420	40,366
Depreciation	194,618	184,100	583,869	542,964
Impairment	702		702
Total expenses	428,136	406,336	1,286,437	1,207,995
Operating income	224,731	217,786	639,254	632,707
Interest and other income	7,864	3,945	14,860	5,708
Other expenses	(7,661)	(1,028)	(14,871)	(3,160)
Interest:
Expense incurred, net	(111,219)	(91,145)	(321,454)	(288,579)
Amortization of deferred financing costs	(3,276)	(2,064)	(9,054)	(6,447)
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	110,439	127,494	308,735	340,229
Income and other tax (expense) benefit	(280)	(228)	(767)	(710)
Income (loss) from investments in unconsolidated entities	(985)	(398)	(2,993)	(2,153)
Net gain (loss) on sales of real estate properties	114,672	17,328	256,834	141,761
Net gain (loss) on sales of land parcels			995	19,170
Net income	223,846	144,196	562,804	498,297
Partially Owned Properties	(750)	(801)	(1,939)	(2,354)
Net income attributable to controlling interests	223,096	143,395	560,865	495,943
ALLOCATION OF NET INCOME:
Preference Units	773	772	2,318	2,318
General Partner	214,164	137,457	538,030	475,694
Limited Partners	8,159	5,166	20,517	17,931
Net income available to Units	$ 222,323	$ 142,623	$ 558,547	$ 493,625
Earnings per Unit – basic:
Net income available to Units	$ 0.58	$ 0.37	$ 1.46	$ 1.30
Weighted average Units outstanding	380,912	379,906	380,791	379,716
Earnings per Unit – diluted:
Net income available to Units	$ 0.58	$ 0.37	$ 1.46	$ 1.29
Weighted average Units outstanding	383,884	382,945	383,433	382,640
Distributions declared per Unit outstanding	$ 0.54	$ 0.50375	$ 1.62	$ 1.51125
ERPOP [Member] | Fee and asset management
REVENUES
Fee and asset management	$ 190	$ 171	$ 563	$ 532

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Comprehensive income:
Net income	$ 223,846	$ 144,196	$ 562,804	$ 498,297
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	12,026	1,709	24,021	5,216
Losses reclassified into earnings from other comprehensive income	4,595	4,768	13,902	14,019
Other comprehensive income (loss)	16,621	6,477	37,923	19,235
Comprehensive income	240,467	150,673	600,727	517,532
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(9,519)	(6,201)	(23,848)	(20,983)
Comprehensive income attributable to controlling interests	230,948	144,472	576,879	496,549
ERPOP [Member]
Comprehensive income:
Net income	223,846	144,196	562,804	498,297
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	12,026	1,709	24,021	5,216
Losses reclassified into earnings from other comprehensive income	4,595	4,768	13,902	14,019
Other comprehensive income (loss)	16,621	6,477	37,923	19,235
Comprehensive income	240,467	150,673	600,727	517,532
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(750)	(801)	(1,939)	(2,354)
Comprehensive income attributable to controlling interests	$ 239,717	$ 149,872	$ 598,788	$ 515,178

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 562,804	$ 498,297
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	583,869	542,964
Amortization of deferred financing costs	9,054	6,447
Amortization of above/below market lease intangibles	3,294	2,729
Amortization of discounts and premiums on debt	21,360	2,018
Amortization of deferred settlements on derivative instruments	13,893	14,010
Impairment	702
Write-off of pursuit costs	3,125	2,329
(Income) loss from investments in unconsolidated entities	2,993	2,153
Distributions from unconsolidated entities – return on capital	1,885	2,031
Net (gain) loss on sales of real estate properties	(256,834)	(141,761)
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	22,270	19,999
Changes in assets and liabilities:
(Increase) decrease in other assets	(18,550)	(23,024)
Increase (decrease) in accounts payable and accrued expenses	58,756	62,635
Increase (decrease) in accrued interest payable	11,097	11,865
Increase (decrease) in other liabilities	1,190	(28,250)
Increase (decrease) in security deposits	2,168	2,606
Net cash provided by operating activities	1,044,191	970,136
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(708,092)	(466,395)
Investment in real estate – development/other	(101,573)	(227,187)
Capital expenditures to real estate	(138,119)	(143,258)
Non-real estate capital additions	(3,155)	(776)
Interest capitalized for real estate under development	(4,547)	(23,164)
Proceeds from disposition of real estate, net	691,526	350,000
Investments in unconsolidated entities	(4,860)	(5,324)
Distributions from unconsolidated entities – return of capital		329
Net cash provided by (used for) investing activities	(268,820)	(515,775)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,355)	(6,272)
Mortgage notes payable, net:
Lump sum payoffs	(847,939)	(493,420)
Scheduled principal repayments	(4,938)	(8,771)
Notes, net:
Proceeds	497,010	692,466
Lump sum payoffs		(394,077)
Line of credit and commercial paper:
Line of credit proceeds	1,635,000	1,845,000
Line of credit repayments	(1,635,000)	(1,845,000)
Commercial paper proceeds	9,624,610	3,891,596
Commercial paper repayments	(9,425,000)	(3,681,750)
Proceeds from (payments on) settlement of derivative instruments	1,638	1,296
Proceeds from Employee Share Purchase Plan (ESPP)	3,074	2,963
Proceeds from exercise of EQR options	6,000	12,967
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	(583,184)	(554,267)
Preference Units	(2,318)	(2,318)
OP Units – Limited Partners	(21,040)	(20,604)
Noncontrolling Interests – Partially Owned Properties	(8,882)	(6,873)
Net cash provided by (used for) financing activities	(787,383)	(579,273)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(12,012)	(124,912)
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	88,750	94,176
Cash and cash equivalents	32,995	46,565
Restricted deposits	55,755	47,611
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	268,966	257,805
Net cash paid for income and other taxes	934	964
Amortization of deferred financing costs:
Other assets	1,809	1,810
Mortgage notes payable, net	4,197	1,943
Notes, net	3,048	2,694
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	19,394	247
Notes, net	1,966	1,771
Amortization of deferred settlements on derivative instruments:
Other liabilities	(9)	(9)
Accumulated other comprehensive income	13,902	14,019
Write-off of pursuit costs:
Investment in real estate, net	3,079	2,292
Other assets	13	17
Accounts payable and accrued expenses	33	20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,973	1,076
Other liabilities	1,020	1,077
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(24,021)	(3,803)
Notes, net	(1,491)	(1,413)
Other liabilities	1,491
Accumulated other comprehensive income	24,021	5,216
Investments in unconsolidated entities:
Investments in unconsolidated entities	(3,180)	(2,324)
Other liabilities	(1,680)	(3,000)
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	562,804	498,297
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	583,869	542,964
Amortization of deferred financing costs	9,054	6,447
Amortization of above/below market lease intangibles	3,294	2,729
Amortization of discounts and premiums on debt	21,360	2,018
Amortization of deferred settlements on derivative instruments	13,893	14,010
Impairment	702
Write-off of pursuit costs	3,125	2,329
(Income) loss from investments in unconsolidated entities	2,993	2,153
Distributions from unconsolidated entities – return on capital	1,885	2,031
Net (gain) loss on sales of real estate properties	(256,834)	(141,761)
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	22,270	19,999
Changes in assets and liabilities:
(Increase) decrease in other assets	(18,550)	(23,024)
Increase (decrease) in accounts payable and accrued expenses	58,756	62,635
Increase (decrease) in accrued interest payable	11,097	11,865
Increase (decrease) in other liabilities	1,190	(28,250)
Increase (decrease) in security deposits	2,168	2,606
Net cash provided by operating activities	1,044,191	970,136
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(708,092)	(466,395)
Investment in real estate – development/other	(101,573)	(227,187)
Capital expenditures to real estate	(138,119)	(143,258)
Non-real estate capital additions	(3,155)	(776)
Interest capitalized for real estate under development	(4,547)	(23,164)
Proceeds from disposition of real estate, net	691,526	350,000
Investments in unconsolidated entities	(4,860)	(5,324)
Distributions from unconsolidated entities – return of capital		329
Net cash provided by (used for) investing activities	(268,820)	(515,775)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,355)	(6,272)
Mortgage notes payable, net:
Lump sum payoffs	(847,939)	(493,420)
Scheduled principal repayments	(4,938)	(8,771)
Notes, net:
Proceeds	497,010	692,466
Lump sum payoffs		(394,077)
Line of credit and commercial paper:
Line of credit proceeds	1,635,000	1,845,000
Line of credit repayments	(1,635,000)	(1,845,000)
Commercial paper proceeds	9,624,610	3,891,596
Commercial paper repayments	(9,425,000)	(3,681,750)
Proceeds from (payments on) settlement of derivative instruments	1,638	1,296
Proceeds from Employee Share Purchase Plan (ESPP)	3,074	2,963
Proceeds from exercise of EQR options	6,000	12,967
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	(583,184)	(554,267)
Preference Units	(2,318)	(2,318)
OP Units – Limited Partners	(21,040)	(20,604)
Noncontrolling Interests – Partially Owned Properties	(8,882)	(6,873)
Net cash provided by (used for) financing activities	(787,383)	(579,273)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(12,012)	(124,912)
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	88,750	94,176
Cash and cash equivalents	32,995	46,565
Restricted deposits	55,755	47,611
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	268,966	257,805
Net cash paid for income and other taxes	934	964
Amortization of deferred financing costs:
Other assets	1,809	1,810
Mortgage notes payable, net	4,197	1,943
Notes, net	3,048	2,694
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	19,394	247
Notes, net	1,966	1,771
Amortization of deferred settlements on derivative instruments:
Other liabilities	(9)	(9)
Accumulated other comprehensive income	13,902	14,019
Write-off of pursuit costs:
Investment in real estate, net	3,079	2,292
Other assets	13	17
Accounts payable and accrued expenses	33	20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	1,973	1,076
Other liabilities	1,020	1,077
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(24,021)	(3,803)
Notes, net	(1,491)	(1,413)
Other liabilities	1,491
Accumulated other comprehensive income	24,021	5,216
Investments in unconsolidated entities:
Investments in unconsolidated entities	(3,180)	(2,324)
Other liabilities	(1,680)	(3,000)
ERPOP [Member] | Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	$ (22,110)	$ (12,258)

CONSOLIDATED STATEMENT OF CHA_2

CONSOLIDATED STATEMENT OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - 9 months ended Sep. 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				356	(356)
Exercise of EQR share options				6,000
EQR's Employee Share Purchase Plan (ESPP)				3,074
Share-based employee compensation expense:
EQR restricted shares				6,804
EQR share options				9,206
EQR ESPP discount				604
Net income available to Units General Partner		$ 538,030		538,030
OP Units General Partner distributions				(596,735)
Offering costs				(27)
Supplemental Executive Retirement Plan (SERP)				(533)
Change in market value of Redeemable Limited Partners				(14,361)
Adjustment for Limited Partners ownership in Operating Partnership				2,619	(2,619)
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				356	(356)
Equity compensation associated with Units Limited Partners					11,074
Net income available to Units Limited Partners		20,517			20,517
Units Limited Partners distributions					(21,560)
Change in carrying value of Redeemable Limited Partners					77
Adjustment for Limited Partners ownership in Operating Partnership				2,619	(2,619)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	$ 24,021	24,021				24,021
Losses reclassified into earnings from other comprehensive income	(13,902)	(13,902)				13,902
NONCONTROLLING INTERESTS PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	$ 562,804	$ 562,804					1,939
Contributions by Noncontrolling Interests							125
Distributions to Noncontrolling Interests							(8,930)
Balance, end of period at Sep. 30, 2018			$ 37,280	$ 10,248,833	$ 233,825	$ (50,689)
Balance, end of period at Sep. 30, 2018							$ (2,158)

Business

Business	9 Months Ended
	Sep. 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 located in urban and high-density suburban markets, which is conducted on its behalf by ERP Operating Limited Partnership (“ERPOP”). 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 September 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 September 30, 2018, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 306 properties located in 11 states and the District of Columbia consisting of 79,260 apartment units. The ownership breakdown includes (table does not include various uncompleted development properties): Properties Apartment Units Wholly Owned Properties 286 74,618 Master-Leased Properties – Consolidated 1 162 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 306 79,260 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	9 Months Ended
	Sep. 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 nine months ended September 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 were recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases in the comparable period. These assets and liabilities were measured using enacted tax rates for which the temporary differences were expected to be recovered or settled. The effects of changes in tax rates on deferred tax assets and liabilities were 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 either the beginning of the earliest comparative period presented or as of the adoption date and provides for certain practical expedients, which the Company currently anticipates electing. The Company is the lessor for its residential and retail/commercial leases and anticipates that these leases 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 the lessee under various corporate office and ground leases, which are required to be recognized 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 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 expects to record right of use assets and related lease liabilities to its opening balance sheet upon adoption of the new standard on January 1, 2019, which it currently estimates to be an amount not likely to exceed $300.0 million. The ultimate impact on the Company’s consolidated results of operations and financial position will depend on our lease portfolio and other factors as of the adoption date, as we continue to evaluate the new leases standard. 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 nine months and quarter ended September 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 nine months and quarter ended September 30, 2017. The following table presents the disaggregation of revenue streams of our rental income for the nine months and quarter ended September 30, 2018 (amounts in thousands): Nine Months Ended September 30, 2018 Quarter Ended September 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 $ 1,803,908 93.7 % $ 611,119 93.6 % Utility recoveries (“RUBS”) Revenue Recognition 46,752 2.4 % 15,817 2.4 % Parking revenue Revenue Recognition 20,249 1.1 % 6,185 1.0 % Other revenue Revenue Recognition 54,219 2.8 % 19,556 3.0 % Rental income $ 1,925,128 100.0 % $ 652,677 100.0 % 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 September 30, 2017, the following cash flows were reclassified (amounts in thousands): Nine Months Ended September 30, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 4,939 $ (2,921 ) $ 2,018 Net (gain) loss on debt extinguishment $ — $ 12,258 $ 12,258 (Increase) decrease in deposits - restricted $ 788 $ (788 ) $ — (Increase) decrease in mortgage deposits $ 1,447 $ (1,447 ) $ — Net cash provided by operating activities $ 963,034 $ 7,102 $ 970,136 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ 39,519 $ (39,519 ) $ — (Increase) decrease in mortgage deposits $ (4,541 ) $ 4,541 $ — Net cash provided by (used for) investing activities $ (480,797 ) $ (34,978 ) $ (515,775 ) Cash Flows from Financing Activities: Mortgage deposits $ 57,057 $ (57,057 ) $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (12,258 ) $ (12,258 ) Line of credit and commercial paper: Commercial paper proceeds $ 3,888,675 $ 2,921 $ 3,891,596 Net cash (used for) financing activities $ (512,879 ) $ (66,394 ) $ (579,273 ) 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 $ 46,565 (adjustments for restricted deposits, end of period) $ 47,611 Cash and cash equivalents and restricted deposits, end of period $ 94,176 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.

Equity, Capital and Other Inter

Equity, Capital and Other Interests	9 Months Ended
	Sep. 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 nine months ended September 30, 2018: 2018 Common Shares Common Shares outstanding at January 1, 368,018,082 Common Shares Issued: Conversion of OP Units 12,510 Exercise of share options 194,796 Employee Share Purchase Plan (ESPP) 61,321 Restricted share grants, net 122,877 Common Shares outstanding at September 30, 368,409,586 Units Units outstanding at January 1, 13,768,438 Restricted unit grants, net 267,074 Conversion of OP Units to Common Shares (12,510 ) Units outstanding at September 30, 14,023,002 Total Common Shares and Units outstanding at September 30, 382,432,588 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 September 30, 2018 and December 31, 2017. The The 2018 Balance at January 1, $ 366,955 Change in market value 14,361 Change in carrying value (77 ) Balance at September 30, $ 381,239 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 September 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 September 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 nine months ended September 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 194,796 EQR’s Employee Share Purchase Plan (ESPP) 61,321 EQR’s restricted share grants, net 122,877 Issued to Limited Partners: Restricted unit grants, net 267,074 General and Limited Partner Units outstanding at September 30, 382,432,588 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 (12,510 ) Limited Partner Units outstanding at September 30, 14,023,002 Limited Partner Units Ownership Interest in Operating Partnership 3.7 % The Limited Partners of the Operating Partnership as of September 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 September 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 nine months ended September 30, 2018 (amounts in thousands): 2018 Balance at January 1, $ 366,955 Change in market value 14,361 Change in carrying value (77 ) Balance at September 30, $ 381,239 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 September 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 September 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 nine months ended September 30, 2018. As of September 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	9 Months Ended
	Sep. 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 September 30, 2018 and December 31, 2017 (amounts in thousands): September 30, 2018 December 31, 2017 Land $ 5,866,457 $ 5,996,024 Depreciable property: Buildings and improvements 18,174,939 17,743,042 Furniture, fixtures and equipment 1,684,794 1,548,961 In-Place lease intangibles 477,014 476,359 Projects under development: Land 34,689 43,226 Construction-in-progress 100,272 120,321 Land held for development: Land 61,038 62,538 Construction-in-progress 26,297 36,425 Investment in real estate 26,425,500 26,026,896 Accumulated depreciation (6,494,770 ) (6,040,378 ) Investment in real estate, net $ 19,930,730 $ 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 September 30, 2018 and December 31, 2017 (amounts in thousands): Description Balance Sheet Location September 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 (25,819 ) (22,434 ) Lease intangible assets, net $ 167,359 $ 170,744 Liabilities Ground lease intangibles – above market Other Liabilities $ 2,400 $ 2,400 Retail lease intangibles – below market Other Liabilities 1,710 5,270 Lease intangible liabilities 4,110 7,670 Accumulated amortization (1,674 ) (5,143 ) Lease intangible liabilities, net $ 2,436 $ 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 Nine Months Ended Quarter Ended September 30, September 30, Description Income Statement Location 2018 2017 2018 2017 Ground lease intangible amortization Property and Maintenance $ (3,348 ) $ (3,253 ) $ (1,116 ) $ (1,092 ) Retail lease intangible amortization Rental Income 54 524 18 80 Total amortization of above/below market lease intangibles $ (3,294 ) $ (2,729 ) $ (1,098 ) $ (1,012 ) 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 $ (1,115 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) Retail lease intangibles 17 71 71 71 27 19 Total $ (1,098 ) $ (4,392 ) $ (4,392 ) $ (4,392 ) $ (4,436 ) $ (4,444 ) During the nine months ended September 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) 5 1,478 $ 707,005 Total 5 1,478 $ 707,005 (1) Purchase price includes an allocation of approximately $113.7 million to land and $594.4 million to depreciable property (inclusive of capitalized closing costs). During the nine months ended September 30, 2018 , the Company disposed of the following to unaffiliated parties (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 5 1,292 $ 706,120 Land Parcels (one) — — 2,700 Total 5 1,292 $ 708,820 The Company recognized a net gain on sales of real estate properties of approximately $256.8 million and a net gain on sales of land parcels of approximately $1.0 million on the above sales. Impairment During the nine months ended September 30, 2018, the Company recorded an approximate $0.7 million non-cash asset impairment charge on a property located in the San Francisco market due to physical property damage as a result of a fire at one of the buildings at the property.

Commitments to Acquire_Dispose

Commitments to Acquire/Dispose of Real Estate	9 Months Ended
	Sep. 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 not entered into any separate agreements to acquire or dispose of rental properties or land parcels as of October 26, 2018.

Investments in Partially Owned

Investments in Partially Owned Entities	9 Months Ended
	Sep. 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 $714.4 million and $315.6 million, respectively, at September 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 September 30, 2018 and December 31, 2017 (amounts in thousands except for ownership percentage): September 30, 2018 December 31, 2017 Ownership Percentage Investments in Unconsolidated Entities: Wisconsin Place Developer (VIE) (1) $ 42,964 $ 44,451 33.3% Operating Properties (Non-VIE) (2) 10,745 12,367 20.0% Other 3,867 1,436 Varies Investments in Unconsolidated Entities $ 57,576 $ 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	9 Months Ended
	Sep. 30, 2018
Deposits Restricted [Abstract]
Restricted Deposits	7. Restricted Deposits The following table presents the Company’s restricted deposits as of September 30, 2018 and December 31, 2017 (amounts in thousands): September 30, 2018 December 31, 2017 Mortgage escrow deposits: Real estate taxes and insurance $ 600 $ 845 Replacement reserves 8,478 8,347 Mortgage principal reserves/sinking funds 8,363 3,167 Other 852 852 Mortgage escrow deposits 18,293 13,211 Restricted cash: Earnest money on pending acquisitions — 750 Restricted deposits on real estate investments 538 58 Resident security and utility deposits 35,379 35,183 Other 1,545 913 Restricted cash 37,462 36,904 Restricted deposits $ 55,755 $ 50,115

Debt

Debt	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Debt	8. Debt EQR Mortgage Notes Payable As of September 30, 2018, the Company had outstanding mortgage debt of approximately $2.8 billion. During the nine months ended September 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 $254.2 million of various tax-exempt mortgage bonds maturing in 2028 through 2042; and • Repaid $4.9 million of scheduled principal repayments on various mortgage debt. The Company recorded $2.8 million of write-offs of unamortized deferred financing costs during the nine months ended September 30, 2018 as additional interest expense related to debt extinguishment of mortgages. The Company also recorded $16.3 million of write-offs of net unamortized discounts during the nine months ended September 30, 2018 as additional interest expense related to debt extinguishment of mortgages. As of September 30, 2018, the Company had $440.9 million of secured debt subject to third party credit enhancement. As 30, 2018 Notes As of September 30, 2018, the Company had outstanding unsecured notes of approximately $5.5 billion. During the nine months ended September 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 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 nine months ended September 30, 2018. Line of Credit and Commercial Paper In November 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. In As 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 September 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	9 Months Ended
	Sep. 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 September 30, 2018 December 31, 2017 Carrying Value Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Mortgage notes payable, net $ 2,789,436 $ 2,710,433 $ 3,618,722 $ 3,615,384 Unsecured debt, net 6,034,357 6,040,798 5,338,569 5,619,744 Total debt, net $ 8,823,793 $ 8,751,231 $ 8,957,291 $ 9,235,128 The September 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 9/30/2018 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 $ 27,526 $ — $ 27,526 $ — Supplemental Executive Retirement Plan Other Assets 144,561 144,561 — — Total $ 172,087 $ 144,561 $ 27,526 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 3,088 $ — $ 3,088 $ — Supplemental Executive Retirement Plan Other Liabilities 144,561 144,561 — — Total $ 147,649 $ 144,561 $ 3,088 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 381,239 $ — $ 381,239 $ — 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 September 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 $ (1,491 ) Fixed rate debt Interest expense $ 1,491 Total $ (1,491 ) $ 1,491 September 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 $ (1,413 ) Fixed rate debt Interest expense $ 1,413 Total $ (1,413 ) $ 1,413 The Effective Portion Ineffective Portion September 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 $ 24,021 Interest expense $ (13,902 ) N/A $ — Total $ 24,021 $ (13,902 ) $ — Effective Portion Ineffective Portion September 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 $ 5,216 Interest expense $ (14,019 ) N/A $ — Total $ 5,216 $ (14,019 ) $ — As December 31, 2017 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	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earning Per Share And Earnings Per Unit	10. Earning Per Share and Earnings Per Equity Residential The Nine Months Ended September 30, Quarter Ended September 30, 2018 2017 2018 2017 Numerator for net income per share – basic: Net income $ 562,804 $ 498,297 $ 223,846 $ 144,196 Allocation to Noncontrolling Interests – Operating Partnership (20,517 ) (17,931 ) (8,159 ) (5,166 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,939 ) (2,354 ) (750 ) (801 ) Preferred distributions (2,318 ) (2,318 ) (773 ) (772 ) Numerator for net income per share – basic $ 538,030 $ 475,694 $ 214,164 $ 137,457 Numerator for net income per share – diluted: Net income $ 562,804 $ 498,297 $ 223,846 $ 144,196 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,939 ) (2,354 ) (750 ) (801 ) Preferred distributions (2,318 ) (2,318 ) (773 ) (772 ) Numerator for net income per share – diluted $ 558,547 $ 493,625 $ 222,323 $ 142,623 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 367,920 366,809 368,028 366,996 Effect of dilutive securities: OP Units 12,871 12,907 12,884 12,910 Long-term compensation shares/units 2,642 2,924 2,972 3,039 Denominator for net income per share – diluted 383,433 382,640 383,884 382,945 Net income per share – basic $ 1.46 $ 1.30 $ 0.58 $ 0.37 Net income per share – diluted $ 1.46 $ 1.29 $ 0.58 $ 0.37 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): Nine Months Ended September 30, Quarter Ended September 30, 2018 2017 2018 2017 Numerator for net income per Unit – basic and diluted: Net income $ 562,804 $ 498,297 $ 223,846 $ 144,196 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,939 ) (2,354 ) (750 ) (801 ) Allocation to Preference Units (2,318 ) (2,318 ) (773 ) (772 ) Numerator for net income per Unit – basic and diluted $ 558,547 $ 493,625 $ 222,323 $ 142,623 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 380,791 379,716 380,912 379,906 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,642 2,924 2,972 3,039 Denominator for net income per Unit – diluted 383,433 382,640 383,884 382,945 Net income per Unit – basic $ 1.46 $ 1.30 $ 0.58 $ 0.37 Net income per Unit – diluted $ 1.46 $ 1.29 $ 0.58 $ 0.37

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 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 September 30, 2018, the Company does have environmental reserves totaling approximately $5.8 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 September 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 $444.0 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	9 Months Ended
	Sep. 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 geographic same store operating segments located in urban and high-density suburban markets represent its reportable segments (the two Denver properties acquired in the third quarter of 2018 are currently included in non-same store). 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 Nine Months Ended September 30, Quarter Ended September 30, 2018 2017 2018 2017 Rental income $ 1,925,128 $ 1,840,170 $ 652,677 $ 623,951 Property and maintenance expense (322,487 ) (306,645 ) (110,541 ) (104,721 ) Real estate taxes and insurance expense (268,784 ) (253,318 ) (87,388 ) (84,087 ) Total operating expenses (591,271 ) (559,963 ) (197,929 ) (188,808 ) Net operating income $ 1,333,857 $ 1,280,207 $ 454,748 $ 435,143 The following tables present NOI for each segment from our rental real estate for the nine months and quarters ended September 30, 2018 and 2017, Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 310,972 $ 89,211 $ 221,761 $ 300,702 $ 85,972 $ 214,730 Orange County 68,513 16,706 51,807 66,082 16,330 49,752 San Diego 68,640 17,984 50,656 66,052 17,415 48,637 Subtotal - Southern California 448,125 123,901 324,224 432,836 119,717 313,119 San Francisco 331,067 80,377 250,690 321,894 81,942 239,952 Washington D.C. 325,480 101,620 223,860 322,310 98,046 224,264 New York 343,239 135,700 207,539 341,295 128,076 213,219 Boston 171,042 47,666 123,376 167,010 45,871 121,139 Seattle 147,311 41,762 105,549 142,564 39,686 102,878 Other Markets 1,453 506 947 1,384 498 886 Total same store 1,767,717 531,532 1,236,185 1,729,293 513,836 1,215,457 Non-same store/other (2) (3) Non-same store 134,308 45,997 88,311 60,446 21,096 39,350 Other (3) 23,103 13,742 9,361 50,431 25,031 25,400 Total non-same store/other 157,411 59,739 97,672 110,877 46,127 64,750 Totals $ 1,925,128 $ 591,271 $ 1,333,857 $ 1,840,170 $ 559,963 $ 1,280,207 (1) For the nine months ended September 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 71,721 apartment (2) For the nine months ended September 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 September 30, 2018 Quarter Ended September 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 108,050 $ 30,848 $ 77,202 $ 104,190 $ 29,470 $ 74,720 Orange County 23,182 5,615 17,567 22,427 5,491 16,936 San Diego 23,215 6,233 16,982 22,432 5,881 16,551 Subtotal - Southern California 154,447 42,696 111,751 149,049 40,842 108,207 San Francisco 116,937 29,271 87,666 113,154 29,527 83,627 Washington D.C. 109,637 34,722 74,915 108,764 33,474 75,290 New York 115,757 45,156 70,601 114,799 42,620 72,179 Boston 57,531 16,073 41,458 56,022 15,726 40,296 Seattle 50,618 14,137 36,481 49,467 13,449 36,018 Other Markets 485 165 320 459 158 301 Total same store 605,412 182,220 423,192 591,714 175,796 415,918 Non-same store/other (2) (3) Non-same store 42,702 13,605 29,097 18,252 6,870 11,382 Other (3) 4,563 2,104 2,459 13,985 6,142 7,843 Total non-same store/other 47,265 15,709 31,556 32,237 13,012 19,225 Totals $ 652,677 $ 197,929 $ 454,748 $ 623,951 $ 188,808 $ 435,143 (1) For the quarters ended September 30, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to July 1, 2017, less properties subsequently sold, which represented 72,561 apartment (2) For the quarters ended September 30, 2018 and 2017, non-same store primarily includes properties acquired after July 1, 2017, plus any properties in lease-up and not stabilized as of July 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Nine Months Ended September 30, 2018 Total Assets Capital Expenditures Same store (1) Los Angeles $ 2,631,459 $ 21,438 Orange County 321,551 6,327 San Diego 410,450 3,665 Subtotal - Southern California 3,363,460 31,430 San Francisco 2,989,059 34,617 Washington D.C. 3,734,007 21,722 New York 4,108,581 17,217 Boston 1,599,983 16,477 Seattle 1,287,733 12,085 Other Markets 12,820 135 Total same store 17,095,643 133,683 Non-same store/other (2) (3) Non-same store 2,884,686 4,171 Other (3) 561,821 265 Total non-same store/other 3,446,507 4,436 Totals $ 20,542,150 $ 138,119 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 71,721 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	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Subsequent to September 30, 2018, the Company: • Repaid $500.0 million of 5.19% mortgage debt held in a Freddie Mac loan pool at par prior to the October 1, 2019 maturity date; and • Reissued $96.9 million of floating rate tax-exempt mortgage bonds which mature on April 1, 2042, remarket weekly and are guaranteed by ERPOP.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 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 nine months ended September 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 were recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases in the comparable period. These assets and liabilities were measured using enacted tax rates for which the temporary differences were expected to be recovered or settled. The effects of changes in tax rates on deferred tax assets and liabilities were 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 either the beginning of the earliest comparative period presented or as of the adoption date and provides for certain practical expedients, which the Company currently anticipates electing. The Company is the lessor for its residential and retail/commercial leases and anticipates that these leases 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 the lessee under various corporate office and ground leases, which are required to be recognized 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 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 expects to record right of use assets and related lease liabilities to its opening balance sheet upon adoption of the new standard on January 1, 2019, which it currently estimates to be an amount not likely to exceed $300.0 million. The ultimate impact on the Company’s consolidated results of operations and financial position will depend on our lease portfolio and other factors as of the adoption date, as we continue to evaluate the new leases standard. 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 nine months and quarter ended September 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 nine months and quarter ended September 30, 2017. The following table presents the disaggregation of revenue streams of our rental income for the nine months and quarter ended September 30, 2018 (amounts in thousands): Nine Months Ended September 30, 2018 Quarter Ended September 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 $ 1,803,908 93.7 % $ 611,119 93.6 % Utility recoveries (“RUBS”) Revenue Recognition 46,752 2.4 % 15,817 2.4 % Parking revenue Revenue Recognition 20,249 1.1 % 6,185 1.0 % Other revenue Revenue Recognition 54,219 2.8 % 19,556 3.0 % Rental income $ 1,925,128 100.0 % $ 652,677 100.0 % 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 September 30, 2017, the following cash flows were reclassified (amounts in thousands): Nine Months Ended September 30, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 4,939 $ (2,921 ) $ 2,018 Net (gain) loss on debt extinguishment $ — $ 12,258 $ 12,258 (Increase) decrease in deposits - restricted $ 788 $ (788 ) $ — (Increase) decrease in mortgage deposits $ 1,447 $ (1,447 ) $ — Net cash provided by operating activities $ 963,034 $ 7,102 $ 970,136 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ 39,519 $ (39,519 ) $ — (Increase) decrease in mortgage deposits $ (4,541 ) $ 4,541 $ — Net cash provided by (used for) investing activities $ (480,797 ) $ (34,978 ) $ (515,775 ) Cash Flows from Financing Activities: Mortgage deposits $ 57,057 $ (57,057 ) $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (12,258 ) $ (12,258 ) Line of credit and commercial paper: Commercial paper proceeds $ 3,888,675 $ 2,921 $ 3,891,596 Net cash (used for) financing activities $ (512,879 ) $ (66,394 ) $ (579,273 ) 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 $ 46,565 (adjustments for restricted deposits, end of period) $ 47,611 Cash and cash equivalents and restricted deposits, end of period $ 94,176 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.

Business (Tables)

Business (Tables)	9 Months Ended
	Sep. 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 286 74,618 Master-Leased Properties – Consolidated 1 162 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 306 79,260 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 Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 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 nine months and quarter ended September 30, 2018 (amounts in thousands): Nine Months Ended September 30, 2018 Quarter Ended September 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 $ 1,803,908 93.7 % $ 611,119 93.6 % Utility recoveries (“RUBS”) Revenue Recognition 46,752 2.4 % 15,817 2.4 % Parking revenue Revenue Recognition 20,249 1.1 % 6,185 1.0 % Other revenue Revenue Recognition 54,219 2.8 % 19,556 3.0 % Rental income $ 1,925,128 100.0 % $ 652,677 100.0 %
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 September 30, 2017, the following cash flows were reclassified (amounts in thousands): Nine Months Ended September 30, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 4,939 $ (2,921 ) $ 2,018 Net (gain) loss on debt extinguishment $ — $ 12,258 $ 12,258 (Increase) decrease in deposits - restricted $ 788 $ (788 ) $ — (Increase) decrease in mortgage deposits $ 1,447 $ (1,447 ) $ — Net cash provided by operating activities $ 963,034 $ 7,102 $ 970,136 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ 39,519 $ (39,519 ) $ — (Increase) decrease in mortgage deposits $ (4,541 ) $ 4,541 $ — Net cash provided by (used for) investing activities $ (480,797 ) $ (34,978 ) $ (515,775 ) Cash Flows from Financing Activities: Mortgage deposits $ 57,057 $ (57,057 ) $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (12,258 ) $ (12,258 ) Line of credit and commercial paper: Commercial paper proceeds $ 3,888,675 $ 2,921 $ 3,891,596 Net cash (used for) financing activities $ (512,879 ) $ (66,394 ) $ (579,273 ) 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 $ 46,565 (adjustments for restricted deposits, end of period) $ 47,611 Cash and cash equivalents and restricted deposits, end of period $ 94,176

Equity, Capital and Other Int_2

Equity, Capital and Other Interests (Tables)	9 Months Ended
	Sep. 30, 2018
Class Of Stock [Line Items]
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 nine months ended September 30, 2018: 2018 Common Shares Common Shares outstanding at January 1, 368,018,082 Common Shares Issued: Conversion of OP Units 12,510 Exercise of share options 194,796 Employee Share Purchase Plan (ESPP) 61,321 Restricted share grants, net 122,877 Common Shares outstanding at September 30, 368,409,586 Units Units outstanding at January 1, 13,768,438 Restricted unit grants, net 267,074 Conversion of OP Units to Common Shares (12,510 ) Units outstanding at September 30, 14,023,002 Total Common Shares and Units outstanding at September 30, 382,432,588 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 14,361 Change in carrying value (77 ) Balance at September 30, $ 381,239
Issued and Outstanding Preferred Shares and Preference Units	The Amounts in thousands Annual Call Dividend Per September 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 September 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]
Class Of Stock [Line Items]
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 nine months ended September 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 194,796 EQR’s Employee Share Purchase Plan (ESPP) 61,321 EQR’s restricted share grants, net 122,877 Issued to Limited Partners: Restricted unit grants, net 267,074 General and Limited Partner Units outstanding at September 30, 382,432,588 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 (12,510 ) Limited Partner Units outstanding at September 30, 14,023,002 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 nine months ended September 30, 2018 (amounts in thousands): 2018 Balance at January 1, $ 366,955 Change in market value 14,361 Change in carrying value (77 ) Balance at September 30, $ 381,239
Issued and Outstanding Preferred Shares and Preference Units	The December 31, 2017 Amounts in thousands Annual Call Dividend Per September 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 September 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 Intangi_2

Real Estate and Lease Intangibles (Tables)	9 Months Ended
	Sep. 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 September 30, 2018 and December 31, 2017 (amounts in thousands): September 30, 2018 December 31, 2017 Land $ 5,866,457 $ 5,996,024 Depreciable property: Buildings and improvements 18,174,939 17,743,042 Furniture, fixtures and equipment 1,684,794 1,548,961 In-Place lease intangibles 477,014 476,359 Projects under development: Land 34,689 43,226 Construction-in-progress 100,272 120,321 Land held for development: Land 61,038 62,538 Construction-in-progress 26,297 36,425 Investment in real estate 26,425,500 26,026,896 Accumulated depreciation (6,494,770 ) (6,040,378 ) Investment in real estate, net $ 19,930,730 $ 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 September 30, 2018 and December 31, 2017 (amounts in thousands): Description Balance Sheet Location September 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 (25,819 ) (22,434 ) Lease intangible assets, net $ 167,359 $ 170,744 Liabilities Ground lease intangibles – above market Other Liabilities $ 2,400 $ 2,400 Retail lease intangibles – below market Other Liabilities 1,710 5,270 Lease intangible liabilities 4,110 7,670 Accumulated amortization (1,674 ) (5,143 ) Lease intangible liabilities, net $ 2,436 $ 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 Nine Months Ended Quarter Ended September 30, September 30, Description Income Statement Location 2018 2017 2018 2017 Ground lease intangible amortization Property and Maintenance $ (3,348 ) $ (3,253 ) $ (1,116 ) $ (1,092 ) Retail lease intangible amortization Rental Income 54 524 18 80 Total amortization of above/below market lease intangibles $ (3,294 ) $ (2,729 ) $ (1,098 ) $ (1,012 )
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 $ (1,115 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) Retail lease intangibles 17 71 71 71 27 19 Total $ (1,098 ) $ (4,392 ) $ (4,392 ) $ (4,392 ) $ (4,436 ) $ (4,444 )
Acquired Properties From Unaffiliated Parties	During the nine months ended September 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) 5 1,478 $ 707,005 Total 5 1,478 $ 707,005 (1) Purchase price includes an allocation of approximately $113.7 million to land and $594.4 million to depreciable property (inclusive of capitalized closing costs).
Disposed Properties to Unaffiliated Parties	During the nine months ended September 30, 2018 , the Company disposed of the following to unaffiliated parties (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 5 1,292 $ 706,120 Land Parcels (one) — — 2,700 Total 5 1,292 $ 708,820

Investments in Partially Owne_2

Investments in Partially Owned Entities (Tables)	9 Months Ended
	Sep. 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 September 30, 2018 and December 31, 2017 (amounts in thousands except for ownership percentage): September 30, 2018 December 31, 2017 Ownership Percentage Investments in Unconsolidated Entities: Wisconsin Place Developer (VIE) (1) $ 42,964 $ 44,451 33.3% Operating Properties (Non-VIE) (2) 10,745 12,367 20.0% Other 3,867 1,436 Varies Investments in Unconsolidated Entities $ 57,576 $ 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)	9 Months Ended
	Sep. 30, 2018
Deposits Restricted [Abstract]
Restricted Deposits	The following table presents the Company’s restricted deposits as of September 30, 2018 and December 31, 2017 (amounts in thousands): September 30, 2018 December 31, 2017 Mortgage escrow deposits: Real estate taxes and insurance $ 600 $ 845 Replacement reserves 8,478 8,347 Mortgage principal reserves/sinking funds 8,363 3,167 Other 852 852 Mortgage escrow deposits 18,293 13,211 Restricted cash: Earnest money on pending acquisitions — 750 Restricted deposits on real estate investments 538 58 Resident security and utility deposits 35,379 35,183 Other 1,545 913 Restricted cash 37,462 36,904 Restricted deposits $ 55,755 $ 50,115

Derivative and Other Fair Val_2

Derivative and Other Fair Value Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Summary of Carrying and Fair Values of Financial Instruments	The September 30, 2018 December 31, 2017 Carrying Value Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Mortgage notes payable, net $ 2,789,436 $ 2,710,433 $ 3,618,722 $ 3,615,384 Unsecured debt, net 6,034,357 6,040,798 5,338,569 5,619,744 Total debt, net $ 8,823,793 $ 8,751,231 $ 8,957,291 $ 9,235,128
Summary of Consolidated Derivative Instruments	The September 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 9/30/2018 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 $ 27,526 $ — $ 27,526 $ — Supplemental Executive Retirement Plan Other Assets 144,561 144,561 — — Total $ 172,087 $ 144,561 $ 27,526 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 3,088 $ — $ 3,088 $ — Supplemental Executive Retirement Plan Other Liabilities 144,561 144,561 — — Total $ 147,649 $ 144,561 $ 3,088 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 381,239 $ — $ 381,239 $ — 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 September 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 $ (1,491 ) Fixed rate debt Interest expense $ 1,491 Total $ (1,491 ) $ 1,491 September 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 $ (1,413 ) Fixed rate debt Interest expense $ 1,413 Total $ (1,413 ) $ 1,413
Summary of Effect of Cash Flow Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The Effective Portion Ineffective Portion September 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 $ 24,021 Interest expense $ (13,902 ) N/A $ — Total $ 24,021 $ (13,902 ) $ — Effective Portion Ineffective Portion September 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 $ 5,216 Interest expense $ (14,019 ) N/A $ — Total $ 5,216 $ (14,019 ) $ —

Earning Per Share and Earning_2

Earning Per Share and Earnings Per Unit (Tables)	9 Months Ended
	Sep. 30, 2018
Schedule of Calculation of Numerator and Denominator in Earning Per Share and Earnings Per Unit	The Nine Months Ended September 30, Quarter Ended September 30, 2018 2017 2018 2017 Numerator for net income per share – basic: Net income $ 562,804 $ 498,297 $ 223,846 $ 144,196 Allocation to Noncontrolling Interests – Operating Partnership (20,517 ) (17,931 ) (8,159 ) (5,166 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,939 ) (2,354 ) (750 ) (801 ) Preferred distributions (2,318 ) (2,318 ) (773 ) (772 ) Numerator for net income per share – basic $ 538,030 $ 475,694 $ 214,164 $ 137,457 Numerator for net income per share – diluted: Net income $ 562,804 $ 498,297 $ 223,846 $ 144,196 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,939 ) (2,354 ) (750 ) (801 ) Preferred distributions (2,318 ) (2,318 ) (773 ) (772 ) Numerator for net income per share – diluted $ 558,547 $ 493,625 $ 222,323 $ 142,623 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 367,920 366,809 368,028 366,996 Effect of dilutive securities: OP Units 12,871 12,907 12,884 12,910 Long-term compensation shares/units 2,642 2,924 2,972 3,039 Denominator for net income per share – diluted 383,433 382,640 383,884 382,945 Net income per share – basic $ 1.46 $ 1.30 $ 0.58 $ 0.37 Net income per share – diluted $ 1.46 $ 1.29 $ 0.58 $ 0.37
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): Nine Months Ended September 30, Quarter Ended September 30, 2018 2017 2018 2017 Numerator for net income per Unit – basic and diluted: Net income $ 562,804 $ 498,297 $ 223,846 $ 144,196 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (1,939 ) (2,354 ) (750 ) (801 ) Allocation to Preference Units (2,318 ) (2,318 ) (773 ) (772 ) Numerator for net income per Unit – basic and diluted $ 558,547 $ 493,625 $ 222,323 $ 142,623 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 380,791 379,716 380,912 379,906 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,642 2,924 2,972 3,039 Denominator for net income per Unit – diluted 383,433 382,640 383,884 382,945 Net income per Unit – basic $ 1.46 $ 1.30 $ 0.58 $ 0.37 Net income per Unit – diluted $ 1.46 $ 1.29 $ 0.58 $ 0.37

Reportable Segments (Tables)

Reportable Segments (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations	The Nine Months Ended September 30, Quarter Ended September 30, 2018 2017 2018 2017 Rental income $ 1,925,128 $ 1,840,170 $ 652,677 $ 623,951 Property and maintenance expense (322,487 ) (306,645 ) (110,541 ) (104,721 ) Real estate taxes and insurance expense (268,784 ) (253,318 ) (87,388 ) (84,087 ) Total operating expenses (591,271 ) (559,963 ) (197,929 ) (188,808 ) Net operating income $ 1,333,857 $ 1,280,207 $ 454,748 $ 435,143
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 nine months and quarters ended September 30, 2018 and 2017, Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 310,972 $ 89,211 $ 221,761 $ 300,702 $ 85,972 $ 214,730 Orange County 68,513 16,706 51,807 66,082 16,330 49,752 San Diego 68,640 17,984 50,656 66,052 17,415 48,637 Subtotal - Southern California 448,125 123,901 324,224 432,836 119,717 313,119 San Francisco 331,067 80,377 250,690 321,894 81,942 239,952 Washington D.C. 325,480 101,620 223,860 322,310 98,046 224,264 New York 343,239 135,700 207,539 341,295 128,076 213,219 Boston 171,042 47,666 123,376 167,010 45,871 121,139 Seattle 147,311 41,762 105,549 142,564 39,686 102,878 Other Markets 1,453 506 947 1,384 498 886 Total same store 1,767,717 531,532 1,236,185 1,729,293 513,836 1,215,457 Non-same store/other (2) (3) Non-same store 134,308 45,997 88,311 60,446 21,096 39,350 Other (3) 23,103 13,742 9,361 50,431 25,031 25,400 Total non-same store/other 157,411 59,739 97,672 110,877 46,127 64,750 Totals $ 1,925,128 $ 591,271 $ 1,333,857 $ 1,840,170 $ 559,963 $ 1,280,207 (1) For the nine months ended September 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 71,721 apartment (2) For the nine months ended September 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 September 30, 2018 Quarter Ended September 30, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 108,050 $ 30,848 $ 77,202 $ 104,190 $ 29,470 $ 74,720 Orange County 23,182 5,615 17,567 22,427 5,491 16,936 San Diego 23,215 6,233 16,982 22,432 5,881 16,551 Subtotal - Southern California 154,447 42,696 111,751 149,049 40,842 108,207 San Francisco 116,937 29,271 87,666 113,154 29,527 83,627 Washington D.C. 109,637 34,722 74,915 108,764 33,474 75,290 New York 115,757 45,156 70,601 114,799 42,620 72,179 Boston 57,531 16,073 41,458 56,022 15,726 40,296 Seattle 50,618 14,137 36,481 49,467 13,449 36,018 Other Markets 485 165 320 459 158 301 Total same store 605,412 182,220 423,192 591,714 175,796 415,918 Non-same store/other (2) (3) Non-same store 42,702 13,605 29,097 18,252 6,870 11,382 Other (3) 4,563 2,104 2,459 13,985 6,142 7,843 Total non-same store/other 47,265 15,709 31,556 32,237 13,012 19,225 Totals $ 652,677 $ 197,929 $ 454,748 $ 623,951 $ 188,808 $ 435,143 (1) For the quarters ended September 30, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to July 1, 2017, less properties subsequently sold, which represented 72,561 apartment (2) For the quarters ended September 30, 2018 and 2017, non-same store primarily includes properties acquired after July 1, 2017, plus any properties in lease-up and not stabilized as of July 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Nine Months Ended September 30, 2018 Total Assets Capital Expenditures Same store (1) Los Angeles $ 2,631,459 $ 21,438 Orange County 321,551 6,327 San Diego 410,450 3,665 Subtotal - Southern California 3,363,460 31,430 San Francisco 2,989,059 34,617 Washington D.C. 3,734,007 21,722 New York 4,108,581 17,217 Boston 1,599,983 16,477 Seattle 1,287,733 12,085 Other Markets 12,820 135 Total same store 17,095,643 133,683 Non-same store/other (2) (3) Non-same store 2,884,686 4,171 Other (3) 561,821 265 Total non-same store/other 3,446,507 4,436 Totals $ 20,542,150 $ 138,119 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 71,721 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)	Sep. 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	11
Properties | Property	306
Apartment units	79,260
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)	Sep. 30, 2018PropertyApartmentUnit
Property/Unit schedule
Properties | Property	306
Apartment Units | ApartmentUnit	79,260
Wholly Owned Properties
Property/Unit schedule
Properties | Property	286
Apartment Units | ApartmentUnit	74,618
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 Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Provision for income tax		$ 280,000	$ 228,000	$ 767,000	$ 710,000
Percentage of rental income excluded from accounting standard adoption				94.00%
Percentage of total revenue subject to revenue recognition standard				6.00%
Accounting Standards Update 2016-02 [Member] | Maximum [Member]
Expected right of use assets and related lease liabilities to opening balance sheet adoption of new accounting standard on leases				$ 300,000,000
Adjustments for New Accounting Principle, Early Adoption
Gain (loss) on equity transaction	$ 0
Federal [Member]
Provision for income tax				$ 0

Summary of Significant Accoun_5

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		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Amount of rental income	$ 652,677	$ 623,951	$ 1,925,128	$ 1,840,170
Percentage of rental income	100.00%		100.00%
Leasing Revenue [Member]
Percentage of rental income	93.60%		93.70%
Amount of rental income	$ 611,119		$ 1,803,908
Utility Recoveries [Member]
Amount of rental income	$ 15,817		$ 46,752
Percentage of rental income	2.40%		2.40%
Parking Revenue [Member]
Amount of rental income	$ 6,185		$ 20,249
Percentage of rental income	1.00%		1.10%
Other Revenue [Member]
Amount of rental income	$ 19,556		$ 54,219
Percentage of rental income	3.00%		2.80%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt	$ 21,360	$ 2,018
Net (gain) loss on debt extinguishment	22,110	12,258
Net cash provided by operating activities	1,044,191	970,136
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash provided by (used for) investing activities	(268,820)	(515,775)
CASH FLOWS FROM FINANCING ACTIVITIES:
Commercial paper proceeds	9,624,610	3,891,596
Net cash (used for) financing activities	(787,383)	(579,273)
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	32,995	46,565
Cash and cash equivalents and restricted deposits, end of period	88,750	94,176
Scenario, Previously Reported [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		4,939
(Increase) decrease in deposits - restricted		788
(Increase) decrease in mortgage deposits		1,447
Net cash provided by operating activities		963,034
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		39,519
(Increase) decrease in mortgage deposits		(4,541)
Net cash provided by (used for) investing activities		(480,797)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		57,057
Commercial paper proceeds		3,888,675
Net cash (used for) financing activities		(512,879)
Cash and cash equivalents, beginning of period		77,207
Cash and cash equivalents, end of period		46,565
Reclassification Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		(2,921)
Net (gain) loss on debt extinguishment		12,258
(Increase) decrease in deposits - restricted		(788)
(Increase) decrease in mortgage deposits		(1,447)
Net cash provided by operating activities		7,102
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		(39,519)
(Increase) decrease in mortgage deposits		4,541
Net cash provided by (used for) investing activities		(34,978)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		(57,057)
Commercial paper proceeds		2,921
Net cash (used for) financing activities		(66,394)
(adjustments for restricted deposits, beginning of period)		141,881
(adjustments for restricted deposits, end of period)		47,611
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 Int_3

Equity, Capital and Other Interests - Changes in Issued and Outstanding Common Shares and Units (Details)	9 Months Ended
	Sep. 30, 2018shares
Equity Capital And Other Interests [Abstract]
Common Stock, Shares, Outstanding	368,018,082
Common Shares Issued:
Conversion of OP Units	12,510
Exercise of share options	194,796
Employee Share Purchase Plan (ESPP)	61,321
Restricted share grants, net	122,877
Common Stock, Shares, Outstanding	368,409,586
Units
Total Units Outstanding	13,768,438
Restricted unit grants, net	267,074
Conversion of OP Units to Common Shares	(12,510)
Total Units Outstanding	14,023,002
Common Shares And Units Outstanding	382,432,588
Units Ownership Interest in Operating Partnership	3.70%

Equity, Capital and Other Int_4

Equity, Capital and Other Interests - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Redeemable noncontrolling interests - operating partnership	$ 381,239	$ 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	$ 381,239	$ 366,955

Equity, Capital and Other Int_5

Equity, Capital and Other Interests - Changes in Redemption Value of Redeemable Noncontrolling Interests - Operating Partnership (Details) $ in Thousands	9 Months Ended
	Sep. 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	14,361
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	(77)
Redeemable Noncontrolling Interests - Operating Partnership	$ 381,239

Equity, Capital and Other Int_6

Equity, Capital and Other Interests - Issued and Outstanding Preferred Shares and Preference Units (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 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 September 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 September 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 September 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 September 30, 2018 and December 31, 2017	$ 37,280	$ 37,280

Equity, Capital and Other Int_7

Equity, Capital and Other Interests - Issued and Outstanding Preferred Shares and Preference Units (Parenthetical) (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 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 Int_8

Equity, Capital and Other Interests - Changes in Operating Partnership's Issued and Outstanding Units (Details)	9 Months Ended
	Sep. 30, 2018shares
General and Limited Partner Units
Exercise of share options	194,796
Employee Share Purchase Plan (ESPP)	61,321
Restricted share grants, net	122,877
Restricted unit grants, net	267,074
Common Shares And Units Outstanding	382,432,588
LIMITED PARTNERS
Total Units Outstanding	13,768,438
Restricted unit grants, net	267,074
Conversion of Limited Partner OP Units to EQR Common Shares	(12,510)
Total Units Outstanding	14,023,002
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	194,796
Employee Share Purchase Plan (ESPP)	61,321
Restricted share grants, net	122,877
Restricted unit grants, net	267,074
Common Shares And Units Outstanding	382,432,588
LIMITED PARTNERS
Total Units Outstanding	13,768,438
Restricted unit grants, net	267,074
Conversion of Limited Partner OP Units to EQR Common Shares	(12,510)
Total Units Outstanding	14,023,002
Units Ownership Interest in Operating Partnership	3.70%

Equity, Capital and Other Int_9

Equity, Capital and Other Interests - Changes in Redemption Value of Redeemable Limited Partners Interest (Details) - ERPOP [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Redeemable Limited Partners	$ 366,955
Limited Partners Change In Redemption Value	14,361
Limited Partners Change In Carrying Value	(77)
Redeemable Limited Partners	$ 381,239

Equity, Capital and Other In_10

Equity, Capital and Other Interests - Other - Additional Information (Details)	9 Months Ended
	Sep. 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
Stock repurchase program, remaining number of shares authorized to be repurchased	13,000,000

Real Estate and Lease Intangi_3

Real Estate and Lease Intangibles - Summary of Carrying Amounts of Investment in Real Estate (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Land	$ 5,866,457	$ 5,996,024
Depreciable property:
Buildings and improvements	18,174,939	17,743,042
Furniture, fixtures and equipment	1,684,794	1,548,961
In-Place lease intangibles	477,014	476,359
Projects under development:
Construction-in-progress	134,961	163,547
Land held for development:
Land	87,335	98,963
Construction-in-progress	134,961	163,547
Investment in real estate	26,425,500	26,026,896
Accumulated depreciation	(6,494,770)	(6,040,378)
Investment in real estate, net	19,930,730	19,986,518
Projects under development [Member]
Projects under development:
Land	34,689	43,226
Construction-in-progress	100,272	120,321
Land held for development:
Construction-in-progress	100,272	120,321
Land held for development [Member]
Projects under development:
Construction-in-progress	26,297	36,425
Land held for development:
Land	61,038	62,538
Construction-in-progress	$ 26,297	$ 36,425

Real Estate and Lease Intangi_4

Real Estate and Lease Intangibles - Summary of Carrying Amounts of Above and Below Market Ground And Retail Lease Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Other Assets [Member]
Lease intangible assets	$ 193,178	$ 193,178
Finite-Lived Intangible Assets, Accumulated Amortization	(25,819)	(22,434)
Lease intangible assets, net	167,359	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	4,110	7,670
Finite Lived Intangible Liabilities Accumulated Amortization	(1,674)	(5,143)
Lease intangible liabilities, net	2,436	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	$ 1,710	$ 5,270

Real Estate and Lease Intangi_5

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		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Total amortization of above/below market lease intangibles	$ (1,098)	$ (1,012)	$ (3,294)	$ (2,729)
Ground Lease [Member] | Property and Maintenance [Member]
Total amortization of above/below market lease intangibles	(1,116)	(1,092)	(3,348)	(3,253)
Retail Lease [Member] | Rental Income [Member]
Total amortization of above/below market lease intangibles	$ 18	$ 80	$ 54	$ 524

Real Estate and Lease Intangi_6

Real Estate and Lease Intangibles - Summary of Aggregate Amortization for Above and Below Market Ground And Retail Lease Intangibles (Details) $ in Thousands	Sep. 30, 2018USD ($)
Finite-lived intangible assets, amortization expense, remainder of fiscal year 2018	$ (1,098)
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	(1,115)
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	17
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 Intangi_7

Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)PropertyApartmentUnit
Properties acquired | Property	5
Property Units acquired | ApartmentUnit	1,478
Purchase Price	$ 707,005
Properties disposed | Property	5
Property Units disposed | ApartmentUnit	1,292
Sales Price	$ 708,820
Rental Properties - Consolidated [Member]
Properties acquired | Property	5
Property Units acquired | ApartmentUnit	1,478
Purchase Price	$ 707,005
Properties disposed | Property	5
Property Units disposed | ApartmentUnit	1,292
Sales Price	$ 706,120
Land [Member]
Purchase Price	113,700
Sales Price	$ 2,700

Real Estate and Lease Intangi_8

Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Parenthetical) (Details) $ in Thousands	Sep. 30, 2018USD ($)
Purchase Price	$ 707,005
Land [Member]
Purchase Price	113,700
Depreciable Property [Member]
Purchase Price	$ 594,400

Real Estate and Lease Intangi_9

Real Estate and Lease Intangibles - Acquisitions and Dispositions - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)Building	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)Building	Sep. 30, 2017USD ($)
Net gain on sales of real estate properties	$ 114,672	$ 17,328	$ 256,834	$ 141,761
Net gain on sales of land parcels			995	$ 19,170
Non-cash asset impairment charge	$ 702		$ 702
San Francisco
Number of buildings damaged due to fire | Building	1		1

Investments in Partially Owne_3

Investments in Partially Owned Entities - Consolidated Variable Interest Entities ("VIEs") - Additional Information (Details) $ in Thousands	Sep. 30, 2018USD ($)PropertyApartmentUnit	Dec. 31, 2017USD ($)
Variable Interest Entity [Line Items]
Properties | Property	306
Apartment units | ApartmentUnit	79,260
Total assets	$ 20,542,150	$ 20,570,599
Total liabilities	$ 9,693,820	9,729,781
Consolidated VIE [Member]
Variable Interest Entity [Line Items]
Properties | Property	17
Apartment units | ApartmentUnit	3,535
Total assets	$ 714,400	518,900
Total liabilities	$ 315,600	$ 307,000

Investments in Partially Owne_4

Investments in Partially Owned Entities - Summary of Companys Investment in Unconsolidated Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 57,576	$ 58,254
Operating Property [Member] | Unconsolidated Non-VIE [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 10,745	12,367
Ownership Percentage	20.00%
Other [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 3,867	1,436
Consolidated VIE [Member] | Wisconsin Place Developer [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 42,964	$ 44,451
Ownership Percentage	33.30%

Investments in Partially Owne_5

Investments in Partially Owned Entities - Summary of Companys Investment in Unconsolidated Entities (Parenthetical) (Details)	9 Months Ended
	Sep. 30, 2018ApartmentUnitJointVenture
Variable Interest Entity [Line Items]
Apartment units	79,260
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	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Mortgage escrow deposits:
Real estate taxes and insurance	$ 600	$ 845
Replacement reserves	8,478	8,347
Mortgage principal reserves/sinking funds	8,363	3,167
Other	852	852
Mortgage escrow deposits	18,293	13,211
Restricted cash:
Earnest money on pending acquisitions		750
Restricted deposits on real estate investments	538	58
Resident security and utility deposits	35,379	35,183
Other	1,545	913
Restricted cash	37,462	36,904
Restricted deposits	$ 55,755	$ 50,115	$ 47,611

Debt - Mortgage Notes Payable -

Debt - Mortgage Notes Payable - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Mortgage notes payable	$ 2,789,436	$ 3,618,722
Debt instrument, maturity date	Jan. 10, 2022
Mortgages [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 4,900
Write off of deferred debt issuance cost	2,800
Write off unamortized discount	$ 16,300
Debt instrument, maturity date	May 28, 2061
Weighted average interest rate	4.19%
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	$ 254,200
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	$ 440,900
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	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unsecured notes	$ 5,534,990	$ 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	4.25%
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	Sep. 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		$ 499,400,000
commercial paper principal outstanding		500,000,000
Unamortized discount		$ 600,000
Weighted average interest rate		2.23%
Commercial paper weighted average days outstanding		18 days
Commercial paper principal outstanding		$ 500,000,000
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		2.65%
Remaining borrowing capacity		$ 1,490,000,000
Amount restricted/dedicated to support letters of credit		$ 6,700,000

Debt - Other - Additional Infor

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

Derivative and Other Fair Val_3

Derivative and Other Fair Value Instruments - Summary of Carrying and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	$ 8,823,793	$ 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	8,751,231	9,235,128
Mortgage Notes Payable, Net [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	2,789,436	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	2,710,433	3,615,384
Unsecured Debt [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	6,034,357	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	$ 6,040,798	$ 5,619,744

Derivative and Other Fair Val_4

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Details)	9 Months Ended
	Sep. 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 Val_5

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Parenthetical) (Details)	9 Months Ended
	Sep. 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 Val_6

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	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	$ 144,561	$ 140,159
Assets, Fair Value Disclosure	172,087	145,302
Other Liabilities, Fair Value Disclosure	144,561	140,159
Liabilities, Fair Value Disclosure	147,649	141,756
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	381,239	366,955
Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3,088	1,597
Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	27,526	5,143
Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	144,561	140,159
Assets, Fair Value Disclosure	144,561	140,159
Other Liabilities, Fair Value Disclosure	144,561	140,159
Liabilities, Fair Value Disclosure	144,561	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
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	27,526	5,143
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	3,088	1,597
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	381,239	366,955
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3,088	1,597
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	27,526	5,143
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

Derivative and Other Fair Val_7

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	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ (1,491)	$ (1,413)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	1,491	1,413
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	(1,491)	(1,413)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	$ 1,491	$ 1,413

Derivative and Other Fair Val_8

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	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	$ 24,021	$ 5,216
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(13,902)	(14,019)
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	24,021	5,216
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(13,902)	(14,019)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	$ 0	$ 0

Derivative and Other Fair Val_9

Derivative and Other Fair Value Instruments - Additional Information (Details) $ in Millions	1 Months Ended	9 Months Ended	12 Months Ended
	Feb. 28, 2018USD ($)DerivativeInstrument	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Derivative [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)		$ 50.7	$ 88.6
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net		$ 19.8
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 Earning_3

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		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 223,846	$ 144,196	$ 562,804	$ 498,297
Allocation to Noncontrolling Interests – Operating Partnership	(8,159)	(5,166)	(20,517)	(17,931)
Partially Owned Properties	(750)	(801)	(1,939)	(2,354)
Preferred distributions	(773)	(772)	(2,318)	(2,318)
Net income available to Common Shares	214,164	137,457	538,030	475,694
Numerator for net income per share – diluted	$ 222,323	$ 142,623	$ 558,547	$ 493,625
Weighted average Common Shares outstanding	368,028	366,996	367,920	366,809
Dilutive Op Units	12,884	12,910	12,871	12,907
Dilutive Securities Options	2,972	3,039	2,642	2,924
Weighted average Common Shares outstanding	383,884	382,945	383,433	382,640
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.30
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.29

Earning Per Share and Earning_4

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		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 223,846	$ 144,196	$ 562,804	$ 498,297
Partially Owned Properties	$ (750)	$ (801)	$ (1,939)	$ (2,354)
Dilutive Securities Options	2,972	3,039	2,642	2,924
Weighted average Common Shares outstanding	383,884	382,945	383,433	382,640
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.30
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.29
ERPOP [Member]
Net income	$ 223,846	$ 144,196	$ 562,804	$ 498,297
Partially Owned Properties	(750)	(801)	(1,939)	(2,354)
Allocation to Preference Units	(773)	(772)	(2,318)	(2,318)
Numerator for net income per Unit – basic and diluted	$ 222,323	$ 142,623	$ 558,547	$ 493,625
Denominator for net income per Unit – basic	380,912	379,906	380,791	379,716
Dilutive Securities Options	2,972	3,039	2,642	2,924
Weighted average Common Shares outstanding	383,884	382,945	383,433	382,640
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.30
Net income available to Common Shares	$ 0.58	$ 0.37	$ 1.46	$ 1.29

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2018USD ($)PropertyApartmentUnit
Accrual for environmental loss contingencies	$ 5,800,000
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	$ 444,000,000
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)	Sep. 30, 2018PropertyCustomer	Sep. 30, 2017Customer
Segment Reporting Information [Line Items]
Number of customer contributed 10% or more of total revenue | Customer	0	0
Denver | Non-same store
Segment Reporting Information [Line Items]
Number of properties acquired | Property	2

Reportable Segments - Reconcili

Reportable Segments - Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	$ 652,677	$ 623,951	$ 1,925,128	$ 1,840,170
Property and maintenance expense	(110,541)	(104,721)	(322,487)	(306,645)
Real estate taxes and insurance expense	(87,388)	(84,087)	(268,784)	(253,318)
Operating income	224,731	217,786	639,254	632,707
Same Store, Non-same Store and Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	652,677	623,951	1,925,128	1,840,170
Property and maintenance expense	(110,541)	(104,721)	(322,487)	(306,645)
Real estate taxes and insurance expense	(87,388)	(84,087)	(268,784)	(253,318)
Total operating expenses	(197,929)	(188,808)	(591,271)	(559,963)
Operating income	$ 454,748	$ 435,143	$ 1,333,857	$ 1,280,207

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		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Rental income	$ 652,677	$ 623,951	$ 1,925,128	$ 1,840,170
Operating income	224,731	217,786	639,254	632,707
Total Assets	20,542,150		20,542,150		$ 20,570,599
Capital Expenditures			138,119
Same store
Segment Reporting Information [Line Items]
Rental income	605,412	591,714	1,767,717	1,729,293
Operating expenses	182,220	175,796	531,532	513,836
Operating income	423,192	415,918	1,236,185	1,215,457
Total Assets	17,095,643		17,095,643
Capital Expenditures			133,683
Non-same store/other
Segment Reporting Information [Line Items]
Rental income	47,265	32,237	157,411	110,877
Operating expenses	15,709	13,012	59,739	46,127
Operating income	31,556	19,225	97,672	64,750
Total Assets	3,446,507		3,446,507
Capital Expenditures			4,436
Same Store, Non-same Store and Other
Segment Reporting Information [Line Items]
Rental income	652,677	623,951	1,925,128	1,840,170
Operating expenses	197,929	188,808	591,271	559,963
Operating income	454,748	435,143	1,333,857	1,280,207
Other markets | Same store
Segment Reporting Information [Line Items]
Rental income	485	459	1,453	1,384
Operating expenses	165	158	506	498
Operating income	320	301	947	886
Total Assets	12,820		12,820
Capital Expenditures			135
Los Angeles | Same store
Segment Reporting Information [Line Items]
Rental income	108,050	104,190	310,972	300,702
Operating expenses	30,848	29,470	89,211	85,972
Operating income	77,202	74,720	221,761	214,730
Total Assets	2,631,459		2,631,459
Capital Expenditures			21,438
Orange County | Same store
Segment Reporting Information [Line Items]
Rental income	23,182	22,427	68,513	66,082
Operating expenses	5,615	5,491	16,706	16,330
Operating income	17,567	16,936	51,807	49,752
Total Assets	321,551		321,551
Capital Expenditures			6,327
San Diego | Same store
Segment Reporting Information [Line Items]
Rental income	23,215	22,432	68,640	66,052
Operating expenses	6,233	5,881	17,984	17,415
Operating income	16,982	16,551	50,656	48,637
Total Assets	410,450		410,450
Capital Expenditures			3,665
Subtotal - Southern California | Same store
Segment Reporting Information [Line Items]
Rental income	154,447	149,049	448,125	432,836
Operating expenses	42,696	40,842	123,901	119,717
Operating income	111,751	108,207	324,224	313,119
Total Assets	3,363,460		3,363,460
Capital Expenditures			31,430
San Francisco | Same store
Segment Reporting Information [Line Items]
Rental income	116,937	113,154	331,067	321,894
Operating expenses	29,271	29,527	80,377	81,942
Operating income	87,666	83,627	250,690	239,952
Total Assets	2,989,059		2,989,059
Capital Expenditures			34,617
Washington DC | Same store
Segment Reporting Information [Line Items]
Rental income	109,637	108,764	325,480	322,310
Operating expenses	34,722	33,474	101,620	98,046
Operating income	74,915	75,290	223,860	224,264
Total Assets	3,734,007		3,734,007
Capital Expenditures			21,722
New York | Same store
Segment Reporting Information [Line Items]
Rental income	115,757	114,799	343,239	341,295
Operating expenses	45,156	42,620	135,700	128,076
Operating income	70,601	72,179	207,539	213,219
Total Assets	4,108,581		4,108,581
Capital Expenditures			17,217
Boston | Same store
Segment Reporting Information [Line Items]
Rental income	57,531	56,022	171,042	167,010
Operating expenses	16,073	15,726	47,666	45,871
Operating income	41,458	40,296	123,376	121,139
Total Assets	1,599,983		1,599,983
Capital Expenditures			16,477
Seattle | Same store
Segment Reporting Information [Line Items]
Rental income	50,618	49,467	147,311	142,564
Operating expenses	14,137	13,449	41,762	39,686
Operating income	36,481	36,018	105,549	102,878
Total Assets	1,287,733		1,287,733
Capital Expenditures			12,085
Non-same store | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	42,702	18,252	134,308	60,446
Operating expenses	13,605	6,870	45,997	21,096
Operating income	29,097	11,382	88,311	39,350
Total Assets	2,884,686		2,884,686
Capital Expenditures			4,171
Other [Member] | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	4,563	13,985	23,103	50,431
Operating expenses	2,104	6,142	13,742	25,031
Operating income	2,459	$ 7,843	9,361	$ 25,400
Total Assets	$ 561,821		561,821
Capital Expenditures			$ 265

Reportable Segments - NOI for_2

Reportable Segments - NOI for Each Segment from Our Rental Real Estate Specific to Continuing Operations (Parenthetical) (Details) - Property	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]
Units in same store properties	72,561	72,561	71,721	71,721

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Millions	Oct. 01, 2018	Sep. 30, 2018
Subsequent Event [Line Items]
Debt instrument, maturity date		Jan. 10, 2022
Mortgages [Member]
Subsequent Event [Line Items]
Repayments of long-term debt		$ 4.9
Debt instrument, maturity date		May 28, 2061
Subsequent Event [Member] | New Floating Rate Tax Exempt Mortgage Bond [Member] | ERPOP [Member]
Subsequent Event [Line Items]
Debt instrument, maturity date	Apr. 1, 2042
Proceeds from issuance of long-term debt	$ 96.9
Freddie Mac Loan Pool [Member] | Subsequent Event [Member] | Mortgages [Member]
Subsequent Event [Line Items]
Repayments of long-term debt	$ 500
Debt instrument, interest rate, stated percentage	5.19%
Debt instrument, maturity date	Oct. 1, 2019