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v2.4.1.9

Equity, Capital and Other Interests EQR Common Shares (Details) (USD $) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Common Stock, Shares, Outstanding January 1, | 362,855,454 us-gaap_CommonStockSharesOutstanding | 360,479,260 us-gaap_CommonStockSharesOutstanding | 325,054,654 us-gaap_CommonStockSharesOutstanding | 297,508,185 us-gaap_CommonStockSharesOutstanding
Common Shares Issued: |  |  |  |
Conversion of OP Units | 94,671 us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits | 67,939 us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits | 675,817 us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits |
Stock Issued During Period, Shares, New Issues | 0 us-gaap_StockIssuedDuringPeriodSharesNewIssues | 34,468,085 us-gaap_StockIssuedDuringPeriodSharesNewIssues | 25,023,919 us-gaap_StockIssuedDuringPeriodSharesNewIssues |
Exercise of share options | 2,086,380 us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised | 586,017 us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised | 1,608,427 us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised |
Employee Share Purchase Plan (ESPP) | 68,807 us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans | 73,468 us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans | 110,054 us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans |
Restricted Share Grants Net | 169,722 eqr_RestrictedShareGrantsNet | 229,097 eqr_RestrictedShareGrantsNet | 128,252 eqr_RestrictedShareGrantsNet |
Common Shares Other: |  |  |  |
Conversion of restricted shares to restricted units | (12,146)eqr_ConversionOfRestrictedSharesToLtipUnitsShares | 0 eqr_ConversionOfRestrictedSharesToLtipUnitsShares | 0 eqr_ConversionOfRestrictedSharesToLtipUnitsShares |
Stock Repurchased and Retired During Period, Shares | (31,240)us-gaap_StockRepurchasedAndRetiredDuringPeriodShares | 0 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares | 0 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares |
Units |  |  |  |
Common Shares And Units Outstanding | 377,154,145 eqr_CommonSharesAndUnitsOutstanding | 374,659,636 eqr_CommonSharesAndUnitsOutstanding | 339,023,412 eqr_CommonSharesAndUnitsOutstanding |
Units Ownership Interest in Operating Partnership | 3.80%eqr_UnitsOwnershipInterestInOperatingPartnership | 3.80%eqr_UnitsOwnershipInterestInOperatingPartnership | 4.10%eqr_UnitsOwnershipInterestInOperatingPartnership |
OP Units Issued: |  |  |  |
Issue Price Per OP Unit |  |  | $ 61.57 eqr_IssuePriceOpUnit |
Valuation Operating Partnership Unit |  |  | $ 66,600,000 eqr_IssuePriceOperatingPartnershipUnit |
Limited Partner [Member] |  |  |  |
Common Shares Other: |  |  |  |
Conversion of restricted shares to restricted units | 12,146 eqr_ConversionOfRestrictedSharesToLtipUnitsShares / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 0 eqr_ConversionOfRestrictedSharesToLtipUnitsShares / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 0 eqr_ConversionOfRestrictedSharesToLtipUnitsShares / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember |
Units |  |  |  |
Total Units Outstanding | 14,298,691 eqr_TotalUnitsOutstanding / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 14,180,376 eqr_TotalUnitsOutstanding / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 13,968,758 eqr_TotalUnitsOutstanding / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 13,492,543 eqr_TotalUnitsOutstanding / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember
Issuance Of Restricted Units | 200,840 eqr_IssuanceOfLtips / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 279,557 eqr_IssuanceOfLtips / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 70,235 eqr_IssuanceOfLtips / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember |
Issuance Of Units | 0 eqr_IssuanceOfUnitsAsConsideration / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 0 eqr_IssuanceOfUnitsAsConsideration / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | 1,081,797 eqr_IssuanceOfUnitsAsConsideration / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember |
Shares Issued During Period Shares Conversion Of Units To Common Shares | (94,671)eqr_SharesIssuedDuringPeriodSharesConversionOfUnitsToCommonShares / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | (67,939)eqr_SharesIssuedDuringPeriodSharesConversionOfUnitsToCommonShares / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember | (675,817)eqr_SharesIssuedDuringPeriodSharesConversionOfUnitsToCommonShares / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember |
OP Units Issued: |  |  |  |
Valuation Operating Partnership Unit |  |  | $ 66,600,000 eqr_IssuePriceOperatingPartnershipUnit / dei_LegalEntityAxis = us-gaap_LimitedPartnerMember |

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- Definition 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. + References No definition available. + Details
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