Erp Operating LTD Partnership 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document And Entity Information [Line Items]
Entity Registrant Name	EQUITY RESIDENTIAL
Entity Central Index Key	906,107
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	EQR
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		368,213,717
ERPOP [Member]
Document And Entity Information [Line Items]
Entity Registrant Name	ERP OPERATING LIMITED PARTNERSHIP
Entity Central Index Key	931,182
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment in real estate
Land	$ 5,960,804	$ 5,996,024
Depreciable property	19,798,353	19,768,362
Projects under development	96,609	163,547
Land held for development	102,851	98,963
Investment in real estate	25,958,617	26,026,896
Accumulated depreciation	(6,173,047)	(6,040,378)
Investment in real estate, net	19,785,570	19,986,518
Cash and cash equivalents	44,453	50,647
Investments in unconsolidated entities	59,091	58,254
Restricted deposits	50,258	50,115
Other assets	444,498	425,065
Total assets	20,383,870	20,570,599
Liabilities:
Mortgage notes payable, net	2,894,344	3,618,722
Notes, net	5,530,815	5,038,812
Line of credit and commercial paper	234,318	299,757
Accounts payable and accrued expenses	167,481	114,766
Accrued interest payable	69,753	58,035
Other liabilities	335,957	341,852
Security deposits	64,748	65,009
Distributions payable	206,794	192,828
Total liabilities	9,504,210	9,729,781
Commitments and contingencies
Redeemable Noncontrolling Interests – Operating Partnership	354,567	366,955
Shareholders’ equity:
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017	37,280	37,280
Common Shares of beneficial interest, $0.01 par value; 1,000,000,000 shares authorized; 368,211,911 shares issued and outstanding as of March 31, 2018 and 368,018,082 shares issued and outstanding as of December 31, 2017	3,682	3,680
Paid in capital	8,910,306	8,886,586
Retained earnings	1,415,638	1,403,530
Accumulated other comprehensive income (loss)	(77,734)	(88,612)
Total shareholders’ equity	10,289,172	10,242,464
Noncontrolling Interests:
Operating Partnership	234,628	226,691
Partially Owned Properties	1,293	4,708
Total Noncontrolling Interests	235,921	231,399
Total equity	10,525,093	10,473,863
Total liabilities and equity/capital	$ 20,383,870	$ 20,570,599

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock, Shares Issued	745,600	745,600
Preferred Stock, Shares Outstanding	745,600	745,600
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Issued	368,211,911	368,018,082
Common Stock, Shares, Outstanding	368,211,911	368,018,082

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES
Rental income	$ 632,831	$ 603,920
Fee and asset management	185	180
Total revenues	633,016	604,100
EXPENSES
Property and maintenance	108,202	102,608
Real estate taxes and insurance	91,914	81,728
Property management	23,444	22,252
General and administrative	16,278	14,173
Depreciation	196,309	178,968
Total expenses	436,147	399,729
Operating income	196,869	204,371
Interest and other income	5,880	601
Other expenses	(3,441)	(1,090)
Interest:
Expense incurred, net	(116,104)	(106,210)
Amortization of deferred financing costs	(3,679)	(2,296)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	79,525	95,376
Income and other tax (expense) benefit	(213)	(262)
Income (loss) from investments in unconsolidated entities	(977)	(1,073)
Net gain (loss) on sales of real estate properties	142,213	36,707
Net gain (loss) on sales of land parcels		19,193
Net income	220,548	149,941
Net (income) loss attributable to Noncontrolling Interests:
Operating Partnership	(8,059)	(5,411)
Partially Owned Properties	(680)	(788)
Net income attributable to controlling interests	211,809	143,742
Preferred distributions	(773)	(773)
Net income available to Common Shares	$ 211,036	$ 142,969
Earnings per share – basic:
Net income available to Common Shares	$ 0.57	$ 0.39
Weighted average Common Shares outstanding	367,800	366,605
Earnings per share – diluted:
Net income available to Common Shares	$ 0.57	$ 0.39
Weighted average Common Shares outstanding	383,018	382,280
Distributions declared per Common Share outstanding	$ 0.54	$ 0.50375

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Comprehensive income:
Net income	$ 220,548	$ 149,941
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	6,087
Losses reclassified into earnings from other comprehensive income	4,791	4,583
Other comprehensive income (loss)	10,878	4,583
Comprehensive income	231,426	154,524
Comprehensive (income) attributable to Noncontrolling Interests	(9,139)	(6,366)
Comprehensive income attributable to controlling interests	$ 222,287	$ 148,158

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 220,548	$ 149,941
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	196,309	178,968
Amortization of deferred financing costs	3,679	2,296
Amortization of above/below market lease intangibles	1,098	856
Amortization of discounts and premiums on debt	1,532	1,130
Amortization of deferred settlements on derivative instruments	4,788	4,580
Write-off of pursuit costs	931	715
(Income) loss from investments in unconsolidated entities	977	1,073
Distributions from unconsolidated entities – return on capital	615	648
Net (gain) loss on sales of real estate properties	(142,213)	(36,707)
Net (gain) loss on sales of land parcels		(19,193)
Net (gain) loss on debt extinguishment	22,110	11,698
Compensation paid with Company Common Shares	10,278	7,873
Changes in assets and liabilities:
(Increase) decrease in other assets	(15,396)	(11,059)
Increase (decrease) in accounts payable and accrued expenses	48,997	42,472
Increase (decrease) in accrued interest payable	11,718	13,437
Increase (decrease) in other liabilities	(4,692)	(45,324)
Increase (decrease) in security deposits	(261)	500
Net cash provided by operating activities	361,018	303,904
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(54,134)
Investment in real estate – development/other	(40,813)	(103,291)
Capital expenditures to real estate	(36,747)	(39,297)
Non-real estate capital additions	(1,191)	(289)
Interest capitalized for real estate under development	(1,688)	(8,238)
Proceeds from disposition of real estate, net	284,670	80,064
Investments in unconsolidated entities	(2,799)	(1,704)
Distributions from unconsolidated entities – return of capital		113
Net cash provided by (used for) investing activities	147,298	(72,642)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,345)
Mortgage notes payable, net:
Lump sum payoffs	(725,639)	(351,774)
Scheduled principal repayments	(1,720)	(1,964)
Notes, net:
Proceeds	497,010
Line of credit and commercial paper:
Line of credit proceeds	415,000
Line of credit repayments	(415,000)
Commercial paper proceeds	1,107,561	1,310,188
Commercial paper repayments	(1,173,000)	(1,015,500)
Proceeds from (payments on) settlement of derivative instruments	1,638
Proceeds from Employee Share Purchase Plan (ESPP)	1,681	1,574
Proceeds from exercise of options	1,600	3,142
Payment of offering costs	(26)	(21)
Contributions – Noncontrolling Interests – Partially Owned Properties	125	125
Contributions – Noncontrolling Interests – Operating Partnership	1
Distributions:
Common Shares	(185,484)	(184,302)
Preferred Shares	(773)	(1,545)
Noncontrolling Interests – Operating Partnership	(6,666)	(7,218)
Noncontrolling Interests – Partially Owned Properties	(4,220)	(5,134)
Net cash provided by (used for) financing activities	(514,367)	(264,127)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(6,051)	(32,865)
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	94,711	186,223
Cash and cash equivalents	44,453	42,139
Restricted deposits	50,258	144,084
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	96,404	86,668
Net cash paid for income and other taxes	462	468
Amortization of deferred financing costs:
Other assets	603	603
Mortgage notes payable, net	2,084	794
Notes, net	992	899
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	897	525
Notes, net	635	605
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	4,791	4,583
Write-off of pursuit costs:
Investment in real estate, net	931	685
Other assets		10
Accounts payable and accrued expenses		20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	627	701
Other liabilities	350	372
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(9,132)	1,106
Notes, net	(2,289)	(1,106)
Other liabilities	5,334
Accumulated other comprehensive income	6,087
Investments in unconsolidated entities:
Investments in unconsolidated entities	(2,079)	(804)
Other liabilities	(720)	(900)
Debt financing costs:
Notes, net	(4,345)
Proceeds from (payments on) settlement of derivative instruments:
Other assets	1,638
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	$ (22,110)	$ (11,698)

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	PREFERRED SHARES	COMMON SHARES, $0.01 PAR VALUE	PAID IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	OPERATING PARTNERSHIP	PARTIALLY OWNED PROPERTIES
Balance, beginning of year at Dec. 31, 2017	$ 10,242,464	$ 37,280	$ 3,680	$ 8,886,586	$ 1,403,530	$ (88,612)
Balance, beginning of year at Dec. 31, 2017	231,399						$ 226,691	$ 4,708
COMMON SHARES, $0.01 PAR VALUE
Conversion of OP Units into Common Shares				134			(134)
Exercise of share options			1	1,599
Employee Share Purchase Plan (ESPP)				1,681
Restricted shares			1	2,622
Share options				7,338
ESPP discount				297
PAID IN CAPITAL
Conversion of OP Units into Common Shares				134			(134)
Exercise of share options			1	1,599
Employee Share Purchase Plan (ESPP)				1,681
Share-based employee compensation expense:
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
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
NONCONTROLLING INTERESTS
Issuance of restricted units to Noncontrolling Interests							1
Conversion of OP Units into Common Shares				134			(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
Net income attributable to Noncontrolling Interests	8,059						8,059	680
PARTIALLY OWNED PROPERTIES
Net income	220,548
Distributions to Noncontrolling Interests							(7,188)	(4,220)
Net income attributable to Noncontrolling Interests	8,059						8,059	680
Contributions by Noncontrolling Interests								125
Balance, end of period at Mar. 31, 2018	10,289,172	$ 37,280	$ 3,682	$ 8,910,306	$ 1,415,638	$ (77,734)
Balance, end of period at Mar. 31, 2018	$ 235,921						$ 234,628	$ 1,293

CONSOLIDATED BALANCE SHEETS OF

CONSOLIDATED BALANCE SHEETS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment in real estate
Land	$ 5,960,804	$ 5,996,024
Depreciable property	19,798,353	19,768,362
Projects under development	96,609	163,547
Land held for development	102,851	98,963
Investment in real estate	25,958,617	26,026,896
Accumulated depreciation	(6,173,047)	(6,040,378)
Investment in real estate, net	19,785,570	19,986,518
Cash and cash equivalents	44,453	50,647
Investments in unconsolidated entities	59,091	58,254
Restricted deposits	50,258	50,115
Other assets	444,498	425,065
Total assets	20,383,870	20,570,599
Liabilities:
Mortgage notes payable, net	2,894,344	3,618,722
Notes, net	5,530,815	5,038,812
Line of credit and commercial paper	234,318	299,757
Accounts payable and accrued expenses	167,481	114,766
Accrued interest payable	69,753	58,035
Other liabilities	335,957	341,852
Security deposits	64,748	65,009
Distributions payable	206,794	192,828
Total liabilities	9,504,210	9,729,781
Commitments and contingencies
Partners’ Capital:
Accumulated other comprehensive income (loss)	(77,734)	(88,612)
Noncontrolling Interests – Partially Owned Properties	1,293	4,708
Total liabilities and equity/capital	20,383,870	20,570,599
ERPOP [Member]
Investment in real estate
Land	5,960,804	5,996,024
Depreciable property	19,798,353	19,768,362
Projects under development	96,609	163,547
Land held for development	102,851	98,963
Investment in real estate	25,958,617	26,026,896
Accumulated depreciation	(6,173,047)	(6,040,378)
Investment in real estate, net	19,785,570	19,986,518
Cash and cash equivalents	44,453	50,647
Investments in unconsolidated entities	59,091	58,254
Restricted deposits	50,258	50,115
Other assets	444,498	425,065
Total assets	20,383,870	20,570,599
Liabilities:
Mortgage notes payable, net	2,894,344	3,618,722
Notes, net	5,530,815	5,038,812
Line of credit and commercial paper	234,318	299,757
Accounts payable and accrued expenses	167,481	114,766
Accrued interest payable	69,753	58,035
Other liabilities	335,957	341,852
Security deposits	64,748	65,009
Distributions payable	206,794	192,828
Total liabilities	9,504,210	9,729,781
Commitments and contingencies
Redeemable Limited Partners	354,567	366,955
Partners’ Capital:
Preference Units	37,280	37,280
General Partner	10,329,626	10,293,796
Limited Partners	234,628	226,691
Accumulated other comprehensive income (loss)	(77,734)	(88,612)
Total partners’ capital	10,523,800	10,469,155
Noncontrolling Interests – Partially Owned Properties	1,293	4,708
Total capital	10,525,093	10,473,863
Total liabilities and equity/capital	$ 20,383,870	$ 20,570,599

CONSOLIDATED STATEMENTS OF OPE9

CONSOLIDATED STATEMENTS OF OPERATIONS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES
Rental income	$ 632,831	$ 603,920
Fee and asset management	185	180
Total revenues	633,016	604,100
EXPENSES
Property and maintenance	108,202	102,608
Real estate taxes and insurance	91,914	81,728
Property management	23,444	22,252
General and administrative	16,278	14,173
Depreciation	196,309	178,968
Total expenses	436,147	399,729
Operating income	196,869	204,371
Interest and other income	5,880	601
Other expenses	(3,441)	(1,090)
Interest:
Expense incurred, net	(116,104)	(106,210)
Amortization of deferred financing costs	(3,679)	(2,296)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	79,525	95,376
Income and other tax (expense) benefit	(213)	(262)
Income (loss) from investments in unconsolidated entities	(977)	(1,073)
Net gain (loss) on sales of real estate properties	142,213	36,707
Net gain (loss) on sales of land parcels		19,193
Net income	220,548	149,941
Partially Owned Properties	(680)	(788)
Net income attributable to controlling interests	$ 211,809	$ 143,742
Earnings per Unit – basic:
Net income available to Units	$ 0.57	$ 0.39
Earnings per Unit – diluted:
Net income available to Units	$ 0.57	$ 0.39
Weighted average Units outstanding	383,018	382,280
ERPOP [Member]
REVENUES
Rental income	$ 632,831	$ 603,920
Fee and asset management	185	180
Total revenues	633,016	604,100
EXPENSES
Property and maintenance	108,202	102,608
Real estate taxes and insurance	91,914	81,728
Property management	23,444	22,252
General and administrative	16,278	14,173
Depreciation	196,309	178,968
Total expenses	436,147	399,729
Operating income	196,869	204,371
Interest and other income	5,880	601
Other expenses	(3,441)	(1,090)
Interest:
Expense incurred, net	(116,104)	(106,210)
Amortization of deferred financing costs	(3,679)	(2,296)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	79,525	95,376
Income and other tax (expense) benefit	(213)	(262)
Income (loss) from investments in unconsolidated entities	(977)	(1,073)
Net gain (loss) on sales of real estate properties	142,213	36,707
Net gain (loss) on sales of land parcels		19,193
Net income	220,548	149,941
Partially Owned Properties	(680)	(788)
Net income attributable to controlling interests	219,868	149,153
ALLOCATION OF NET INCOME:
Preference Units	773	773
General Partner	211,036	142,969
Limited Partners	8,059	5,411
Net income available to Units	$ 219,095	$ 148,380
Earnings per Unit – basic:
Net income available to Units	$ 0.57	$ 0.39
Weighted average Units outstanding	380,663	379,504
Earnings per Unit – diluted:
Net income available to Units	$ 0.57	$ 0.39
Weighted average Units outstanding	383,018	382,280
Distributions declared per Unit outstanding	$ 0.54	$ 0.50375

CONSOLIDATED STATEMENTS OF CO10

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Comprehensive income:
Net income	$ 220,548	$ 149,941
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	6,087
Losses reclassified into earnings from other comprehensive income	4,791	4,583
Other comprehensive income (loss)	10,878	4,583
Comprehensive income	231,426	154,524
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(9,139)	(6,366)
Comprehensive income attributable to controlling interests	222,287	148,158
ERPOP [Member]
Comprehensive income:
Net income	220,548	149,941
Other comprehensive income (loss) – derivative instruments:
Unrealized holding gains (losses) arising during the period	6,087
Losses reclassified into earnings from other comprehensive income	4,791	4,583
Other comprehensive income (loss)	10,878	4,583
Comprehensive income	231,426	154,524
Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties	(680)	(788)
Comprehensive income attributable to controlling interests	$ 230,746	$ 153,736

CONSOLIDATED STATEMENTS OF CA11

CONSOLIDATED STATEMENTS OF CASH FLOWS OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 220,548	$ 149,941
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	196,309	178,968
Amortization of deferred financing costs	3,679	2,296
Amortization of above/below market lease intangibles	1,098	856
Amortization of discounts and premiums on debt	1,532	1,130
Amortization of deferred settlements on derivative instruments	4,788	4,580
Write-off of pursuit costs	931	715
(Income) loss from investments in unconsolidated entities	977	1,073
Distributions from unconsolidated entities – return on capital	615	648
Net (gain) loss on sales of real estate properties	(142,213)	(36,707)
Net (gain) loss on sales of land parcels		(19,193)
Net (gain) loss on debt extinguishment	22,110	11,698
Compensation paid with Company Common Shares	10,278	7,873
Changes in assets and liabilities:
(Increase) decrease in other assets	(15,396)	(11,059)
Increase (decrease) in accounts payable and accrued expenses	48,997	42,472
Increase (decrease) in accrued interest payable	11,718	13,437
Increase (decrease) in other liabilities	(4,692)	(45,324)
Increase (decrease) in security deposits	(261)	500
Net cash provided by operating activities	361,018	303,904
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(54,134)
Investment in real estate – development/other	(40,813)	(103,291)
Capital expenditures to real estate	(36,747)	(39,297)
Non-real estate capital additions	(1,191)	(289)
Interest capitalized for real estate under development	(1,688)	(8,238)
Proceeds from disposition of real estate, net	284,670	80,064
Investments in unconsolidated entities	(2,799)	(1,704)
Distributions from unconsolidated entities – return of capital		113
Net cash provided by (used for) investing activities	147,298	(72,642)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,345)
Mortgage notes payable, net:
Lump sum payoffs	(725,639)	(351,774)
Scheduled principal repayments	(1,720)	(1,964)
Notes, net:
Proceeds	497,010
Line of credit and commercial paper:
Line of credit proceeds	415,000
Line of credit repayments	(415,000)
Commercial paper proceeds	1,107,561	1,310,188
Commercial paper repayments	(1,173,000)	(1,015,500)
Proceeds from (payments on) settlement of derivative instruments	1,638
Proceeds from EQR’s Employee Share Purchase Plan (ESPP)	1,681	1,574
Proceeds from exercise of EQR options	1,600	3,142
Payment of offering costs	(26)	(21)
Contributions – Noncontrolling Interests – Partially Owned Properties	125	125
Contributions – Limited Partners	1
Distributions:
OP Units – General Partner	(185,484)	(184,302)
Preference Units	(773)	(1,545)
OP Units – Limited Partners	(6,666)	(7,218)
Noncontrolling Interests – Partially Owned Properties	(4,220)	(5,134)
Net cash provided by (used for) financing activities	(514,367)	(264,127)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(6,051)	(32,865)
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	94,711	186,223
Cash and cash equivalents	44,453	42,139
Restricted deposits	50,258	144,084
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	96,404	86,668
Net cash paid for income and other taxes	462	468
Amortization of deferred financing costs:
Other assets	603	603
Mortgage notes payable, net	2,084	794
Notes, net	992	899
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	897	525
Notes, net	635	605
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	4,791	4,583
Write-off of pursuit costs:
Investment in real estate, net	931	685
Other assets		10
Accounts payable and accrued expenses		20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	627	701
Other liabilities	350	372
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(9,132)	1,106
Notes, net	(2,289)	(1,106)
Other liabilities	5,334
Accumulated other comprehensive income	6,087
Investments in unconsolidated entities:
Investments in unconsolidated entities	(2,079)	(804)
Other liabilities	(720)	(900)
Debt financing costs:
Notes, net	(4,345)
Proceeds from (payments on) settlement of derivative instruments:
Other assets	1,638
Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	(22,110)	(11,698)
ERPOP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	220,548	149,941
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	196,309	178,968
Amortization of deferred financing costs	3,679	2,296
Amortization of above/below market lease intangibles	1,098	856
Amortization of discounts and premiums on debt	1,532	1,130
Amortization of deferred settlements on derivative instruments	4,788	4,580
Write-off of pursuit costs	931	715
(Income) loss from investments in unconsolidated entities	977	1,073
Distributions from unconsolidated entities – return on capital	615	648
Net (gain) loss on sales of real estate properties	(142,213)	(36,707)
Net (gain) loss on sales of land parcels		(19,193)
Net (gain) loss on debt extinguishment	22,110	11,698
Compensation paid with Company Common Shares	10,278	7,873
Changes in assets and liabilities:
(Increase) decrease in other assets	(15,396)	(11,059)
Increase (decrease) in accounts payable and accrued expenses	48,997	42,472
Increase (decrease) in accrued interest payable	11,718	13,437
Increase (decrease) in other liabilities	(4,692)	(45,324)
Increase (decrease) in security deposits	(261)	500
Net cash provided by operating activities	361,018	303,904
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in real estate – acquisitions	(54,134)
Investment in real estate – development/other	(40,813)	(103,291)
Capital expenditures to real estate	(36,747)	(39,297)
Non-real estate capital additions	(1,191)	(289)
Interest capitalized for real estate under development	(1,688)	(8,238)
Proceeds from disposition of real estate, net	284,670	80,064
Investments in unconsolidated entities	(2,799)	(1,704)
Distributions from unconsolidated entities – return of capital		113
Net cash provided by (used for) investing activities	147,298	(72,642)
CASH FLOWS FROM FINANCING ACTIVITIES:
Debt financing costs	(4,345)
Mortgage notes payable, net:
Lump sum payoffs	(725,639)	(351,774)
Scheduled principal repayments	(1,720)	(1,964)
Notes, net:
Proceeds	497,010
Line of credit and commercial paper:
Line of credit proceeds	415,000
Line of credit repayments	(415,000)
Commercial paper proceeds	1,107,561	1,310,188
Commercial paper repayments	(1,173,000)	(1,015,500)
Proceeds from (payments on) settlement of derivative instruments	1,638
Proceeds from EQR’s Employee Share Purchase Plan (ESPP)	1,681	1,574
Proceeds from exercise of EQR options	1,600	3,142
Payment of offering costs	(26)	(21)
Contributions – Noncontrolling Interests – Partially Owned Properties	125	125
Contributions – Limited Partners	1
Distributions:
OP Units – General Partner	(185,484)	(184,302)
Preference Units	(773)	(1,545)
OP Units – Limited Partners	(6,666)	(7,218)
Noncontrolling Interests – Partially Owned Properties	(4,220)	(5,134)
Net cash provided by (used for) financing activities	(514,367)	(264,127)
Net increase (decrease) in cash and cash equivalents and restricted deposits	(6,051)	(32,865)
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents and restricted deposits, end of period	94,711	186,223
Cash and cash equivalents	44,453	42,139
Restricted deposits	50,258	144,084
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	96,404	86,668
Net cash paid for income and other taxes	462	468
Amortization of deferred financing costs:
Other assets	603	603
Mortgage notes payable, net	2,084	794
Notes, net	992	899
Amortization of discounts and premiums on debt:
Mortgage notes payable, net	897	525
Notes, net	635	605
Amortization of deferred settlements on derivative instruments:
Other liabilities	(3)	(3)
Accumulated other comprehensive income	4,791	4,583
Write-off of pursuit costs:
Investment in real estate, net	931	685
Other assets		10
Accounts payable and accrued expenses		20
(Income) loss from investments in unconsolidated entities:
Investments in unconsolidated entities	627	701
Other liabilities	350	372
Realized/unrealized (gain) loss on derivative instruments:
Other assets	(9,132)	1,106
Notes, net	(2,289)	(1,106)
Other liabilities	5,334
Accumulated other comprehensive income	6,087
Investments in unconsolidated entities:
Investments in unconsolidated entities	(2,079)	(804)
Other liabilities	(720)	(900)
Debt financing costs:
Notes, net	(4,345)
Proceeds from (payments on) settlement of derivative instruments:
Other assets	1,638
ERPOP [Member] | Mortgage Notes Payable, Net [Member]
Mortgage notes payable, net:
Net gain (loss) on debt extinguishment	$ (22,110)	$ (11,698)

CONSOLIDATED STATEMENT OF CHA12

CONSOLIDATED STATEMENT OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	ERPOP [Member]	PREFERRED SHARESERPOP [Member]	General Partner [Member]ERPOP [Member]	Limited Partner [Member]ERPOP [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)ERPOP [Member]	PARTIALLY OWNED PROPERTIES [Member]ERPOP [Member]
Balance, beginning of year at Dec. 31, 2017			$ 37,280	$ 10,293,796	$ 226,691	$ (88,612)
Balance, beginning of year at Dec. 31, 2017							$ 4,708
OP Unit Issuance:
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				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
Issuance of restricted units to Noncontrolling Interests					1
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

Business

Business	3 Months Ended
	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business	1. Business Equity Residential (“EQR”), a Maryland real estate investment trust (“REIT”) formed in March 1993, is an S&P 500 company focused on the acquisition, development and management of rental apartment properties in urban and high-density suburban coastal gateway markets. ERP Operating Limited Partnership (“ERPOP”), an Illinois limited partnership, was formed in May 1993 to conduct the multifamily residential property business of Equity Residential. EQR has elected to be REIT. ERPOP. ERPOP. EQR is the general partner of, and as of March 31, 2018 owned an approximate 96.3% ownership interest in, ERPOP. All of the Company’s property ownership, development and related business operations are conducted through the Operating Partnership ERPOP. ERPOP, As of March 31, 2018, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 303 properties located in 10 states and the District of Columbia consisting of 78,399 apartment units. The ownership breakdown includes (table does not include various uncompleted development properties): Properties Apartment Units Wholly Owned Properties 282 73,160 Master-Leased Properties – Consolidated 2 759 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 303 78,399 Note: Effective February 1, 2018, the Company took over management of one of its Master-Leased properties containing 94 apartment units located in Boston.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Summary Of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) and certain reclassifications considered necessary for a fair presentation have been included. Certain reclassifications have been made to the prior period financial statements in order to conform to the current year presentation. These reclassifications did not have an impact on net income previously reported. Operating results for the quarter ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. In preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. The balance sheets at December 31, 2017 have been derived from the audited financial statements at that date but do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. For further information, including definitions of capitalized terms not defined herein, refer to the consolidated financial statements and footnotes thereto included in the Company’s and the Operating Partnership’s Annual Report on Form 10-K for the year ended December 31, 2017. Income and Other Taxes Due to the structure of EQR as a REIT and the nature of the operations of its operating properties, no provision for federal income taxes has been made at the EQR level. In addition, ERPOP generally is not liable for federal income taxes as the partners recognize their proportionate share of income or loss in their tax returns; therefore no provision for federal income taxes has been made at the ERPOP level. Historically, the Company has generally only incurred certain state and local income, excise and franchise taxes. The Company has elected Taxable REIT Subsidiary (“TRS”) status for certain of its corporate subsidiaries and as a result, these entities will incur both federal and state income taxes on any taxable income of such entities after consideration of any net operating losses. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. These assets and liabilities are measured using enacted tax rates for which the temporary differences are expected to be recovered or settled. The effects of changes in tax rates on deferred tax assets and liabilities are recognized in earnings in the period enacted. The Company’s deferred tax assets were generally the result of tax affected suspended interest deductions, net operating losses, differing depreciable lives on capitalized assets and the timing of expense recognition for certain accrued liabilities. In December 2017, the President signed into law H.R. 1, informally titled the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act is not expected to have a material impact on our REIT or subsidiary entities, our ability to continue to qualify as a REIT or on our results of operations. However, the complete impact of the Tax Act is not yet fully known and there can be no assurances that it will have a neutral or favorable impact. Recently Issued Accounting Pronouncements In • Lessors – Leases will be accounted for using an approach that is substantially equivalent to existing guidance for operating, sales-type and financing leases, but aligned with the new revenue recognition standard. Lessors will be required to allocate lease payments to separate lease and non-lease components of each lease agreement, with the non-lease components evaluated under the new revenue recognition standard. • Lessees – Leases will be accounted for using a dual approach, classifying leases as either operating or finance based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized on a straight-line basis over the term of the lease (for operating leases) or based on an effective interest method with a front-loaded expense recognition (for finance leases). A lessee is also required to record a right-of-use asset and a lease liability on its balance sheet for all leases with a term of greater than 12 months regardless of their classification as operating or finance leases. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. The new standard will be effective for the Company beginning on January 1, 2019, with early adoption permitted, though the Company currently anticipates adopting the new standard on the effective date. The new standard must be adopted using a modified retrospective method, which requires application of the new guidance at the beginning of the earliest comparative period presented and provides for certain practical expedients, which the Company currently anticipates electing. The Company anticipates that its residential and retail/commercial leases where it is the lessor will continue to be accounted for as operating leases under the new standard. Therefore, the Company does not currently anticipate significant changes in the accounting for its lease revenues. The Company is also the lessee under various corporate office and ground leases, which it will be required to recognize right of use assets and related lease liabilities on its consolidated balance sheets upon adoption. The Company currently anticipates that its corporate office leases where it is the lessee will continue to be accounted for as operating leases under the new standard. Based on its anticipated election of the practical expedients, the Company would not be required to reassess the classification of existing ground leases and therefore these leases would continue to be accounted for as operating leases. However, in the event we modify existing ground leases and/or enter into new ground leases after adoption of the new standard, such leases will likely be classified as finance leases. The Company will continue to evaluate the impact of adopting the new leases standard on its consolidated results of operations and financial position. In June 2016, the FASB In August 2017, the FASB issued a final standard which makes changes to the hedge accounting model to enable entities to better portray their risk management activities in the financial statements. The new standard expands an entity’s ability to hedge nonfinancial and financial risk components, reduces complexity in fair value hedges of interest rate risk and eases certain documentation and assessment requirements. The new standard also eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of any hedging instrument to be presented in the same income statement line as the hedged instrument. The new standard will be effective for the Company beginning on January 1, 2019 and early adoption is permitted. The Company is currently evaluating the impact of adopting the new standard on its consolidated results of operations and financial position. Recently Adopted Accounting Pronouncements In FASB Revenue from Contracts with Customers any, For the remaining approximately 6% of rental income that is subject to the new revenue recognition standard, the Company’s disaggregated revenue streams are disclosed in the table below for the quarter ended March 31, 2018. These revenue streams have the same timing and pattern of revenue recognition across our reportable segments, with consistent allocations between the leasing and revenue recognition standards. The revenue streams and percentages are comparable with the percentage of rental income for the quarter ended March 31, 2017. The following table presents the disaggregation of revenue streams of our rental income for the quarter ended March 31, 2018 (amounts in thousands): Quarter Ended March 31, 2018 Revenue Stream Applicable Standard Amount of Rental Income Percentage of Rental Income Leasing revenue Leases $ 592,813 93.7 % Utility recoveries (“RUBS”) Revenue Recognition 15,375 2.4 % Parking revenue Revenue Recognition 7,797 1.2 % Other revenue Revenue Recognition 16,846 2.7 % Rental income $ 632,831 100.0 % Additionally, as part of the new revenue recognition standard, the FASB issued amendments related to partial sales of real estate (see further discussion below). Adoption of the new partial sales standard did not result in a change of accounting for the Company related to its disposition process. We concluded that the Company’s typical dispositions will continue to meet the criteria for sale and associated profit recognition under both new standards. In FASB In FASB • Cash payments related to debt prepayments or extinguishment costs are to be classified within financing • The portion of the cash payment made to settle a zero-coupon bond or a bond with an insignificant cash coupon attributable to accreted interest related to a debt discount is to be classified as a cash outflow within operating activities, and the portion attributable to the principal is to be classified within financing • Insurance settlement proceeds are to be classified based on the nature of the • Companies must elect to classify distributions received from equity method investees using either a cumulative earnings approach or a look-through approach and the election must be disclosed; • Restricted Total The While overall cash flows did not change, there are changes between cash flow classifications due primarily to the debt prepayment penalties that the Company has incurred in the comparative period. As of March 31, 2017, the following cash flows were reclassified (amounts in thousands): Quarter Ended March 31, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 1,637 $ (507 ) $ 1,130 Net (gain) loss on debt extinguishment $ — $ 11,698 $ 11,698 (Increase) decrease in deposits - restricted $ 256 $ (256 ) $ — (Increase) decrease in mortgage deposits $ 315 $ (315 ) $ — Net cash provided by operating activities $ 293,284 $ 10,620 $ 303,904 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ 637 $ (637 ) $ — (Increase) decrease in mortgage deposits $ (1,030 ) $ 1,030 $ — Net cash provided by (used for) investing activities $ (73,035 ) $ 393 $ (72,642 ) Cash Flows from Financing Activities: Mortgage deposits $ (2,381 ) $ 2,381 $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (11,698 ) $ (11,698 ) Line of credit and commercial paper: Commercial paper proceeds $ 1,309,681 $ 507 $ 1,310,188 Net cash (used for) financing activities $ (255,317 ) $ (8,810 ) $ (264,127 ) Cash and cash equivalents, beginning of period $ 77,207 (adjustments for restricted deposits, beginning of period) $ 141,881 Cash and cash equivalents and restricted deposits, beginning of period $ 219,088 Cash and cash equivalents, end of period $ 42,139 (adjustments for restricted deposits, end of period) $ 144,084 Cash and cash equivalents and restricted deposits, end of period $ 186,223 In FASB In FASB clarifies the accounting treatment for partial sales of nonfinancial assets (i.e. real estate). The standard clarifies that partial sales transactions include contributions of nonfinancial assets to a joint venture or other noncontrolled investee. Companies must recognize a full gain or loss on transfers of nonfinancial assets to equity method investees. The standard requires companies to derecognize distinct nonfinancial assets or distinct in substance nonfinancial assets in partial sale transactions when it does not have a controlling financial interest in the legal entity that holds the asset and transfers control of the asset. Once the distinct nonfinancial asset is transferred, the company is required to measure any non-controlling interest it receives or retains at fair value and recognize a full gain or loss on the transaction. If a company transfers ownership interests in a consolidated subsidiary and continues to maintain a controlling financial interest, the company does not derecognize the assets or liabilities, and accounts for the transaction as an equity transaction and no gain or loss is recognized. The Company has not had a partial sale of nonfinancial assets in the current or comparative periods, therefore the adoption of this standard did not have a material impact on its consolidated results of operations and financial position. Other The Company is the controlling partner in various consolidated partnerships owning 17 properties consisting of 3,535 apartment units having a noncontrolling interest book value of $1.3 million at March 31, 2018. The Company is required to make certain disclosures regarding noncontrolling interests in consolidated limited-life subsidiaries. Of the consolidated entities described above, the Company is the controlling partner in limited-life partnerships owning four properties having a noncontrolling interest deficit balance of $8.7 million. These four partnership agreements contain provisions that require the partnerships to be liquidated through the sale of their assets upon reaching a date specified in each respective partnership agreement. The Company, as controlling partner, has an obligation to cause the property owning partnerships to distribute the proceeds of liquidation to the Noncontrolling Interests in these Partially Owned Properties only to the extent that the net proceeds received by the partnerships from the sale of their assets warrant a distribution based on the partnership agreements. As of March 31, 2018, the Company estimates the value of Noncontrolling Interest distributions for these four properties would have been approximately $66.3 million (“Settlement Value”) had the partnerships been liquidated. This Settlement Value is based on estimated third party consideration realized by the partnerships upon disposition of the four Partially Owned Properties and is net of all other assets and liabilities, including yield maintenance on the mortgages encumbering the properties, that would have been due on had those mortgages been prepaid. Due to, among other things, the inherent uncertainty in the sale of real estate assets, the amount of any potential distribution to the Noncontrolling Interests in the Company’s Partially Owned Properties is subject to change. To the extent that the partnerships’ underlying assets are worth less than the underlying liabilities, the Company has no obligation to remit any consideration to the Noncontrolling Interests in these Partially Owned Properties

Equity, Capital and Other Inter

Equity, Capital and Other Interests	3 Months Ended
	Mar. 31, 2018
Equity Capital And Other Interests [Abstract]
Equity, Capital and Other Interests	3. Equity, Capital and Other Equity and Redeemable Noncontrolling Interests of Equity Residential The following tables present the changes in the Company’s issued and outstanding Common Shares and “Units” (which includes OP Units and restricted units) for the quarter ended March 31, 2018: 2018 Common Shares Common Shares outstanding at January 1, 368,018,082 Common Shares Issued: Conversion of OP Units 5,000 Exercise of share options 45,391 Employee Share Purchase Plan (ESPP) 35,177 Restricted share grants, net 108,261 Common Shares outstanding at March 31, 368,211,911 Units Units outstanding at January 1, 13,768,438 Restricted unit grants, net 263,048 Conversion of OP Units to Common Shares (5,000 ) Units outstanding at March 31, 14,026,486 Total Common Shares and Units outstanding at March 31, 382,238,397 Units Ownership Interest in Operating Partnership 3.7 % The equity positions of various individuals and entities that contributed their properties to the Operating Partnership in exchange for OP Units, as well as the equity positions of the holders of restricted units, are collectively referred to as the “Noncontrolling Interests – Operating Partnership”. Subject to certain exceptions (including the “book-up” requirements of restricted units), the Noncontrolling Interests – Operating Partnership may exchange their Units with EQR for Common Shares on a one-for-one basis. The carrying value of the Noncontrolling Interests – Operating Partnership (including redeemable interests) is allocated based on the number of Noncontrolling Interests – Operating Partnership Units in total in proportion to the number of Noncontrolling Interests – Operating Partnership Units in total plus the number of Common Shares. Net income is allocated to the Noncontrolling Interests – Operating Partnership based on the weighted average ownership percentage during the period. The Operating Partnership has the right but not the obligation to make a cash payment instead of issuing Common Shares to any and all holders of Noncontrolling Interests – Operating Partnership Units requesting an exchange of their OP Units with EQR. Once the Operating Partnership elects not to redeem the Noncontrolling Interests – Operating Partnership Units for cash, EQR is obligated to deliver Common Shares to the exchanging holder of the Noncontrolling Interests – Operating Partnership Units. The law, Instruments that require settlement in registered shares cannot be classified in permanent equity as it is not always completely within an issuer’s control to deliver registered shares. Therefore, settlement in cash is assumed and that responsibility for settlement in cash is deemed to fall to the Operating Partnership as the primary source of cash for EQR, resulting in presentation in the mezzanine section of the balance sheet. The Redeemable Noncontrolling Interests – Operating Partnership are adjusted to the greater of carrying value or fair market value based on the Common Share price of EQR at the end of each respective reporting period. EQR has the ability to deliver unregistered Common Shares for the remaining portion of the Noncontrolling Interests – Operating Partnership Units that are classified in permanent equity at March 31, 2018 and December 31, 2017. The The 2018 Balance at January 1, $ 366,955 Change in market value (12,831 ) Change in carrying value 443 Balance at March 31, $ 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) 2018 2017 Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized: 8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call date, redeemable preferred shares may be redeemed for cash at the option of the Company, in whole or in part, at a redemption price equal to the liquidation price per share, plus accrued and unpaid distributions, if any. (2) Dividends on Preferred Shares are payable quarterly. Capital and Redeemable Limited Partners of ERP Operating Limited Partnership The following tables present the changes in the Operating Partnership’s issued and outstanding Units and in the limited partners’ Units for the quarter ended March 31, 2018: 2018 General and Limited Partner Units General and Limited Partner Units outstanding at January 1, 381,786,520 Issued to General Partner: Exercise of EQR share options 45,391 EQR’s Employee Share Purchase Plan (ESPP) 35,177 EQR’s restricted share grants, net 108,261 Issued to Limited Partners: Restricted unit grants, net 263,048 General and Limited Partner Units outstanding at March 31, 382,238,397 Limited Partner Units Limited Partner Units outstanding at January 1, 13,768,438 Limited Partner restricted unit grants, net 263,048 Conversion of Limited Partner OP Units to EQR Common Shares (5,000 ) Limited Partner Units outstanding at March 31, 14,026,486 Limited Partner Units Ownership Interest in Operating Partnership 3.7 % The Limited Partners of the Operating Partnership as of March 31, 2018 include various individuals and entities that contributed their properties to the Operating Partnership in exchange for OP Units, as well as the equity positions of the holders of restricted units. Subject to certain exceptions (including the “book-up” requirements of restricted units), Limited Partners may exchange their Units with EQR for Common Shares on a one-for-one basis. The carrying value of the Limited Partner Units (including redeemable interests) is allocated based on the number of Limited Partner Units in total in proportion to the number of Limited Partner Units in total plus the number of General Partner Units. Net income is allocated to the Limited Partner Units based on the weighted average ownership percentage during the period. The Operating Partnership has the right but not the obligation to make a cash payment instead of issuing Common Shares to any and all holders of Limited Partner Units requesting an exchange of their OP Units with EQR. Once the Operating Partnership elects not to redeem the Limited Partner Units for cash, EQR is obligated to deliver Common Shares to the exchanging limited partner. The Limited Partner Units are classified as either mezzanine equity or permanent equity. If EQR is required, either by contract or securities law, to deliver registered Common Shares, such Limited Partner Units are differentiated and referred to as “Redeemable Limited Partner Units”. Instruments that require settlement in registered shares cannot be classified in permanent equity as it is not always completely within an issuer’s control to deliver registered shares. Therefore, settlement in cash is assumed and that responsibility for settlement in cash is deemed to fall to the Operating Partnership as the primary source of cash for EQR, resulting in presentation in the mezzanine section of the balance sheet. The Redeemable Limited Partner Units are adjusted to the greater of carrying value or fair market value based on the Common Share price of EQR at the end of each respective reporting period. EQR has the ability to deliver unregistered Common Shares for the remaining portion of the Limited Partner Units that are classified in permanent equity at March 31, 2018 and . The carrying value of the Redeemable Limited Partner Units is allocated based on the number of Redeemable Limited Partner The following table presents the changes in the redemption value of the Redeemable Limited Partners for the quarter ended March 31, 2018 (amounts in thousands): 2018 Balance at January 1, $ 366,955 Change in market value (12,831 ) Change in carrying value 443 Balance at March 31, $ 354,567 EQR contributes all net proceeds from its various equity offerings (including proceeds from exercise of options for Common ERPOP. The December 31, 2017 Amounts in thousands Annual Call Dividend Per March 31, December 31, Date (1) Unit (2) 2018 2017 Preference Units: 8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 745,600 units issued and outstanding as of March 31, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call date, redeemable preference units may be redeemed for cash at the option of the Operating Partnership, in whole or in part, at a redemption price equal to the liquidation price per unit, plus accrued and unpaid distributions, if any, in conjunction with the concurrent redemption of the corresponding Company Preferred Shares. (2) Dividends on Preference Units are payable quarterly. Other In September 2009, the Company announced the establishment of an At-The-Market (“ATM”) The Company may repurchase up to 13.0 million Common Shares under its share repurchase program. No shares were repurchased during the quarter ended March 31, 2018. As of March 31, 2018, EQR has remaining authorization to repurchase up to 13.0 million of its shares under the repurchase program.

Real Estate and Lease Intangibl

Real Estate and Lease Intangibles	3 Months Ended
	Mar. 31, 2018
Real Estate [Abstract]
Real Estate and Lease Intangibles	4. Real Estate and Lease Intangibles The following table summarizes the carrying amounts for the Company’s investment in real estate (at cost) as of March 31, 2018 and December 31, 2017 (amounts in thousands): March 31, 2018 December 31, 2017 Land $ 5,960,804 $ 5,996,024 Depreciable property: Buildings and improvements 17,748,897 17,743,042 Furniture, fixtures and equipment 1,575,934 1,548,961 In-Place lease intangibles 473,522 476,359 Projects under development: Land 30,605 43,226 Construction-in-progress 66,004 120,321 Land held for development: Land 62,538 62,538 Construction-in-progress 40,313 36,425 Investment in real estate 25,958,617 26,026,896 Accumulated depreciation (6,173,047 ) (6,040,378 ) Investment in real estate, net $ 19,785,570 $ 19,986,518 The following table summarizes the carrying amounts for the Company’s above and below market ground and retail lease intangibles as of March 31, 2018 and December 31, 2017 (amounts in thousands): Description Balance Sheet Location March 31, 2018 December 31, 2017 Assets Ground lease intangibles – below market Other Assets $ 191,918 $ 191,918 Retail lease intangibles – above market Other Assets 1,260 1,260 Lease intangible assets 193,178 193,178 Accumulated amortization (23,562 ) (22,434 ) Lease intangible assets, net $ 169,616 $ 170,744 Liabilities Ground lease intangibles – above market Other Liabilities $ 2,400 $ 2,400 Retail lease intangibles – below market Other Liabilities 5,270 5,270 Lease intangible liabilities 7,670 7,670 Accumulated amortization (5,173 ) (5,143 ) Lease intangible liabilities, net $ 2,497 $ 2,527 The following table provides a summary of the effect of the amortization for above and below market ground and retail lease intangibles on Quarter Ended March 31, Description Income Statement Location 2018 2017 Ground lease intangible amortization Property and Maintenance $ (1,116 ) $ (1,080 ) Retail lease intangible amortization Rental Income 18 224 Total amortization of above/below market lease intangibles $ (1,098 ) $ (856 ) The following table provides a summary of the aggregate amortization for above and below market ground and retail lease intangibles for each of the next five years (amounts in thousands): Remaining 2018 2019 2020 2021 2022 2023 Ground lease intangibles $ (3,347 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) Retail lease intangibles 53 71 71 71 27 19 Total $ (3,294 ) $ (4,392 ) $ (4,392 ) $ (4,392 ) $ (4,436 ) $ (4,444 ) During the quarter ended March 31, 2018, the Company acquired the entire equity interest in the following from unaffiliated parties (purchase price in thousands): Properties Apartment Units Purchase Price Rental Properties – Consolidated (1) 1 117 $ 53,700 Total 1 117 $ 53,700 (1) Purchase price includes an allocation of approximately $14.8 million to land and $39.3 million to depreciable property (inclusive of capitalized closing costs). During the quarter ended March 31, 2018 , the Company disposed of the following to unaffiliated parties (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 4 786 $ 290,020 Total 4 786 $ 290,020 The Company recognized a net gain on sales of real estate properties of approximately $142.2 million on the above sales.

Commitments to Acquire_Dispose

Commitments to Acquire/Dispose of Real Estate	3 Months Ended
	Mar. 31, 2018
Commitments To Acquire Dispose Of Real Estate [Abstract]
Commitments to Acquire/Dispose of Real Estate	5. Commitments to Acquire/Dispose of Real The Company has not entered into any separate agreements to acquire rental properties or land parcels as of the date of this filing. The Company has entered into a separate agreement to dispose of the following (sales price in thousands): Properties Apartment Units Sales Price Land Parcels (one) — — $ 2,700 Total — — $ 2,700 The closing of this pending transaction is subject to certain conditions and restrictions, therefore, there can be no assurance that this transaction will be consummated or that the final terms will not differ in material respects from those summarized above.

Investments in Partially Owned

Investments in Partially Owned Entities	3 Months Ended
	Mar. 31, 2018
Investments In Partially Owned Entities [Abstract]
Investments in Partially Owned Entities	6. Investments in Partially Owned The March 31, 2018 Consolidated Unconsolidated (VIE) (Non-VIE) (VIE) (1) Total Total properties 17 2 — 2 Total apartment units 3,535 945 — 945 Balance sheet information at 3/31/2018 (at 100%): ASSETS Investment in real estate $ 875,187 $ 236,854 $ 172,995 $ 409,849 Accumulated depreciation (235,426 ) (46,190 ) (51,420 ) (97,610 ) Investment in real estate, net 639,761 190,664 121,575 312,239 Cash and cash equivalents 13,061 6,587 225 6,812 Investments in unconsolidated entities 43,926 — — — Restricted deposits 381 258 — 258 Other assets 25,879 243 320 563 Total assets $ 723,008 $ 197,752 $ 122,120 $ 319,872 LIABILITIES AND EQUITY/CAPITAL Mortgage notes payable, net (2) $ 302,656 $ 145,424 $ — $ 145,424 Accounts payable & accrued expenses 3,344 1,361 115 1,476 Accrued interest payable 1,037 691 — 691 Other liabilities 3,683 261 15 276 Security deposits 2,470 525 — 525 Total liabilities 313,190 148,262 130 148,392 Noncontrolling Interests – Partially Owned Properties/Partners’ equity 1,293 51,079 84,038 135,117 Company equity/General and Limited Partners’ Capital 408,525 (1,589 ) 37,952 36,363 Total equity/capital 409,818 49,490 121,990 171,480 Total liabilities and equity/capital $ 723,008 $ 197,752 $ 122,120 $ 319,872 Consolidated Unconsolidated (VIE) (Non-VIE) (VIE) (1) Total Operating information for the quarter ended 3/31/2018 (at 100%): Operating revenue $ 26,447 $ 6,942 $ 1,258 $ 8,200 Operating expenses 6,637 2,268 581 2,849 Net operating income 19,810 4,674 677 5,351 Property management 955 199 19 218 General and administrative 17 — — — Depreciation 10,479 2,677 1,375 4,052 Operating income (loss) 8,359 1,798 (717 ) 1,081 Interest and other income 27 — — — Interest: Expense incurred, net (3,312 ) (2,072 ) — (2,072 ) Amortization of deferred financing costs (68 ) — — — Income (loss) before income and other taxes and income (loss) from investments in unconsolidated entities 5,006 (274 ) (717 ) (991 ) Income and other tax (expense) benefit (18 ) (13 ) — (13 ) Income (loss) from investments in unconsolidated entities (393 ) — — — Net income (loss) $ 4,595 $ (287 ) $ (717 ) $ (1,004 ) (1) Includes the Company’s unconsolidated interest in an entity that owns the land underlying our Wisconsin Place apartment property and owns and operates the parking facility. This entity is excluded from the property and apartment unit count. (2) All debt is non-recourse to the Company. Note: The above tables exclude EQR’s ownership interest in ERPOP, private equity fund investments, and the Company’s interests in unconsolidated joint ventures established in connection with the acquisition of certain real estate related assets from Archstone Enterprise LP (“Archstone”). Operating Properties The Company has various equity interests in certain limited partnerships owning 16 properties containing 3,103 apartment units. Each partnership owns a multifamily property. The Company is the general partner of these limited partnerships and is responsible for managing the operations and affairs of the partnerships as well as making all decisions regarding the businesses of the partnerships. The limited partners are not able to exercise substantive kick-out or participating rights. As a result, the partnerships qualify as variable interest entities (“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 partnerships are required to be consolidated on the Company’s financial statements. The Company has a 75% equity interest in the Wisconsin Place joint venture. The project contains a mixed-use site located in Chevy Chase, Maryland consisting of residential, retail, office and accessory uses, including underground parking facilities. The joint venture owns the 432 unit residential component, but has no ownership interest in the retail and office components. At March 31, 2018, the residential component had a net book value of $159.4 million. The Company is the managing member and is responsible for conducting all administrative day-to-day matters and affairs of the joint venture as well as implementing all decisions with respect to the joint venture. The limited partner is not able to exercise substantive kick-out or participating rights. As a result, the joint venture qualifies as a VIE. The Company has a controlling financial interest in the VIE and, thus, is the VIE’s primary beneficiary. The Company has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance as well as 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 residential component is required to be consolidated on the Company’s financial statements. The Wisconsin Place joint venture also retains an unconsolidated interest in an entity that owns the land underlying the entire project and owns and operates the parking facility. At March 31, 2018, the basis of this investment was $43.9 million. 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. The Company has a 20% equity interest in each of the Nexus Sawgrass and Domain joint ventures under separate agreements. The Nexus Sawgrass joint venture owns a 501 unit apartment property located in Sunrise, Florida and the Company’s interest had a basis of $4.0 million at March 31, 2018. The Domain joint venture owns a 444 unit apartment property located in San Jose, California and the Company’s interest had a basis of $7.9 million at March 31, 2018. Both properties were funded with long-term, non-recourse secured loans from the partner. The mortgage loan on Nexus Sawgrass has a current unconsolidated outstanding balance of $48.6 million, bears interest at 5.60% and matures January 1, 2021. The mortgage loan on Domain has a current unconsolidated outstanding balance of $96.8 million, bears interest at 5.75% and matures January 1, 2022. While the Company is the managing member of both of the joint ventures, the joint venture partner has significant participating rights and has active involvement in the oversight of the operations. As a result, the entities do not qualify as VIEs. The Company alone does not have the power to direct the activities of the entities that most significantly impact the entities’ economic performance and as a result, the entities are unconsolidated and recorded using the equity method of accounting. Other 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. As a result, ERPOP is required to be consolidated on EQR’s financial statements. The Company agreed to a maximum investment of $5.0 million each for two private equity funds, both of which primarily focus on real estate technology investments. The Company accounts for both investments under the equity method of accounting. As of March 31, 2018, the Company’s interest in these investments had a combined basis of $4.1 million. On February 27, 2013, in connection with the acquisition of Archstone, subsidiaries of the Company entered into three limited liability company agreements (collectively, the “Residual JV”). The Residual JV owned certain Archstone assets and succeeded to certain residual Archstone liabilities/litigation. The Residual JV is owned 60% by the Company and 40% by its joint venture partner. The On February 27, 2013, in connection with the acquisition of Archstone, a subsidiary of the Company entered into a limited liability company agreement (the “Legacy JV”), through which they assumed obligations of Archstone in the form of preferred interests, some of which are governed by tax protection arrangements. At March 31, 2018, the remaining preferred interests had an aggregate liquidation value of $37.3 million, our share of which is included in other liabilities in the accompanying consolidated balance sheets. Obligations of the Legacy JV are borne 60% by the Company and 40% by its joint venture partner. The Legacy JV is managed by a Management Committee consisting of two members from each of the Company and its joint venture partner. Both partners have equal participation in the Management Committee and all significant participating rights are shared by both partners. As a result, the Legacy JV does not qualify as a VIE. The Company alone does not have the power to direct the activities of the Legacy JV that most significantly impact the Legacy JV’s economic performance and as a result, the Legacy JV is unconsolidated and recorded using the equity method of accounting.

Restricted Deposits

Restricted Deposits	3 Months Ended
	Mar. 31, 2018
Deposits Restricted [Abstract]
Restricted Deposits	7. Restricted Deposits The following table presents the Company’s restricted deposits as of March 31, 2018 and December 31, 2017 (amounts in thousands): March 31, 2018 December 31, 2017 Mortgage escrow deposits: Real estate taxes and insurance $ 1,279 $ 845 Replacement reserves 7,423 8,347 Mortgage principal reserves/sinking funds 4,778 3,167 Other 852 852 Mortgage escrow deposits 14,332 13,211 Restricted cash: Earnest money on pending acquisitions — 750 Restricted deposits on real estate investments 53 58 Resident security and utility deposits 34,967 35,183 Other 906 913 Restricted cash 35,926 36,904 Restricted deposits $ 50,258 $ 50,115

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	8. Debt EQR Mortgage Notes Payable As of March 31, 2018, the Company had outstanding mortgage debt of approximately $2.9 billion. During the quarter ended March 31, 2018, the Company: • Repaid $550.0 million of 6.08% mortgage debt held in a Fannie Mae loan pool maturing in 2020 and incurred a prepayment penalty of approximately $22.1 million; • Repaid $43.7 million of conventional fixed-rate mortgage loans maturing in 2018; • Repaid $131.9 million of various tax-exempt mortgage bonds maturing in 2028 through 2042; and • Repaid $1.7 million of scheduled principal repayments on various mortgage debt. The Company recorded $1.6 million of write-offs of unamortized deferred financing costs during the quarter ended March 31, 2018 as additional interest expense related to debt extinguishment of mortgages. The Company also recorded $0.2 million of write-offs of net unamortized premiums during the quarter ended March 31, 2018 as a reduction of interest expense related to debt extinguishment of mortgages. As of March 31, 2018, the Company had $563.5 million of secured debt subject to third party credit enhancement. As March 31, 2018 Notes As of March 31, 2018, the Company had outstanding unsecured notes of approximately $5.5 billion. During the quarter ended March 31, 2018, the Company issued $500.0 million of ten-year 3.50% unsecured notes, receiving net proceeds of approximately $497.0 million before underwriting fees, hedge termination costs and other expenses, at an all-in effective interest rate of 3.61%. As March 31, 2018 The Company’s unsecured public debt contains certain financial and operating covenants including, among other things, maintenance of certain financial ratios. The Company was in compliance with its unsecured public debt covenants for the quarter ended March 31, 2018. Line of Credit and Commercial Paper On November 3, 2016, the Company replaced its existing $2.5 billion facility with a $2.0 billion unsecured revolving credit facility maturing January 10, 2022. The Company has the ability to increase available borrowings by an additional $750.0 million by adding additional banks to the facility or obtaining the agreement of existing banks to increase their commitments. The interest rate on advances under the facility will generally be LIBOR plus a spread (currently 0.825%), or based on bids received from the lending group, and the Company pays an annual facility fee (currently 12.5 basis points). Both the spread and the facility fee are dependent on the credit rating of the Company’s long term debt. On March 31, 2018 As March 31, 2018 Other On April 24, 2017, the Company executed a new letter of credit facility with a third party financial institution which is not backed by or collateralized by borrowings on the Company’s unsecured revolving credit facility. As of March 31, 2018

Derivative and Other Fair Value

Derivative and Other Fair Value Instruments	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Derivative and Other Fair Value Instruments	9. Derivative and Other Fair Value The valuation of financial instruments requires the Company to make estimates and judgments that affect the fair value of the instruments. The Company, where possible, bases the fair values of its financial instruments, including its derivative instruments, on listed market prices and third party quotes. Where these are not available, the Company bases its estimates on current instruments with similar terms and maturities or on other factors relevant to the financial instruments. In the normal course of business, the Company is exposed to the effect of interest rate changes. The Company seeks to manage these risks by following established risk management policies and procedures including the use of derivatives to hedge interest rate risk on debt instruments. The Company may also use derivatives to manage commodity prices in the daily operations of the business. A • Level 1 – Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2 – Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. • Level 3 – Inputs to the valuation methodology are unobservable and significant to the fair value The Company’s derivative positions are valued using models developed by the respective counterparty as well as models developed internally by the Company that use as their basis readily observable market parameters (such as forward yield curves and credit default swap data). Employee holdings other than Common Shares within the supplemental executive retirement plan (the “SERP”) are valued using quoted market prices for identical assets and are included in other assets and other liabilities on the consolidated balance sheets. Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners are valued using the quoted market price of Common Shares. The fair values disclosed for mortgage notes payable and unsecured debt (including its commercial paper and line of credit, if applicable) were calculated using indicative rates provided by lenders of similar loans in the case of mortgage notes payable and the private unsecured debt (including its commercial paper and line of credit, if applicable) and quoted market prices for each underlying issuance in the case of the public unsecured notes. The fair values of the Company’s financial instruments (other than mortgage notes payable, unsecured notes, commercial paper, line of credit and derivative instruments), including cash and cash equivalents and other financial instruments, approximate their carrying or contract value. The March 31, 2018 December 31, 2017 Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Carrying Value Mortgage notes payable, net $ 2,841,288 $ 2,894,344 $ 3,615,384 $ 3,618,722 Unsecured debt, net 5,878,000 5,765,133 5,619,744 5,338,569 Total debt, net $ 8,719,288 $ 8,659,477 $ 9,235,128 $ 8,957,291 The March 31, 2018 Fair Value Hedges (1) Forward Starting Swaps (2) Current Notional Balance $ 450,000 $ 600,000 Lowest Interest Rate 2.375 % 2.1478 % Highest Interest Rate 2.375 % 3.0030 % Earliest Maturity Date 2019 2028 Latest Maturity Date 2019 2029 (1) Fair Value Hedges – Converts outstanding fixed rate unsecured notes ($450.0 million 2.375% notes due July 1, 2019) to a floating interest rate of 90-Day LIBOR plus 0.61%. (2) Forward Starting Swaps – Designed to partially fix interest rates in advance of planned future debt issuances. Of the $600.0 million notional balance, $250.0 million of these swaps have mandatory counterparty terminations in 2019 and are targeted for certain 2018 debt issuances while $350.0 million of these swaps have mandatory counterparty terminations in 2020 and are targeted for certain 2019 debt issuances. The Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 3/31/2018 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 $ 12,637 $ — $ 12,637 $ — Supplemental Executive Retirement Plan Other Assets 138,444 138,444 — — Total $ 151,081 $ 138,444 $ 12,637 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 3,886 $ — $ 3,886 $ — Forward Starting Swaps Other Liabilities 3,045 — 3,045 — Supplemental Executive Retirement Plan Other Liabilities 138,444 138,444 — — Total $ 145,375 $ 138,444 $ 6,931 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 354,567 $ — $ 354,567 $ — Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 12/31/2017 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Staring Swaps Other Assets $ 5,143 $ — $ 5,143 $ — Supplemental Executive Retirement Plan Other Assets 140,159 140,159 — — Total $ 145,302 $ 140,159 $ 5,143 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 1,597 $ — $ 1,597 $ — Supplemental Executive Retirement Plan Other Liabilities 140,159 140,159 — — Total $ 141,756 $ 140,159 $ 1,597 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 366,955 $ — $ 366,955 $ — The 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 March 31, 2017 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (1,106 ) Fixed rate debt Interest expense $ 1,106 Total $ (1,106 ) $ 1,106 The 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 ) $ — Effective Portion Ineffective Portion March 31, 2017 Type of Cash Flow Hedge Amount of Gain/(Loss) Recognized in OCI on Derivative Location of Gain/(Loss) Reclassified from Accumulated OCI into Income Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ — Interest expense $ (4,583 ) N/A $ — Total $ — $ (4,583 ) $ — As March 31, 2018 December 31, 2017 March 31, 2018 In February 2018, the Company received approximately $1.6 million to settle two forward starting swaps in conjunction with the issuance of $500.0 million of ten-year unsecured public notes. The entire $1.6 million was initially deferred as a component of accumulated other comprehensive income (loss) and will be recognized as a decrease to interest expense over the ten-year term of the notes.

Earning Per Share and Earnings

Earning Per Share and Earnings Per Unit	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earning Per Share And Earnings Per Unit	10. Earning Per Share and Earnings Per Equity Residential The Quarter Ended March 31, 2018 2017 Numerator for net income per share – basic: Net income $ 220,548 $ 149,941 Allocation to Noncontrolling Interests – Operating Partnership (8,059 ) (5,411 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (680 ) (788 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – basic $ 211,036 $ 142,969 Numerator for net income per share – diluted: Net income $ 220,548 $ 149,941 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (680 ) (788 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – diluted $ 219,095 $ 148,380 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 367,800 366,605 Effect of dilutive securities: OP Units 12,863 12,899 Long-term compensation shares/units 2,355 2,776 Denominator for net income per share – diluted 383,018 382,280 Net income per share – basic $ 0.57 $ 0.39 Net income per share – diluted $ 0.57 $ 0.39 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, 2018 2017 Numerator for net income per Unit – basic and diluted: Net income $ 220,548 $ 149,941 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (680 ) (788 ) Allocation to Preference Units (773 ) (773 ) Numerator for net income per Unit – basic and diluted $ 219,095 $ 148,380 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 380,663 379,504 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,355 2,776 Denominator for net income per Unit – diluted 383,018 382,280 Net income per Unit – basic $ 0.57 $ 0.39 Net income per Unit – diluted $ 0.57 $ 0.39

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. The Company, as an owner of real estate, is subject to various Federal, state and local environmental laws. Compliance by the Company with existing laws has not had a material adverse effect on the Company. However, the Company cannot predict the impact of new or changed laws or regulations on its current properties or on properties that it may acquire in the future. As of March 31, 2018, the Company does have environmental reserves totaling approximately $5.2 million related to three of its properties. The The Company does not believe there is any litigation pending or threatened against it that, individually or in the aggregate, may reasonably be expected to have a material adverse effect on the Company. As of March 31, 2018, the Company has three wholly owned projects totaling 443 apartment units in various stages of development with remaining commitments to fund of approximately $105.2 million and estimated completion dates ranging through December 31, 2019, as well as other completed development projects that are in various stages of lease-up or are stabilized. As March 31, 2018

Reportable Segments

Reportable Segments	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Reportable Segments	12. Reportable Operating segments are defined as components of an enterprise that engage in business activities from which they may earn revenues and incur expenses and about which discrete financial information is available that is evaluated regularly by the chief The Company’s primary business is the acquisition, development and management of multifamily residential properties, which includes the generation of rental and other related income through the leasing of apartment units to residents. The chief operating decision maker evaluates the Company’s operating performance geographically by market and both on a same store and non-same store basis. The Company’s same store operating segments located in its coastal gateway markets represent its reportable segments. The Company’s operating segments located in its other markets (Phoenix) that are not material have also been included in the tables presented below. The Company’s fee and asset management and development activities are other business activities that do not constitute an operating segment and as such, have been aggregated in the “Other” category in the tables presented below. All The primary financial measure for the Company’s rental real estate segment is net operating income (“NOI”), which represents The Quarter Ended March 31, 2018 2017 Rental income $ 632,831 $ 603,920 Property and maintenance expense (108,202 ) (102,608 ) Real estate taxes and insurance expense (91,914 ) (81,728 ) Total operating expenses (200,116 ) (184,336 ) Net operating income $ 432,715 $ 419,584 The following tables present NOI for each segment from our rental real estate for the quarters ended March 31, 2018 and 2017, March 31, 2018 Quarter Ended March 31, 2018 Quarter Ended March 31, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 102,484 $ 29,860 $ 72,624 $ 98,636 $ 28,651 $ 69,985 Orange County 22,502 5,527 16,975 21,656 5,462 16,194 San Diego 22,493 5,963 16,530 21,723 5,799 15,924 Subtotal - Southern California 147,479 41,350 106,129 142,015 39,912 102,103 San Francisco 109,212 26,995 82,217 106,306 26,928 79,378 Washington D.C. 107,155 33,663 73,492 106,443 32,332 74,111 New York 119,626 47,825 71,801 119,363 45,439 73,924 Boston 57,814 16,672 41,142 56,388 15,783 40,605 Seattle 48,611 13,688 34,923 46,425 13,015 33,410 Other Markets 487 165 322 464 196 268 Total same store 590,384 180,358 410,026 577,404 173,605 403,799 Non-same store/other (2) (3) Non-same store 38,622 13,733 24,889 15,961 5,894 10,067 Other (3) 3,825 6,025 (2,200 ) 10,555 4,837 5,718 Total non-same store/other 42,447 19,758 22,689 26,516 10,731 15,785 Totals $ 632,831 $ 200,116 $ 432,715 $ 603,920 $ 184,336 $ 419,584 (1) For the quarters ended March 31, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,204 apartment (2) For the quarters ended March 31, 2018 and 2017, non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Quarter Ended March 31, 2018 Total Assets Capital Expenditures Same store (1) Los Angeles $ 2,670,909 $ 5,939 Orange County 325,898 1,620 San Diego 417,593 1,270 Subtotal - Southern California 3,414,400 8,829 San Francisco 3,020,673 8,743 Washington D.C. 3,771,999 5,964 New York 4,447,994 5,216 Boston 1,637,837 4,358 Seattle 1,306,512 3,048 Other Markets 12,918 77 Total same store 17,612,333 36,235 Non-same store/other (2) (3) Non-same store 2,276,821 454 Other (3) 494,716 58 Total non-same store/other 2,771,537 512 Totals $ 20,383,870 $ 36,747 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,204 apartment (2) Non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and capital expenditures for properties

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Subsequent to March 31, 2018, the Company acquired one property consisting of 240 apartment units for $146.0 million.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Summary Of Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) and certain reclassifications considered necessary for a fair presentation have been included. Certain reclassifications have been made to the prior period financial statements in order to conform to the current year presentation. These reclassifications did not have an impact on net income previously reported. Operating results for the quarter ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. In preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. The balance sheets at December 31, 2017 have been derived from the audited financial statements at that date but do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. For further information, including definitions of capitalized terms not defined herein, refer to the consolidated financial statements and footnotes thereto included in the Company’s and the Operating Partnership’s Annual Report on Form 10-K for the year ended December 31, 2017.
Income and Other Taxes	Income and Other Taxes Due to the structure of EQR as a REIT and the nature of the operations of its operating properties, no provision for federal income taxes has been made at the EQR level. In addition, ERPOP generally is not liable for federal income taxes as the partners recognize their proportionate share of income or loss in their tax returns; therefore no provision for federal income taxes has been made at the ERPOP level. Historically, the Company has generally only incurred certain state and local income, excise and franchise taxes. The Company has elected Taxable REIT Subsidiary (“TRS”) status for certain of its corporate subsidiaries and as a result, these entities will incur both federal and state income taxes on any taxable income of such entities after consideration of any net operating losses. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. These assets and liabilities are measured using enacted tax rates for which the temporary differences are expected to be recovered or settled. The effects of changes in tax rates on deferred tax assets and liabilities are recognized in earnings in the period enacted. The Company’s deferred tax assets were generally the result of tax affected suspended interest deductions, net operating losses, differing depreciable lives on capitalized assets and the timing of expense recognition for certain accrued liabilities. In December 2017, the President signed into law H.R. 1, informally titled the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act is not expected to have a material impact on our REIT or subsidiary entities, our ability to continue to qualify as a REIT or on our results of operations. However, the complete impact of the Tax Act is not yet fully known and there can be no assurances that it will have a neutral or favorable impact.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In • Lessors – Leases will be accounted for using an approach that is substantially equivalent to existing guidance for operating, sales-type and financing leases, but aligned with the new revenue recognition standard. Lessors will be required to allocate lease payments to separate lease and non-lease components of each lease agreement, with the non-lease components evaluated under the new revenue recognition standard. • Lessees – Leases will be accounted for using a dual approach, classifying leases as either operating or finance based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized on a straight-line basis over the term of the lease (for operating leases) or based on an effective interest method with a front-loaded expense recognition (for finance leases). A lessee is also required to record a right-of-use asset and a lease liability on its balance sheet for all leases with a term of greater than 12 months regardless of their classification as operating or finance leases. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. The new standard will be effective for the Company beginning on January 1, 2019, with early adoption permitted, though the Company currently anticipates adopting the new standard on the effective date. The new standard must be adopted using a modified retrospective method, which requires application of the new guidance at the beginning of the earliest comparative period presented and provides for certain practical expedients, which the Company currently anticipates electing. The Company anticipates that its residential and retail/commercial leases where it is the lessor will continue to be accounted for as operating leases under the new standard. Therefore, the Company does not currently anticipate significant changes in the accounting for its lease revenues. The Company is also the lessee under various corporate office and ground leases, which it will be required to recognize right of use assets and related lease liabilities on its consolidated balance sheets upon adoption. The Company currently anticipates that its corporate office leases where it is the lessee will continue to be accounted for as operating leases under the new standard. Based on its anticipated election of the practical expedients, the Company would not be required to reassess the classification of existing ground leases and therefore these leases would continue to be accounted for as operating leases. However, in the event we modify existing ground leases and/or enter into new ground leases after adoption of the new standard, such leases will likely be classified as finance leases. The Company will continue to evaluate the impact of adopting the new leases standard on its consolidated results of operations and financial position. In June 2016, the FASB In August 2017, the FASB issued a final standard which makes changes to the hedge accounting model to enable entities to better portray their risk management activities in the financial statements. The new standard expands an entity’s ability to hedge nonfinancial and financial risk components, reduces complexity in fair value hedges of interest rate risk and eases certain documentation and assessment requirements. The new standard also eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of any hedging instrument to be presented in the same income statement line as the hedged instrument. The new standard will be effective for the Company beginning on January 1, 2019 and early adoption is permitted. The Company is currently evaluating the impact of adopting the new standard on its consolidated results of operations and financial position. Recently Adopted Accounting Pronouncements In FASB Revenue from Contracts with Customers any, For the remaining approximately 6% of rental income that is subject to the new revenue recognition standard, the Company’s disaggregated revenue streams are disclosed in the table below for the quarter ended March 31, 2018. These revenue streams have the same timing and pattern of revenue recognition across our reportable segments, with consistent allocations between the leasing and revenue recognition standards. The revenue streams and percentages are comparable with the percentage of rental income for the quarter ended March 31, 2017. The following table presents the disaggregation of revenue streams of our rental income for the quarter ended March 31, 2018 (amounts in thousands): Quarter Ended March 31, 2018 Revenue Stream Applicable Standard Amount of Rental Income Percentage of Rental Income Leasing revenue Leases $ 592,813 93.7 % Utility recoveries (“RUBS”) Revenue Recognition 15,375 2.4 % Parking revenue Revenue Recognition 7,797 1.2 % Other revenue Revenue Recognition 16,846 2.7 % Rental income $ 632,831 100.0 % Additionally, as part of the new revenue recognition standard, the FASB issued amendments related to partial sales of real estate (see further discussion below). Adoption of the new partial sales standard did not result in a change of accounting for the Company related to its disposition process. We concluded that the Company’s typical dispositions will continue to meet the criteria for sale and associated profit recognition under both new standards. In FASB In FASB • Cash payments related to debt prepayments or extinguishment costs are to be classified within financing • The portion of the cash payment made to settle a zero-coupon bond or a bond with an insignificant cash coupon attributable to accreted interest related to a debt discount is to be classified as a cash outflow within operating activities, and the portion attributable to the principal is to be classified within financing • Insurance settlement proceeds are to be classified based on the nature of the • Companies must elect to classify distributions received from equity method investees using either a cumulative earnings approach or a look-through approach and the election must be disclosed; • Restricted Total The While overall cash flows did not change, there are changes between cash flow classifications due primarily to the debt prepayment penalties that the Company has incurred in the comparative period. As of March 31, 2017, the following cash flows were reclassified (amounts in thousands): Quarter Ended March 31, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 1,637 $ (507 ) $ 1,130 Net (gain) loss on debt extinguishment $ — $ 11,698 $ 11,698 (Increase) decrease in deposits - restricted $ 256 $ (256 ) $ — (Increase) decrease in mortgage deposits $ 315 $ (315 ) $ — Net cash provided by operating activities $ 293,284 $ 10,620 $ 303,904 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ 637 $ (637 ) $ — (Increase) decrease in mortgage deposits $ (1,030 ) $ 1,030 $ — Net cash provided by (used for) investing activities $ (73,035 ) $ 393 $ (72,642 ) Cash Flows from Financing Activities: Mortgage deposits $ (2,381 ) $ 2,381 $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (11,698 ) $ (11,698 ) Line of credit and commercial paper: Commercial paper proceeds $ 1,309,681 $ 507 $ 1,310,188 Net cash (used for) financing activities $ (255,317 ) $ (8,810 ) $ (264,127 ) Cash and cash equivalents, beginning of period $ 77,207 (adjustments for restricted deposits, beginning of period) $ 141,881 Cash and cash equivalents and restricted deposits, beginning of period $ 219,088 Cash and cash equivalents, end of period $ 42,139 (adjustments for restricted deposits, end of period) $ 144,084 Cash and cash equivalents and restricted deposits, end of period $ 186,223 In FASB In FASB clarifies the accounting treatment for partial sales of nonfinancial assets (i.e. real estate). The standard clarifies that partial sales transactions include contributions of nonfinancial assets to a joint venture or other noncontrolled investee. Companies must recognize a full gain or loss on transfers of nonfinancial assets to equity method investees. The standard requires companies to derecognize distinct nonfinancial assets or distinct in substance nonfinancial assets in partial sale transactions when it does not have a controlling financial interest in the legal entity that holds the asset and transfers control of the asset. Once the distinct nonfinancial asset is transferred, the company is required to measure any non-controlling interest it receives or retains at fair value and recognize a full gain or loss on the transaction. If a company transfers ownership interests in a consolidated subsidiary and continues to maintain a controlling financial interest, the company does not derecognize the assets or liabilities, and accounts for the transaction as an equity transaction and no gain or loss is recognized. The Company has not had a partial sale of nonfinancial assets in the current or comparative periods, therefore the adoption of this standard did not have a material impact on its consolidated results of operations and financial position.
Other	Other The Company is the controlling partner in various consolidated partnerships owning 17 properties consisting of 3,535 apartment units having a noncontrolling interest book value of $1.3 million at March 31, 2018. The Company is required to make certain disclosures regarding noncontrolling interests in consolidated limited-life subsidiaries. Of the consolidated entities described above, the Company is the controlling partner in limited-life partnerships owning four properties having a noncontrolling interest deficit balance of $8.7 million. These four partnership agreements contain provisions that require the partnerships to be liquidated through the sale of their assets upon reaching a date specified in each respective partnership agreement. The Company, as controlling partner, has an obligation to cause the property owning partnerships to distribute the proceeds of liquidation to the Noncontrolling Interests in these Partially Owned Properties only to the extent that the net proceeds received by the partnerships from the sale of their assets warrant a distribution based on the partnership agreements. As of March 31, 2018, the Company estimates the value of Noncontrolling Interest distributions for these four properties would have been approximately $66.3 million (“Settlement Value”) had the partnerships been liquidated. This Settlement Value is based on estimated third party consideration realized by the partnerships upon disposition of the four Partially Owned Properties and is net of all other assets and liabilities, including yield maintenance on the mortgages encumbering the properties, that would have been due on had those mortgages been prepaid. Due to, among other things, the inherent uncertainty in the sale of real estate assets, the amount of any potential distribution to the Noncontrolling Interests in the Company’s Partially Owned Properties is subject to change. To the extent that the partnerships’ underlying assets are worth less than the underlying liabilities, the Company has no obligation to remit any consideration to the Noncontrolling Interests in these Partially Owned Properties

Business (Tables)

Business (Tables)	3 Months Ended
	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Ownership Breakdown	The ownership breakdown includes (table does not include various uncompleted development properties): Properties Apartment Units Wholly Owned Properties 282 73,160 Master-Leased Properties – Consolidated 2 759 Partially Owned Properties – Consolidated 17 3,535 Partially Owned Properties – Unconsolidated 2 945 303 78,399 Note: Effective February 1, 2018, the Company took over management of one of its Master-Leased properties containing 94 apartment units located in Boston.

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Summary Of Significant Accounting Policies [Abstract]
Schedule of Disaggregation of Revenue Streams of Rental Income and Percentage of Rental Income	The following table presents the disaggregation of revenue streams of our rental income for the quarter ended March 31, 2018 (amounts in thousands): Quarter Ended March 31, 2018 Revenue Stream Applicable Standard Amount of Rental Income Percentage of Rental Income Leasing revenue Leases $ 592,813 93.7 % Utility recoveries (“RUBS”) Revenue Recognition 15,375 2.4 % Parking revenue Revenue Recognition 7,797 1.2 % Other revenue Revenue Recognition 16,846 2.7 % Rental income $ 632,831 100.0 %
Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties	While overall cash flows did not change, there are changes between cash flow classifications due primarily to the debt prepayment penalties that the Company has incurred in the comparative period. As of March 31, 2017, the following cash flows were reclassified (amounts in thousands): Quarter Ended March 31, 2017 As Originally Presented Reclassification Adjustments As Presented Herein Cash Flows from Operating Activities: Amortization of discounts and premiums on debt $ 1,637 $ (507 ) $ 1,130 Net (gain) loss on debt extinguishment $ — $ 11,698 $ 11,698 (Increase) decrease in deposits - restricted $ 256 $ (256 ) $ — (Increase) decrease in mortgage deposits $ 315 $ (315 ) $ — Net cash provided by operating activities $ 293,284 $ 10,620 $ 303,904 Cash Flows from Investing Activities: (Increase) decrease in deposits on real estate acquisitions and investments, net $ 637 $ (637 ) $ — (Increase) decrease in mortgage deposits $ (1,030 ) $ 1,030 $ — Net cash provided by (used for) investing activities $ (73,035 ) $ 393 $ (72,642 ) Cash Flows from Financing Activities: Mortgage deposits $ (2,381 ) $ 2,381 $ — Mortgage notes payable, net: Net gain (loss) on debt extinguishment $ — $ (11,698 ) $ (11,698 ) Line of credit and commercial paper: Commercial paper proceeds $ 1,309,681 $ 507 $ 1,310,188 Net cash (used for) financing activities $ (255,317 ) $ (8,810 ) $ (264,127 ) Cash and cash equivalents, beginning of period $ 77,207 (adjustments for restricted deposits, beginning of period) $ 141,881 Cash and cash equivalents and restricted deposits, beginning of period $ 219,088 Cash and cash equivalents, end of period $ 42,139 (adjustments for restricted deposits, end of period) $ 144,084 Cash and cash equivalents and restricted deposits, end of period $ 186,223

Equity, Capital and Other Int29

Equity, Capital and Other Interests (Tables)	3 Months Ended
	Mar. 31, 2018
Changes in Issued and Outstanding Common Shares and Units	The following tables present the changes in the Company’s issued and outstanding Common Shares and “Units” (which includes OP Units and restricted units) for the quarter ended March 31, 2018: 2018 Common Shares Common Shares outstanding at January 1, 368,018,082 Common Shares Issued: Conversion of OP Units 5,000 Exercise of share options 45,391 Employee Share Purchase Plan (ESPP) 35,177 Restricted share grants, net 108,261 Common Shares outstanding at March 31, 368,211,911 Units Units outstanding at January 1, 13,768,438 Restricted unit grants, net 263,048 Conversion of OP Units to Common Shares (5,000 ) Units outstanding at March 31, 14,026,486 Total Common Shares and Units outstanding at March 31, 382,238,397 Units Ownership Interest in Operating Partnership 3.7 %
Changes in Redemption Value of Redeemable Noncontrolling Interests and Limited Partners Interest	The 2018 Balance at January 1, $ 366,955 Change in market value (12,831 ) Change in carrying value 443 Balance at March 31, $ 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) 2018 2017 Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized: 8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call date, redeemable preferred shares may be redeemed for cash at the option of the Company, in whole or in part, at a redemption price equal to the liquidation price per share, plus accrued and unpaid distributions, if any. (2) Dividends on Preferred Shares are payable quarterly.
ERPOP [Member]
Changes in Issued and Outstanding Common Shares and Units	The following tables present the changes in the Operating Partnership’s issued and outstanding Units and in the limited partners’ Units for the quarter ended March 31, 2018: 2018 General and Limited Partner Units General and Limited Partner Units outstanding at January 1, 381,786,520 Issued to General Partner: Exercise of EQR share options 45,391 EQR’s Employee Share Purchase Plan (ESPP) 35,177 EQR’s restricted share grants, net 108,261 Issued to Limited Partners: Restricted unit grants, net 263,048 General and Limited Partner Units outstanding at March 31, 382,238,397 Limited Partner Units Limited Partner Units outstanding at January 1, 13,768,438 Limited Partner restricted unit grants, net 263,048 Conversion of Limited Partner OP Units to EQR Common Shares (5,000 ) Limited Partner Units outstanding at March 31, 14,026,486 Limited Partner Units Ownership Interest in Operating Partnership 3.7 %
Changes in Redemption Value of Redeemable Noncontrolling Interests and Limited Partners Interest	The following table presents the changes in the redemption value of the Redeemable Limited Partners for the quarter ended March 31, 2018 (amounts in thousands): 2018 Balance at January 1, $ 366,955 Change in market value (12,831 ) Change in carrying value 443 Balance at March 31, $ 354,567
Issued and Outstanding Preferred Shares and Preference Units	The December 31, 2017 Amounts in thousands Annual Call Dividend Per March 31, December 31, Date (1) Unit (2) 2018 2017 Preference Units: 8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 745,600 units issued and outstanding as of March 31, 2018 and December 31, 2017 12/10/26 $ 4.145 $ 37,280 $ 37,280 $ 37,280 $ 37,280 (1) On or after the call date, redeemable preference units may be redeemed for cash at the option of the Operating Partnership, in whole or in part, at a redemption price equal to the liquidation price per unit, plus accrued and unpaid distributions, if any, in conjunction with the concurrent redemption of the corresponding Company Preferred Shares. (2) Dividends on Preference Units are payable quarterly.

Real Estate and Lease Intangi30

Real Estate and Lease Intangibles (Tables)	3 Months Ended
	Mar. 31, 2018
Real Estate [Abstract]
Summary of Carrying Amounts of Investment in Real Estate	The following table summarizes the carrying amounts for the Company’s investment in real estate (at cost) as of March 31, 2018 and December 31, 2017 (amounts in thousands): March 31, 2018 December 31, 2017 Land $ 5,960,804 $ 5,996,024 Depreciable property: Buildings and improvements 17,748,897 17,743,042 Furniture, fixtures and equipment 1,575,934 1,548,961 In-Place lease intangibles 473,522 476,359 Projects under development: Land 30,605 43,226 Construction-in-progress 66,004 120,321 Land held for development: Land 62,538 62,538 Construction-in-progress 40,313 36,425 Investment in real estate 25,958,617 26,026,896 Accumulated depreciation (6,173,047 ) (6,040,378 ) Investment in real estate, net $ 19,785,570 $ 19,986,518
Summary of Carrying Amounts of Above and Below Market Ground And Retail Lease Intangibles	The following table summarizes the carrying amounts for the Company’s above and below market ground and retail lease intangibles as of March 31, 2018 and December 31, 2017 (amounts in thousands): Description Balance Sheet Location March 31, 2018 December 31, 2017 Assets Ground lease intangibles – below market Other Assets $ 191,918 $ 191,918 Retail lease intangibles – above market Other Assets 1,260 1,260 Lease intangible assets 193,178 193,178 Accumulated amortization (23,562 ) (22,434 ) Lease intangible assets, net $ 169,616 $ 170,744 Liabilities Ground lease intangibles – above market Other Liabilities $ 2,400 $ 2,400 Retail lease intangibles – below market Other Liabilities 5,270 5,270 Lease intangible liabilities 7,670 7,670 Accumulated amortization (5,173 ) (5,143 ) Lease intangible liabilities, net $ 2,497 $ 2,527
Summary of the Effect of the Amortization for Above and Below Market Ground and Retail Lease Intangibles	The following table provides a summary of the effect of the amortization for above and below market ground and retail lease intangibles on Quarter Ended March 31, Description Income Statement Location 2018 2017 Ground lease intangible amortization Property and Maintenance $ (1,116 ) $ (1,080 ) Retail lease intangible amortization Rental Income 18 224 Total amortization of above/below market lease intangibles $ (1,098 ) $ (856 )
Summary of Aggregate Amortization for Above and Below Market Ground And Retail Lease Intangibles	The following table provides a summary of the aggregate amortization for above and below market ground and retail lease intangibles for each of the next five years (amounts in thousands): Remaining 2018 2019 2020 2021 2022 2023 Ground lease intangibles $ (3,347 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) $ (4,463 ) Retail lease intangibles 53 71 71 71 27 19 Total $ (3,294 ) $ (4,392 ) $ (4,392 ) $ (4,392 ) $ (4,436 ) $ (4,444 )
Acquired Properties From Unaffiliated Parties	During the quarter ended March 31, 2018, the Company acquired the entire equity interest in the following from unaffiliated parties (purchase price in thousands): Properties Apartment Units Purchase Price Rental Properties – Consolidated (1) 1 117 $ 53,700 Total 1 117 $ 53,700 (1) Purchase price includes an allocation of approximately $14.8 million to land and $39.3 million to depreciable property (inclusive of capitalized closing costs).
Disposed Properties to Unaffiliated Parties	During the quarter ended March 31, 2018 , the Company disposed of the following to unaffiliated parties (sales price in thousands): Properties Apartment Units Sales Price Rental Properties – Consolidated 4 786 $ 290,020 Total 4 786 $ 290,020

Commitments To Acquire_Dispos31

Commitments To Acquire/Dispose of Real Estate (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments To Acquire Dispose Of Real Estate [Abstract]
Separate Agreement to Dispose of	The Company has entered into a separate agreement to dispose of the following (sales price in thousands): Properties Apartment Units Sales Price Land Parcels (one) — — $ 2,700 Total — — $ 2,700

Investments in Partially Owne32

Investments in Partially Owned Entities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments In Partially Owned Entities [Abstract]
Partially Owned Property Balance Sheet Schedule	The following tables and information summarize the Company’s investments March 31, 2018 Consolidated Unconsolidated (VIE) (Non-VIE) (VIE) (1) Total Total properties 17 2 — 2 Total apartment units 3,535 945 — 945 Balance sheet information at 3/31/2018 (at 100%): ASSETS Investment in real estate $ 875,187 $ 236,854 $ 172,995 $ 409,849 Accumulated depreciation (235,426 ) (46,190 ) (51,420 ) (97,610 ) Investment in real estate, net 639,761 190,664 121,575 312,239 Cash and cash equivalents 13,061 6,587 225 6,812 Investments in unconsolidated entities 43,926 — — — Restricted deposits 381 258 — 258 Other assets 25,879 243 320 563 Total assets $ 723,008 $ 197,752 $ 122,120 $ 319,872 LIABILITIES AND EQUITY/CAPITAL Mortgage notes payable, net (2) $ 302,656 $ 145,424 $ — $ 145,424 Accounts payable & accrued expenses 3,344 1,361 115 1,476 Accrued interest payable 1,037 691 — 691 Other liabilities 3,683 261 15 276 Security deposits 2,470 525 — 525 Total liabilities 313,190 148,262 130 148,392 Noncontrolling Interests – Partially Owned Properties/Partners’ equity 1,293 51,079 84,038 135,117 Company equity/General and Limited Partners’ Capital 408,525 (1,589 ) 37,952 36,363 Total equity/capital 409,818 49,490 121,990 171,480 Total liabilities and equity/capital $ 723,008 $ 197,752 $ 122,120 $ 319,872
Partially Owned Property Income Statement Schedule	Consolidated Unconsolidated (VIE) (Non-VIE) (VIE) (1) Total Operating information for the quarter ended 3/31/2018 (at 100%): Operating revenue $ 26,447 $ 6,942 $ 1,258 $ 8,200 Operating expenses 6,637 2,268 581 2,849 Net operating income 19,810 4,674 677 5,351 Property management 955 199 19 218 General and administrative 17 — — — Depreciation 10,479 2,677 1,375 4,052 Operating income (loss) 8,359 1,798 (717 ) 1,081 Interest and other income 27 — — — Interest: Expense incurred, net (3,312 ) (2,072 ) — (2,072 ) Amortization of deferred financing costs (68 ) — — — Income (loss) before income and other taxes and income (loss) from investments in unconsolidated entities 5,006 (274 ) (717 ) (991 ) Income and other tax (expense) benefit (18 ) (13 ) — (13 ) Income (loss) from investments in unconsolidated entities (393 ) — — — Net income (loss) $ 4,595 $ (287 ) $ (717 ) $ (1,004 ) (1) Includes the Company’s unconsolidated interest in an entity that owns the land underlying our Wisconsin Place apartment property and owns and operates the parking facility. This entity is excluded from the property and apartment unit count. (2) All debt is non-recourse to the Company. Note: The above tables exclude EQR’s ownership interest in ERPOP, private equity fund investments, and the Company’s interests in unconsolidated joint ventures established in connection with the acquisition of certain real estate related assets from Archstone Enterprise LP (“Archstone”).

Restricted Deposits (Tables)

Restricted Deposits (Tables)	3 Months Ended
	Mar. 31, 2018
Deposits Restricted [Abstract]
Restricted Deposits	The following table presents the Company’s restricted deposits as of March 31, 2018 and December 31, 2017 (amounts in thousands): March 31, 2018 December 31, 2017 Mortgage escrow deposits: Real estate taxes and insurance $ 1,279 $ 845 Replacement reserves 7,423 8,347 Mortgage principal reserves/sinking funds 4,778 3,167 Other 852 852 Mortgage escrow deposits 14,332 13,211 Restricted cash: Earnest money on pending acquisitions — 750 Restricted deposits on real estate investments 53 58 Resident security and utility deposits 34,967 35,183 Other 906 913 Restricted cash 35,926 36,904 Restricted deposits $ 50,258 $ 50,115

Derivative and Other Fair Val34

Derivative and Other Fair Value Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Summary of Carrying and Fair Values of Financial Instruments	The March 31, 2018 December 31, 2017 Estimated Fair Value (Level 2) Carrying Value Estimated Fair Value (Level 2) Carrying Value Mortgage notes payable, net $ 2,841,288 $ 2,894,344 $ 3,615,384 $ 3,618,722 Unsecured debt, net 5,878,000 5,765,133 5,619,744 5,338,569 Total debt, net $ 8,719,288 $ 8,659,477 $ 9,235,128 $ 8,957,291
Summary of Consolidated Derivative Instruments	The March 31, 2018 Fair Value Hedges (1) Forward Starting Swaps (2) Current Notional Balance $ 450,000 $ 600,000 Lowest Interest Rate 2.375 % 2.1478 % Highest Interest Rate 2.375 % 3.0030 % Earliest Maturity Date 2019 2028 Latest Maturity Date 2019 2029 (1) Fair Value Hedges – Converts outstanding fixed rate unsecured notes ($450.0 million 2.375% notes due July 1, 2019) to a floating interest rate of 90-Day LIBOR plus 0.61%. (2) Forward Starting Swaps – Designed to partially fix interest rates in advance of planned future debt issuances. Of the $600.0 million notional balance, $250.0 million of these swaps have mandatory counterparty terminations in 2019 and are targeted for certain 2018 debt issuances while $350.0 million of these swaps have mandatory counterparty terminations in 2020 and are targeted for certain 2019 debt issuances.
Summary of Fair Value Measurements for Each Major Category of Assets and Liabilities Measured at Fair Value on Recurring Basis	The Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 3/31/2018 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 $ 12,637 $ — $ 12,637 $ — Supplemental Executive Retirement Plan Other Assets 138,444 138,444 — — Total $ 151,081 $ 138,444 $ 12,637 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 3,886 $ — $ 3,886 $ — Forward Starting Swaps Other Liabilities 3,045 — 3,045 — Supplemental Executive Retirement Plan Other Liabilities 138,444 138,444 — — Total $ 145,375 $ 138,444 $ 6,931 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 354,567 $ — $ 354,567 $ — Fair Value Measurements at Reporting Date Using Description Balance Sheet Location 12/31/2017 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Staring Swaps Other Assets $ 5,143 $ — $ 5,143 $ — Supplemental Executive Retirement Plan Other Assets 140,159 140,159 — — Total $ 145,302 $ 140,159 $ 5,143 $ — Liabilities Derivatives designated as hedging instruments: Interest Rate Contracts: Fair Value Hedges Other Liabilities $ 1,597 $ — $ 1,597 $ — Supplemental Executive Retirement Plan Other Liabilities 140,159 140,159 — — Total $ 141,756 $ 140,159 $ 1,597 $ — Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners Mezzanine $ 366,955 $ — $ 366,955 $ —
Summary of Effect of Fair Value Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The 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 March 31, 2017 Type of Fair Value Hedge Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Recognized in Income on Derivative Hedged Item Income Statement Location of Hedged Item Gain/(Loss) Amount of Gain/(Loss) Recognized in Income on Hedged Item Derivatives designated as hedging instruments: Interest Rate Contracts: Interest Rate Swaps Interest expense $ (1,106 ) Fixed rate debt Interest expense $ 1,106 Total $ (1,106 ) $ 1,106
Summary of Effect of Cash Flow Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income	The 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 ) $ — Effective Portion Ineffective Portion March 31, 2017 Type of Cash Flow Hedge Amount of Gain/(Loss) Recognized in OCI on Derivative Location of Gain/(Loss) Reclassified from Accumulated OCI into Income Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Location of Gain/(Loss) Recognized in Income on Derivative Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivatives designated as hedging instruments: Interest Rate Contracts: Forward Starting Swaps $ — Interest expense $ (4,583 ) N/A $ — Total $ — $ (4,583 ) $ —

Earning Per Share and Earning35

Earning Per Share and Earnings Per Unit (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Calculation of Numerator and Denominator in Earning Per Share and Earnings Per Unit	The Quarter Ended March 31, 2018 2017 Numerator for net income per share – basic: Net income $ 220,548 $ 149,941 Allocation to Noncontrolling Interests – Operating Partnership (8,059 ) (5,411 ) Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (680 ) (788 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – basic $ 211,036 $ 142,969 Numerator for net income per share – diluted: Net income $ 220,548 $ 149,941 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (680 ) (788 ) Preferred distributions (773 ) (773 ) Numerator for net income per share – diluted $ 219,095 $ 148,380 Denominator for net income per share – basic and diluted: Denominator for net income per share – basic 367,800 366,605 Effect of dilutive securities: OP Units 12,863 12,899 Long-term compensation shares/units 2,355 2,776 Denominator for net income per share – diluted 383,018 382,280 Net income per share – basic $ 0.57 $ 0.39 Net income per share – diluted $ 0.57 $ 0.39
ERPOP [Member]
Schedule of Calculation of Numerator and Denominator in Earning Per Share and Earnings Per Unit	The following tables set forth the computation of net income per Unit – basic and net income per Unit – diluted for the Operating Partnership (amounts in thousands except per Unit amounts): Quarter Ended March 31, 2018 2017 Numerator for net income per Unit – basic and diluted: Net income $ 220,548 $ 149,941 Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties (680 ) (788 ) Allocation to Preference Units (773 ) (773 ) Numerator for net income per Unit – basic and diluted $ 219,095 $ 148,380 Denominator for net income per Unit – basic and diluted: Denominator for net income per Unit – basic 380,663 379,504 Effect of dilutive securities: Dilution for Units issuable upon assumed exercise/vesting of the Company’s long-term compensation shares/units 2,355 2,776 Denominator for net income per Unit – diluted 383,018 382,280 Net income per Unit – basic $ 0.57 $ 0.39 Net income per Unit – diluted $ 0.57 $ 0.39

Reportable Segments (Tables)

Reportable Segments (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Schedule of Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations	The Quarter Ended March 31, 2018 2017 Rental income $ 632,831 $ 603,920 Property and maintenance expense (108,202 ) (102,608 ) Real estate taxes and insurance expense (91,914 ) (81,728 ) Total operating expenses (200,116 ) (184,336 ) Net operating income $ 432,715 $ 419,584
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, 2018 and 2017, March 31, 2018 Quarter Ended March 31, 2018 Quarter Ended March 31, 2017 Rental Income Operating Expenses NOI Rental Income Operating Expenses NOI Same store (1) Los Angeles $ 102,484 $ 29,860 $ 72,624 $ 98,636 $ 28,651 $ 69,985 Orange County 22,502 5,527 16,975 21,656 5,462 16,194 San Diego 22,493 5,963 16,530 21,723 5,799 15,924 Subtotal - Southern California 147,479 41,350 106,129 142,015 39,912 102,103 San Francisco 109,212 26,995 82,217 106,306 26,928 79,378 Washington D.C. 107,155 33,663 73,492 106,443 32,332 74,111 New York 119,626 47,825 71,801 119,363 45,439 73,924 Boston 57,814 16,672 41,142 56,388 15,783 40,605 Seattle 48,611 13,688 34,923 46,425 13,015 33,410 Other Markets 487 165 322 464 196 268 Total same store 590,384 180,358 410,026 577,404 173,605 403,799 Non-same store/other (2) (3) Non-same store 38,622 13,733 24,889 15,961 5,894 10,067 Other (3) 3,825 6,025 (2,200 ) 10,555 4,837 5,718 Total non-same store/other 42,447 19,758 22,689 26,516 10,731 15,785 Totals $ 632,831 $ 200,116 $ 432,715 $ 603,920 $ 184,336 $ 419,584 (1) For the quarters ended March 31, 2018 and 2017, same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,204 apartment (2) For the quarters ended March 31, 2018 and 2017, non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and operations prior to disposition for properties sold. Quarter Ended March 31, 2018 Total Assets Capital Expenditures Same store (1) Los Angeles $ 2,670,909 $ 5,939 Orange County 325,898 1,620 San Diego 417,593 1,270 Subtotal - Southern California 3,414,400 8,829 San Francisco 3,020,673 8,743 Washington D.C. 3,771,999 5,964 New York 4,447,994 5,216 Boston 1,637,837 4,358 Seattle 1,306,512 3,048 Other Markets 12,918 77 Total same store 17,612,333 36,235 Non-same store/other (2) (3) Non-same store 2,276,821 454 Other (3) 494,716 58 Total non-same store/other 2,771,537 512 Totals $ 20,383,870 $ 36,747 (1) Same store primarily includes all properties acquired or completed that were stabilized prior to January 1, 2017, less properties subsequently sold, which represented 72,204 apartment (2) Non-same store primarily includes properties acquired after January 1, 2017, plus any properties in lease-up and not stabilized as of January 1, (3) Other includes development, other corporate operations and capital expenditures for properties

Business - Additional Informati

Business - Additional Information (Details)	Mar. 31, 2018StatePropertyApartmentUnit	Feb. 01, 2018ApartmentUnit
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of states in which entity operates | State	10
Properties | Property	303
Apartment units	78,399
Master-Leased Properties – Consolidated
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Properties | Property	2
Apartment units	759
Master-Leased Properties – Consolidated | Boston
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of self managed apartments		94
ERPOP [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Noncontrolling interest, ownership percentage by parent	96.30%

Business - Ownership Breakdown

Business - Ownership Breakdown (Details)	Mar. 31, 2018PropertyApartmentUnit
Property/Unit schedule
Properties | Property	303
Apartment Units | ApartmentUnit	78,399
Wholly Owned Properties
Property/Unit schedule
Properties | Property	282
Apartment Units | ApartmentUnit	73,160
Master-Leased Properties – Consolidated
Property/Unit schedule
Properties | Property	2
Apartment Units | ApartmentUnit	759
Partially Owned Properties – Consolidated
Property/Unit schedule
Properties | Property	17
Apartment Units | ApartmentUnit	3,535
Partially Owned Properties – Unconsolidated
Property/Unit schedule
Properties | Property	2
Apartment Units | ApartmentUnit	945

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	3 Months Ended
	Feb. 28, 2017USD ($)	Mar. 31, 2018USD ($)PropertyApartmentUnit	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Provision for income tax		$ 213,000	$ 262,000
Percentage of rental income excluded from accounting standard adoption		94.00%
Percentage of total revenue subject to revenue recognition standard		6.00%
Properties | Property		303
Apartment Units | ApartmentUnit		78,399
Noncontrolling interests partially owned properties		$ 1,293,000		$ 4,708,000
Partially Owned Properties – Consolidated
Properties | Property		17
Apartment Units | ApartmentUnit		3,535
Limited Life Partnership Properties [Member]
Properties | Property		4
Noncontrolling interests equity (deficit) partially owned properties		$ 8,700,000
Noncontrolling interests settlement value		66,300,000
Adjustments for New Accounting Principle, Early Adoption
Gain (loss) on equity transaction	$ 0
Federal [Member]
Provision for income tax		$ 0

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Schedule of Disaggregation of Revenue Streams of Rental Income and Percentage of Rental Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Amount of rental income	$ 632,831	$ 603,920
Percentage of rental income	100.00%
Amount of rental income	$ 592,813
Leasing Revenue [Member}
Percentage of rental income	93.70%
Utility Recoveries [Member]
Amount of rental income	$ 15,375
Percentage of rental income	2.40%
Parking Revenue [Member]
Amount of rental income	$ 7,797
Percentage of rental income	1.20%
Other Revenue [Member]
Amount of rental income	$ 16,846
Percentage of rental income	2.70%

Summary of Significant Accoun41

Summary of Significant Accounting Policies - Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt	$ 1,532	$ 1,130
Net (gain) loss on debt extinguishment	22,110	11,698
Net cash provided by operating activities	361,018	303,904
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash provided by (used for) investing activities	147,298	(72,642)
CASH FLOWS FROM FINANCING ACTIVITIES:
Commercial paper proceeds	1,107,561	1,310,188
Net cash (used for) financing activities	(514,367)	(264,127)
Cash and cash equivalents, beginning of period	50,647
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents, end of period	44,453	42,139
Cash and cash equivalents and restricted deposits, end of period	94,711	186,223
Mortgage Notes Payable, Net [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment	$ (22,110)	(11,698)
Scenario, Previously Reported [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		1,637
(Increase) decrease in deposits - restricted		256
(Increase) decrease in mortgage deposits		315
Net cash provided by operating activities		293,284
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		637
(Increase) decrease in mortgage deposits		(1,030)
Net cash provided by (used for) investing activities		(73,035)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		(2,381)
Commercial paper proceeds		1,309,681
Net cash (used for) financing activities		(255,317)
Cash and cash equivalents, beginning of period		77,207
Cash and cash equivalents, end of period		42,139
Reclassification Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		(507)
Net (gain) loss on debt extinguishment		11,698
(Increase) decrease in deposits - restricted		(256)
(Increase) decrease in mortgage deposits		(315)
Net cash provided by operating activities		10,620
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		(637)
(Increase) decrease in mortgage deposits		1,030
Net cash provided by (used for) investing activities		393
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		2,381
Commercial paper proceeds		507
Net cash (used for) financing activities		(8,810)
(adjustments for restricted deposits, beginning of period)		141,881
(adjustments for restricted deposits, end of period)		144,084
Reclassification Adjustments [Member] | Mortgage Notes Payable, Net [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment		$ (11,698)

Equity, Capital and Other Int42

Equity, Capital and Other Interests - Changes in Issued and Outstanding Common Shares and Units (Details)	3 Months Ended
	Mar. 31, 2018shares
Equity Capital And Other Interests [Abstract]
Common Stock, Shares, Outstanding	368,018,082
Common Shares Issued:
Conversion of OP Units	5,000
Exercise of share options	45,391
Employee Share Purchase Plan (ESPP)	35,177
Restricted share grants, net	108,261
Common Stock, Shares, Outstanding	368,211,911
Units
Total Units Outstanding	13,768,438
Restricted unit grants, net	263,048
Conversion of OP Units to Common Shares	(5,000)
Total Units Outstanding	14,026,486
Common Shares And Units Outstanding	382,238,397
Units Ownership Interest in Operating Partnership	3.70%

Equity, Capital and Other Int43

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

Equity, Capital and Other Int44

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

Equity, Capital and Other Int45

Equity, Capital and Other Interests - Issued and Outstanding Preferred Shares and Preference Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017	$ 37,280	$ 37,280
ERPOP [Member]
Class Of Stock [Line Items]
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017	$ 37,280	37,280
Preferred Stock
Class Of Stock [Line Items]
Preferred Stocks Preference Units Call Date	Dec. 10, 2026
Annual Dividend Per Preferred Share Preference Unit	$ 4.145
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017	$ 37,280	37,280
Preferred Stock | ERPOP [Member]
Class Of Stock [Line Items]
Preferred Stocks Preference Units Call Date	Dec. 10, 2026
Annual Dividend Per Preferred Share Preference Unit	$ 4.145
8.29% Series K Cumulative Redeemable Preferred; liquidation value $50 per share; 745,600 shares issued and outstanding as of March 31, 2018 and December 31, 2017	$ 37,280	$ 37,280

Equity, Capital and Other Int46

Equity, Capital and Other Interests - Issued and Outstanding Preferred Shares and Preference Units (Parenthetical) (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Preference Units Issued	745,600	745,600
Preferred Stock Preference Units Outstanding	745,600	745,600
Preferred Stock Preference Units Redemption Price Per Share	$ 50	$ 50
Preferred Stock Preference Units Dividend Rate Percentage	8.29%	8.29%
Preferred Stock | ERPOP [Member]
Class Of Stock [Line Items]
Preferred Stock Preference Units Issued	745,600	745,600
Preferred Stock Preference Units Outstanding	745,600	745,600
Preferred Stock Preference Units Redemption Price Per Share	$ 50	$ 50
Preferred Stock Preference Units Dividend Rate Percentage	8.29%	8.29%

Equity, Capital and Other Int47

Equity, Capital and Other Interests - Changes in Operating Partnership's Issued and Outstanding Units (Details)	3 Months Ended
	Mar. 31, 2018shares
General and Limited Partner Units
Exercise of share options	45,391
Employee Share Purchase Plan (ESPP)	35,177
Restricted share grants, net	108,261
Restricted unit grants, net	263,048
Common Shares And Units Outstanding	382,238,397
LIMITED PARTNERS
Total Units Outstanding	13,768,438
Restricted unit grants, net	263,048
Conversion of Limited Partner OP Units to EQR Common Shares	(5,000)
Total Units Outstanding	14,026,486
Units Ownership Interest in Operating Partnership	3.70%
ERPOP [Member]
General and Limited Partner Units
Common Shares And Units Outstanding	381,786,520
Exercise of share options	45,391
Employee Share Purchase Plan (ESPP)	35,177
Restricted share grants, net	108,261
Restricted unit grants, net	263,048
Common Shares And Units Outstanding	382,238,397
LIMITED PARTNERS
Total Units Outstanding	13,768,438
Restricted unit grants, net	263,048
Conversion of Limited Partner OP Units to EQR Common Shares	(5,000)
Total Units Outstanding	14,026,486
Units Ownership Interest in Operating Partnership	3.70%

Equity, Capital and Other Int48

Equity, Capital and Other Interests - Changes in Redemption Value of Redeemable Limited Partners Interest (Details) - ERPOP [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Redeemable Limited Partners	$ 366,955
Limited Partners Change In Redemption Value	(12,831)
Limited Partners Change In Carrying Value	443
Redeemable Limited Partners	$ 354,567

Equity, Capital and Other Int49

Equity, Capital and Other Interests - Other - Additional Information (Details)	3 Months Ended
	Mar. 31, 2018shares
Equity Capital And Other Interests [Abstract]
Additional common shares authorized	13,000,000
Stock repurchase program, number of shares authorized to be repurchased	13,000,000
Stock repurchased and retired during period, shares	0

Real Estate and Lease Intangi50

Real Estate and Lease Intangibles - Summary of Carrying Amounts of Investment in Real Estate (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Land	$ 5,960,804	$ 5,996,024
Depreciable property:
Buildings and improvements	17,748,897	17,743,042
Furniture, fixtures and equipment	1,575,934	1,548,961
In-Place lease intangibles	473,522	476,359
Projects under development:
Construction-in-progress	96,609	163,547
Land held for development:
Land	102,851	98,963
Construction-in-progress	96,609	163,547
Investment in real estate	25,958,617	26,026,896
Accumulated depreciation	(6,173,047)	(6,040,378)
Investment in real estate, net	19,785,570	19,986,518
Projects under development [Member]
Projects under development:
Land	30,605	43,226
Construction-in-progress	66,004	120,321
Land held for development:
Construction-in-progress	66,004	120,321
Land held for development [Member]
Projects under development:
Construction-in-progress	40,313	36,425
Land held for development:
Land	62,538	62,538
Construction-in-progress	$ 40,313	$ 36,425

Real Estate and Lease Intangi51

Real Estate and Lease Intangibles - Summary of Carrying Amounts of Above and Below Market Ground And Retail Lease Intangibles (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Assets [Member]
Lease intangible assets	$ 193,178	$ 193,178
Finite-Lived Intangible Assets, Accumulated Amortization	(23,562)	(22,434)
Lease intangible assets, net	169,616	170,744
Other Assets [Member] | Ground Lease [Member]
Finite-Lived Intangible Asset, Off-market Lease, Favorable, Gross	191,918	191,918
Other Assets [Member] | Retail Lease [Member]
Finite-Lived Intangible Asset, Off-market Lease, Favorable, Gross	1,260	1,260
Other Liabilities [Member]
Lease Intangible Liabilities	7,670	7,670
Finite Lived Intangible Liabilities Accumulated Amortization	(5,173)	(5,143)
Lease intangible liabilities, net	2,497	2,527
Other Liabilities [Member] | Ground Lease [Member]
Finite-Lived Intangible Liabilities, Off-market Lease, Unfavorable, Gross	2,400	2,400
Other Liabilities [Member] | Retail Lease [Member]
Finite-Lived Intangible Liabilities, Off-market Lease, Unfavorable, Gross	$ 5,270	$ 5,270

Real Estate and Lease Intangi52

Real Estate and Lease Intangibles - Summary of the Effect of the Amortization for Above and Below Market Ground and Retail Lease Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Total amortization of above/below market lease intangibles	$ (1,098)	$ (856)
Ground Lease [Member] | Property and Maintenance [Member]
Total amortization of above/below market lease intangibles	(1,116)	(1,080)
Retail Lease [Member] | Rental Income [Member]
Total amortization of above/below market lease intangibles	$ 18	$ 224

Real Estate and Lease Intangi53

Real Estate and Lease Intangibles - Summary of Aggregate Amortization for Above and Below Market Ground And Retail Lease Intangibles (Details) $ in Thousands	Mar. 31, 2018USD ($)
Finite-lived intangible assets, amortization expense, remainder of fiscal year 2018	$ (3,294)
Finite-Lived Intangible Assets, Amortization Expense, Year 2019	(4,392)
Finite-lived intangible assets, amortization expense, year 2020	(4,392)
Finite-lived intangible assets, amortization expense, year 2021	(4,392)
Finite-lived intangible assets, amortization expense, year 2022	(4,436)
Finite-lived intangible assets, amortization expense, year 2023	(4,444)
Ground Lease [Member]
Finite-lived intangible assets, amortization expense, remainder of fiscal year 2018	(3,347)
Finite-Lived Intangible Assets, Amortization Expense, Year 2019	(4,463)
Finite-lived intangible assets, amortization expense, year 2020	(4,463)
Finite-lived intangible assets, amortization expense, year 2021	(4,463)
Finite-lived intangible assets, amortization expense, year 2022	(4,463)
Finite-lived intangible assets, amortization expense, year 2023	(4,463)
Retail Lease [Member]
Finite lived intangible assets amortization income, reminder of fiscal year 2018	53
Finite-lived intangible assets; amortization income, year 2019	71
Finite-lived intangible assets; amortization income, year 2020	71
Finite-lived intangible assets; amortization income, year 2021	71
Finite-lived intangible assets; amortization income, year 2022	27
Finite-lived intangible assets; amortization income, year 2023	$ 19

Real Estate and Lease Intangi54

Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)PropertyApartmentUnit
Properties acquired | Property	1
Property Units acquired | ApartmentUnit	117
Purchase Price | $	$ 53,700
Properties disposed | Property	4
Property Units disposed | ApartmentUnit	786
Sales Price | $	$ 290,020
Rental Properties - Consolidated [Member]
Properties acquired | Property	1
Property Units acquired | ApartmentUnit	117
Purchase Price | $	$ 53,700
Properties disposed | Property	4
Property Units disposed | ApartmentUnit	786
Sales Price | $	$ 290,020

Real Estate and Lease Intangi55

Real Estate and Lease Intangibles - Real Estate Acquisitions and Dispositions (Parenthetical) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Purchase Price	$ 53,700
Land [Member]
Purchase Price	14,800
Depreciable Property [Member]
Purchase Price	$ 39,300

Real Estate and Lease Intangi56

Real Estate and Lease Intangibles - Acquisitions and Dispositions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Real Estate [Abstract]
Net gain on sales of real estate properties	$ 142,213	$ 36,707

Commitments to Acquire_Dispos57

Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Dispose of (Details) - Subsequent Event [Member] $ in Thousands	Apr. 27, 2018USD ($)
Property/Unit schedule
Sales Price	$ 2,700
Land [Member]
Property/Unit schedule
Sales Price	$ 2,700

Commitments to Acquire_Dispos58

Commitments to Acquire/Dispose of Real Estate - Separate Agreement to Dispose of (Parenthetical) (Details)	Apr. 27, 2018Land
Subsequent Event [Member] | Land [Member]
Property/Unit schedule
Land Parcels	1

Investments in Partially Owne59

Investments in Partially Owned Entities - Partially Owned Property Balance Sheet Schedule (Details) $ in Thousands	Mar. 31, 2018USD ($)PropertyApartmentUnit	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)
Partially Owned Property Balance Sheet Schedule
Total properties | Property	303
Apartment Units | ApartmentUnit	78,399
ASSETS
Investment in real estate	$ 25,958,617	$ 26,026,896
Accumulated depreciation	(6,173,047)	(6,040,378)
Investment in real estate, net	19,785,570	19,986,518
Cash and cash equivalents	44,453	50,647	$ 42,139
Investments in unconsolidated entities	59,091	58,254
Restricted deposits	50,258	50,115	$ 144,084
Other assets	444,498	425,065
Total assets	20,383,870	20,570,599
LIABILITIES AND EQUITY
Mortgage notes payable, net	2,894,344	3,618,722
Accounts payable and accrued expenses	167,481	114,766
Accrued interest payable	69,753	58,035
Other liabilities	335,957	341,852
Security deposits	64,748	65,009
Total liabilities	9,504,210	9,729,781
Partially Owned Properties	1,293	4,708
Total equity	10,525,093	10,473,863
Total liabilities and equity/capital	$ 20,383,870	$ 20,570,599
Unconsolidated Non-VIE
Partially Owned Property Balance Sheet Schedule
Total properties | Property	2
Apartment Units | ApartmentUnit	945
ASSETS
Investment in real estate	$ 236,854
Accumulated depreciation	(46,190)
Investment in real estate, net	190,664
Cash and cash equivalents	6,587
Investments in unconsolidated entities	0
Restricted deposits	258
Other assets	243
Total assets	197,752
LIABILITIES AND EQUITY
Mortgage notes payable, net	145,424
Accounts payable and accrued expenses	1,361
Accrued interest payable	691
Other liabilities	261
Security deposits	525
Total liabilities	148,262
Partially Owned Properties	51,079
Company equity/General and Limited Partners’ Capital	(1,589)
Total equity	49,490
Total liabilities and equity/capital	$ 197,752
Consolidated VIE
Partially Owned Property Balance Sheet Schedule
Total properties | Property	17
Apartment Units | ApartmentUnit	3,535
ASSETS
Investment in real estate	$ 875,187
Accumulated depreciation	(235,426)
Investment in real estate, net	639,761
Cash and cash equivalents	13,061
Investments in unconsolidated entities	43,926
Restricted deposits	381
Other assets	25,879
Total assets	723,008
LIABILITIES AND EQUITY
Mortgage notes payable, net	302,656
Accounts payable and accrued expenses	3,344
Accrued interest payable	1,037
Other liabilities	3,683
Security deposits	2,470
Total liabilities	313,190
Partially Owned Properties	1,293
Company equity/General and Limited Partners’ Capital	408,525
Total equity	409,818
Total liabilities and equity/capital	$ 723,008
Unconsolidated VIE
Partially Owned Property Balance Sheet Schedule
Total properties | Property	0
Apartment Units | ApartmentUnit	0
ASSETS
Investment in real estate	$ 172,995
Accumulated depreciation	(51,420)
Investment in real estate, net	121,575
Cash and cash equivalents	225
Investments in unconsolidated entities	0
Restricted deposits	0
Other assets	320
Total assets	122,120
LIABILITIES AND EQUITY
Mortgage notes payable, net	0
Accounts payable and accrued expenses	115
Accrued interest payable	0
Other liabilities	15
Security deposits	0
Total liabilities	130
Partially Owned Properties	84,038
Company equity/General and Limited Partners’ Capital	37,952
Total equity	121,990
Total liabilities and equity/capital	$ 122,120
Partially Owned Properties – Unconsolidated
Partially Owned Property Balance Sheet Schedule
Total properties | Property	2
Apartment Units | ApartmentUnit	945
ASSETS
Investment in real estate	$ 409,849
Accumulated depreciation	(97,610)
Investment in real estate, net	312,239
Cash and cash equivalents	6,812
Investments in unconsolidated entities	0
Restricted deposits	258
Other assets	563
Total assets	319,872
LIABILITIES AND EQUITY
Mortgage notes payable, net	145,424
Accounts payable and accrued expenses	1,476
Accrued interest payable	691
Other liabilities	276
Security deposits	525
Total liabilities	148,392
Partially Owned Properties	135,117
Company equity/General and Limited Partners’ Capital	36,363
Total equity	171,480
Total liabilities and equity/capital	$ 319,872

Investments in Partially Owne60

Investments in Partially Owned Entities - Partially Owned Property Income Statement Schedule (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Partially Owned Property Income Statement Schedule
Operating revenue	$ 633,016	$ 604,100
Property management	23,444	22,252
General and administrative	16,278	14,173
Depreciation	196,309	178,968
Operating income	196,869	204,371
Interest and other income	5,880	601
Interest:
Expense incurred, net	(116,104)	(106,210)
Amortization of deferred financing costs	(3,679)	(2,296)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	79,525	95,376
Income and other tax (expense) benefit	(213)	(262)
Income (loss) from investments in unconsolidated entities	(977)	(1,073)
Net income	220,548	$ 149,941
Unconsolidated Non-VIE
Partially Owned Property Income Statement Schedule
Operating revenue	6,942
Operating expenses	2,268
Net operating income	4,674
Property management	199
General and administrative	0
Depreciation	2,677
Operating income	1,798
Interest and other income	0
Interest:
Expense incurred, net	(2,072)
Amortization of deferred financing costs	0
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	(274)
Income and other tax (expense) benefit	(13)
Income (loss) from investments in unconsolidated entities	0
Net income	(287)
Consolidated VIE
Partially Owned Property Income Statement Schedule
Operating revenue	26,447
Operating expenses	6,637
Net operating income	19,810
Property management	955
General and administrative	17
Depreciation	10,479
Operating income	8,359
Interest and other income	27
Interest:
Expense incurred, net	(3,312)
Amortization of deferred financing costs	(68)
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	5,006
Income and other tax (expense) benefit	(18)
Income (loss) from investments in unconsolidated entities	(393)
Net income	4,595
Unconsolidated VIE
Partially Owned Property Income Statement Schedule
Operating revenue	1,258
Operating expenses	581
Net operating income	677
Property management	19
General and administrative	0
Depreciation	1,375
Operating income	(717)
Interest and other income	0
Interest:
Expense incurred, net	0
Amortization of deferred financing costs	0
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	(717)
Income and other tax (expense) benefit	0
Income (loss) from investments in unconsolidated entities	0
Net income	(717)
Partially Owned Properties – Unconsolidated
Partially Owned Property Income Statement Schedule
Operating revenue	8,200
Operating expenses	2,849
Net operating income	5,351
Property management	218
General and administrative	0
Depreciation	4,052
Operating income	1,081
Interest and other income	0
Interest:
Expense incurred, net	(2,072)
Amortization of deferred financing costs	0
Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of real estate properties and land parcels	(991)
Income and other tax (expense) benefit	(13)
Income (loss) from investments in unconsolidated entities	0
Net income	$ (1,004)

Investments in Partially Owne61

Investments in Partially Owned Entities - Partially Owned Property Income Statement Schedule (Parenthetical) (Details) - Unconsolidated Non-VIE $ in Millions	Mar. 31, 2018USD ($)
Legacy JV [Member]
Liquidation Value Preferred Interests	$ 37.3
PARTIALLY OWNED PROPERTIES
Joint venture ownership percentage owned by company	60.00%
Residual JV [Member]
PARTIALLY OWNED PROPERTIES
Joint venture ownership percentage owned by company	60.00%

Investments in Partially Owne62

Investments in Partially Owned Entities - Operating Properties - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)PropertyApartmentUnit	Dec. 31, 2017USD ($)
Variable Interest Entity [Line Items]
Properties | Property	303
Apartment units | ApartmentUnit	78,399
Investments in unconsolidated entities	$ 59,091	$ 58,254
Secured Debt	$ 2,894,344	$ 3,618,722
Debt instrument, maturity date	Jan. 10, 2022
Nexus Sawgrass [Member]
Variable Interest Entity [Line Items]
Apartment units | ApartmentUnit	501
Investments in unconsolidated entities	$ 4,000
Equity Method Investment, Ownership Percentage	20.00%
Secured Debt	$ 48,600
Debt instrument, interest rate, stated percentage	5.60%
Debt instrument, maturity date	Jan. 1, 2021
Consolidated VIE
Variable Interest Entity [Line Items]
Properties | Property	17
Apartment units | ApartmentUnit	3,535
Investments in unconsolidated entities	$ 43,926
Secured Debt	$ 302,656
Unconsolidated VIE
Variable Interest Entity [Line Items]
Properties | Property	0
Apartment units | ApartmentUnit	0
Investments in unconsolidated entities	$ 0
Secured Debt	$ 0
Operating Property [Member] | Consolidated VIE
Variable Interest Entity [Line Items]
Properties | Property	16
Apartment units | ApartmentUnit	3,103
Wisconsin Place [Member] | Consolidated VIE
Variable Interest Entity [Line Items]
Apartment units | ApartmentUnit	432
Joint venture ownership percentage owned by company	75.00%
Basis of joint venture	$ 159,400
Wisconsin Place [Member] | Unconsolidated VIE
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 43,900
Domain [Member]
Variable Interest Entity [Line Items]
Apartment units | ApartmentUnit	444
Investments in unconsolidated entities	$ 7,900
Equity Method Investment, Ownership Percentage	20.00%
Secured Debt	$ 96,800
Debt instrument, interest rate, stated percentage	5.75%
Debt instrument, maturity date	Jan. 1, 2022

Investments in Partially Owne63

Investments in Partially Owned Entities - Other - Additional Information (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 59,091,000	$ 58,254,000
Unconsolidated Non-VIE
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	0
Unconsolidated Non-VIE | Residual JV [Member]
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 800,000
Joint venture ownership percentage owned by company	60.00%
Joint venture partner ownership percentage	40.00%
Unconsolidated Non-VIE | Legacy JV [Member]
Variable Interest Entity [Line Items]
Joint venture ownership percentage owned by company	60.00%
Joint venture partner ownership percentage	40.00%
Liquidation Value Preferred Interests	$ 37,300,000
Private Equity Fund | Capital Commitment
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	4,100,000
Private Equity Fund | Maximum [Member]
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 5,000,000

Restricted Deposits - Restricte

Restricted Deposits - Restricted Deposits (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Mortgage escrow deposits:
Real estate taxes and insurance	$ 1,279	$ 845
Replacement reserves	7,423	8,347
Mortgage principal reserves/sinking funds	4,778	3,167
Other	852	852
Mortgage escrow deposits	14,332	13,211
Restricted cash:
Earnest money on pending acquisitions		750
Restricted deposits on real estate investments	53	58
Resident security and utility deposits	34,967	35,183
Other	906	913
Restricted cash	35,926	36,904
Restricted deposits	$ 50,258	$ 50,115	$ 144,084

Debt - Mortgage Notes Payable -

Debt - Mortgage Notes Payable - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Mortgage notes payable	$ 2,894,344	$ 3,618,722
Debt instrument, maturity date	Jan. 10, 2022
Mortgages [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 1,700
Write off of deferred debt issuance cost	1,600
Write off unamortized (premium) discount	$ (200)
Debt instrument, maturity date	May 28, 2061
Weighted average interest rate	4.24%
Mortgages [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.10%
Mortgages [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	6.90%
Conventional Mortgage Loan [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 43,700
Debt instrument, maturity year	2,018
Bonds [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 131,900
Debt instrument maturity year, start	2,028
Debt instrument maturity year, end	2,042
Credit enhanced debt [Member]
Debt Instrument [Line Items]
Mortgage notes payable	$ 563,500
Fannie Mae Pool 3 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 550,000
Debt instrument, interest rate, stated percentage	6.08%
Debt instrument, maturity year	2,020
Prepayment penalty charges	$ 22,100

Debt - Notes - Additional Infor

Debt - Notes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unsecured notes	$ 5,530,815	$ 5,038,812
Debt instrument, maturity date	Jan. 10, 2022
3.50% Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of unsecured debt	$ 500,000
Debt instrument, interest rate, stated percentage	3.50%
Proceeds from debt, net of issuance costs	$ 497,000
Debt instrument, interest rate, effective percentage	3.61%
Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Aug. 1, 2047
Weighted average interest rate	4.28%
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, 2018	Nov. 02, 2016	Feb. 02, 2015
Line of Credit Facility [Line Items]
Debt instrument, maturity date		Jan. 10, 2022
Commercial Paper [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility				$ 500,000,000
Commercial paper, net		$ 234,300,000
commercial paper principal outstanding		235,000,000
Unamortized discount		$ 700,000
Weighted average interest rate		1.94%
Commercial paper weighted average days outstanding		46 days
Commercial paper principal outstanding		$ 235,000,000
Unsecured Revolving Credit Facility
Line of Credit Facility [Line Items]
Unsecured revolving credit facility	$ 2,000,000,000		$ 2,500,000,000
Ability to increase LOC facility	$ 750,000,000
Debt instrument, basis spread on variable rate	0.825%
Percentage points of line of credit facility commitment fee		0.125%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Weighted average interest rate		2.29%
Remaining borrowing capacity		$ 1,720,000,000
Amount restricted/dedicated to support letters of credit		$ 41,600,000

Debt - Other - Additional Infor

Debt - Other - Additional Information (Details) $ in Millions	Mar. 31, 2018USD ($)
Debt Disclosure [Abstract]
Letters of credit outstanding	$ 9

Derivative and Other Fair Val69

Derivative and Other Fair Value Instruments - Summary of Carrying and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	$ 8,719,288	$ 9,235,128
Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	8,659,477	8,957,291
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	2,841,288	3,615,384
Mortgage Notes Payable, Net [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	2,894,344	3,618,722
Unsecured Debt [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	5,878,000	5,619,744
Unsecured Debt [Member] | Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt, net	$ 5,765,133	$ 5,338,569

Derivative and Other Fair Val70

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Details)	3 Months Ended
	Mar. 31, 2018USD ($)
Fair Value Hedges [Member]
Derivative [Line Items]
Current Notional Balance	$ 450,000,000
Earliest Maturity Date	2,019
Latest Maturity Date	2,019
Fair Value Hedges [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.375%
Fair Value Hedges [Member] | Maximum [Member]
Derivative [Line Items]
Interest Rate	2.375%
Forward Starting Swaps [Member]
Derivative [Line Items]
Current Notional Balance	$ 600,000,000
Earliest Maturity Date	2,028
Latest Maturity Date	2,029
Forward Starting Swaps [Member] | Minimum [Member]
Derivative [Line Items]
Interest Rate	2.1478%
Forward Starting Swaps [Member] | Maximum [Member]
Derivative [Line Items]
Interest Rate	3.003%

Derivative and Other Fair Val71

Derivative and Other Fair Value Instruments - Summary of Consolidated Derivative Instruments (Parenthetical) (Details)	3 Months Ended
	Mar. 31, 2018USD ($)
Derivative [Line Items]
Debt instrument, maturity date	Jan. 10, 2022
Forward Starting Swaps [Member]
Derivative [Line Items]
Current Notional Balance	$ 600,000,000
Forward Starting Swaps Mandatory Counterparty Terminations in 2019 [Member]
Derivative [Line Items]
Current Notional Balance	250,000,000
Forward Starting Swaps Mandatory Counterparty Terminations in 2020 [Member]
Derivative [Line Items]
Current Notional Balance	350,000,000
2.375% Notes [Member]
Derivative [Line Items]
Proceeds from issuance of unsecured debt	$ 450,000,000
Debt instrument, interest rate, stated percentage	2.375%
Debt instrument, maturity date	Jul. 1, 2019
2.375% Notes [Member] | London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Debt instrument, basis spread on variable rate	0.61%
Debt instrument, description of variable rate basis	90-Day LIBOR

Derivative and Other Fair Val72

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, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	$ 138,444	$ 140,159
Assets, Fair Value Disclosure	151,081	145,302
Other Liabilities, Fair Value Disclosure	138,444	140,159
Liabilities, Fair Value Disclosure	145,375	141,756
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	354,567	366,955
Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3,886	1,597
Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	12,637	5,143
Other Liabilities, Forward Starting Swaps	3,045
Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	138,444	140,159
Assets, Fair Value Disclosure	138,444	140,159
Other Liabilities, Fair Value Disclosure	138,444	140,159
Liabilities, Fair Value Disclosure	138,444	140,159
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Fair Value, Inputs, Level 1 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0
Other Liabilities, Forward Starting Swaps	0
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	12,637	5,143
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	6,931	1,597
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	354,567	366,955
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3,886	1,597
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	12,637	5,143
Other Liabilities, Forward Starting Swaps	3,045
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair Value Of SERP Investments	0	0
Assets, Fair Value Disclosure	0	0
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	0	0
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Fair Value, Inputs, Level 3 [Member] | Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0	$ 0
Other Liabilities, Forward Starting Swaps	$ 0

Derivative and Other Fair Val73

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, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ (2,289)	$ (1,106)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	2,289	1,106
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	(2,289)	(1,106)
Amount of Gain/(Loss) Recognized in Income on Hedged Item	$ 2,289	$ 1,106

Derivative and Other Fair Val74

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, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	$ 6,087	$ 0
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(4,791)	(4,583)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	0	0
Forward Starting Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative	6,087	0
Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income	(4,791)	(4,583)
Ineffective Portion - Amount of Gain/ (Loss) Reclassified from Accumulated OCI into Income	$ 0	$ 0

Derivative and Other Fair Val75

Derivative and Other Fair Value Instruments - Additional Information (Details) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 28, 2018USD ($)DerivativeInstrument	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Derivative [Line Items]
Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss)		$ 77.7	$ 88.6
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net		$ 20.3
Forward Starting Swaps [Member]
Derivative [Line Items]
Proceeds from settlement of derivative instruments	$ 1.6
Forward starting swaps settled | DerivativeInstrument	2
Public notes, face value	$ 500
Debt instrument, term	10 years

Earning Per Share and Earning76

Earning Per Share and Earnings Per Unit - Computation of Net Income per Share Basic and Net Income per Share Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 220,548	$ 149,941
Allocation to Noncontrolling Interests – Operating Partnership	(8,059)	(5,411)
Partially Owned Properties	(680)	(788)
Preferred distributions	(773)	(773)
Net income available to Common Shares	211,036	142,969
Numerator for net income per share – diluted	$ 219,095	$ 148,380
Weighted average Common Shares outstanding	367,800	366,605
Dilutive Op Units	12,863	12,899
Dilutive Securities Options	2,355	2,776
Weighted average Common Shares outstanding	383,018	382,280
Net income available to Common Shares	$ 0.57	$ 0.39
Net income available to Common Shares	$ 0.57	$ 0.39

Earning Per Share and Earning77

Earning Per Share and Earnings Per Unit - Computation of Net Income per Unit Basic and Net Income per Unit Diluted for Operating Partnership (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income	$ 220,548	$ 149,941
Partially Owned Properties	$ (680)	$ (788)
Dilutive Securities Options	2,355	2,776
Weighted average Common Shares outstanding	383,018	382,280
Net income available to Common Shares	$ 0.57	$ 0.39
Net income available to Common Shares	$ 0.57	$ 0.39
ERPOP [Member]
Net income	$ 220,548	$ 149,941
Partially Owned Properties	(680)	(788)
Allocation to Preference Units	(773)	(773)
Numerator for net income per Unit – basic and diluted	$ 219,095	$ 148,380
Denominator for net income per Unit – basic	380,663	379,504
Dilutive Securities Options	2,355	2,776
Weighted average Common Shares outstanding	383,018	382,280
Net income available to Common Shares	$ 0.57	$ 0.39
Net income available to Common Shares	$ 0.57	$ 0.39

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)PropertyApartmentUnit
Accrual for environmental loss contingencies | $	$ 5.2
Number of properties with environmental reserves | Property	3
Loss contingency accrual | $	$ 0.9
Projects in various stages of development | Property	3
Units in various stages of development | ApartmentUnit	443
Consolidated project under development commitment fund | $	$ 105.2
Various stages of development with estimated completion dates ranging through December 31, 2019	Dec. 31, 2019
Partially Owned Properties – Unconsolidated
Number of unconsolidated projects | Property	2

Reportable Segments - Additiona

Reportable Segments - Additional Information (Details) - Customer	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]
Number of customer contributed 10% or more of total revenue	0	0

Reportable Segments - Reconcili

Reportable Segments - Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	$ 632,831	$ 603,920
Property and maintenance expense	(108,202)	(102,608)
Real estate taxes and insurance expense	(91,914)	(81,728)
Operating income	196,869	204,371
Same Store, Non-same Store and Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Rental income	632,831	603,920
Property and maintenance expense	(108,202)	(102,608)
Real estate taxes and insurance expense	(91,914)	(81,728)
Total operating expenses	(200,116)	(184,336)
Operating income	$ 432,715	$ 419,584

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, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Rental income	$ 632,831	$ 603,920
Operating income	196,869	204,371
Total Assets	20,383,870		$ 20,570,599
Capital Expenditures	36,747
Same store
Segment Reporting Information [Line Items]
Rental income	590,384	577,404
Operating expenses	180,358	173,605
Operating income	410,026	403,799
Total Assets	17,612,333
Capital Expenditures	36,235
Non-same store/other
Segment Reporting Information [Line Items]
Rental income	42,447	26,516
Operating expenses	19,758	10,731
Operating income	22,689	15,785
Total Assets	2,771,537
Capital Expenditures	512
Same Store, Non-same Store and Other
Segment Reporting Information [Line Items]
Rental income	632,831	603,920
Operating expenses	200,116	184,336
Operating income	432,715	419,584
Other markets | Same store
Segment Reporting Information [Line Items]
Rental income	487	464
Operating expenses	165	196
Operating income	322	268
Total Assets	12,918
Capital Expenditures	77
Los Angeles | Same store
Segment Reporting Information [Line Items]
Rental income	102,484	98,636
Operating expenses	29,860	28,651
Operating income	72,624	69,985
Total Assets	2,670,909
Capital Expenditures	5,939
Orange County | Same store
Segment Reporting Information [Line Items]
Rental income	22,502	21,656
Operating expenses	5,527	5,462
Operating income	16,975	16,194
Total Assets	325,898
Capital Expenditures	1,620
San Diego | Same store
Segment Reporting Information [Line Items]
Rental income	22,493	21,723
Operating expenses	5,963	5,799
Operating income	16,530	15,924
Total Assets	417,593
Capital Expenditures	1,270
Subtotal - Southern California | Same store
Segment Reporting Information [Line Items]
Rental income	147,479	142,015
Operating expenses	41,350	39,912
Operating income	106,129	102,103
Total Assets	3,414,400
Capital Expenditures	8,829
San Francisco | Same store
Segment Reporting Information [Line Items]
Rental income	109,212	106,306
Operating expenses	26,995	26,928
Operating income	82,217	79,378
Total Assets	3,020,673
Capital Expenditures	8,743
Washington DC | Same store
Segment Reporting Information [Line Items]
Rental income	107,155	106,443
Operating expenses	33,663	32,332
Operating income	73,492	74,111
Total Assets	3,771,999
Capital Expenditures	5,964
New York | Same store
Segment Reporting Information [Line Items]
Rental income	119,626	119,363
Operating expenses	47,825	45,439
Operating income	71,801	73,924
Total Assets	4,447,994
Capital Expenditures	5,216
Boston | Same store
Segment Reporting Information [Line Items]
Rental income	57,814	56,388
Operating expenses	16,672	15,783
Operating income	41,142	40,605
Total Assets	1,637,837
Capital Expenditures	4,358
Seattle | Same store
Segment Reporting Information [Line Items]
Rental income	48,611	46,425
Operating expenses	13,688	13,015
Operating income	34,923	33,410
Total Assets	1,306,512
Capital Expenditures	3,048
Non-same store | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	38,622	15,961
Operating expenses	13,733	5,894
Operating income	24,889	10,067
Total Assets	2,276,821
Capital Expenditures	454
Other | Non-same store/other
Segment Reporting Information [Line Items]
Rental income	3,825	10,555
Operating expenses	6,025	4,837
Operating income	(2,200)	$ 5,718
Total Assets	494,716
Capital Expenditures	$ 58

Reportable Segments - NOI for82

Reportable Segments - NOI for Each Segment from Our Rental Real Estate Specific to Continuing Operations (Parenthetical) (Details) - Property	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract]
Units in same store properties	72,204	72,204

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) $ in Thousands	Apr. 27, 2018USD ($)PropertyApartmentUnit	Mar. 31, 2018USD ($)PropertyApartmentUnit
Subsequent Event [Line Items]
Properties acquired | Property		1
Property Units acquired | ApartmentUnit		117
Purchase Price | $		$ 53,700
Subsequent Event [Member]
Subsequent Event [Line Items]
Properties acquired | Property	1
Property Units acquired | ApartmentUnit	240
Purchase Price | $	$ 146,000