XML 29 R11.htm IDEA: XBRL DOCUMENT
v3.5.0.2

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Unaudited) - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands | Total | PREFERRED SHARES | COMMON SHARES, $0.01 PAR VALUE | Additional Paid-in Capital [Member] | RETAINED EARNINGS | Accumulated Other Comprehensive (Loss) | NONCONTROLLING INTERESTS | Partially Owned [Domain]
--- | --- | --- | --- | --- | --- | --- | --- | ---
Balance, beginning of year at Dec. 31, 2015 | $ 10,470,368 | $ 37,280 | $ 3,648 | $ 8,572,365 | $ 2,009,091 | $ (152,016) |  |
Balance, beginning of year at Dec. 31, 2015 | 225,987 |  |  |  |  |  | $ 221,379 | $ 4,608
COMMON SHARES, $0.01 PAR VALUE |  |  |  |  |  |  |  |
Exercise of share options |  |  | 6 | 26,135 |  |  |  |
Restricted shares |  |  | 2 | 9,625 |  |  |  |
PAID IN CAPITAL |  |  |  |  |  |  |  |
Conversion of OP Units into Common Shares |  |  |  | 271 |  |  | (271) |
EQR's Employee Share Purchase Plan (ESPP) |  |  |  | 2,023 |  |  |  |
Share-based employee compensation expense: |  |  |  |  |  |  |  |
Share options |  |  |  | 2,733 |  |  |  |
ESPP discount |  |  |  | 357 |  |  |  |
Supplemental Executive Retirement Plan (SERP) |  |  |  | 801 |  |  |  |
Change in market value of Redeemable Noncontrolling Interests – Operating Partnership | (99,190) |  |  | 99,190 |  |  |  |
Adjustment for Noncontrolling Interests ownership in Operating Partnership |  |  |  | 4,865 |  |  | (4,865) |
RETAINED EARNINGS |  |  |  |  |  |  |  |
Net income attributable to controlling interests | 3,806,597 |  |  |  | 3,806,597 |  |  |
Common Share distributions |  |  |  |  | (3,289,355) |  |  |
Preferred Share distributions |  |  |  |  | (1,545) |  |  |
Other comprehensive (loss) income – derivative instruments: |  |  |  |  |  |  |  |
Unrealized holding (losses) gains arising during the period | (4,467) |  |  |  |  | (4,467) |  |
Losses reclassified into earnings from other comprehensive income | (32,922) |  |  |  |  | 32,922 |  |
Currency translation adjustments arising during the period | 50 |  |  |  |  | 50 |  |
OPERATING PARTNERSHIP |  |  |  |  |  |  |  |
Issuance of restricted units to Noncontrolling Interests |  |  |  |  |  |  | 1 |
Equity compensation associated with Noncontrolling Interests |  |  |  |  |  |  | 13,903 |
Net income attributable to Noncontrolling Interests | (152,089) |  |  |  |  |  | 152,089 |
Distributions to Noncontrolling Interests |  |  |  |  |  |  | (129,757) | (27,714)
Change in carrying value of Redeemable Noncontrolling Interests – Operating Partnership | 10,731 |  |  |  |  |  | (10,731) |
PARTIALLY OWNED PROPERTIES |  |  |  |  |  |  |  |
Net income attributable to Noncontrolling Interests | 1,545 |  |  |  |  |  |  | 1,545
Other |  |  |  |  |  |  |  | 25,839
Balance, end of period at Jun. 30, 2016 | 11,160,578 | $ 37,280 | $ 3,656 | $ 8,718,365 | $ 2,524,788 | $ (123,511) |  |
Balance, end of period at Jun. 30, 2016 | $ 246,026 |  |  |  |  |  | $ 241,748 | $ 4,278

X
- Definition Amount of net (income) loss for the period allocated to noncontrolling partners in partially owned properties. + References No definition available. + Details
Name: | eqr_AllocationOfNetIncomeLossToNoncontrollingInterestsPartiallyOwnedProperties
Namespace Prefix: | eqr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total value of the initial contributions made by participants in the Company's LTIP Unit plan during the period. + References No definition available. + Details
Name: | eqr_ContributionValueLongTermIncentivePlanUnit
Namespace Prefix: | eqr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Investments in Partially Owned Entities. + References No definition available. + Details
Name: | eqr_InvestmentsInPartiallyOwnedEntitiesAbstract
Namespace Prefix: | eqr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other - Partially Owned Properties + References No definition available. + Details
Name: | eqr_Other
Namespace Prefix: | eqr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Change in the value of company common shares contained in the company's supplemental executive retirement plan. + References No definition available. + Details
Name: | eqr_SupplementalExecutiveRetirementPlanSerp
Namespace Prefix: | eqr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AdditionalPaidInCapitalAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the amount of recognized equity-based compensation related to employee stock purchase programs during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). + References No definition available. + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of equity-based compensation, related to restricted stock units or restricted stock awards, recognized as expense or an asset, if compensation is capitalized. + References No definition available. + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This element represents the amount of recognized equity-based compensation related to stock options during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). + References No definition available. + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This element represents the amount of recognized equity-based compensation related to other long-term incentive plans during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). + References No definition available. + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of paid and unpaid common stock dividends declared with the form of settlement in cash. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_DividendsCommonStockCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 405 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_DividendsPreferredStockCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 27 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 7 + Details
Name: | us-gaap_MinorityInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Change in noncontrolling interest during the period as a result of a change in the redemption value of redeemable noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 15 -URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 16(c) -URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 14 -URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764 + Details
Name: | us-gaap_MinorityInterestChangeInRedemptionValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Net Increase or Decrease in balance of noncontrolling interest in the subsidiary during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4568740-111683 + Details
Name: | us-gaap_MinorityInterestPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Net Income -URI http://asc.fasb.org/extlink&oid=51831255 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.19) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.18) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.22) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Other Comprehensive Income -URI http://asc.fasb.org/extlink&oid=51831270 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 19 -Article 5 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 20 -Article 9 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of Net Income (Loss) attributable to noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4J -URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684 + Details
Name: | us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPeriodIncreaseDecreaseAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32211-110900 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (a-c) -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669646-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32022-110900 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=6915805&loc=d3e32157-110900 + Details
Name: | us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e689-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph c -URI http://asc.fasb.org/extlink&oid=56946850&loc=d3e41638-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669646-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6441202&loc=d3e80720-113993 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959 + Details
Name: | us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PartnersCapitalAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ProceedsFromIssuanceOrSaleOfEquityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RetainedEarningsAccumulatedDeficitAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of stock issued during the period upon the conversion of units. An example of a convertible unit is an umbrella partnership real estate investment trust unit (UPREIT unit). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueConversionOfUnits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Aggregate change in value for stock issued during the period as a result of employee stock purchase plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Value of stock issued as a result of the exercise of stock options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E + Details
Name: | us-gaap_StockholdersEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Change in the value of each type or class of stock classified as temporary equity during the period. The redemption requirement does not constitute an unconditional obligation that will be settled in a variable number of shares constituting a monetary value predominantly indexed to (a) a fixed monetary amount known at inception, (b) an amount inversely correlated with the residual value of the entity, or (c) an amount determined by reference to something other than the fair value of issuer's stock. Does not include mandatorily redeemable stock. The exception is if redemption is required upon liquidation or termination of the reporting entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (27) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27011957&loc=d3e177068-122764 + Details
Name: | us-gaap_TemporaryEquityIssuePeriodIncreaseOrDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AdditionalPaidInCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_RetainedEarningsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedOtherComprehensiveIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_NoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=eqr_PartiallyOwnedDomain
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |