Entity Central Index Key Depreciable property. Amount of lessee's right to use underlying asset under operating and finance lease. The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Also includes the carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days. Carrying value as of the balance sheet date of obligations incurred and payable pertaining to goods and services received from vendors, are incurred in connection with contractual obligations or accumulate over time and for which invoices have not yet been received or will not be rendered. Present value of lessee's discounted obligation for lease payments from operating and finance lease. The greater of carrying value (book value) or fair market value of an entity's issued and outstanding Units which is not included within Partner's Capital in Capital. Represents a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the units to another class of equity. Cost of property management. The component of interest expense comprised of the periodic charge against earnings over the life of the financing arrangement for cash outflows paid to third parties in connection with debt origination. Includes both continuing operations and discontinued operations. The difference between the book value and the sale price of land parcels sold within the period. Amount of net income (loss) for the period allocated to noncontrolling partners in partially owned properties. Amount of amortization expense attributable to right-of-use asset from operating and finance lease. Increase (decrease) in lease liabilities. Payments for capital expenditures to real estate. Non-real estate capital additions. Payments of interest capitalized for real estate under development. The cash outflow from the lump sum payment of collateralized debt obligations (backed by pledge, mortgage or other lien in the entity's assets). The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Assumption that units were converted into Common Shares for computing the dilutive effects of convertible units. The amount resulting from the "as if" assumption that stock options were exercised for purposes of computing the dilutive effect of convertible securities. Cover [Abstract] Document Information [Table] Document Information [Table] Legal Entity Legal Entity [Axis] Entity Entity [Domain] ERP operating limited partnership. ERPOP [Member] E R P O P [Member] Document Information [Line Items] Document Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol No Trading Symbol Flag No Trading Symbol Flag Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Entity Shell Company Entity Shell Company Entity File Number Entity File Number Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address Address Line1 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Title of 12(b) Security Security12b Title Security Exchange Name Security Exchange Name Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Entity Interactive Data Current Entity Interactive Data Current Carrying amount of equity interests owned by noncontrolling partners in partially owned properties. Statement Of Financial Position [Abstract] ASSETS Assets [Abstract] Land Land Depreciable property Depreciable Property Projects under development Development In Process Land held for development Land Available For Development Investment in real estate Real Estate Investment Property At Cost Accumulated depreciation Real Estate Investment Property Accumulated Depreciation Investment in real estate, net Real Estate Investment Property Net Investments in unconsolidated entities Investments In Affiliates Subsidiaries Associates And Joint Ventures Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Restricted deposits Restricted Cash And Cash Equivalents Right-of-use assets Operating And Finance Lease Right Of Use Asset Other assets Other Assets Total assets Assets LIABILITIES AND EQUITY Liabilities And Stockholders Equity [Abstract] Liabilities: Liabilities [Abstract] Mortgage notes payable, net Secured Debt Notes, net Notes Payable Line of credit and commercial paper Line Of Credit And Commercial Paper Accounts payable and accrued expenses Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable Accrued interest payable Interest Payable Current And Noncurrent Lease liabilities Operating And Finance Lease Liability Other liabilities Other Liabilities Security deposits Security Deposit Liability Distributions payable Dividends Payable Current And Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments And Contingencies Redeemable Noncontrolling Interests – Operating Partnership Redeemable Noncontrolling Interest Equity Carrying Amount Equity: Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract] Shareholders' equity: Stockholders Equity [Abstract] Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 745,600 shares issued and outstanding as of June 30, 2020 and December 31, 2019 Preferred Stock Value Common Shares of beneficial interest, $0.01 par value; 1,000,000,000 shares authorized; 372,209,012 shares issued and outstanding as of June 30, 2020 and 371,670,884 shares issued and outstanding as of December 31, 2019 Common Stock Value Paid in capital Additional Paid In Capital Retained earnings Retained Earnings Accumulated Deficit Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income Loss Net Of Tax Total shareholders’ equity Stockholders Equity Noncontrolling Interests: Noncontrolling Interest Items [Abstract] Operating Partnership Minority Interest In Operating Partnerships Partially Owned Properties Noncontrolling Interests Partially Owned Properties Total Noncontrolling Interests Minority Interest Total equity Stockholders Equity Including Portion Attributable To Noncontrolling Interest Total liabilities and equity/capital Liabilities And Stockholders Equity Preferred Stock, Par or Stated Value Per Share Preferred Stock Par Or Stated Value Per Share Preferred Stock, Shares Authorized Preferred Stock Shares Authorized Preferred Stock, Shares Issued Preferred Stock Shares Issued Preferred Stock, Shares Outstanding Preferred Stock Shares Outstanding Common Stock, Par or Stated Value Per Share Common Stock Par Or Stated Value Per Share Common Stock, Shares Authorized Common Stock Shares Authorized Common Stock, Shares, Issued Common Stock Shares Issued Common Stock, Shares, Outstanding Common Stock Shares Outstanding Income Statement [Abstract] REVENUES Revenues [Abstract] Rental income Operating Leases Income Statement Lease Revenue Type of Revenue [Extensible List] Type Of Revenue Extensible List EXPENSES Costs And Expenses [Abstract] Property and maintenance Cost Of Property Repairs And Maintenance Real estate taxes and insurance Real Estate Taxes And Insurance Property management Cost Of Property Management General and administrative General And Administrative Expense Depreciation Depreciation Total expenses Costs And Expenses Net gain (loss) on sales of real estate properties Gains Losses On Sales Of Investment Real Estate Operating income Operating Income Loss Interest and other income Interest And Other Income Other expenses Other Nonoperating Expense Interest: Interest Expense [Abstract] Expense incurred, net Interest Expense Debt Amortization of deferred financing costs Amortization Of Deferred Financing Costs Income before income and other taxes, income (loss) from investments in unconsolidated entities and net gain (loss) on sales of land parcels Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments Income and other tax (expense) benefit Income Tax Expense Benefit Income (loss) from investments in unconsolidated entities Income Loss From Equity Method Investments Net gain (loss) on sales of land parcels Gain Loss On Sales Of Land Parcels Net income Profit Loss Net (income) loss attributable to Noncontrolling Interests: Minority Interest In Net Income Loss Of Consolidated Entities [Abstract] Operating Partnership Net Income Loss Attributable To Noncontrolling Interest Partially Owned Properties Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties Net income attributable to controlling interests Net Income Loss Preferred distributions Preferred Stock Dividends Income Statement Impact Net income available to Common Shares Net Income Loss Available To Common Stockholders Basic Earnings per share – basic: Earnings Per Share Basic [Abstract] Net income available to Common Shares Earnings Per Share Basic Weighted average Common Shares outstanding Weighted Average Number Of Shares Outstanding Basic Earnings per share – diluted: Earnings Per Share Diluted [Abstract] Net income available to Common Shares Earnings Per Share Diluted Weighted average Common Shares outstanding Weighted Average Number Of Diluted Shares Outstanding Other comprehensive income loss. Statement Of Income And Comprehensive Income [Abstract] Comprehensive income: Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest [Abstract] Net income Other comprehensive income (loss): Other Comprehensive Income Loss [Abstract] Other comprehensive income (loss) – derivative instruments: Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Period Increase Decrease [Abstract] Unrealized holding gains (losses) arising during the period Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax Losses reclassified into earnings from other comprehensive income Other Comprehensive Income Loss Reclassification Adjustment From A O C I On Derivatives Net Of Tax Other comprehensive income (loss) Other Comprehensive Income Loss Net Of Tax Comprehensive income Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest Comprehensive (income) attributable to Noncontrolling Interests Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest Comprehensive income attributable to controlling interests Comprehensive Income Net Of Tax Statement Of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Amortization of deferred financing costs Amortization Of Financing Costs Amortization of above/below market lease intangibles Amortization Of Above And Below Market Leases Amortization of discounts and premiums on debt Amortization Of Debt Discount Premium Amortization of deferred settlements on derivative instruments Amortization Of Deferred Hedge Gains Amortization of right-of-use assets Operating And Finance Lease Right Of Use Asset Amortization Write-off of pursuit costs Noncash Project Abandonment Costs (Income) loss from investments in unconsolidated entities Distributions from unconsolidated entities – return on capital Equity Method Investment Dividends Or Distributions Net (gain) loss on sales of real estate properties Net (gain) loss on sales of land parcels Realized/unrealized (gain) loss on derivative instruments Gain Loss On Sale Of Derivatives Compensation paid with Company Common Shares Share Based Compensation Other operating activities, net Proceeds From Other Operating Activities Changes in assets and liabilities: Increase Decrease In Operating Capital [Abstract] (Increase) decrease in other assets Increase Decrease In Other Operating Assets Increase (decrease) in accounts payable and accrued expenses Increase Decrease In Accounts Payable And Accrued Liabilities Increase (decrease) in accrued interest payable Increase Decrease In Interest Payable Net Increase (decrease) in lease liabilities Increase Decrease In Lease Liabilities Increase (decrease) in other liabilities Increase Decrease In Other Operating Liabilities Increase (decrease) in security deposits Increase Decrease In Security Deposits Net cash provided by operating activities Net Cash Provided By Used In Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided By Used In Investing Activities [Abstract] Investment in real estate – acquisitions Payments To Acquire Real Estate Investment in real estate – development/other Payments To Develop Real Estate Assets Capital expenditures to real estate Payments For Capital Expenditures To Real Estate Non-real estate capital additions Non Real Estate Capital Additions Interest capitalized for real estate under development Payments Of Interest Capitalized For Real Estate Under Development Proceeds from disposition of real estate, net Proceeds From Sale Of Real Estate Heldforinvestment Investments in unconsolidated entities Payments To Acquire Equity Method Investments Distributions from unconsolidated entities – return of capital Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital Purchase of investment securities and other investments Payments To Acquire Other Investments Net cash provided by (used for) investing activities Net Cash Provided By Used In Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided By Used In Financing Activities [Abstract] Debt financing costs Payments Of Financing Costs Mortgage notes payable, net: Secured Longterm Debt Current And Noncurrent [Abstract] Proceeds Proceeds From Secured Notes Payable Lump sum payoffs Mortgage Notes Payable Lump Sum Pay Offs Scheduled principal repayments Repayments Of Mortgage Notes Payable Notes, net: Unsecured Longterm Debt Current And Noncurrent [Abstract] Proceeds Proceeds From Unsecured Notes Payable Line of credit and commercial paper: Line Of Credit Facility [Abstract] Line of credit proceeds Proceeds From Lines Of Credit Line of credit repayments Repayments Of Lines Of Credit Commercial paper proceeds Proceeds From Issuance Of Commercial Paper Commercial paper repayments Repayments Of Commercial Paper Proceeds from (payments on) settlement of derivative instruments Payments For Proceeds From Hedge Financing Activities Proceeds from Employee Share Purchase Plan (ESPP) Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Proceeds from exercise of options Proceeds From Stock Options Exercised Payment of offering costs Payments Of Stock Issuance Costs Other financing activities, net Proceeds From Payments For Other Financing Activities Contributions – Noncontrolling Interests – Partially Owned Properties Proceeds From Minority Shareholders Contributions – Noncontrolling Interests – Operating Partnership Proceeds From Partnership Contribution Distributions: Payments Of Dividends [Abstract] Common Shares Payments Of Dividends Common Stock Preferred Shares Payments Of Dividends Preferred Stock And Preference Stock Noncontrolling Interests – Operating Partnership Distribution Made To Limited Partner Cash Distributions Paid Noncontrolling Interests – Partially Owned Properties Payments Of Dividends Minority Interest Net cash provided by (used for) financing activities Net Cash Provided By Used In Financing Activities Net increase (decrease) in cash and cash equivalents and restricted deposits Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect Cash and cash equivalents and restricted deposits, beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Cash and cash equivalents and restricted deposits, end of period Amortization of deferred financing costs investment in real estate net. Amount of amortization of other deferred financing costs associated with other assets. Amount of amortization of other deferred financing costs associated with mortgage notes payable, net. Amount of amortization of other deferred financing costs associated with notes, net. The component of interest expense representing the noncash expenses charged against earnings in the period to amortize debt discount and premium associated with the mortgage notes payable during the period. The component of interest expense representing the noncash expenses charged against earnings in the period to amortize debt discount and premium associated with the unsecured notes during the period. Net of tax effect of the reclassification adjustment for deferred gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges included in other liabilities that was charged against earnings during the period. The expense charged against investment in real estate to eliminate the capitalized costs of projects that have been terminated during the reporting period. The expense charged against other assets to eliminate the capitalized costs of projects that have been terminated during the reporting period. The expense charged against accounts payable and accrued expenses to eliminate the capitalized costs of projects that have been eliminated during the reporting period. Represents the charge against earnings for the indirect costs incurred from a material business combination such as severance and retention bonuses. Represents the accrual of indirect costs incurred from a material business combination such as severance and retention bonuses. The increases (decreases) in the market value of derivative instruments designated and qualifying as cash flow hedging instruments that was recognized in other assets during the current period. The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in unsecured notes for the period. The increases (decreases) in the market value of derivative instruments designated and qualifying as cash flow hedging instruments that was recognized in other liabilities during the current period. The value of unconsolidated entities real estate assumed by the Company during the reporting period. The value of other liabilities assumed by the Company for investments in unconsolidated entities during the reporting period. Debt financing costs other assets. Debt financing costs mortgage notes payable, net. Debt financing costs notes, net. Debt financing costs other liabilities. Initial measurement and reclassifications right-of-use assets. Initial measurement and reclassifications other assets. Initial measurement and reclassifications lease liabilities. Initial measurement and reclassifications other liabilities. Amortization of deferred financing costs. The component of interest expense representing the noncash expenses charged against earnings in the period to amortize debt discount and premium associated with the realted debt instruments. The amount of expense charged against earnings by an Entity to record deferred gains and losses on hedge instruments. The expense charged against earnings to eliminate the capitalized costs of projects that have been terminated during the reporting period, which is added back to net income when calculating cash provided by (used in) operations using the indirect method. Income (loss) from investments in unconsolidated entities. The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. Investments in unconsolidated entities. Debt financing costs. Right-of-use assets and lease liabilities initial measurement and reclassifications. SUPPLEMENTAL INFORMATION: Supplemental Cash Flow Information [Abstract] Cash paid for interest, net of amounts capitalized Interest Paid Net Net cash paid (received) for income and other taxes Income Taxes Paid Net Amortization of deferred financing costs: Amortization Of Deferred Financing Costs [Abstract] Investment in real estate, net Amortization Of Deferred Financing Costs Investment In Real Estate Net Other assets Amortization Of Deferred Financing Costs Other Assets Mortgage notes payable, net Amortization Of Deferred Financing Costs Mortgage Notes Payable Net Notes, net Amortization Of Deferred Financing Costs Notes Net Amortization of discounts and premiums on debt: Amortization Of Discounts And Premiums On Debt [Abstract] Mortgage notes payable, net Amortization Of Discounts And Premiums On Debt Mortgage Notes Payable Notes, net Amortization Of Discounts And Premiums On Debt Notes Net Amortization of deferred settlements on derivative instruments: Amortization Of Deferred Settlements On Derivative Instruments [Abstract] Other liabilities Amortization Of Deferred Settlements On Derivative Instruments Other Liabilities Accumulated other comprehensive income Write-off of pursuit costs: Write Off Of Pursuit Costs [Abstract] Investment in real estate, net Write Off Pursuit Costs Investment In Real Estate Other assets Write Off Of Pursuit Costs Other Assets Accounts payable and accrued expenses Write Off Of Pursuit Costs Accounts Payable And Accrued Expenses (Income) loss from investments in unconsolidated entities: Income Loss From Investments In Unconsolidated Entities [Abstract] Investments in unconsolidated entities Income Loss From Equity Method Investments Merger Other liabilities Other Liabilities Loss From Investments In Unconsolidated Entities Merger Realized/unrealized (gain) loss on derivative instruments: Unrealized Gain Loss On Derivative Instruments [Abstract] Other assets Unrealized Gain Loss On Derivative Instruments Other Assets Notes, net Unrealized Gain Loss On Derivative Instruments Notes Net Other liabilities Unrealized Gain Loss On Derivative Instruments Other Liabilities Accumulated other comprehensive income Investments in unconsolidated entities: Investments In Unconsolidated Entities [Abstract] Investments in unconsolidated entities Investments In Unconsolidated Entities Other liabilities Investments In Unconsolidated Entities Other Liabilities Debt financing costs: Debt Financing Costs [Abstract] Other assets Debt Financing Costs Other Assets Mortgage notes payable, net Debt Financing Costs Mortgage Notes Payable Net Notes, net Debt Financing Costs Notes Net Other liabilities Debt Financing Costs Other Liabilities Right-of-use assets and lease liabilities initial measurement and reclassifications: Right Of Use Assets And Lease Liabilities Initial Measurement And Reclassifications [Abstract] Right-of-use assets Initial Measurement And Reclassifications Right Of Use Assets Other assets Initial Measurement And Reclassifications Other Assets Lease liabilities Initial Measurement And Reclassifications Lease Liabilities Other liabilities Initial Measurement And Reclassifications Other Liabilities Adjustment to additional paid in capital resulting from conversion of capital units. Change in the value of company common shares contained in the company's supplemental executive retirement plan. Adjustment to additional paid in capital and noncontrolling ownership interest. Stock issued during period value share options in-lieu of bonus. Value of long term incentive plan units issued during the period. Represents the change in the proportional relationship between the carrying values of equity associated with common shares relative to that of the noncontrolling interests. Investments in partially owned entities. Minority interest increase from contributions by non-controlling interests partially owned properties. Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] PREFERRED SHARES Preferred Stock [Member] COMMON SHARES, $0.01 PAR VALUE Common Stock [Member] PAID IN CAPITAL Additional Paid In Capital [Member] RETAINED EARNINGS Retained Earnings [Member] ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Accumulated Other Comprehensive Income [Member] Distributions. DISTRIBUTIONS Distributions [Member] OPERATING PARTNERSHIP Noncontrolling Interest [Member] Partially owned. PARTIALLY OWNED PROPERTIES Partially Owned [Member] Statement [Line Items] Statement [Line Items] Balance, beginning of year Balance, beginning of year COMMON SHARES, $0.01 PAR VALUE Stock Issued During Period Sharebased Compensation [Abstract] Conversion of OP Units into Common Shares Adjustment To Additional Paid In Capital Resulting From Conversion Of Capital Units Exercise of share options Stock Issued During Period Value Stock Options Exercised Employee Share Purchase Plan (ESPP) Stock Issued During Period Value Employee Stock Purchase Plan Share-based employee compensation expense: Share Based Compensation [Abstract] Restricted shares Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition PAID IN CAPITAL Adjustments To Additional Paid In Capital [Abstract] Share options in-lieu of bonus Stock Issued During Period Value Share Options In Lieu Of Bonus Share options Adjustments To Additional Paid In Capital Share Based Compensation Stock Options Requisite Service Period Recognition ESPP discount Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition Offering costs Adjustments To Additional Paid In Capital Stock Issued Issuance Costs Supplemental Executive Retirement Plan (SERP) Supplemental Executive Retirement Plan Serp Change in market value of Redeemable Noncontrolling Interests –Operating Partnership Minority Interest Change In Redemption Value Adjustment for Noncontrolling Interests ownership in Operating Partnership Adjustment To Additional Paid In Capital And Noncontrolling Ownership Interest RETAINED EARNINGS Retained Earnings Accumulated Deficit [Abstract] Net income attributable to controlling interests Common Share distributions Dividends Common Stock Cash Preferred Share distributions Dividends Preferred Stock Cash ACCUMULATED OTHER COMPREHENSIVE (LOSS) Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract] Accumulated other comprehensive income (loss) - derivative instruments: Losses reclassified into earnings from other comprehensive income DISTRIBUTIONS Dividends Common Stock [Abstract] Distributions declared per Common Share outstanding Common Stock Dividends Per Share Declared NONCONTROLLING INTERESTS Noncontrolling Interest [Abstract] OPERATING PARTNERSHIP Partners Capital [Abstract] Issuance of restricted units to Noncontrolling Interests Issuance Of Long Term Incentive Plan Units Into Noncontrolling Interest Conversion of OP Units held by Noncontrolling Interests into OP Units held by General Partner Stock Issued During Period Value Conversion Of Units Equity compensation associated with Noncontrolling Interests Adjustments To Additional Paid In Capital Sharebased Compensation Other Longterm Incentive Plans Requisite Service Period Recognition Net income attributable to Noncontrolling Interests Distributions to Noncontrolling Interests Minority Interest Decrease From Distributions To Noncontrolling Interest Holders Change in carrying value of Redeemable Noncontrolling Interests – Operating Partnership Minority Interest Change In Carrying Value PARTIALLY OWNED PROPERTIES Investments In Partially Owned Entities [Abstract] Contributions by Noncontrolling Interests Minority Interest Increase From Contributions By Noncontrolling Interests Partially Owned Properties Other Stockholders Equity Other Balance, end of period Balance, end of period Redeemable Limited Partners Redeemable Limited Partners Capital: Partners Capital Including Portion Attributable To Noncontrolling Interest [Abstract] Partners’ Capital: Preference Units Preferred Units Preferred Partners Capital Accounts General Partner General Partners Capital Account Limited Partners Limited Partners Capital Account Total partners’ capital Partners Capital Noncontrolling Interests – Partially Owned Properties Total capital Partners Capital Including Portion Attributable To Noncontrolling Interest Aggregate cash, stock and paid-in-kind dividends declared for preference unitholders during the period. Net income loss per outstanding limited partnership and general partnership unit. ALLOCATION OF NET INCOME: Net Income Loss [Abstract] Preference Units Dividends Preference Units General Partner Net Income Loss Allocated To General Partners Limited Partners Net Income Loss Allocated To Limited Partners Net income available to Units Income Loss Including Portion Attributable To Noncontrolling Interest Earnings per Unit – basic: Net Income Loss Per Outstanding Limited Partnership And General Partnership Unit Basic [Abstract] Net income available to Units Weighted average Units outstanding Weighted Average Limited Partnership And General Partnership Units Outstanding Basic Earnings per Unit – diluted: Net Income Loss Per Outstanding Limited Partnership And General Partnership Unit Diluted [Abstract] Net income available to Units Weighted average Units outstanding Comprehensive income: Comprehensive (income) attributable to Noncontrolling Interests – Partially Owned Properties Proceeds from exercise of EQR options Contributions – Limited Partners OP Units – General Partner Preference Units OP Units – Limited Partners Loss from investments in unconsolidated entities. Investment in real estate, net (Income) loss from investments in unconsolidated entities: Loss From Investments In Unconsolidated Entities [Abstract] Other liabilities Total of Partners' Capital (deficit) items attributable to the parent. This excludes temporary equity and is sometimes called permanent equity. Value of Units exchanged between Limited Partners and the General Partner. Total Units outstanding remains consistent. Decrease in General Partner balance from payment of dividends or other distributions. Total change in redeemable limited partners during the period due to redemptions and adjustments to redemption value of limited partners. Change in capital as a result of a reallocation of General Partner's capital to Limited Partners due to the General Partner using Units. Decrease in Limited Partners balance from payment of dividends or other distributions. Represents the change in the proportional relationship between the carrying values of Redeemable Limited Partners relative to that of Limited Partners. OP unit issuance. Partner Type Partner Type Of Partners Capital Account [Axis] Partner Type of Partners' Capital Account, Name Partner Type Of Partners Capital Account Name [Domain] General Partner [Member] General Partner [Member] Limited Partner Limited Partner [Member] DISTRIBUTIONS [Member] PARTIALLY OWNED PROPERTIES [Member] Partially Owned Properties [Member] Balance, beginning of year Partners Capital Attributable To Parent Balance, beginning of year Partners Capital Attributable To Noncontrolling Interest GENERAL PARTNER General Partners Capital Account [Abstract] OP Unit Issuance: Op Unit Issuance [Abstract] Conversion of OP Units held by Limited Partners into OP Units held by General Partner Exchange Of O P Units Between Limited Partner And General Partner Exercise of EQR share options EQR's Employee Share Purchase Plan (ESPP) Share-based employee compensation expense: EQR restricted shares EQR share options EQR ESPP discount Net income available to Units - General Partner OP Units General Partner distributions General Partner Distribution Change in market value of Redeemable Limited Partners Limited Partners Redemptions Adjustment for Limited Partners ownership in Operating Partnership Adjustment For Limited Partners Ownership In Operating Partnership LIMITED PARTNERS Limited Partners Capital Account [Abstract] Issuance of restricted units to Limited Partners Equity compensation associated with Units - Limited Partners Net income available to Units - Limited Partners Units - Limited Partners distributions Units Limited Partners Distributions Change in carrying value of Redeemable Limited Partners Change In Carrying Value Of Redeemable Limited Partners Distributions declared per Unit outstanding Distributions Per Limited Partnership And General Partnership Unit Outstanding Basic NONCONTROLLING INTERESTS – PARTIALLY OWNED PROPERTIES Net income attributable to Noncontrolling Interests Balance, end of period Balance, end of period Net income attributable to Noncontrolling Interests Organization Consolidation And Presentation Of Financial Statements [Abstract] Business Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Summary of significant accounting policies. Summary Of Significant Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] The entire disclosure for shareholders' equity as well as for the formation, structure, control and ownership of the partnership. Including, but not limited to: (1) balances of common stock, preferred stock, paid-in capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) balances of general partners capital account, limited partners capital account, preferred partners capital account and total partners capital account and units outstanding; (9) amount and nature of changes to amount of partner's capital and units outstanding by class, rights and privileges for each class of units; and (10) distribution policies and distributions paid by unit class. Represents the Equity of the Parent Company and the Capital of the Operating Partnership as well as the interests of Partially Owned and Limited Partners. Equity Capital And Other Interests [Abstract] Equity, Capital and Other Interests Equity Capital And Other Interests [Text Block] Real Estate [Abstract] Real Estate Real Estate Disclosure [Text Block] Disclosure of acquisition/disposition transactions with closing dates subsequent to the balance sheet date for which the Company had entered into separate agreements prior to the balance sheet date. The closing of these transactions is subject to certain conditions and restrictions such that there can be no assurance that these transactions will be consummated or that the final terms will not differ in material respects from the original agreements. Commitments to Acquire/Dispose of Real Estate. Commitments To Acquire Dispose Of Real Estate [Abstract] Commitments to Acquire/Dispose of Real Estate Commitments To Acquire Dispose Of Real Estate [Text Block] Disclosure of investments in various properties with unrelated third parties which are either consolidated or accounted for under the equity method of accounting (unconsolidated). Investments in Partially Owned Entities Investments In Partially Owned Entities [Text Block] Deposits - restricted. Deposits - Restricted [Abstract] Restricted Deposits Restricted Assets Disclosure [Text Block] Leases disclosure. Leases [Abstract] Leases Leases Disclosure [Text Block] Debt Disclosure [Abstract] Debt Debt Disclosure [Text Block] Fair Value Disclosures [Abstract] Derivative and Other Fair Value Instruments Derivatives And Fair Value [Text Block] Earnings Per Share [Abstract] Earnings Per Share And Earnings Per Unit Earnings Per Share [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Segment Reporting [Abstract] Reportable Segments Segment Reporting Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Income and Other Taxes Income Tax Policy [Text Block] Recently Issued and Adopted Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Ownership Breakdown Schedule Of Real Estate Properties Table [Text Block] Represents changes in the Company's issued and outstanding Common Shares and Units for the period. Schedule Of Stock By Class [Table] Schedule Of Stock By Class [Table] Class Of Stock [Line Items] Class Of Stock [Line Items] Changes in Issued and Outstanding Common Shares and Units Common Shares And Units Rollforward Table [Text Block] Changes in Redemption Value of Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners Redeemable Noncontrolling Interest Table [Text Block] Tabular disclosure for term, amounts, nature of changes, rights and privileges, dividends and other matters related to preferred stock or preference units. Issued and Outstanding Preferred Shares and Preference Units Schedule Of Preferred Stock Table [Text Block] Tabular disclosure of the cost of land, buildings and improvements, furniture and fixtures and accumulated depreciation in aggregate for all consolidated properties owned at the balance sheet date. Summary of Carrying Amounts of Investment in Real Estate Schedule Of Real Estate Investments And Accumulated Depreciation Table [Text Block] Discloses properties and associated units that the Company disposed of to unaffiliated parties as well as sales price. Includes both rental properties and condominium conversion properties. Disposed Properties to Unaffiliated Parties Disposed Properties Table Text Block Table [Text Block] Breakdown of rental properties, units and land parcels to be disposed of subsequent to the balance sheet date per separate agreements entered into prior to the balance sheet date. Separate Agreements to Dispose Real Estate To Be Disposed Of Table [Text Block] Summary of Companys Investment in Unconsolidated Entities Equity Method Investments [Text Block] Deposits Restricted [Abstract] Restricted Deposits Schedule Of Restricted Cash And Cash Equivalents [Text Block] Summary of Lease Income Types Relating to Lease Payments along with Total Other Rental Income Operating Lease Lease Income Table [Text Block] Debt Instrument [Table] Debt Instrument [Table] Long-term Debt, Type Longterm Debt Type [Axis] Long-term Debt, Type Longterm Debt Type [Domain] Mortgages [Member] Mortgages [Member] Notes [Member] Notes Payable Other Payables [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Summary of Mortgage Notes Payable Activity Mortgage Notes Payable Disclosure [Text Block] Summary of Certain Interest Rate and Maturity Date Information Schedule Of Debt Instruments [Text Block] Summary of notes activity. Summary of Notes Activity Summary Of Notes Activity Table [Text Block] Schedule of Unsecured Revolving Credit Facility Schedule Of Line Of Credit Facilities [Text Block] Summary of Carrying and Fair Values of Financial Instruments Fair Value By Balance Sheet Grouping [Text Block] Summary of Fair Value Measurements for Each Major Category of Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value [Text Block] Summary of Effect of Fair Value Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance [Text Block] Summary of Effect of Cash Flow Hedges on the Accompanying Consolidated Statements of Operations and Comprehensive Income Schedule Of Cash Flow Hedging Instruments Statements Of Financial Performance And Financial Position Location Table [Text Block] Schedule of Calculation of Numerator and Denominator in Earnings Per Share and Earnings Per Unit Schedule Of Earnings Per Share Basic And Diluted Table [Text Block] Represents a reconciliation of net operating income from rental real estate specific to continuing operations using rental income and operating expenses. Schedule of Reconciliation of NOI from Rental Real Estate Specific to Continuing Operations Reconciliation Of Noi Text Block Table [Text Block] Schedule of NOI for Each Segment from Rental Real Estate Specific to Continuing Operations Schedule Of Segment Reporting Information By Segment [Text Block] Organization consolidation and presentation of financial statements disclosure. Organization consolidation and presentation of financial statements disclosure. Organization Consolidation And Presentation Of Financial Statements Disclosure [Table] Organization Consolidation And Presentation Of Financial Statements Disclosure [Table] Ownership Ownership [Axis] Ownership Ownership [Domain] Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] Noncontrolling interest, ownership percentage by parent Minority Interest Ownership Percentage By Parent Number of states in which entity operates Number Of States In Which Entity Operates Properties Number Of Real Estate Properties Apartment units Number Of Units In Real Estate Property Schedule Of Real Estate Properties [Table] Schedule Of Real Estate Properties [Table] Real Estate Property Ownership Real Estate Properties [Axis] Real Estate Properties Real Estate Properties [Domain] Wholly Owned Properties Wholly Owned Properties [Member] Master leased property. Master-Leased Property Consolidated Master Leased Property [Member] Partially Owned Properties – Consolidated Consolidated Properties [Member] Property/Unit schedule Real Estate Properties [Line Items] Apartment Units Income Tax Authority Income Tax Authority [Axis] Income Tax Authority Income Tax Authority [Domain] Federal [Member] Domestic Country [Member] Provision for income tax Remaining AMT refunds Deferred Tax Assets Tax Credit Carryforwards Alternative Minimum Tax Deferred rent payment. Decrease in rental revenues. Rent payment deferrals Deferred Rent Payment Decrease in rental revenues Decrease In Rental Revenues Right-of-use assets Operating Lease Right Of Use Asset Lease liabilities Operating Lease Liability The number of restricted shares granted during the reporting period, net of cancellations. Units outstanding. Number of units issued during the period as a result of a long-term incentive plan. OP Units converted into shares of stock during the period. An example of a convertible unit is an umbrella partnership real estate investment trust unit (UPREIT unit). Subject to certain exceptions, this unit can be exchanged for Common Shares on a one-for-one basis. Number of all classes of common stock held by shareholders, which is net of related treasury stock, and number of all Operating Partnership Units held by various individuals and entities that contributed their properties to the Operating Partnership. Represents the noncontrolling interests (comprised of Units and LTIP Units) ownership interest in the Operating Partnership. Common Shares Issued. Units. Common Stock, Shares, Outstanding Common Shares Issued: Common Shares Issued [Abstract] Conversion of OP Units Stock Issued During Period Shares Conversion Of Units Exercise of share options Stock Issued During Period Shares Stock Options Exercised Employee Share Purchase Plan (ESPP) Stock Issued During Period Shares Employee Stock Purchase Plans Restricted share grants, net Restricted Share Grants Net Common Stock, Shares, Outstanding Units Units [Abstract] Total Units Outstanding Units Outstanding Restricted unit grants, net Issuance Of Ltips Conversion of OP Units to Common Shares Shares Issued During Period Shares Conversion Of Units To Common Shares Total Units Outstanding Common Shares And Units Outstanding Common Shares And Units Outstanding Units Ownership Interest in Operating Partnership Units Ownership Interest In Operating Partnership General and Limited Partner Units General And Limited Partners Capital Account [Abstract] Common Shares And Units Outstanding Common Shares And Units Outstanding Limited Partner Units Conversion of Limited Partner OP Units to EQR Common Shares The greater of carrying value (book value) or fair market value of an entity's issued and outstanding stock which is not included within permanent equity in Stockholders Equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. Redeemable noncontrolling interests - operating partnership Redeemable Noncontrolling Interests Operating Partnership Redeemable Noncontrolling Interests - Operating Partnership Units Change in market value of Redeemable Noncontrolling Interests – Operating Partnership Change in carrying value of Redeemable Noncontrolling Interests - Operating Partnership Redeemable Noncontrolling Interests - Operating Partnership Units Change in the value of Redeemable Limited Partners Units as a result of changes in the fair value of the company's common shares during the period. Represents the change in the proportional relationship between the carrying values of capital associated with general partner units relative to that of the Limited Partners. Redeemable Limited Partners Limited Partners Change In Redemption Value Limited Partners Change In Redemption Value Limited Partners Change In Carrying Value Limited Partners Change In Carrying Value Redeemable Limited Partners Preferred stock, shares authorized Preferred stock, par or stated value per share Preferred stocks preference units call date. Aggregate dividends payable during the year for each share/unit of preferred stock/preference units outstanding. Preferred Stock Preferred Stocks Preference Units Call Date Preferred Stocks Preference Units Call Date Annual Dividend Per Preferred Share Preference Unit Annual Dividend Per Preferred Share Preference Unit 8.29% Series K Cumulative Redeemable Preferred Shares/Preference Units; liquidation value $50 per share; 745,600 shares issued and outstanding as of June 30, 2020 and December 31, 2019 Preferred Stock Value Outstanding Total number of preferred shares/preference units issued to security holders. May be all or portion of the number of preferred shares/preference units authorized. Excludes preferred shares/preference units that are classified as debt. Aggregate number of preferred shares/preference units held by security holders. Does not include preferred shares/preference units that have been repurchased. The price per share/unit at which the preferred share/preference units of the entity has priority over common shares/units in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of these preferred shares/units are solely within the control of the issuer. The percentage rate used to calculate dividend payments on preferred shares/preference units. Preferred Stock Preference Units Issued Preferred Stock Preference Units Issued Preferred Stock Preference Units Outstanding Preferred Stock Preference Units Outstanding Preferred Stock Preference Units Redemption Price Per Share Preferred Stock Preference Units Redemption Price Per Share Unit Preferred Stock Preference Units Dividend Rate Percentage Preferred Stock Preference Units Dividend Rate Percentage Represents the remaining number of shares to be issued into the existing trading market at current market prices as well as through negotiated transactions under the Company's at-the-market share offering program. Additional common shares authorized Additional Common Shares Authorized Stock repurchase program, number of shares authorized to be repurchased Stock Repurchase Program Number Of Shares Authorized To Be Repurchased Stock open market repurchased and retired during period, shares Stock Repurchased And Retired During Period Shares Stock repurchase program, remaining number of shares authorized to be repurchased Stock Repurchase Program Remaining Number Of Shares Authorized To Be Repurchased Projects under development. Land held for development. Long-Lived Tangible Asset Property Plant And Equipment By Type [Axis] Long-Lived Tangible Asset Property Plant And Equipment Type [Domain] Land [Member] Land [Member] Construction-in-progress [Member] Construction In Progress [Member] Depreciable property: Property Plant And Equipment Gross [Abstract] Buildings and improvements Investment Building And Building Improvements Furniture, fixtures and equipment Fixtures And Equipment Gross In-Place lease intangibles Finite Lived Intangible Asset Acquired In Place Leases Projects under development: Projectsunderdevelopment [Abstract] Land held for development: Landheldfordevelopment [Abstract] The total number of rental properties that the Company disposed of to unaffiliated parties during the period. Total number of rental units associated with rental properties that the company disposed of to unaffiliated third parties during the period. The cash inflow from the sale of real estate investment property. Consolidated rental properties. Rental Properties – Consolidated [Member] Consolidated Rental Properties [Member] Properties disposed Disposed Properties Property Units disposed Disposed Units Sales Price Proceeds From Sale Of Property Net gain on sales of real estate properties Total number of rental properties to be disposed of subsequent to the balance sheet date per separate agreements entered into prior to the balance sheet date. Total number of rental units to be disposed of subsequent to the balance sheet date per separate agreements entered into prior to the balance sheet date. The amount of the fixed and determinable portion of an unrecorded sales commitment for the disposition of a rental property, land parcel or other property subsequent to the balance sheet date. Discontinued Operations And Disposal Groups [Abstract] Properties Properties Contracted To Be Disposed Apartment Units Units Contracted To Be Disposed Sales Price Sales Price For Commitments To Dispose Net Book Value Sale Leaseback Transaction Net Book Value Schedule Of Variable Interest Entities [Table] Schedule Of Variable Interest Entities [Table] Consolidated Entities Consolidated Entities [Axis] Consolidated Entities Consolidated Entities [Domain] Consolidated VIE [Member] Variable Interest Entity Primary Beneficiary [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Total assets Total liabilities Investments in partially owned entities. Investments In Partially Owned Entities Textuals [Abstract] Investments by Consolidated and Nonconsolidated Entities Investments By Consolidated And Nonconsolidated Entities [Axis] Investments by Consolidated and Nonconsolidated Entities Investments By Consolidated And Nonconsolidated Entities [Domain] Variable interest entity primary beneficiary unconsolidated. Unconsolidated VIE [Member] Variable Interest Entity Primary Beneficiary Unconsolidated [Member] Investment, Name Schedule Of Equity Method Investment Equity Method Investee Name [Axis] Investment, Name Equity Method Investee Name [Domain] Operating property. Operating Property [Member] Operating Property [Member] Real estate technology or other. Real Estate Technology/Other [Member] Real Estate Technology Or Other [Member] Investments in Unconsolidated Entities Equity Method Investments Ownership Percentage Equity Method Investment Ownership Percentage Mortgage escrow deposits. The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes, insurance and replacement reserve obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. Restricted cash and cash items pertaining to "like-kind" exchanges (i.e. the proceeds from the previous sale of a property are used in part or in whole to acquire a new (replacement) property). Restricted cash and cash items primarily pertaining to deposits held by a joint venture to collateralize construction guarantees or miscellaneous deposits held in escrow that were assumed in conjunction with a business combination. Restricted cash and cash items pertaining to security deposits and utility deposits from residents. Other cash and cash items not otherwise listed in the existing taxonomy that are pledged or subject to withdrawal restrictions. Cash And Cash Equivalents [Abstract] Mortgage escrow deposits: Mortgage Escrow Deposits [Abstract] Replacement reserves Replacement Reserve Escrow Mortgage principal reserves/sinking funds Debt Instrument Cumulative Sinking Fund Payments Mortgage escrow deposits Escrow Deposits For Mortgage And Replacement Reserves Restricted cash: Restricted Cash [Abstract] Tax-deferred (1031) exchange proceeds Tax Deferred Exchange Proceeds Restricted deposits on real estate investments Restricted Deposits On Real Estate Investments Resident security and utility deposits Resident Security And Utility Deposits Other Other Restricted Cash Restricted cash Restricted Cash Restricted deposits Percentage of rental income. Schedule Of Operating Leased Assets [Table] Schedule Of Operating Leased Assets [Table] Collaborative Arrangement and Arrangement Other than Collaborative Type Of Arrangement [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Arrangements And Nonarrangement Transactions [Member] Residential apartment leases. Residential Apartment Leases [Member] Residential Apartment Leases [Member] Non-residential leases. Non-residential Leases [Member] Non Residential Leases [Member] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Percentage of rental income Percentage Of Rental Income Retail leases term Lessor Operating Lease Term Of Contract Operating lease lease income (loss). Product and Service Product Or Service [Axis] Product and Service Products And Services [Domain] Residential and non-residential rent. Residential and Non-Residential Rent [Member] Residential And Non Residential Rent [Member] Utility recoveries. Utility Recoveries (RUBS Income) [Member] Utility Recoveries [Member] Parking Rent [Member] Parking [Member] Storage rent. Storage Rent [Member] Storage Rent [Member] Pet rent. Pet Rent [Member] Pet Rent [Member] Other rental income. Other Rental Income [Member] Other Rental Income [Member] Residential leases. Residential Leases [Member] Residential Leases [Member] Non-Residential Leases [Member] Residential and non-residential rent Operating Lease Lease Income Loss Amount of amortization of other deferred financing costs net associated with mortgage notes payable, net. Fixed rate debt. Fixed Rate Debt [Member] Fixed Rate Debt [Member] Floating rate debt. Floating Rate Debt [Member] Floating Rate Debt [Member] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument Name [Domain] Secured – conventional. Secured – Conventional [Member] Secured Conventional [Member] Secured – tax exempt. Secured – Tax Exempt [Member] Secured Tax Exempt [Member] Mortgage notes payable, net beginning balance Scheduled principal repayments Repayments Of Long Term Debt Amortization of premiums/ discounts Amortization of deferred financing costs, net Amortization Of Deferred Financing Costs Net Mortgage Notes Payable Net Mortgage notes payable, net ending balance Freddie Mac loan pool. Fannie Mae Loan Pool [Member] Freddie Mac Loan Pool [Member] Debt instrument, interest rate, stated percentage Debt Instrument Interest Rate Stated Percentage Debt instrument, maturity date Debt Instrument Maturity Date Write-offs of unamortized deferred financing costs Write Off Of Deferred Debt Issuance Cost Interest Rate Ranges Weighted Average Interest Rate Debt Weighted Average Interest Rate Debt instrument maturity year, start. Debt instrument maturity year, end. Maturity Date Ranges, Start Debt Instrument Maturity Year Start Maturity Date Ranges, End Debt Instrument Maturity Year End Credit enhanced debt. Credit Enhanced Debt [Member] Credit Enhanced Debt [Member] Mortgage notes payable Amount of amortization of other deferred financing costs associated with notes payable, net. Unsecured public. Unsecured – Public [Member] Unsecured Public [Member] Notes, net beginning balance Lump sum payoffs Repayments Of Unsecured Debt Amortization of premiums/ discounts Amortization of deferred financing costs, net Amortization Of Deferred Financing Costs Notes Payable Net Notes, net ending balance 5.75% Notes [Member] Notes [Member] Notes [Member] Represents the amount by which available borrowings on the unsecured revolving credit facility may be increased. The available borrowings may be increased by adding additional banks to the facility or obtaining the agreement of existing banks to increase their commitments. Percentage points of line of credit facility commitment fee. Line Of Credit Facility [Table] Line Of Credit Facility [Table] Credit Facility Credit Facility [Axis] Credit Facility Credit Facility [Domain] Unsecured revolving credit facility Unsecured Revolving Credit Facility [Member] Unsecured Revolving Credit Facility [Member] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Commercial Paper [Member] Commercial Paper [Member] Line of Credit Facility [Line Items] Line Of Credit Facility [Line Items] Unsecured revolving credit facility Line Of Credit Facility Maximum Borrowing Capacity Ability to increase LOC facility Ability To Increase Line Of Credit Debt instrument, basis spread on variable rate Debt Instrument Basis Spread On Variable Rate1 Percentage points of line of credit facility commitment fee Percentage Points Of Line Of Credit Facility Commitment Fee Weighted average interest rates Commercial paper balance outstanding Commercial Paper Weighted average amount outstanding Line Of Credit Facility Average Outstanding Amount Unsecured revolving credit facility commitment Commercial paper balance outstanding Unsecured revolving credit facility balance outstanding Line Of Credit Other restricted amounts Line Of Credit Facility Increase Decrease Other Net Unsecured revolving credit facility availability Line Of Credit Facility Current Borrowing Capacity Fair Value By Balance Sheet Grouping [Table] Fair Value By Balance Sheet Grouping [Table] Mortgage Notes Payable, Net [Member] Secured Debt [Member] Unsecured Debt [Member] Unsecured Debt [Member] Measurement Basis Fair Value By Measurement Basis [Axis] Fair Value Disclosure Item Amounts [Default] Portion At Fair Value Fair Value Disclosure [Member] Fair Value Measurement Fair Value Disclosure Item Amounts [Domain] Carrying Value [Member] Carrying Reported Amount Fair Value Disclosure [Member] Estimate of Fair Value Measurement [Member] Estimate Of Fair Value Fair Value Disclosure [Member] Fair Value Hierarchy and NAV Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 2 [Member] Fair Value Inputs Level2 [Member] Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] Total debt, net Debt Instrument Fair Value Fair value of employee holdings other than common shares within the supplemental executive retirement plan at the balance sheet date. Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Fair Value, Inputs, Level 1 [Member] Fair Value Inputs Level1 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value Inputs Level3 [Member] Derivative Instrument Derivative Instrument Risk [Axis] Derivative Contract Derivative Contract Type [Domain] Forward starting swaps. Forward Starting Swaps [Member] Forward Starting Swaps [Member] Derivatives, Fair Value [Line Items] Derivatives Fair Value [Line Items] Forward Starting Swaps Derivative Assets Fair Value Of SERP Investments Fair Value Of Serp Investments Other Liabilities, Fair Value Disclosure Other Liabilities Fair Value Disclosure Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Interest Rate Swap [Member] Interest Rate Swap [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments Gain Loss [Line Items] Amount of Gain/(Loss) Recognized in Income on Derivative Increase Decrease In Fair Value Of Interest Rate Fair Value Hedging Instruments1 Amount of Gain/(Loss) Recognized in Income on Hedged Item Increase Decrease In Fair Value Of Hedged Item In Interest Rate Fair Value Hedge1 Effective Portion - Amount of Gain/(Loss) Recognized in OCI on Derivative Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax Effective Portion - Amount of Gain/(Loss) Reclassified from Accumulated OCI into Income Derivative Instruments Gain Loss Reclassified From Accumulated O C I Into Income Effective Portion Net Derivative [Table] Derivative [Table] Derivative [Line Items] Derivative [Line Items] Unrealized gain (loss) on interest rate cash flow hedges, pretax, accumulated other comprehensive income (loss) Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Net Number of derivative instrument settled. Amount recorded in accumulated other comprehensive loss that will be recognized as an increase (decrease) to interest expense over the term of the note. Mortgage notes period. Secured conventional mortgage notes period. Payments for settlement of derivative instruments Payments For Hedge Financing Activities Forward starting swaps settled Number Of Derivative Instrument Settled Debt instrument face amount Debt Instrument Face Amount Secured conventional mortgage notes period Secured Conventional Mortgage Notes Period Increase (decrease) in charges hedge termination activities Increase Decrease In Charges Hedge Termination Activities Mortgage notes period Mortgage Notes Period Net income Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest Allocation to Noncontrolling Interests – Operating Partnership Income Loss Attributable To Noncontrolling Interest Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties Preferred distributions Dividends Preferred Stock Numerator for net income per share – diluted Net Income Loss Available To Common Stockholders Diluted OP Units Dilutive Op Units Dilutive Securities Options Dilutive Securities Options Denominator for net income per share – diluted Net income per share – basic Net income per share – diluted Net income after adjustments for dividends on preference units. Allocation to Preference Units Numerator for net income per Unit – basic and diluted Net Income Loss Available To Op Unitholders Basic Diluted Numerator Denominator for net income per Unit – basic Net income per Unit – basic Net income per Unit – diluted Total number of open development projects. May include projects that are held for and/or under development, completed and not stabilized or completed and stabilized. These projects are consolidated. Represents the company's remaining funding obligation (i.e. total project costs less book value) for consolidated projects that are under development. Represents the latest completion date for the current projects under development. Number of partially owned projects in various stages of development. Total number of units that are associated with open development projects. May include projects that are held for and/or under development, completed and not stabilized or completed and stabilized. These units are consolidated. Number of projects completed and stabilized. Current occupancy percentage of completed project. Commitments and Contingencies. Commitments And Contingencies [Abstract] Projects in various stages of development Number Of Projects In Various Stages Of Development Partially owned projects in various stages of development Number Of Partially Owned Projects In Various Stages Of Development Units in various stages of development Number Of Units In Various Stages Of Development Consolidated project under development commitment fund Consolidated Project Under Development Commitment Fund Various stages of development with estimated completion dates ranging through September 30, 2021 Various Stages Of Development Date Maturity Number of projects completed and stabilized Number Of Projects Completed And Stabilized Completed project current occupancy percent Current Occupancy Percentage Of Completed Project Number of joint venture agreements. Number of joint venture agreements Number Of Joint Venture Agreements Segment Reporting Disclosure Of Entitys Reportable Segments [Abstract] Schedule Of Segment Reporting Information By Segment [Table] Schedule Of Segment Reporting Information By Segment [Table] Concentration Risk Benchmark Concentration Risk By Benchmark [Axis] Concentration Risk Benchmark Concentration Risk Benchmark [Domain] Revenue [Member] Sales Revenue Net [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Concentration risk, percentage Concentration Risk Percentage1 Number of customer. Number of customer contributed 10% or more of total revenue Number Of Customer Reconciliation Of Operating Profit Loss From Segments To Consolidated [Table] Reconciliation Of Operating Profit Loss From Segments To Consolidated [Table] Segments Statement Business Segments [Axis] Segments Segment [Domain] Same store non same store and other. Same Store, Non-same Store and Other Same Store Non Same Store And Other [Member] Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items] Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items] Property and maintenance expense Real estate taxes and insurance expense Total operating expenses Operating Expenses Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] Los Angeles. Los Angeles Los Angeles [Member] Orange County. Orange County Orange County [Member] San Diego. San Diego San Diego [Member] Southern California. Subtotal - Southern California Southern California [Member] San Francisco. San Francisco San Francisco [Member] Washington DC DISTRICT OF COLUMBIA New York NEW YORK Boston. Boston Boston [Member] Seattle. Seattle Seattle [Member] Denver. Denver Denver [Member] Non-same store. Non-same store Non Same Store [Member] Other. Other Other [Member] Same store. Same Store Same Store [Member] Non-same store and other. Non-same store/other Non Same Store And Other [Member] Operating expenses Operating income Total number of units associated with properties acquired or completed and stabilized two or more fiscal years ago, less properties subsequently sold. Units in same store properties Number Of Units In Same Store Properties Total Assets Capital Expenditures Payments To Acquire Other Property Plant And Equipment Subsequent Event [Table] Subsequent Event [Table] Four point seven four zero mortgage. 4.740% Mortgage [Member] Four Point Seven Four Zero Mortgage [Member] Subsequent Event Type Subsequent Event Type [Axis] Subsequent Event Type Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Repayments of long-term debt