Equity Residential (EQR) 10-Q 6 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document And Entity Information [Line Items]
Entity Registrant Name	EQUITY RESIDENTIAL
Entity Central Index Key	0000906107
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
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		370,535,630
ERPOP [Member]
Document And Entity Information [Line Items]
Entity Registrant Name	ERP OPERATING LIMITED PARTNERSHIP
Entity Central Index Key	0000931182
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
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	Mar. 31, 2019	Dec. 31, 2018
ASSETS
Land	$ 5,918,994	$ 5,875,803
Depreciable property	20,691,304	20,435,901
Projects under development	135,191	109,409
Land held for development	91,647	89,909
Investment in real estate	26,837,136	26,511,022
Accumulated depreciation	(6,900,496)	(6,696,281)
Investment in real estate, net	19,936,640	19,814,741
Investments in unconsolidated entities	62,853	58,349
Cash and cash equivalents	29,391	47,442
Restricted deposits	64,115	68,871
Right-of-use assets	434,683	0
Other assets	241,129	404,806
Total assets	20,768,811	20,394,209
Liabilities:
Mortgage notes payable, net	2,671,491	2,385,470
Notes, net	5,936,335	5,933,286
Line of credit and commercial paper	344,844	499,183
Accounts payable and accrued expenses	152,831	102,471
Accrued interest payable	74,028	62,622
Lease liabilities	282,237	0
Other liabilities	321,172	358,563
Security deposits	68,335	67,258
Distributions payable	218,471	206,601
Total liabilities	10,069,744	9,615,454
Commitments and contingencies
Redeemable Noncontrolling Interests – Operating Partnership	432,562	379,106
Shareholders’ equity:
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 745,600 shares issued and outstanding as of March 31, 2019 and December 31, 2018	37,280	37,280
Common Shares of beneficial interest, $0.01 par value; 1,000,000,000 shares authorized; 370,462,401 shares issued and outstanding as of March 31, 2019 and 369,405,161 shares issued and outstanding as of December 31, 2018	3,705	3,694
Paid in capital	8,925,882	8,935,453
Retained earnings	1,155,032	1,261,763
Accumulated other comprehensive income (loss)	(75,013)	(64,986)
Total shareholders’ equity	10,046,886	10,173,204
Noncontrolling Interests:
Operating Partnership	225,081	228,738
Partially Owned Properties	(5,462)	(2,293)
Total Noncontrolling Interests	219,619	226,445
Total equity	10,266,505	10,399,649
Total liabilities and equity/capital	$ 20,768,811	$ 20,394,209

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
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	370,462,401	369,405,161
Common Stock, Shares, Outstanding	370,462,401	369,405,161

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
REVENUES
Rental income	$ 662,302	$ 632,831
Fee and asset management	$ 192	$ 185
Type of Revenue [Extensible List]	us-gaap:ManagementServiceMember	us-gaap:ManagementServiceMember
Total revenues	$ 662,494	$ 633,016
EXPENSES
Property and maintenance	115,070	108,202
Real estate taxes and insurance	91,442	91,914
Property management	26,396	23,444
General and administrative	15,381	16,278
Depreciation	204,215	196,309
Total expenses	452,504	436,147
Net gain (loss) on sales of real estate properties	(21)	142,213
Operating income	209,969	339,082
Interest and other income	581	5,880
Other expenses	(3,275)	(3,441)
Interest:
Expense incurred, net	(94,938)	(116,104)
Amortization of deferred financing costs	(2,136)	(3,679)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of land parcels	110,201	221,738
Income and other tax (expense) benefit	(238)	(213)
Income (loss) from investments in unconsolidated entities	(707)	(977)
Net gain (loss) on sales of land parcels	1
Net income	109,257	220,548
Net (income) loss attributable to Noncontrolling Interests:
Operating Partnership	(3,919)	(8,059)
Partially Owned Properties	(799)	(680)
Net income attributable to controlling interests	104,539	211,809
Preferred distributions	(773)	(773)
Net income available to Common Shares	$ 103,766	$ 211,036
Earnings per share – basic:
Net income available to Common Shares	$ 0.28	$ 0.57
Weighted average Common Shares outstanding	369,558	367,800
Earnings per share – diluted:
Net income available to Common Shares	$ 0.28	$ 0.57
Weighted average Common Shares outstanding	385,184	383,018

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Comprehensive income:
Net income	$ 109,257	$ 220,548
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	(14,420)	6,087
Losses reclassified into earnings from other comprehensive income	4,393	4,791
Other comprehensive income (loss)	(10,027)	10,878
Comprehensive income	99,230	231,426
Comprehensive (income) attributable to Noncontrolling Interests	(4,353)	(9,139)
Comprehensive income attributable to controlling interests	$ 94,877	$ 222,287

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 109,257	$ 220,548
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	204,215	196,309
Amortization of deferred financing costs	2,136	3,679
Amortization of above/below market lease intangibles	(18)	1,098
Amortization of discounts and premiums on debt	1,418	1,532
Amortization of deferred settlements on derivative instruments	4,390	4,788
Amortization of right-of-use assets	4,022
Write-off of pursuit costs	1,448	931
(Income) loss from investments in unconsolidated entities	707	977
Distributions from unconsolidated entities – return on capital	693	615
Net (gain) loss on sales of real estate properties	21	(142,213)
Net (gain) loss on sales of land parcels	(1)
Net (gain) loss on debt extinguishment		22,110
Compensation paid with Company Common Shares	9,806	10,278
Changes in assets and liabilities:
(Increase) decrease in other assets	(14,325)	(15,396)
Increase (decrease) in accounts payable and accrued expenses	63,789	48,997
Increase (decrease) in accrued interest payable	11,406	11,718
Increase (decrease) in other liabilities	(25,942)	(4,692)
Increase (decrease) in security deposits	1,077	(261)
Increase (decrease) in lease liabilities	(554)
Net cash provided by operating activities	373,545	361,018
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(258,938)	(54,134)
Investment in real estate – development/other	(45,327)	(40,813)
Capital expenditures to real estate	(34,018)	(36,747)
Non-real estate capital additions	(1,018)	(1,191)
Interest capitalized for real estate under development	(1,202)	(1,688)
Proceeds from disposition of real estate, net		284,670
Investments in unconsolidated entities	(6,281)	(2,799)
Purchase of investment securities and other investments	(251)
Net cash provided by (used for) investing activities	(347,035)	147,298
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(1,492)	(4,345)
Mortgage notes payable, net:
Proceeds	288,120
Lump sum payoffs		(725,639)
Scheduled principal repayments	(1,619)	(1,720)
Notes, net:
Proceeds		497,010
Line of credit and commercial paper:
Line of credit proceeds	1,995,000	415,000
Line of credit repayments	(1,995,000)	(415,000)
Commercial paper proceeds	3,985,661	1,107,561
Commercial paper repayments	(4,140,000)	(1,173,000)
Proceeds from (payments on) settlement of derivative instruments		1,638
Proceeds from Employee Share Purchase Plan (ESPP)	1,126	1,681
Proceeds from exercise of options	29,860	1,600
Payment of offering costs		(26)
Contributions – Noncontrolling Interests – Partially Owned Properties		125
Contributions – Noncontrolling Interests – Operating Partnership		1
Distributions:
Common Shares	(199,749)	(185,484)
Preferred Shares		(773)
Noncontrolling Interests – Operating Partnership	(7,256)	(6,666)
Noncontrolling Interests – Partially Owned Properties	(3,968)	(4,220)
Net cash provided by (used for) financing activities	(49,317)	(514,367)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(22,807)	(6,051)
Cash and cash equivalents and restricted deposits, beginning of period	116,313	100,762
Cash and cash equivalents and restricted deposits, end of period	93,506	94,711
Cash and cash equivalents	29,391	44,453
Restricted deposits	64,115	50,258
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	74,777	96,404
Net cash paid for income and other taxes	531	462
Amortization of deferred financing costs:
Other assets	603	603
Mortgage notes payable, net	416	2,084
Notes, net	1,117	992
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	736	897
Notes, net	682	635
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	4,393	4,791
Write-off of pursuit costs:
Investment in real estate, net	1,437	931
Other assets	11
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	364	627
Other liabilities	343	350
Realized/unrealized (gain) loss on derivative instruments:
Other assets	1,337	(9,132)
Notes, net	1,255	(2,289)
Other liabilities	11,828	5,334
Accumulated other comprehensive income	(14,420)	6,087
Investments in unconsolidated entities:
Investments in unconsolidated entities	(5,561)	(2,079)
Other liabilities	(720)	(720)
Debt financing costs:
Other assets	145
Mortgage notes payable, net	(1,632)
Notes, net	(5)	(4,345)
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(438,705)
Other assets	184,116
Lease liabilities	282,791
Other liabilities	$ (28,202)
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment		$ (22,110)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	PREFERRED SHARES	COMMON SHARES, $0.01 PAR VALUE	PAID IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	DISTRIBUTIONS	OPERATING PARTNERSHIP	PARTIALLY OWNED PROPERTIES
Balance, beginning of year at Dec. 31, 2017		$ 37,280	$ 3,680	$ 8,886,586	$ 1,403,530	$ (88,612)
Balance, beginning of year at Dec. 31, 2017								$ 226,691	$ 4,708
COMMON SHARES, $0.01 PAR VALUE
Conversion of OP Units into Common Shares				134
Exercise of share options			1	1,599
Employee Share Purchase Plan (ESPP)				1,681
Share-based employee compensation expense:
Restricted shares			1	2,622
Share options				7,338
ESPP discount				297
Offering costs				(26)
Supplemental Executive Retirement Plan (SERP)				83
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	$ (12,831)			12,831
Adjustment for Noncontrolling Interests ownership in Operating Partnership				(2,839)				2,839
PAID IN CAPITAL
Conversion of OP Units into Common Shares				134
Exercise of share options			1	1,599
Employee Share Purchase Plan (ESPP)				1,681
RETAINED EARNINGS
Net income attributable to controlling interests	211,809				211,809
Common Share distributions					(198,928)
Preferred Share distributions					(773)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	6,087					6,087
Losses reclassified into earnings from other comprehensive income	(4,791)					4,791
DISTRIBUTIONS
Distributions declared per Common Share outstanding							$ 0.54
NONCONTROLLING INTERESTS
Issuance of restricted units to Noncontrolling Interests								1
Conversion of OP Units into Common Shares				134
Equity compensation associated with Noncontrolling Interests								4,803
Net income	220,548
Distributions to Noncontrolling Interests								(7,188)	(4,220)
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	443							(443)
Adjustment for Noncontrolling Interests ownership in Operating Partnership				(2,839)				2,839
Conversion of OP Units held by Noncontrolling Interests into OP Units held by General Partner								(134)
Net income attributable to Noncontrolling Interests	8,059							8,059	680
PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	8,059							8,059	680
Contributions by Noncontrolling Interests									125
Distributions to Noncontrolling Interests								(7,188)	(4,220)
Balance, end of period at Mar. 31, 2018		37,280	3,682	8,910,306	1,415,638	(77,734)
Balance, end of period at Mar. 31, 2018								234,628	1,293
Balance, beginning of year at Dec. 31, 2018	10,173,204	37,280	3,694	8,935,453	1,261,763	(64,986)
Balance, beginning of year at Dec. 31, 2018	226,445							228,738	(2,293)
COMMON SHARES, $0.01 PAR VALUE
Conversion of OP Units into Common Shares			2	4,785
Exercise of share options			7	29,853
Employee Share Purchase Plan (ESPP)				1,126
Share-based employee compensation expense:
Restricted shares			2	4,576
Share options				793
ESPP discount				267
Supplemental Executive Retirement Plan (SERP)				(602)
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	55,021			(55,021)
Adjustment for Noncontrolling Interests ownership in Operating Partnership				4,652				(4,652)
PAID IN CAPITAL
Conversion of OP Units into Common Shares			2	4,785
Exercise of share options			7	29,853
Employee Share Purchase Plan (ESPP)				1,126
RETAINED EARNINGS
Net income attributable to controlling interests	104,539				104,539
Common Share distributions					(210,497)
Preferred Share distributions					(773)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	(14,420)					(14,420)
Losses reclassified into earnings from other comprehensive income	(4,393)					4,393
DISTRIBUTIONS
Distributions declared per Common Share outstanding							$ 0.5675
NONCONTROLLING INTERESTS
Conversion of OP Units into Common Shares			2	4,785
Equity compensation associated with Noncontrolling Interests								7,903
Net income	109,257
Distributions to Noncontrolling Interests								(7,605)	(3,968)
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	(1,565)							1,565
Adjustment for Noncontrolling Interests ownership in Operating Partnership				4,652				(4,652)
Conversion of OP Units held by Noncontrolling Interests into OP Units held by General Partner								(4,787)
Net income attributable to Noncontrolling Interests	3,919							3,919	799
PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	3,919							3,919	799
Distributions to Noncontrolling Interests								(7,605)	(3,968)
Balance, end of period at Mar. 31, 2019	10,046,886	$ 37,280	$ 3,705	$ 8,925,882	$ 1,155,032	$ (75,013)
Balance, end of period at Mar. 31, 2019	$ 219,619							$ 225,081	$ (5,462)

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Statement Of Stockholders Equity [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01

CONSOLIDATED BALANCE SHEETS OF

CONSOLIDATED BALANCE SHEETS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
ASSETS
Land	$ 5,918,994	$ 5,875,803
Depreciable property	20,691,304	20,435,901
Projects under development	135,191	109,409
Land held for development	91,647	89,909
Investment in real estate	26,837,136	26,511,022
Accumulated depreciation	(6,900,496)	(6,696,281)
Investment in real estate, net	19,936,640	19,814,741
Investments in unconsolidated entities	62,853	58,349
Cash and cash equivalents	29,391	47,442
Restricted deposits	64,115	68,871
Right-of-use assets	434,683	0
Other assets	241,129	404,806
Total assets	20,768,811	20,394,209
Liabilities:
Mortgage notes payable, net	2,671,491	2,385,470
Notes, net	5,936,335	5,933,286
Line of credit and commercial paper	344,844	499,183
Accounts payable and accrued expenses	152,831	102,471
Accrued interest payable	74,028	62,622
Lease liabilities	282,237	0
Other liabilities	321,172	358,563
Security deposits	68,335	67,258
Distributions payable	218,471	206,601
Total liabilities	10,069,744	9,615,454
Commitments and contingencies
Partners’ Capital:
Accumulated other comprehensive income (loss)	(75,013)	(64,986)
Noncontrolling Interests – Partially Owned Properties	(5,462)	(2,293)
Total liabilities and equity/capital	20,768,811	20,394,209
ERPOP [Member]
ASSETS
Land	5,918,994	5,875,803
Depreciable property	20,691,304	20,435,901
Projects under development	135,191	109,409
Land held for development	91,647	89,909
Investment in real estate	26,837,136	26,511,022
Accumulated depreciation	(6,900,496)	(6,696,281)
Investment in real estate, net	19,936,640	19,814,741
Investments in unconsolidated entities	62,853	58,349
Cash and cash equivalents	29,391	47,442
Restricted deposits	64,115	68,871
Right-of-use assets	434,683
Other assets	241,129	404,806
Total assets	20,768,811	20,394,209
Liabilities:
Mortgage notes payable, net	2,671,491	2,385,470
Notes, net	5,936,335	5,933,286
Line of credit and commercial paper	344,844	499,183
Accounts payable and accrued expenses	152,831	102,471
Accrued interest payable	74,028	62,622
Lease liabilities	282,237
Other liabilities	321,172	358,563
Security deposits	68,335	67,258
Distributions payable	218,471	206,601
Total liabilities	10,069,744	9,615,454
Commitments and contingencies
Redeemable Limited Partners	432,562	379,106
Partners’ Capital:
Preference Units	37,280	37,280
General Partner	10,084,619	10,200,910
Limited Partners	225,081	228,738
Accumulated other comprehensive income (loss)	(75,013)	(64,986)
Total partners’ capital	10,271,967	10,401,942
Noncontrolling Interests – Partially Owned Properties	(5,462)	(2,293)
Total capital	10,266,505	10,399,649
Total liabilities and equity/capital	$ 20,768,811	$ 20,394,209

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
REVENUES
Rental income	$ 662,302	$ 632,831
Fee and asset management	$ 192	$ 185
Type of Revenue [Extensible List]	us-gaap:ManagementServiceMember	us-gaap:ManagementServiceMember
Total revenues	$ 662,494	$ 633,016
EXPENSES
Property and maintenance	115,070	108,202
Real estate taxes and insurance	91,442	91,914
Property management	26,396	23,444
General and administrative	15,381	16,278
Depreciation	204,215	196,309
Total expenses	452,504	436,147
Net gain (loss) on sales of real estate properties	(21)	142,213
Operating income	209,969	339,082
Interest and other income	581	5,880
Other expenses	(3,275)	(3,441)
Interest:
Expense incurred, net	(94,938)	(116,104)
Amortization of deferred financing costs	(2,136)	(3,679)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of land parcels	110,201	221,738
Income and other tax (expense) benefit	(238)	(213)
Income (loss) from investments in unconsolidated entities	(707)	(977)
Net gain (loss) on sales of land parcels	1
Net income	109,257	220,548
Partially Owned Properties	(799)	(680)
Net income attributable to controlling interests	$ 104,539	$ 211,809
Earnings per Unit – basic:
Net income available to Units	$ 0.28	$ 0.57
Earnings per Unit – diluted:
Net income available to Units	$ 0.28	$ 0.57
Weighted average Units outstanding	385,184	383,018
ERPOP [Member]
REVENUES
Rental income	$ 662,302	$ 632,831
Fee and asset management	$ 192	$ 185
Type of Revenue [Extensible List]	us-gaap:ManagementServiceMember	us-gaap:ManagementServiceMember
Total revenues	$ 662,494	$ 633,016
EXPENSES
Property and maintenance	115,070	108,202
Real estate taxes and insurance	91,442	91,914
Property management	26,396	23,444
General and administrative	15,381	16,278
Depreciation	204,215	196,309
Total expenses	452,504	436,147
Net gain (loss) on sales of real estate properties	(21)	142,213
Operating income	209,969	339,082
Interest and other income	581	5,880
Other expenses	(3,275)	(3,441)
Interest:
Expense incurred, net	(94,938)	(116,104)
Amortization of deferred financing costs	(2,136)	(3,679)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of land parcels	110,201	221,738
Income and other tax (expense) benefit	(238)	(213)
Income (loss) from investments in unconsolidated entities	(707)	(977)
Net gain (loss) on sales of land parcels	1
Net income	109,257	220,548
Partially Owned Properties	(799)	(680)
Net income attributable to controlling interests	108,458	219,868
ALLOCATION OF NET INCOME:
Preference Units	773	773
General Partner	103,766	211,036
Limited Partners	3,919	8,059
Net income available to Units	$ 107,685	$ 219,095
Earnings per Unit – basic:
Net income available to Units	$ 0.28	$ 0.57
Weighted average Units outstanding	382,477	380,663
Earnings per Unit – diluted:
Net income available to Units	$ 0.28	$ 0.57
Weighted average Units outstanding	385,184	383,018

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Comprehensive income:
Net income	$ 109,257	$ 220,548
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	(14,420)	6,087
Losses reclassified into earnings from other comprehensive income	4,393	4,791
Other comprehensive income (loss)	(10,027)	10,878
Comprehensive income	99,230	231,426
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(4,353)	(9,139)
Comprehensive income attributable to controlling interests	94,877	222,287
ERPOP [Member]
Comprehensive income:
Net income	109,257	220,548
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	(14,420)	6,087
Losses reclassified into earnings from other comprehensive income	4,393	4,791
Other comprehensive income (loss)	(10,027)	10,878
Comprehensive income	99,230	231,426
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(799)	(680)
Comprehensive income attributable to controlling interests	$ 98,431	$ 230,746

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 109,257	$ 220,548
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	204,215	196,309
Amortization of deferred financing costs	2,136	3,679
Amortization of above/below market lease intangibles	(18)	1,098
Amortization of discounts and premiums on debt	1,418	1,532
Amortization of deferred settlements on derivative instruments	4,390	4,788
Amortization of right-of-use assets	4,022
Write-off of pursuit costs	1,448	931
(Income) loss from investments in unconsolidated entities	707	977
Distributions from unconsolidated entities – return on capital	693	615
Net (gain) loss on sales of real estate properties	21	(142,213)
Net (gain) loss on sales of land parcels	(1)
Net (gain) loss on debt extinguishment		22,110
Compensation paid with Company Common Shares	9,806	10,278
Changes in assets and liabilities:
(Increase) decrease in other assets	(14,325)	(15,396)
Increase (decrease) in accounts payable and accrued expenses	63,789	48,997
Increase (decrease) in accrued interest payable	11,406	11,718
Increase (decrease) in lease liabilities	(554)
Increase (decrease) in other liabilities	(25,942)	(4,692)
Increase (decrease) in security deposits	1,077	(261)
Net cash provided by operating activities	373,545	361,018
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(258,938)	(54,134)
Investment in real estate – development/other	(45,327)	(40,813)
Capital expenditures to real estate	(34,018)	(36,747)
Non-real estate capital additions	(1,018)	(1,191)
Interest capitalized for real estate under development	(1,202)	(1,688)
Proceeds from disposition of real estate, net		284,670
Investments in unconsolidated entities	(6,281)	(2,799)
Purchase of investment securities and other investments	(251)
Net cash provided by (used for) investing activities	(347,035)	147,298
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(1,492)	(4,345)
Mortgage notes payable, net:
Proceeds	288,120
Lump sum payoffs		(725,639)
Scheduled principal repayments	(1,619)	(1,720)
Notes, net:
Proceeds		497,010
Line of credit and commercial paper:
Line of credit proceeds	1,995,000	415,000
Line of credit repayments	(1,995,000)	(415,000)
Commercial paper proceeds	3,985,661	1,107,561
Commercial paper repayments	(4,140,000)	(1,173,000)
Proceeds from (payments on) settlement of derivative instruments		1,638
Proceeds from Employee Share Purchase Plan (ESPP)	1,126	1,681
Proceeds from exercise of EQR options	29,860	1,600
Payment of offering costs		(26)
Contributions – Noncontrolling Interests – Partially Owned Properties		125
Contributions – Limited Partners		1
Distributions:
OP Units – General Partner	(199,749)	(185,484)
Preference Units		(773)
OP Units – Limited Partners	(7,256)	(6,666)
Noncontrolling Interests – Partially Owned Properties	(3,968)	(4,220)
Net cash provided by (used for) financing activities	(49,317)	(514,367)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(22,807)	(6,051)
Cash and cash equivalents and restricted deposits, beginning of period	116,313	100,762
Cash and cash equivalents and restricted deposits, end of period	93,506	94,711
Cash and cash equivalents	29,391	44,453
Restricted deposits	64,115	50,258
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	74,777	96,404
Net cash paid for income and other taxes	531	462
Amortization of deferred financing costs:
Other assets	603	603
Mortgage notes payable, net	416	2,084
Notes, net	1,117	992
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	736	897
Notes, net	682	635
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	4,393	4,791
Write-off of pursuit costs:
Investment in real estate, net	1,437	931
Other assets	11
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	364	627
Other liabilities	343	350
Realized/unrealized (gain) loss on derivative instruments:
Other assets	1,337	(9,132)
Notes, net	1,255	(2,289)
Other liabilities	11,828	5,334
Accumulated other comprehensive income	(14,420)	6,087
Investments in unconsolidated entities:
Investments in unconsolidated entities	(5,561)	(2,079)
Other liabilities	(720)	(720)
Debt financing costs:
Other assets	145
Mortgage notes payable, net	(1,632)
Notes, net	(5)	(4,345)
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(438,705)
Other assets	184,116
Lease liabilities	282,791
Other liabilities	(28,202)
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment		(22,110)
ERPOP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	109,257	220,548
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	204,215	196,309
Amortization of deferred financing costs	2,136	3,679
Amortization of above/below market lease intangibles	(18)	1,098
Amortization of discounts and premiums on debt	1,418	1,532
Amortization of deferred settlements on derivative instruments	4,390	4,788
Amortization of right-of-use assets	4,022
Write-off of pursuit costs	1,448	931
(Income) loss from investments in unconsolidated entities	707	977
Distributions from unconsolidated entities – return on capital	693	615
Net (gain) loss on sales of real estate properties	21	(142,213)
Net (gain) loss on sales of land parcels	(1)
Net (gain) loss on debt extinguishment		22,110
Compensation paid with Company Common Shares	9,806	10,278
Changes in assets and liabilities:
(Increase) decrease in other assets	(14,325)	(15,396)
Increase (decrease) in accounts payable and accrued expenses	63,789	48,997
Increase (decrease) in accrued interest payable	11,406	11,718
Increase (decrease) in lease liabilities	(554)
Increase (decrease) in other liabilities	(25,942)	(4,692)
Increase (decrease) in security deposits	1,077	(261)
Net cash provided by operating activities	373,545	361,018
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(258,938)	(54,134)
Investment in real estate – development/other	(45,327)	(40,813)
Capital expenditures to real estate	(34,018)	(36,747)
Non-real estate capital additions	(1,018)	(1,191)
Interest capitalized for real estate under development	(1,202)	(1,688)
Proceeds from disposition of real estate, net		284,670
Investments in unconsolidated entities	(6,281)	(2,799)
Purchase of investment securities and other investments	(251)
Net cash provided by (used for) investing activities	(347,035)	147,298
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(1,492)	(4,345)
Mortgage notes payable, net:
Proceeds	288,120
Lump sum payoffs		(725,639)
Scheduled principal repayments	(1,619)	(1,720)
Notes, net:
Proceeds		497,010
Line of credit and commercial paper:
Line of credit proceeds	1,995,000	415,000
Line of credit repayments	(1,995,000)	(415,000)
Commercial paper proceeds	3,985,661	1,107,561
Commercial paper repayments	(4,140,000)	(1,173,000)
Proceeds from (payments on) settlement of derivative instruments		1,638
Proceeds from Employee Share Purchase Plan (ESPP)	1,126	1,681
Proceeds from exercise of EQR options	29,860	1,600
Payment of offering costs		(26)
Contributions – Noncontrolling Interests – Partially Owned Properties		125
Contributions – Limited Partners		1
Distributions:
OP Units – General Partner	(199,749)	(185,484)
Preference Units		(773)
OP Units – Limited Partners	(7,256)	(6,666)
Noncontrolling Interests – Partially Owned Properties	(3,968)	(4,220)
Net cash provided by (used for) financing activities	(49,317)	(514,367)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(22,807)	(6,051)
Cash and cash equivalents and restricted deposits, beginning of period	116,313	100,762
Cash and cash equivalents and restricted deposits, end of period	93,506	94,711
Cash and cash equivalents	29,391	44,453
Restricted deposits	64,115	50,258
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	74,777	96,404
Net cash paid for income and other taxes	531	462
Amortization of deferred financing costs:
Other assets	603	603
Mortgage notes payable, net	416	2,084
Notes, net	1,117	992
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	736	897
Notes, net	682	635
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	4,393	4,791
Write-off of pursuit costs:
Investment in real estate, net	1,437	931
Other assets	11
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	364	627
Other liabilities	343	350
Realized/unrealized (gain) loss on derivative instruments:
Other assets	1,337	(9,132)
Notes, net	1,255	(2,289)
Other liabilities	11,828	5,334
Accumulated other comprehensive income	(14,420)	6,087
Investments in unconsolidated entities:
Investments in unconsolidated entities	(5,561)	(2,079)
Other liabilities	(720)	(720)
Debt financing costs:
Other assets	145
Mortgage notes payable, net	(1,632)
Notes, net	(5)	(4,345)
Right-of-use assets and lease liabilities initial measurement and reclassifications:
Right-of-use assets	(438,705)
Other assets	184,116
Lease liabilities	282,791
Other liabilities	$ (28,202)
ERPOP [Member] | Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment		$ (22,110)

CONSOLIDATED STATEMENTS OF CH_3

CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Total	ERPOP [Member]	PREFERRED SHARESERPOP [Member]	General Partner [Member]	General Partner [Member]ERPOP [Member]	Limited Partner [Member]ERPOP [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)ERPOP [Member]	DISTRIBUTIONS	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					134	(134)
Exercise of EQR share options					1,600
EQR’s Employee Share Purchase Plan (ESPP)				$ 1,681
Share-based employee compensation expense:
EQR restricted shares					2,623
EQR share options					7,338
EQR ESPP discount					297
Net income available to Units – General Partner		$ 211,036			211,036
OP Units General Partner distributions					(198,928)
Offering costs					(26)
Supplemental Executive Retirement Plan (SERP)					83
Change in market value of Redeemable Limited Partners					12,831
Adjustment for Limited Partners ownership in Operating Partnership					(2,839)	2,839
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					134	(134)
Equity compensation associated with Units – Limited Partners						4,803
Net income available to Units – Limited Partners		8,059				8,059
Units – Limited Partners distributions						(7,188)
Change in carrying value of Redeemable Limited Partners						(443)
Adjustment for Limited Partners ownership in Operating Partnership					(2,839)	2,839
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	$ 6,087	6,087					6,087
Losses reclassified into earnings from other comprehensive income	(4,791)	(4,791)					4,791
NONCONTROLLING INTERESTS PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	220,548	220,548							680
Contributions by Noncontrolling Interests									125
Distributions to Noncontrolling Interests									(4,220)
Balance, end of period at Mar. 31, 2018			37,280		10,329,626	234,628	(77,734)
Balance, end of period at Mar. 31, 2018									1,293
DISTRIBUTIONS
Distributions declared per Unit outstanding								$ 0.54
Balance, beginning of year at Dec. 31, 2018			37,280		10,200,910	228,738	(64,986)
Balance, beginning of year at Dec. 31, 2018									(2,293)
OP Unit Issuance:
Conversion of OP Units held by Limited Partners into OP Units held by General Partner					4,787	(4,787)
Exercise of EQR share options					29,860
EQR’s Employee Share Purchase Plan (ESPP)				$ 1,126
Share-based employee compensation expense:
EQR restricted shares					4,578
EQR share options					793
EQR ESPP discount					267
Net income available to Units – General Partner		103,766			103,766
OP Units General Partner distributions					(210,497)
Supplemental Executive Retirement Plan (SERP)					(602)
Change in market value of Redeemable Limited Partners					(55,021)
Adjustment for Limited Partners ownership in Operating Partnership					4,652	(4,652)
LIMITED PARTNERS
Conversion of OP Units held by Limited Partners into OP Units held by General Partner					4,787	(4,787)
Equity compensation associated with Units – Limited Partners						7,903
Net income available to Units – Limited Partners		3,919				3,919
Units – Limited Partners distributions						(7,605)
Change in carrying value of Redeemable Limited Partners						1,565
Adjustment for Limited Partners ownership in Operating Partnership					4,652	(4,652)
Accumulated other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	(14,420)	(14,420)					(14,420)
Losses reclassified into earnings from other comprehensive income	(4,393)	(4,393)					4,393
NONCONTROLLING INTERESTS PARTIALLY OWNED PROPERTIES
Net income attributable to Noncontrolling Interests	$ 109,257	$ 109,257							799
Distributions to Noncontrolling Interests									(3,968)
Balance, end of period at Mar. 31, 2019			$ 37,280		$ 10,084,619	$ 225,081	$ (75,013)
Balance, end of period at Mar. 31, 2019									$ (5,462)
DISTRIBUTIONS
Distributions declared per Unit outstanding								$ 0.5675

Business

Business	3 Months Ended
	Mar. 31, 2019
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, a business that 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 March 31, 2019 owned an approximate 96.4% 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 March 31, 2019, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 310 properties located in 11 states and the District of Columbia consisting of 80,061 apartment units. The ownership breakdown includes (table does not include various uncompleted development properties): Properties Apartment Units Wholly Owned Properties 290 75,419 Master-Leased Properties – Consolidated 1 162 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 310 80,061

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
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 quarter ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. 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, 2018 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, 2018. 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 may incur both federal and state income taxes on any taxable income of such entities after consideration of any net operating losses. In December 2017, H.R. 1, informally titled the Tax Cuts and Jobs Act (the “Tax Act”), became law. As of March 31, 2019, the Tax Act did not 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. Recently Issued Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“ FASB”) 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 included in the Company’s and the Operating Partnership’s Annual Report on Form 10-K for the year ended December 31, 2018 and are comparable with the percentage of rental income for the quarter ended March 31, 2019. 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. Additionally, as part of the new revenue recognition standard, the FASB issued amendments related to partial sales of real estate. 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 • Lessors – Leases are 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 are 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 are 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 determines 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 are accounted for similar to existing guidance for operating leases. The Company adopted this new standard as required effective January 1, 2019 using a modified retrospective method and the Company applied the new guidance as of the adoption date and elected certain practical expedients, as described below. The standard impacted our consolidated balance sheets but did not impact our consolidated statements of operations. Right-of-use (“ROU”) assets and lease liabilities where the Company is the lessee were recognized for various corporate office leases and ground leases. The Company recorded ROU assets and related lease liabilities to its opening balance sheet upon adoption on January 1, 2019 of $434.2 million and $278.3 million, respectively. The Company calculated the net present value of the lease liabilities on January 1, 2019 and reclassed the following amounts from other assets and other liabilities to record our initial ROU assets (amounts in thousands): January 1, 2019 Balance Sheet Reclass: Initial lease liabilities $ 278,287 Reclassifications: Prepaid ground leases 17,886 Other Assets Ground lease intangibles – below market, net 166,230 Other Assets Ground lease intangibles – above market, net (2,110 ) Other Liabilities Straight-line rent liabilities (1) (26,092 ) Other Liabilities Initial right-of-use assets $ 434,201 (1) Straight-line rent liabilities relate to corporate office leases and certain ground leases. 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 elected the practical expedient to account for both its lease and non-lease components as a single component under the leases standard and elected the new transition option as of the date of adoption effective January 1, 2019. See Note 8 for additional discussion regarding the new lease standard. 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 Company adopted this new standard as required effective January 1, 2019 and it did not have a material effect on its consolidated results of operations or financial position.

Equity, Capital and Other Inter

Equity, Capital and Other Interests	3 Months Ended
	Mar. 31, 2019
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 quarters ended March 31, 2019 and 2018: 2019 2018 Common Shares Common Shares outstanding at January 1, 369,405,161 368,018,082 Common Shares Issued: Conversion of OP Units 184,878 5,000 Exercise of share options 709,071 45,391 Employee Share Purchase Plan (ESPP) 18,901 35,177 Restricted share grants, net 144,390 108,261 Common Shares outstanding at March 31, 370,462,401 368,211,911 Units Units outstanding at January 1, 13,904,035 13,768,438 Restricted unit grants, net 133,214 263,048 Conversion of OP Units to Common Shares (184,878 ) (5,000 ) Units outstanding at March 31, 13,852,371 14,026,486 Total Common Shares and Units outstanding at March 31, 384,314,772 382,238,397 Units Ownership Interest in Operating Partnership 3.6 % 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 March 31, 2019 and December 31, 2018. The The 2019 2018 Balance at January 1, $ 379,106 $ 366,955 Change in market value 55,021 (12,831 ) Change in carrying value (1,565 ) 443 Balance at March 31, $ 432,562 $ 354,567 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 March 31, December 31, Date (1) Share (2) 2019 2018 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 March 31, 2019 and December 31, 2018 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 quarters ended March 31, 2019 and 2018: 2019 2018 General and Limited Partner Units General and Limited Partner Units outstanding at January 1, 383,309,196 381,786,520 Issued to General Partner: Exercise of EQR share options 709,071 45,391 EQR’s Employee Share Purchase Plan (ESPP) 18,901 35,177 EQR’s restricted share grants, net 144,390 108,261 Issued to Limited Partners: Restricted unit grants, net 133,214 263,048 General and Limited Partner Units outstanding at March 31, 384,314,772 382,238,397 Limited Partner Units Limited Partner Units outstanding at January 1, 13,904,035 13,768,438 Limited Partner restricted unit grants, net 133,214 263,048 Conversion of Limited Partner OP Units to EQR Common Shares (184,878 ) (5,000 ) Limited Partner Units outstanding at March 31, 13,852,371 14,026,486 Limited Partner Units Ownership Interest in Operating Partnership 3.6 % 3.7 % The Limited Partners of the Operating Partnership as of March 31, 2019 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 March 31, 2019 . 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 quarters ended March 31, 2019 and 2018 (amounts in thousands): 2019 2018 Balance at January 1, $ 379,106 $ 366,955 Change in market value 55,021 (12,831 ) Change in carrying value (1,565 ) 443 Balance at March 31, $ 432,562 $ 354,567 EQR contributes all net proceeds from its various equity offerings (including proceeds from exercise of options for Common ERPOP. The December 31, 2018 Amounts in thousands Annual Call Dividend Per March 31, December 31, Date (1) Unit (2) 2019 2018 Preference Units: 8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 745,600 units issued and outstanding as of March 31, 2019 and December 31, 2018 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 The Company has an At-The-Market (“ATM”) The Company may repurchase up to 13.0 million Common Shares under its share repurchase program. No open market repurchases have occurred since 2008 and no repurchases of any kind have occurred since February 2014. As of March 31, 2019, EQR has remaining authorization to repurchase up to 13.0 million of its shares under the repurchase program.

Real Estate

Real Estate	3 Months Ended
	Mar. 31, 2019
Real Estate [Abstract]
Real Estate	4. Real Estate The following table summarizes the carrying amounts for the Company’s investment in real estate (at cost) as of March 31, 2019 and December 31, 2018 (amounts in thousands): March 31, 2019 December 31, 2018 Land $ 5,918,994 $ 5,875,803 Depreciable property: Buildings and improvements 18,440,716 18,232,625 Furniture, fixtures and equipment 1,761,906 1,722,231 In-Place lease intangibles 488,682 481,045 Projects under development: Land 25,430 25,429 Construction-in-progress 109,761 83,980 Land held for development: Land 61,038 61,038 Construction-in-progress 30,609 28,871 Investment in real estate 26,837,136 26,511,022 Accumulated depreciation (6,900,496 ) (6,696,281 ) Investment in real estate, net $ 19,936,640 $ 19,814,741 During the quarter ended March 31, 2019, 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) 3 579 $ 258,650 Total 3 579 $ 258,650 (1) Purchase price includes an allocation of approximately $43.2 million to land and $215.7 million to depreciable property (inclusive of capitalized closing costs).

Commitments to Acquire_Dispose

Commitments to Acquire/Dispose of Real Estate	3 Months Ended
	Mar. 31, 2019
Commitments To Acquire Dispose Of Real Estate [Abstract]
Commitments to Acquire/Dispose of Real Estate	5. Commitments to Acquire/Dispose of Real The Company has entered into a separate agreement to acquire the following (purchase price in thousands): Properties Apartment Units Purchase Price Land Parcels (one) — — $ 28,000 Total — — $ 28,000 The Company has entered into separate agreements to dispose of the following (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 2 593 $ 282,250 Rental Properties – Unconsolidated (1) 1 444 255,500 Land Parcels (one) — — 1,900 Total 3 1,037 $ 539,650 (1) The Company has a 20.0% ownership in this property. See Notes 6 and 12 for additional discussion regarding unconsolidated properties.

Investments in Partially Owned

Investments in Partially Owned Entities	3 Months Ended
	Mar. 31, 2019
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 $694.7 million and $316.1 million, respectively, at March 31, 2019 and approximately $713.6 million and $313.9 million, respectively, at December 31, 2018. 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 March 31, 2019 and December 31, 2018 (amounts in thousands except for ownership percentage): March 31, 2019 December 31, 2018 Ownership Percentage Investments in Unconsolidated Entities: Wisconsin Place Developer (VIE) (1) $ 41,828 $ 42,365 33.3% Operating Properties (Non-VIE) (2) 10,207 10,494 20.0% Other 10,818 5,490 Varies Investments in Unconsolidated Entities $ 62,853 $ 58,349 (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	3 Months Ended
	Mar. 31, 2019
Deposits Restricted [Abstract]
Restricted Deposits	7. Restricted Deposits The following table presents the Company’s restricted deposits as of March 31, 2019 and December 31, 2018 (amounts in thousands): March 31, 2019 December 31, 2018 Mortgage escrow deposits: Real estate taxes and insurance $ 1,311 $ 876 Replacement reserves 9,023 8,641 Mortgage principal reserves/sinking funds 11,514 9,754 Other 852 852 Mortgage escrow deposits 22,700 20,123 Restricted cash: Earnest money on pending acquisitions 3,125 5,000 Restricted deposits on real estate investments 534 540 Resident security and utility deposits 36,213 35,659 Other 1,543 7,549 Restricted cash 41,415 48,748 Restricted deposits $ 64,115 $ 68,871

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	8 . Leases Lessor Accounting The Company is the lessor for its residential and retail leases (including commercial leases) and these leases will continue to be accounted for as operating leases under the new standard as described in Note 2. Therefore, the Company did not have significant changes in the accounting for its lease revenues. As of March 31, 2019, approximately 97.0% of the Company’s total lease revenue is generated from residential apartment leases that are generally for twelve months or less in length. The residential apartment leases may include lease income related to such items as parking, storage and pet rent that the Company treats as a single lease component because the amenities cannot be leased on their own and the timing and pattern of revenue recognition are the same. The collection of lease payments at lease commencement is probable and therefore the Company subsequently recognizes lease income over the lease term on a straight-line basis. Residential leases are renewable upon consent of both parties on an annual or monthly basis. As of March 31, 2019, approximately 3.0% of the Company’s total lease revenue is generated by retail leases that are generally for terms ranging between 5-10 years. The retail leases generally consist of ground floor retail spaces and master-leased parking garages that serve as additional amenities for our residents. The retail leases may include lease income related to such items as parking and storage rent that the Company treats as a single lease component because the amenities cannot be leased on their own and the timing and pattern of revenue recognition are the same. The collection of lease payments at lease commencement is probable and therefore the Company subsequently recognizes lease income over the lease term on a straight-line basis. Retail leases are renewable with market-based renewal options. The Company elected the practical expedient to account for both its lease and non-lease components (specifically common area maintenance charges) as a single lease component under the leases standard. The following table presents the lease income types relating to lease payments for residential and retail leases for the quarter ended March 31, 2019 (amounts in thousands): Quarter Ended March 31, 2019 Lease Income Type Residential Leases Retail Leases Total Residential and retail rent $ 592,520 $ 18,470 $ 610,990 Parking rent 9,137 72 9,209 Storage rent 919 44 963 Pet rent 2,887 — 2,887 Total lease revenue (1) $ 605,463 $ 18,586 $ 624,049 (1) Excludes other rental income of $38.3 million, which is accounted for under the revenue recognition standard. Lessee Accounting The Company is the lessee under various corporate office and ground leases for which the Company recognized ROU assets and related lease liabilities effective January 1, 2019. The following table presents the Company’s ROU assets and related lease liabilities as of March 31, 2019 (amounts in thousands): 2019 Right-of-use assets: Corporate office leases (1) $ 16,024 Ground leases 418,659 Right-of-use assets $ 434,683 Lease liabilities: Corporate office leases (1) $ 17,585 Ground leases 264,652 Lease liabilities $ 282,237 (1) The Company has two corporate office leases that are considered short-term and therefore, there is no balance sheet impact and both leases continue to be expensed on a straight-line basis throughout the year. As the standard requires the recognition of a liability for the lease obligation, discount rates are used to determine the net present value of the lease payments. The discount rate for the lease is the rate implicit in the lease or, if that rate cannot be readily determined, the incremental borrowing rate. As the Company does not know the amount of the lessors’ initial direct costs, it cannot readily determine the rate implicit in the lease and instead must apply the incremental borrowing rate. The Company has estimated the discount rate ranges of 3.3% to 3.9% for corporate office leases and 4.4% to 5.5% for ground leases. Since the Company’s credit backs the corporate office lease obligations and the lease terms are ten years or less, the discount rate range was estimated by using the Company’s borrowing rates for actual pricing. The discount range for ground leases takes into account various factors, including the longer life of the ground leases, and was estimated by using the Company’s borrowing rates for actual pricing through 30 years and other long-term market rates. Corporate office leases The Company leases nine corporate offices with remaining lease terms of one to ten years. The Company’s corporate office leases continue to be accounted for as operating leases under the new standard. When there is a material lease modification, the Company is required to remeasure the lease liability. The Company leases its corporate headquarters from an entity controlled by EQR’s Chairman of the Board of Trustees. The lease terminates on January 31, 2022. The amount incurred for such office space for the quarter ended March 31, 2019 was approximately $0.6 million. The Company believes this amount approximates market rates for such rental space. Ground leases The Company maintains long-term ground leases for 14 operating properties with lease expiration dates ranging from 2042 through 2113. The Company owns the building and improvements. Based on its election of the package of practical expedients, the Company was not required to reassess the classification of existing ground leases and therefore these leases continue to be accounted for as operating leases. However, in the event we materially modify existing ground leases and/or enter into new ground leases, such leases will likely be classified as finance leases. Additional disclosures The following table illustrates the quantitative disclosures for lessees as of and for the quarter ended March 31, 2019 (amounts in thousands): 2019 Lease cost: Operating lease cost: Corporate office leases $ 918 Ground leases 5,550 Short-term lease cost: Corporate office leases 56 Ground leases — Variable lease cost: Corporate office leases 261 Ground leases 851 Total lease cost $ 7,636 Other information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases: Corporate office leases $ 1,248 Ground leases $ 4,493 ROU assets obtained in exchange for new operating lease liabilities: Corporate office leases $ 16,687 Ground leases $ 422,018 Weighted-average remaining lease term – operating leases: Corporate office leases 6.5 years Ground leases 56.8 years Weighted-average discount rate – operating leases: Corporate office leases 3.7 % Ground leases 5.0 % The following table summarizes the Company’s undiscounted cash flows for contractual obligations for minimum rent payments/receipts under operating leases for the next five years and thereafter as of March 31, 2019: (Payments)/Receipts Due by Year (in thousands) Remaining 2019 2020 2021 2022 2023 2024 Thereafter Total Operating Leases: Minimum Rent Payments (a) $ (12,607 ) $ (17,208 ) $ (17,148 ) $ (14,993 ) $ (14,843 ) $ (15,101 ) $ (938,561 ) $ (1,030,461 ) Minimum Rent Receipts (b) $ 49,268 $ 62,481 $ 58,439 $ 54,378 $ 46,987 $ 39,364 $ 135,548 $ 446,465 (a) Minimum basic rent due for corporate office leases and base rent due on ground leases where the Company is the lessee. (b) Minimum basic rent receipts due for various retail space where the Company is the lessor. Excludes residential leases due to their short-term nature. The following table provides a reconciliation of lease liabilities from our undiscounted cash flows for minimum rent payments for the quarter ended March 31, 2019 (amount in thousands): 2019 Total minimum rent payments $ 1,030,461 Less: Lease discount (748,224 ) Lease liabilities $ 282,237

Debt

Debt	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt	9 . Debt EQR Mortgage Notes Payable As of March 31, 2019, the Company had outstanding mortgage debt of approximately $2.7 billion. During the quarter ended March 31, 2019, the Company obtained $288.1 million in 3.94% fixed rate mortgage debt held in a Fannie Mae loan pool maturing on March 1, 2029. As of March 31, 2019, the Company had $440.6 million of secured debt (primarily tax-exempt bonds) subject to third party credit enhancement. As Notes As of March 31, 2019, the Company had outstanding unsecured notes of approximately $5.9 billion. As March 31, 2019 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 quarter ended March 31, 2019. 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 ). Both the spread and the facility fee are dependent on the Company’s senior unsecured credit rating. In As t Other In 2017, the Company executed a letter of credit facility with a third party financial institution which is not backed or collateralized by borrowings on the Company’s unsecured revolving credit facility. As of March 31, 2019

Derivative and Other Fair Value

Derivative and Other Fair Value Instruments	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Derivative and Other Fair Value Instruments	10 . 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 applied internally by the Company that use as their inputs 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 March 31, 2019 December 31, 2018 Carrying Value Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Mortgage notes payable, net $ 2,671,491 $ 2,646,252 $ 2,385,470 $ 2,352,502 Unsecured debt, net 6,281,179 6,533,696 6,432,469 6,481,426 Total debt, net $ 8,952,670 $ 9,179,948 $ 8,817,939 $ 8,833,928 The March 31, 2019 Fair Value Hedges (1) Forward Starting Swaps (2) Current Notional Balance $ 450,000 $ 500,000 Lowest Interest Rate 2.375 % 2.2665 % Highest Interest Rate 2.375 % 3.1163 % 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. 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 3/31/2019 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 $ 665 $ — $ 665 $ — Supplemental Executive Retirement Plan Other Assets 142,075 142,075 — — Total $ 142,740 $ 142,075 $ 665 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 1,022 $ — $ 1,022 $ — Forward Starting Swaps Other Liabilities 22,936 — 22,936 — Supplemental Executive Retirement Plan Other Liabilities 142,075 142,075 — — Total $ 166,033 $ 142,075 $ 23,958 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 432,562 $ — $ 432,562 $ — Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 12/31/2018 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 $ 2,000 $ — $ 2,000 $ — Supplemental Executive Retirement Plan Other Assets 134,088 134,088 — — Total $ 136,088 $ 134,088 $ 2,000 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 2,277 $ — $ 2,277 $ — Forward Starting Swaps Other Liabilities 9,851 — 9,851 — Supplemental Executive Retirement Plan Other Liabilities 134,088 134,088 — — Total $ 146,216 $ 134,088 $ 12,128 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 379,106 $ — $ 379,106 $ — The March 31, 2019 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 $ 1,255 Fixed rate debt Interest expense $ (1,255 ) Total $ 1,255 $ (1,255 ) March 31, 2018 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (2,289 ) Fixed rate debt Interest expense $ 2,289 Total $ (2,289 ) $ 2,289 The Effective Portion March 31, 2019 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 Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ (14,420 ) Interest expense $ (4,393 ) Total $ (14,420 ) $ (4,393 ) Effective Portion Ineffective Portion March 31, 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 $ 6,087 Interest expense $ (4,791 ) N/A $ — Total $ 6,087 $ (4,791 ) $ — As December 31, 2018 1, 2019

Earnings Per Share and Earnings

Earnings Per Share and Earnings Per Unit	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share And Earnings Per Unit	1 1 . Earnings Per Share and Earnings Per Equity Residential The Quarter Ended March 31, 2019 2018 Numerator for net income per share – basic: Net income $ 109,257 $ 220,548 Allocation to Noncontrolling Interests – Operating Partnership (3,919 ) (8,059 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (799 ) (680 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – basic $ 103,766 $ 211,036 Numerator for net income per share – diluted: Net income $ 109,257 $ 220,548 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (799 ) (680 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – diluted $ 107,685 $ 219,095 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 369,558 367,800 Effect of dilutive securities: OP Units 12,919 12,863 Long-term compensation shares/units 2,707 2,355 Denominator for net income per share – diluted 385,184 383,018 Net income per share – basic $ 0.28 $ 0.57 Net income per share – diluted $ 0.28 $ 0.57 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): Quarter Ended March 31, 2019 2018 Numerator for net income per Unit – basic and diluted: Net income $ 109,257 $ 220,548 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (799 ) (680 ) Allocation to Preference Units (773 ) (773 ) Numerator for net income per Unit – basic and diluted $ 107,685 $ 219,095 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 382,477 380,663 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,707 2,355 Denominator for net income per Unit – diluted 385,184 383,018 Net income per Unit – basic $ 0.28 $ 0.57 Net income per Unit – diluted $ 0.28 $ 0.57

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 2 . 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 March 31, 2019, the Company does have environmental reserves totaling approximately $4.3 million related to three of its properties. 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 March 31, 2019, the Company has three wholly owned projects totaling 691 apartment units in various stages of development with remaining commitments to fund of approximately $388.4 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	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Reportable Segments	1 3 . 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 three Denver properties owned by the Company 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 Quarter Ended March 31, 2019 2018 Rental income $ 662,302 $ 632,831 Property and maintenance expense (115,070 ) (108,202 ) Real estate taxes and insurance expense (91,442 ) (91,914 ) Total operating expenses (206,512 ) (200,116 ) Net operating income $ 455,790 $ 432,715 The following tables present NOI for each segment from our rental real estate for the quarters ended March 31, 2019 and 2018, Quarter Ended March 31, 2019 Quarter Ended March 31, 2018 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 115,399 $ 34,484 $ 80,915 $ 110,996 $ 32,041 $ 78,955 Orange County 25,828 6,205 19,623 24,803 6,091 18,712 San Diego 23,304 6,127 17,177 22,492 5,964 16,528 Subtotal - Southern California 164,531 46,816 117,715 158,291 44,096 114,195 San Francisco 121,761 30,417 91,344 117,352 29,410 87,942 Washington D.C. 110,784 34,674 76,110 108,528 33,910 74,618 New York 116,064 49,089 66,975 113,328 45,549 67,779 Boston 58,320 16,611 41,709 56,294 16,199 40,095 Seattle 50,621 13,531 37,090 49,516 13,853 35,663 Other Markets 522 185 337 488 164 324 Total same store 622,603 191,323 431,280 603,797 183,181 420,616 Non-same store/other (2) (3) Non-same store 39,409 13,293 26,116 17,396 7,105 10,291 Other (3) 290 1,896 (1,606 ) 11,638 9,830 1,808 Total non-same store/other 39,699 15,189 24,510 29,034 16,935 12,099 Totals $ 662,302 $ 206,512 $ 455,790 $ 632,831 $ 200,116 $ 432,715 (1) For the quarters ended March 31, 2019 and 2018, same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2018, less properties subsequently sold, which represented 74,166 apartment (2) For the quarters ended March 31, 2019 and 2018, non-same store primarily includes properties acquired after January 1, 2018, 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 March 31, 2019 Total Assets Capital Expenditures Same store (1) Los Angeles $ 3,049,292 $ 7,061 Orange County 415,698 1,833 San Diego 401,881 630 Subtotal - Southern California 3,866,871 9,524 San Francisco 3,400,898 6,039 Washington D.C. 3,749,155 3,683 New York 4,144,468 3,754 Boston 1,581,121 5,981 Seattle 1,322,060 2,773 Other Markets 12,852 44 Total same store 18,077,425 31,798 Non-same store/other (2) (3) Non-same store 2,192,615 2,220 Other (3) 498,771 — Total non-same store/other 2,691,386 2,220 Totals $ 20,768,811 $ 34,018 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2018, less properties subsequently sold, which represented 74,166 apartment (2) Non-same store primarily includes properties acquired after January 1, 2018, 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	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	1 4 . Subsequent to March 31, 2019, the Company: • Acquired one property consisting of 366 apartment units for $103.5 million; • Sold one wholly-owned property consisting of 266 apartment units for $237.5 million; and • Repaid $95.5 million of tax-exempt mortgage bonds maturing in 2036 in conjunction with the sale of the wholly owned property noted above.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
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 quarter ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. 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, 2018 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, 2018.
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 may incur both federal and state income taxes on any taxable income of such entities after consideration of any net operating losses. In December 2017, H.R. 1, informally titled the Tax Cuts and Jobs Act (the “Tax Act”), became law. As of March 31, 2019, the Tax Act did not 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.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“ FASB”) 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 included in the Company’s and the Operating Partnership’s Annual Report on Form 10-K for the year ended December 31, 2018 and are comparable with the percentage of rental income for the quarter ended March 31, 2019. 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. Additionally, as part of the new revenue recognition standard, the FASB issued amendments related to partial sales of real estate. 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 • Lessors – Leases are 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 are 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 are 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 determines 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 are accounted for similar to existing guidance for operating leases.

Business (Tables)

Business (Tables)	3 Months Ended
	Mar. 31, 2019
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 290 75,419 Master-Leased Properties – Consolidated 1 162 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 310 80,061

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
Summary Of Significant Accounting Policies [Abstract]
Schedule of Reclassification's to Initial Right-of-use Assets	The Company calculated the net present value of the lease liabilities on January 1, 2019 and reclassed the following amounts from other assets and other liabilities to record our initial ROU assets (amounts in thousands): January 1, 2019 Balance Sheet Reclass: Initial lease liabilities $ 278,287 Reclassifications: Prepaid ground leases 17,886 Other Assets Ground lease intangibles – below market, net 166,230 Other Assets Ground lease intangibles – above market, net (2,110 ) Other Liabilities Straight-line rent liabilities (1) (26,092 ) Other Liabilities Initial right-of-use assets $ 434,201 (1) Straight-line rent liabilities relate to corporate office leases and certain ground leases.

Equity, Capital and Other Int_2

Equity, Capital and Other Interests (Tables)	3 Months Ended
	Mar. 31, 2019
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 quarters ended March 31, 2019 and 2018: 2019 2018 Common Shares Common Shares outstanding at January 1, 369,405,161 368,018,082 Common Shares Issued: Conversion of OP Units 184,878 5,000 Exercise of share options 709,071 45,391 Employee Share Purchase Plan (ESPP) 18,901 35,177 Restricted share grants, net 144,390 108,261 Common Shares outstanding at March 31, 370,462,401 368,211,911 Units Units outstanding at January 1, 13,904,035 13,768,438 Restricted unit grants, net 133,214 263,048 Conversion of OP Units to Common Shares (184,878 ) (5,000 ) Units outstanding at March 31, 13,852,371 14,026,486 Total Common Shares and Units outstanding at March 31, 384,314,772 382,238,397 Units Ownership Interest in Operating Partnership 3.6 % 3.7 %
Changes in Redemption Value of Redeemable Noncontrolling Interests and Limited Partners Interest	The 2019 2018 Balance at January 1, $ 379,106 $ 366,955 Change in market value 55,021 (12,831 ) Change in carrying value (1,565 ) 443 Balance at March 31, $ 432,562 $ 354,567
Issued and Outstanding Preferred Shares and Preference Units	The Amounts in thousands Annual Call Dividend Per March 31, December 31, Date (1) Share (2) 2019 2018 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 March 31, 2019 and December 31, 2018 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 quarters ended March 31, 2019 and 2018: 2019 2018 General and Limited Partner Units General and Limited Partner Units outstanding at January 1, 383,309,196 381,786,520 Issued to General Partner: Exercise of EQR share options 709,071 45,391 EQR’s Employee Share Purchase Plan (ESPP) 18,901 35,177 EQR’s restricted share grants, net 144,390 108,261 Issued to Limited Partners: Restricted unit grants, net 133,214 263,048 General and Limited Partner Units outstanding at March 31, 384,314,772 382,238,397 Limited Partner Units Limited Partner Units outstanding at January 1, 13,904,035 13,768,438 Limited Partner restricted unit grants, net 133,214 263,048 Conversion of Limited Partner OP Units to EQR Common Shares (184,878 ) (5,000 ) Limited Partner Units outstanding at March 31, 13,852,371 14,026,486 Limited Partner Units Ownership Interest in Operating Partnership 3.6 % 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 quarters ended March 31, 2019 and 2018 (amounts in thousands): 2019 2018 Balance at January 1, $ 379,106 $ 366,955 Change in market value 55,021 (12,831 ) Change in carrying value (1,565 ) 443 Balance at March 31, $ 432,562 $ 354,567
Issued and Outstanding Preferred Shares and Preference Units	The December 31, 2018 Amounts in thousands Annual Call Dividend Per March 31, December 31, Date (1) Unit (2) 2019 2018 Preference Units: 8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 745,600 units issued and outstanding as of March 31, 2019 and December 31, 2018 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 (Tables)

Real Estate (Tables)	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 and December 31, 2018 (amounts in thousands): March 31, 2019 December 31, 2018 Land $ 5,918,994 $ 5,875,803 Depreciable property: Buildings and improvements 18,440,716 18,232,625 Furniture, fixtures and equipment 1,761,906 1,722,231 In-Place lease intangibles 488,682 481,045 Projects under development: Land 25,430 25,429 Construction-in-progress 109,761 83,980 Land held for development: Land 61,038 61,038 Construction-in-progress 30,609 28,871 Investment in real estate 26,837,136 26,511,022 Accumulated depreciation (6,900,496 ) (6,696,281 ) Investment in real estate, net $ 19,936,640 $ 19,814,741
Acquired Properties From Unaffiliated Parties	During the quarter ended March 31, 2019, 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) 3 579 $ 258,650 Total 3 579 $ 258,650 (1) Purchase price includes an allocation of approximately $43.2 million to land and $215.7 million to depreciable property (inclusive of capitalized closing costs).

Commitments to Acquire_Dispos_2

Commitments to Acquire/Dispose of Real Estate (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments To Acquire Dispose Of Real Estate [Abstract]
Separate Agreement to Acquire	The Company has entered into a separate agreement to acquire the following (purchase price in thousands): Properties Apartment Units Purchase Price Land Parcels (one) — — $ 28,000 Total — — $ 28,000
Separate Agreements to Dispose	The Company has entered into separate agreements to dispose of the following (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 2 593 $ 282,250 Rental Properties – Unconsolidated (1) 1 444 255,500 Land Parcels (one) — — 1,900 Total 3 1,037 $ 539,650 (1) The Company has a 20.0% ownership in this property. See Notes 6 and 12 for additional discussion regarding unconsolidated properties.

Investments in Partially Owne_2

Investments in Partially Owned Entities (Tables)	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 and December 31, 2018 (amounts in thousands except for ownership percentage): March 31, 2019 December 31, 2018 Ownership Percentage Investments in Unconsolidated Entities: Wisconsin Place Developer (VIE) (1) $ 41,828 $ 42,365 33.3% Operating Properties (Non-VIE) (2) 10,207 10,494 20.0% Other 10,818 5,490 Varies Investments in Unconsolidated Entities $ 62,853 $ 58,349 (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)	3 Months Ended
	Mar. 31, 2019
Deposits Restricted [Abstract]
Restricted Deposits	The following table presents the Company’s restricted deposits as of March 31, 2019 and December 31, 2018 (amounts in thousands): March 31, 2019 December 31, 2018 Mortgage escrow deposits: Real estate taxes and insurance $ 1,311 $ 876 Replacement reserves 9,023 8,641 Mortgage principal reserves/sinking funds 11,514 9,754 Other 852 852 Mortgage escrow deposits 22,700 20,123 Restricted cash: Earnest money on pending acquisitions 3,125 5,000 Restricted deposits on real estate investments 534 540 Resident security and utility deposits 36,213 35,659 Other 1,543 7,549 Restricted cash 41,415 48,748 Restricted deposits $ 64,115 $ 68,871

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Summary of Lease Income Types Relating to Lease Payments	The following table presents the lease income types relating to lease payments for residential and retail leases for the quarter ended March 31, 2019 (amounts in thousands): Quarter Ended March 31, 2019 Lease Income Type Residential Leases Retail Leases Total Residential and retail rent $ 592,520 $ 18,470 $ 610,990 Parking rent 9,137 72 9,209 Storage rent 919 44 963 Pet rent 2,887 — 2,887 Total lease revenue (1) $ 605,463 $ 18,586 $ 624,049 (1) Excludes other rental income of $38.3 million, which is accounted for under the revenue recognition standard.
Summary of Right-of-Use Assets and Related Lease Liabilities	The following table presents the Company’s ROU assets and related lease liabilities as of March 31, 2019 (amounts in thousands): 2019 Right-of-use assets: Corporate office leases (1) $ 16,024 Ground leases 418,659 Right-of-use assets $ 434,683 Lease liabilities: Corporate office leases (1) $ 17,585 Ground leases 264,652 Lease liabilities $ 282,237 (1) The Company has two corporate office leases that are considered short-term and therefore, there is no balance sheet impact and both leases continue to be expensed on a straight-line basis throughout the year.
Summary of Quantitative Disclosures for Lessees	The following table illustrates the quantitative disclosures for lessees as of and for the quarter ended March 31, 2019 (amounts in thousands): 2019 Lease cost: Operating lease cost: Corporate office leases $ 918 Ground leases 5,550 Short-term lease cost: Corporate office leases 56 Ground leases — Variable lease cost: Corporate office leases 261 Ground leases 851 Total lease cost $ 7,636 Other information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases: Corporate office leases $ 1,248 Ground leases $ 4,493 ROU assets obtained in exchange for new operating lease liabilities: Corporate office leases $ 16,687 Ground leases $ 422,018 Weighted-average remaining lease term – operating leases: Corporate office leases 6.5 years Ground leases 56.8 years Weighted-average discount rate – operating leases: Corporate office leases 3.7 % Ground leases 5.0 %
Summary of Undiscounted Cash Flows for Contractual Obligations for Minimum Rent Payments/Receipts	The following table summarizes the Company’s undiscounted cash flows for contractual obligations for minimum rent payments/receipts under operating leases for the next five years and thereafter as of March 31, 2019: (Payments)/Receipts Due by Year (in thousands) Remaining 2019 2020 2021 2022 2023 2024 Thereafter Total Operating Leases: Minimum Rent Payments (a) $ (12,607 ) $ (17,208 ) $ (17,148 ) $ (14,993 ) $ (14,843 ) $ (15,101 ) $ (938,561 ) $ (1,030,461 ) Minimum Rent Receipts (b) $ 49,268 $ 62,481 $ 58,439 $ 54,378 $ 46,987 $ 39,364 $ 135,548 $ 446,465 (a) Minimum basic rent due for corporate office leases and base rent due on ground leases where the Company is the lessee. (b) Minimum basic rent receipts due for various retail space where the Company is the lessor. Excludes residential leases due to their short-term nature.
Summary of Reconciliation of Lease Liabilities	The following table provides a reconciliation of lease liabilities from our undiscounted cash flows for minimum rent payments for the quarter ended March 31, 2019 (amount in thousands): 2019 Total minimum rent payments $ 1,030,461 Less: Lease discount (748,224 ) Lease liabilities $ 282,237

Derivative and Other Fair Val_2

Derivative and Other Fair Value Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Summary of Carrying and Fair Values of Financial Instruments	The March 31, 2019 December 31, 2018 Carrying Value Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Mortgage notes payable, net $ 2,671,491 $ 2,646,252 $ 2,385,470 $ 2,352,502 Unsecured debt, net 6,281,179 6,533,696 6,432,469 6,481,426 Total debt, net $ 8,952,670 $ 9,179,948 $ 8,817,939 $ 8,833,928
Summary of Consolidated Derivative Instruments	The March 31, 2019 Fair Value Hedges (1) Forward Starting Swaps (2) Current Notional Balance $ 450,000 $ 500,000 Lowest Interest Rate 2.375 % 2.2665 % Highest Interest Rate 2.375 % 3.1163 % 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. 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 3/31/2019 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 $ 665 $ — $ 665 $ — Supplemental Executive Retirement Plan Other Assets 142,075 142,075 — — Total $ 142,740 $ 142,075 $ 665 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 1,022 $ — $ 1,022 $ — Forward Starting Swaps Other Liabilities 22,936 — 22,936 — Supplemental Executive Retirement Plan Other Liabilities 142,075 142,075 — — Total $ 166,033 $ 142,075 $ 23,958 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 432,562 $ — $ 432,562 $ — Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 12/31/2018 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 $ 2,000 $ — $ 2,000 $ — Supplemental Executive Retirement Plan Other Assets 134,088 134,088 — — Total $ 136,088 $ 134,088 $ 2,000 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 2,277 $ — $ 2,277 $ — Forward Starting Swaps Other Liabilities 9,851 — 9,851 — Supplemental Executive Retirement Plan Other Liabilities 134,088 134,088 — — Total $ 146,216 $ 134,088 $ 12,128 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 379,106 $ — $ 379,106 $ —
Summary of Effect of Fair Value Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The March 31, 2019 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 $ 1,255 Fixed rate debt Interest expense $ (1,255 ) Total $ 1,255 $ (1,255 ) March 31, 2018 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (2,289 ) Fixed rate debt Interest expense $ 2,289 Total $ (2,289 ) $ 2,289
Summary of Effect of Cash Flow Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The Effective Portion March 31, 2019 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 Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ (14,420 ) Interest expense $ (4,393 ) Total $ (14,420 ) $ (4,393 ) Effective Portion Ineffective Portion March 31, 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 $ 6,087 Interest expense $ (4,791 ) N/A $ — Total $ 6,087 $ (4,791 ) $ —

Earnings Per Share and Earnin_2

Earnings Per Share and Earnings Per Unit (Tables)	3 Months Ended
	Mar. 31, 2019
Schedule of Calculation of Numerator and Denominator in Earnings Per Share and Earnings Per Unit	The Quarter Ended March 31, 2019 2018 Numerator for net income per share – basic: Net income $ 109,257 $ 220,548 Allocation to Noncontrolling Interests – Operating Partnership (3,919 ) (8,059 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (799 ) (680 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – basic $ 103,766 $ 211,036 Numerator for net income per share – diluted: Net income $ 109,257 $ 220,548 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (799 ) (680 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – diluted $ 107,685 $ 219,095 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 369,558 367,800 Effect of dilutive securities: OP Units 12,919 12,863 Long-term compensation shares/units 2,707 2,355 Denominator for net income per share – diluted 385,184 383,018 Net income per share – basic $ 0.28 $ 0.57 Net income per share – diluted $ 0.28 $ 0.57
ERPOP [Member]
Schedule of Calculation of Numerator and Denominator in Earnings 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): Quarter Ended March 31, 2019 2018 Numerator for net income per Unit – basic and diluted: Net income $ 109,257 $ 220,548 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (799 ) (680 ) Allocation to Preference Units (773 ) (773 ) Numerator for net income per Unit – basic and diluted $ 107,685 $ 219,095 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 382,477 380,663 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,707 2,355 Denominator for net income per Unit – diluted 385,184 383,018 Net income per Unit – basic $ 0.28 $ 0.57 Net income per Unit – diluted $ 0.28 $ 0.57

Reportable Segments (Tables)

Reportable Segments (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Schedule of Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations	The Quarter Ended March 31, 2019 2018 Rental income $ 662,302 $ 632,831 Property and maintenance expense (115,070 ) (108,202 ) Real estate taxes and insurance expense (91,442 ) (91,914 ) Total operating expenses (206,512 ) (200,116 ) Net operating income $ 455,790 $ 432,715
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 quarters ended March 31, 2019 and 2018, Quarter Ended March 31, 2019 Quarter Ended March 31, 2018 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 115,399 $ 34,484 $ 80,915 $ 110,996 $ 32,041 $ 78,955 Orange County 25,828 6,205 19,623 24,803 6,091 18,712 San Diego 23,304 6,127 17,177 22,492 5,964 16,528 Subtotal - Southern California 164,531 46,816 117,715 158,291 44,096 114,195 San Francisco 121,761 30,417 91,344 117,352 29,410 87,942 Washington D.C. 110,784 34,674 76,110 108,528 33,910 74,618 New York 116,064 49,089 66,975 113,328 45,549 67,779 Boston 58,320 16,611 41,709 56,294 16,199 40,095 Seattle 50,621 13,531 37,090 49,516 13,853 35,663 Other Markets 522 185 337 488 164 324 Total same store 622,603 191,323 431,280 603,797 183,181 420,616 Non-same store/other (2) (3) Non-same store 39,409 13,293 26,116 17,396 7,105 10,291 Other (3) 290 1,896 (1,606 ) 11,638 9,830 1,808 Total non-same store/other 39,699 15,189 24,510 29,034 16,935 12,099 Totals $ 662,302 $ 206,512 $ 455,790 $ 632,831 $ 200,116 $ 432,715 (1) For the quarters ended March 31, 2019 and 2018, same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2018, less properties subsequently sold, which represented 74,166 apartment (2) For the quarters ended March 31, 2019 and 2018, non-same store primarily includes properties acquired after January 1, 2018, 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 March 31, 2019 Total Assets Capital Expenditures Same store (1) Los Angeles $ 3,049,292 $ 7,061 Orange County 415,698 1,833 San Diego 401,881 630 Subtotal - Southern California 3,866,871 9,524 San Francisco 3,400,898 6,039 Washington D.C. 3,749,155 3,683 New York 4,144,468 3,754 Boston 1,581,121 5,981 Seattle 1,322,060 2,773 Other Markets 12,852 44 Total same store 18,077,425 31,798 Non-same store/other (2) (3) Non-same store 2,192,615 2,220 Other (3) 498,771 — Total non-same store/other 2,691,386 2,220 Totals $ 20,768,811 $ 34,018 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2018, less properties subsequently sold, which represented 74,166 apartment (2) Non-same store primarily includes properties acquired after January 1, 2018, 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)	Mar. 31, 2019StatePropertyApartmentUnit
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of states in which entity operates | State	11
Properties | Property	310
Apartment units | ApartmentUnit	80,061
ERPOP [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Noncontrolling interest, ownership percentage by parent	96.40%

Business - Ownership Breakdown

Business - Ownership Breakdown (Details)	Mar. 31, 2019PropertyApartmentUnit
Property/Unit schedule
Properties | Property	310
Apartment Units | ApartmentUnit	80,061
Wholly Owned Properties
Property/Unit schedule
Properties | Property	290
Apartment Units | ApartmentUnit	75,419
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 ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019	Dec. 31, 2018
Provision for income tax	$ 238,000	$ 213,000
Percentage of rental income excluded from accounting standard adoption	94.00%
Percentage of total revenue subject to revenue recognition standard	6.00%
Right-of-use assets	$ 434,683,000		$ 434,201,000	$ 0
Lease liabilities	282,237,000		$ 278,287,000	$ 0
Federal [Member]
Provision for income tax	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Computation of Initial Right-of-use Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Line Items]
Lease liabilities	$ 282,237	$ 278,287	$ 0
Reclassifications:
Right-of-use assets	$ 434,683	434,201	$ 0
Other Assets [Member]
Reclassifications:
Prepaid ground leases		17,886
Ground lease intangibles – below market, net		166,230
Other Liabilities [Member]
Reclassifications:
Ground lease intangibles – above market, net		(2,110)
Straight line rent liabilities		$ (26,092)

Equity, Capital and Other Int_3

Equity, Capital and Other Interests - Changes in Issued and Outstanding Common Shares and Units (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Equity Capital And Other Interests [Abstract]
Common Stock, Shares, Outstanding	369,405,161	368,018,082
Common Shares Issued:
Conversion of OP Units	184,878	5,000
Exercise of share options	709,071	45,391
Employee Share Purchase Plan (ESPP)	18,901	35,177
Restricted share grants, net	144,390	108,261
Common Stock, Shares, Outstanding	370,462,401	368,211,911
Units
Total Units Outstanding	13,904,035	13,768,438
Restricted unit grants, net	133,214	263,048
Conversion of OP Units to Common Shares	(184,878)	(5,000)
Total Units Outstanding	13,852,371	14,026,486
Common Shares And Units Outstanding	384,314,772	382,238,397
Units Ownership Interest in Operating Partnership	3.60%	3.70%

Equity, Capital and Other Int_4

Equity, Capital and Other Interests - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Redeemable noncontrolling interests - operating partnership	$ 432,562	$ 379,106	$ 354,567	$ 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	$ 432,562	$ 379,106	$ 354,567	$ 366,955

Equity, Capital and Other Int_5

Equity, Capital and Other Interests - Changes in Redemption Value of Redeemable Noncontrolling Interests - Operating Partnership (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Equity Capital And Other Interests [Abstract]
Redeemable Noncontrolling Interests - Operating Partnership	$ 379,106	$ 366,955
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership	55,021	(12,831)
Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership	(1,565)	443
Redeemable Noncontrolling Interests - Operating Partnership	$ 432,562	$ 354,567

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	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
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 March 31, 2019 and December 31, 2018	$ 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 March 31, 2019 and December 31, 2018	$ 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 March 31, 2019 and December 31, 2018	$ 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 March 31, 2019 and December 31, 2018	$ 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	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
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) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
General and Limited Partner Units
Exercise of share options	709,071	45,391
Employee Share Purchase Plan (ESPP)	18,901	35,177
Restricted share grants, net	144,390	108,261
Restricted unit grants, net	133,214	263,048
Common Shares And Units Outstanding	384,314,772	382,238,397
LIMITED PARTNERS
Total Units Outstanding	13,904,035	13,768,438
Restricted unit grants, net	133,214	263,048
Conversion of Limited Partner OP Units to EQR Common Shares	(184,878)	(5,000)
Total Units Outstanding	13,852,371	14,026,486
Units Ownership Interest in Operating Partnership	3.60%	3.70%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	383,309,196	381,786,520
Exercise of share options	709,071	45,391
Employee Share Purchase Plan (ESPP)	18,901	35,177
Restricted share grants, net	144,390	108,261
Restricted unit grants, net	133,214	263,048
Common Shares And Units Outstanding	384,314,772	382,238,397
LIMITED PARTNERS
Total Units Outstanding	13,904,035	13,768,438
Restricted unit grants, net	133,214	263,048
Conversion of Limited Partner OP Units to EQR Common Shares	(184,878)	(5,000)
Total Units Outstanding	13,852,371	14,026,486
Units Ownership Interest in Operating Partnership	3.60%	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] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Redeemable Limited Partners	$ 379,106	$ 366,955
Limited Partners Change In Redemption Value	55,021	(12,831)
Limited Partners Change In Carrying Value	(1,565)	443
Redeemable Limited Partners	$ 432,562	$ 354,567

Equity, Capital and Other In_10

Equity, Capital and Other Interests - Other - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019shares
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 open market repurchased and retired during period, shares	0
Stock repurchase program, remaining number of shares authorized to be repurchased	13,000,000

Real Estate - Summary of Carryi

Real Estate - Summary of Carrying Amounts of Investment in Real Estate (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Land	$ 5,918,994	$ 5,875,803
Depreciable property:
Buildings and improvements	18,440,716	18,232,625
Furniture, fixtures and equipment	1,761,906	1,722,231
In-Place lease intangibles	488,682	481,045
Projects under development:
Construction-in-progress	135,191	109,409
Land held for development:
Land	91,647	89,909
Construction-in-progress	135,191	109,409
Investment in real estate	26,837,136	26,511,022
Accumulated depreciation	(6,900,496)	(6,696,281)
Investment in real estate, net	19,936,640	19,814,741
Projects under development [Member]
Projects under development:
Land	25,430	25,429
Construction-in-progress	109,761	83,980
Land held for development:
Construction-in-progress	109,761	83,980
Land held for development [Member]
Projects under development:
Construction-in-progress	30,609	28,871
Land held for development:
Land	61,038	61,038
Construction-in-progress	$ 30,609	$ 28,871

Real Estate - Acquired Properti

Real Estate - Acquired Properties From Unaffiliated Parties (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)PropertyApartmentUnit
Properties acquired | Property	3
Property Units acquired | ApartmentUnit	579
Purchase Price | $	$ 258,650
Rental Properties - Consolidated [Member]
Properties acquired | Property	3
Property Units acquired | ApartmentUnit	579
Purchase Price | $	$ 258,650

Real Estate - Acquired Proper_2

Real Estate - Acquired Properties From Unaffiliated Parties (Parenthetical) (Details) $ in Thousands	Mar. 31, 2019USD ($)
Purchase Price	$ 258,650
Land [Member]
Purchase Price	43,200
Depreciable Property [Member]
Purchase Price	$ 215,700

Commitments to Acquire_Dispos_3

Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Acquire (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Property/Unit schedule
Purchase Price	$ 28,000
Land [Member]
Property/Unit schedule
Purchase Price	$ 28,000

Commitments to Acquire_Dispos_4

Commitments to Acquire/Dispose of Real Estate - Separate Agreements to Dispose (Details) $ in Thousands	Mar. 31, 2019USD ($)PropertyApartmentUnit
Property/Unit schedule
Properties | Property	3
Apartment Units | ApartmentUnit	1,037
Sales Price	$ 539,650
Rental Properties Disposed [Member] | Consolidated [Member]
Property/Unit schedule
Properties | Property	2
Apartment Units | ApartmentUnit	593
Sales Price	$ 282,250
Rental Properties Disposed [Member] | Unconsolidated [Member]
Property/Unit schedule
Properties | Property	1
Apartment Units | ApartmentUnit	444
Sales Price	$ 255,500
Land [Member]
Property/Unit schedule
Sales Price	$ 1,900

Commitments to Acquire_Dispos_5

Commitments to Acquire/Dispose of Real Estate - Separate Agreements to Dispose (Parenthetical) (Details)	3 Months Ended
	Mar. 31, 2019
Discontinued Operations And Disposal Groups [Abstract]
Ownership percentage	20.00%

Investments in Partially Owne_3

Investments in Partially Owned Entities - Consolidated Variable Interest Entities ("VIEs") - Additional Information (Details) $ in Thousands	Mar. 31, 2019USD ($)PropertyApartmentUnit	Dec. 31, 2018USD ($)
Variable Interest Entity [Line Items]
Properties | Property	310
Apartment units | ApartmentUnit	80,061
Total assets	$ 20,768,811	$ 20,394,209
Total liabilities	$ 10,069,744	9,615,454
Consolidated VIE [Member]
Variable Interest Entity [Line Items]
Properties | Property	17
Apartment units | ApartmentUnit	3,535
Total assets	$ 694,700	713,600
Total liabilities	$ 316,100	$ 313,900

Investments in Partially Owne_4

Investments in Partially Owned Entities - Summary of Companys Investment in Unconsolidated Entities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 62,853	$ 58,349
Operating Property [Member] | Unconsolidated Non-VIE [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 10,207	10,494
Ownership Percentage	20.00%
Other [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 10,818	5,490
Consolidated VIE [Member] | Wisconsin Place Developer [Member]
Variable Interest Entity [Line Items]
Investments in Unconsolidated Entities	$ 41,828	$ 42,365
Ownership Percentage	33.30%

Investments in Partially Owne_5

Investments in Partially Owned Entities - Summary of Companys Investment in Unconsolidated Entities (Parenthetical) (Details)	3 Months Ended
	Mar. 31, 2019ApartmentUnitJointVenture
Variable Interest Entity [Line Items]
Apartment units	80,061
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	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Mortgage escrow deposits:
Real estate taxes and insurance	$ 1,311	$ 876
Replacement reserves	9,023	8,641
Mortgage principal reserves/sinking funds	11,514	9,754
Other	852	852
Mortgage escrow deposits	22,700	20,123
Restricted cash:
Earnest money on pending acquisitions	3,125	5,000
Restricted deposits on real estate investments	534	540
Resident security and utility deposits	36,213	35,659
Other	1,543	7,549
Restricted cash	41,415	48,748
Restricted deposits	$ 64,115	$ 68,871	$ 50,258

Leases - Additional Information

Leases - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)PropertyCorporateOfficeLease
Corporate Office Leases [Member]
Operating Leased Assets [Line Items]
Number of operating leases | CorporateOfficeLease	9
Lease termination date	Jan. 31, 2022
Amount incurred for leased office space | $	$ 0.6
Ground Leases [Member]
Operating Leased Assets [Line Items]
Unsecured borrowing rates for actual pricing period used for calculating discount rate	30 years
Number of operating properties | Property	14
Minimum [Member] | Corporate Office Leases [Member]
Operating Leased Assets [Line Items]
Discount rate	3.30%
Remaining lease terms	1 year
Minimum [Member] | Ground Leases [Member]
Operating Leased Assets [Line Items]
Discount rate	4.40%
Operating lease expiration year	2042
Maximum [Member] | Corporate Office Leases [Member]
Operating Leased Assets [Line Items]
Discount rate	3.90%
Remaining lease terms	10 years
Maximum [Member] | Ground Leases [Member]
Operating Leased Assets [Line Items]
Discount rate	5.50%
Operating lease expiration year	2113
Residential Apartment Leases [Member]
Operating Leased Assets [Line Items]
Percentage of rental income	97.00%
Retail Commercial Leases [Member]
Operating Leased Assets [Line Items]
Percentage of rental income	3.00%
Retail Commercial Leases [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Retail/commercial leases term	5 years
Retail Commercial Leases [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Retail/commercial leases term	10 years

Leases - Summary of Lease Incom

Leases - Summary of Lease Income Types Relating to Lease Payments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Operating Leased Assets [Line Items]
Total lease revenue	$ 624,049
Residential Leases [Member]
Operating Leased Assets [Line Items]
Total lease revenue	605,463
Retail Lease [Member]
Operating Leased Assets [Line Items]
Total lease revenue	18,586
Residential and Retail Rent [Member]
Operating Leased Assets [Line Items]
Total lease revenue	610,990
Residential and Retail Rent [Member] | Residential Leases [Member]
Operating Leased Assets [Line Items]
Total lease revenue	592,520
Residential and Retail Rent [Member] | Retail Lease [Member]
Operating Leased Assets [Line Items]
Total lease revenue	18,470
Parking Rent [Member]
Operating Leased Assets [Line Items]
Total lease revenue	9,209
Parking Rent [Member] | Residential Leases [Member]
Operating Leased Assets [Line Items]
Total lease revenue	9,137
Parking Rent [Member] | Retail Lease [Member]
Operating Leased Assets [Line Items]
Total lease revenue	72
Storage Rent
Operating Leased Assets [Line Items]
Total lease revenue	963
Storage Rent | Residential Leases [Member]
Operating Leased Assets [Line Items]
Total lease revenue	919
Storage Rent | Retail Lease [Member]
Operating Leased Assets [Line Items]
Total lease revenue	44
Pet Rent [Member]
Operating Leased Assets [Line Items]
Total lease revenue	2,887
Pet Rent [Member] | Residential Leases [Member]
Operating Leased Assets [Line Items]
Total lease revenue	$ 2,887

Leases - Summary of Lease Inc_2

Leases - Summary of Lease Income Types Relating to Lease Payments (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Leased Assets [Line Items]
Other rental income	$ 662,302	$ 632,831
Rental [Member]
Operating Leased Assets [Line Items]
Other rental income	$ 38,300

Leases - Summary of Right-of-Us

Leases - Summary of Right-of-Use Assets and Related Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leased Assets [Line Items]
Right-of-use assets	$ 434,683	$ 434,201	$ 0
Lease liabilities	282,237	$ 278,287	$ 0
Corporate Office Leases [Member]
Operating Leased Assets [Line Items]
Right-of-use assets	16,024
Lease liabilities	17,585
Ground Leases [Member]
Operating Leased Assets [Line Items]
Right-of-use assets	418,659
Lease liabilities	$ 264,652

Leases - Summary of Right-of-_2

Leases - Summary of Right-of-Use Assets and Related Lease Liabilities (Parenthetical) (Details)	3 Months Ended
	Mar. 31, 2019CorporateOfficeLease
Corporate Office Leases [Member]
Operating Leased Assets [Line Items]
Number of short-term operating leases	2

Leases - Summary of Quantitativ

Leases - Summary of Quantitative Disclosures for Lessees (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Lease cost:
Total lease cost	$ 7,636
Corporate Office Leases [Member]
Lease cost:
Operating lease cost	918
Short-term lease cost	56
Variable lease cost	261
Operating cash flows from Operating leases	1,248
ROU assets obtained in exchange for new operating lease liabilities	$ 16,687
Weighted-average remaining lease term – operating leases	6 years 6 months
Weighted-average discount rate – operating leases	3.70%
Ground Leases [Member]
Lease cost:
Operating lease cost	$ 5,550
Variable lease cost	851
Operating cash flows from Operating leases	4,493
ROU assets obtained in exchange for new operating lease liabilities	$ 422,018
Weighted-average remaining lease term – operating leases	56 years 9 months 18 days
Weighted-average discount rate – operating leases	5.00%

Leases - Summary of Undiscounte

Leases - Summary of Undiscounted Cash Flows for Contractual Obligations for Minimum Rent Payments/Receipts (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
Remaining 2019	$ (12,607)
2020	(17,208)
2021	(17,148)
2022	(14,993)
2023	(14,843)
2024	(15,101)
Thereafter	(938,561)
Total	(1,030,461)
Remaining 2019	49,268
2020	62,481
2021	58,439
2022	54,378
2023	46,987
2024	39,364
Thereafter	135,548
Total	$ 446,465

Leases - Summary of Reconciliat

Leases - Summary of Reconciliation of Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Total minimum rent payments	$ 1,030,461
Less: Lease discount	(748,224)
Lease liabilities	$ 282,237	$ 278,287	$ 0

Debt - Mortgage Notes Payable -

Debt - Mortgage Notes Payable - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Mortgage notes payable	$ 2,671,491,000	$ 2,385,470,000
Debt instrument, maturity date	Jan. 10, 2022
Mortgages [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	May 28, 2061
Weighted average interest rate	4.01%
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%
Credit enhanced debt [Member]
Debt Instrument [Line Items]
Mortgage notes payable	$ 440,600,000
Fannie Mae Pool 3 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt	$ 288,100
Debt instrument, maturity date	Mar. 1, 2029
Debt instrument, interest rate, stated percentage	3.94%

Debt - Notes - Additional Infor

Debt - Notes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unsecured notes	$ 5,936,335	$ 5,933,286
Debt instrument, maturity date	Jan. 10, 2022
Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Aug. 1, 2047
Weighted average interest rate	4.32%
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	Mar. 31, 2019	Oct. 31, 2016	Feb. 28, 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		$ 344,800,000
Commercial paper principal outstanding		345,000,000
Unamortized discount		$ 200,000
Weighted average interest rate		2.75%
Commercial paper weighted average days outstanding		7 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		3.25%
Commercial paper principal outstanding		$ 0
Amount restricted/dedicated to support letters of credit		6,700,000
Line of credit facility current borrowing capacity		$ 1,550,000,000

Debt - Other - Additional Infor

Debt - Other - Additional Information (Details) $ in Millions	Mar. 31, 2019USD ($)
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	Mar. 31, 2019	Dec. 31, 2018
Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	$ 8,952,670	$ 8,817,939
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	9,179,948	8,833,928
Mortgage Notes Payable, Net [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	2,671,491	2,385,470
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	2,646,252	2,352,502
Unsecured Debt [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	6,281,179	6,432,469
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	$ 6,533,696	$ 6,481,426

Derivative and Other Fair Val_4

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Details)	3 Months Ended
	Mar. 31, 2019USD ($)
Fair Value Hedges [Member]
Derivative [Line Items]
Current Notional Balance	$ 450,000,000
Maturity Date	2019
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	$ 500,000,000
Maturity Date	2029
Forward Starting Swaps [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.2665%
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) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Derivative [Line Items]
Debt instrument, maturity date	Jan. 10, 2022
2.375% Notes [Member]
Derivative [Line Items]
Proceeds from issuance of unsecured debt	$ 450
Interest Rate Ranges	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	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	$ 142,075	$ 134,088
Assets, Fair Value Disclosure	142,740	136,088
Other Liabilities, Fair Value Disclosure	142,075	134,088
Liabilities, Fair Value Disclosure	166,033	146,216
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	432,562	379,106	$ 354,567	$ 366,955
Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	1,022	2,277
Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	665	2,000
Other Liabilities, Forward Starting Swaps	22,936	9,851
Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	142,075	134,088
Assets, Fair Value Disclosure	142,075	134,088
Other Liabilities, Fair Value Disclosure	142,075	134,088
Liabilities, Fair Value Disclosure	142,075	134,088
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Fair Value, Inputs, Level 1 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Other Liabilities, Forward Starting Swaps	0	0
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	665	2,000
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	23,958	12,128
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	432,562	379,106
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	1,022	2,277
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	665	2,000
Other Liabilities, Forward Starting Swaps	22,936	9,851
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	0	0
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	0	0
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Fair Value, Inputs, Level 3 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Other Liabilities, Forward Starting Swaps	$ 0	$ 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	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ 1,255	$ (2,289)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	(1,255)	2,289
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	1,255	(2,289)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	$ (1,255)	$ 2,289

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	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	$ (14,420)	$ 6,087
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(4,393)	(4,791)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income		0
Forward Starting Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	(14,420)	6,087
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	$ (4,393)	(4,791)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income		$ 0

Derivative and Other Fair Val_9

Derivative and Other Fair Value Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)	$ 75	$ 65
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	$ 22.8

Earnings Per Share and Earnin_3

Earnings 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
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 109,257	$ 220,548
Allocation to Noncontrolling Interests – Operating Partnership	(3,919)	(8,059)
Partially Owned Properties	(799)	(680)
Preferred distributions	(773)	(773)
Net income available to Common Shares	103,766	211,036
Numerator for net income per share – diluted	$ 107,685	$ 219,095
Weighted average Common Shares outstanding	369,558	367,800
OP Units	12,919	12,863
Dilutive Securities Options	2,707	2,355
Denominator for net income per share – diluted	385,184	383,018
Net income available to Common Shares	$ 0.28	$ 0.57
Net income available to Common Shares	$ 0.28	$ 0.57

Earnings Per Share and Earnin_4

Earnings 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
	Mar. 31, 2019	Mar. 31, 2018
Net income	$ 109,257	$ 220,548
Partially Owned Properties	$ (799)	$ (680)
Dilutive Securities Options	2,707	2,355
Denominator for net income per share – diluted	385,184	383,018
Net income available to Common Shares	$ 0.28	$ 0.57
Net income available to Common Shares	$ 0.28	$ 0.57
ERPOP [Member]
Net income	$ 109,257	$ 220,548
Partially Owned Properties	(799)	(680)
Allocation to Preference Units	(773)	(773)
Numerator for net income per Unit – basic and diluted	$ 107,685	$ 219,095
Denominator for net income per Unit – basic	382,477	380,663
Dilutive Securities Options	2,707	2,355
Denominator for net income per share – diluted	385,184	383,018
Net income available to Common Shares	$ 0.28	$ 0.57
Net income available to Common Shares	$ 0.28	$ 0.57

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)PropertyApartmentUnit
Accrual for environmental loss contingencies | $	$ 4.3
Number of properties with environmental reserves	3
Projects in various stages of development	3
Units in various stages of development | ApartmentUnit	691
Consolidated project under development commitment fund | $	$ 388.4
Various stages of development with estimated completion dates ranging through September 30, 2021	Sep. 30, 2021
Partially Owned Properties - Unconsolidated
Number of unconsolidated projects	2

Reportable Segments - Additiona

Reportable Segments - Additional Information (Details)	Mar. 31, 2019PropertyCustomer	Mar. 31, 2018Customer
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	3

Reportable Segments - Reconcili

Reportable Segments - Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	$ 662,302	$ 632,831
Property and maintenance expense	(115,070)	(108,202)
Real estate taxes and insurance expense	(91,442)	(91,914)
Operating income	209,969	339,082
Same Store, Non-same Store and Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	662,302	632,831
Property and maintenance expense	(115,070)	(108,202)
Real estate taxes and insurance expense	(91,442)	(91,914)
Total operating expenses	(206,512)	(200,116)
Operating income	$ 455,790	$ 432,715

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
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Rental income	$ 662,302	$ 632,831
Operating income	209,969	339,082
Total Assets	20,768,811		$ 20,394,209
Capital Expenditures	34,018
Same store
Segment Reporting Information [Line Items]
Rental income	622,603	603,797
Operating expenses	191,323	183,181
Operating income	431,280	420,616
Total Assets	18,077,425
Capital Expenditures	31,798
Non-same store/other
Segment Reporting Information [Line Items]
Rental income	39,699	29,034
Operating expenses	15,189	16,935
Operating income	24,510	12,099
Total Assets	2,691,386
Capital Expenditures	2,220
Same Store, Non-same Store and Other
Segment Reporting Information [Line Items]
Rental income	662,302	632,831
Operating expenses	206,512	200,116
Operating income	455,790	432,715
Other markets | Same store
Segment Reporting Information [Line Items]
Rental income	522	488
Operating expenses	185	164
Operating income	337	324
Total Assets	12,852
Capital Expenditures	44
Los Angeles | Same store
Segment Reporting Information [Line Items]
Rental income	115,399	110,996
Operating expenses	34,484	32,041
Operating income	80,915	78,955
Total Assets	3,049,292
Capital Expenditures	7,061
Orange County | Same store
Segment Reporting Information [Line Items]
Rental income	25,828	24,803
Operating expenses	6,205	6,091
Operating income	19,623	18,712
Total Assets	415,698
Capital Expenditures	1,833
San Diego | Same store
Segment Reporting Information [Line Items]
Rental income	23,304	22,492
Operating expenses	6,127	5,964
Operating income	17,177	16,528
Total Assets	401,881
Capital Expenditures	630
Subtotal - Southern California | Same store
Segment Reporting Information [Line Items]
Rental income	164,531	158,291
Operating expenses	46,816	44,096
Operating income	117,715	114,195
Total Assets	3,866,871
Capital Expenditures	9,524
San Francisco | Same store
Segment Reporting Information [Line Items]
Rental income	121,761	117,352
Operating expenses	30,417	29,410
Operating income	91,344	87,942
Total Assets	3,400,898
Capital Expenditures	6,039
Washington DC | Same store
Segment Reporting Information [Line Items]
Rental income	110,784	108,528
Operating expenses	34,674	33,910
Operating income	76,110	74,618
Total Assets	3,749,155
Capital Expenditures	3,683
New York | Same store
Segment Reporting Information [Line Items]
Rental income	116,064	113,328
Operating expenses	49,089	45,549
Operating income	66,975	67,779
Total Assets	4,144,468
Capital Expenditures	3,754
Boston | Same store
Segment Reporting Information [Line Items]
Rental income	58,320	56,294
Operating expenses	16,611	16,199
Operating income	41,709	40,095
Total Assets	1,581,121
Capital Expenditures	5,981
Seattle | Same store
Segment Reporting Information [Line Items]
Rental income	50,621	49,516
Operating expenses	13,531	13,853
Operating income	37,090	35,663
Total Assets	1,322,060
Capital Expenditures	2,773
Non-same store | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	39,409	17,396
Operating expenses	13,293	7,105
Operating income	26,116	10,291
Total Assets	2,192,615
Capital Expenditures	2,220
Other [Member] | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	290	11,638
Operating expenses	1,896	9,830
Operating income	(1,606)	$ 1,808
Total Assets	$ 498,771

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
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]
Units in same store properties	74,166	74,166

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) $ in Thousands	May 06, 2019USD ($)PropertyApartmentUnit	Mar. 31, 2019USD ($)PropertyApartmentUnit
Subsequent Event [Line Items]
Properties acquired | Property		3
Property Units acquired | ApartmentUnit		579
Purchase Price		$ 258,650
Bonds [Member]
Subsequent Event [Line Items]
Repayments of long-term debt	$ 95,500
Debt Instrument Maturity Date	2036
Subsequent Event
Subsequent Event [Line Items]
Properties acquired | Property	1
Property Units acquired | ApartmentUnit	366
Purchase Price	$ 103,500
Number of properties sold | Property	1
Number of self managed apartments | ApartmentUnit	266
Amount of property sold	$ 237,500