$EQR
EQUITY RESIDENTIAL Stock $eqr

$eqr Overview Financials Valuation SEC Filings Company Website

2012 Q4 Form 8-K Financial Statement

#000090610713000021 Filed on June 17, 2013

Income Statement

Concept	2012 Q4	2012 Q1	2011 Q4
Revenue	$485.9M	$446.4M	$433.7M
YoY Change	12.03%	14.56%	-4.89%
Cost Of Revenue	$150.5M	$163.9M	$157.4M
YoY Change	-4.38%	-8.28%	19.7%
Gross Profit	$294.2M	$266.4M	$302.2M
YoY Change	-2.65%	-6.13%	34.79%
Gross Profit Margin	60.55%	59.67%	69.68%
Selling, General & Admin	$10.10M	$13.70M	$11.10M
YoY Change	-9.01%	20.18%	24.72%
% of Gross Profit	3.43%	5.14%	3.67%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$168.1M	$148.2M	$167.2M
YoY Change	0.54%	-6.44%	-2.62%
% of Gross Profit	57.14%	55.65%	55.33%
Operating Expenses	$148.6M	$157.5M	$156.3M
YoY Change	-4.93%	-6.75%	17.96%
Operating Profit	$148.2M	$102.1M	$129.0M
YoY Change	14.93%	12.45%	72.97%
Interest Expense	-$40.20M	-$120.4M	-$116.8M
YoY Change	-65.58%	-1.63%	2.28%
% of Operating Profit	-27.12%	-117.91%	-90.55%
Other Income/Expense, Net	-$7.300M	$2.600M	-$5.000M
YoY Change	46.0%	18.18%	117.39%
Pretax Income	$98.10M	-$13.26M	$24.10M
YoY Change	307.05%	51.86%	-156.97%
Income Tax	-$100.0K	$170.0K	$100.0K
% Of Pretax Income	-0.1%		0.41%
Net Earnings	$384.4M	$145.3M	$107.4M
YoY Change	257.91%	14.11%	-45.82%
Net Earnings / Revenue	79.12%	32.55%	24.76%
Basic Earnings Per Share	$1.18	$0.47	$0.33
Diluted Earnings Per Share	$1.17	$0.47	$0.33
COMMON SHARES
Basic Shares Outstanding	310.4M shares	298.8M shares	296.0M shares
Diluted Shares Outstanding	327.1M shares	298.8M shares	312.7M shares

Balance Sheet

Concept	2012 Q4	2012 Q1	2011 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$613.0M	$220.0M	$384.0M
YoY Change	59.64%	-28.1%	-10.9%
Cash & Equivalents	$612.6M	$219.6M	$383.9M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$613.0M	$220.0M	$384.0M
YoY Change	59.64%	-28.1%	-10.9%
LONG-TERM ASSETS
Property, Plant & Equipment	$16.10B	$15.88B	$15.87B
YoY Change	1.44%	3.97%	3.27%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$18.00M	$15.00M	$12.00M
YoY Change	50.0%	275.0%	300.0%
Other Assets	$304.0M	$239.0M	$208.0M
YoY Change	46.15%	-33.8%	-11.86%
Total Long-Term Assets	$16.59B	$16.26B	$16.28B
YoY Change	1.92%	3.12%	3.31%
TOTAL ASSETS
Total Short-Term Assets	$613.0M	$220.0M	$384.0M
Total Long-Term Assets	$16.59B	$16.26B	$16.28B
Total Assets	$17.20B	$16.48B	$16.66B
YoY Change	3.25%	2.53%	2.94%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$38.00M	$77.00M	$35.00M
YoY Change	8.57%	-3.75%	-10.26%
Accrued Expenses	$76.00M	$79.00M	$88.00M
YoY Change	-13.64%	9.72%	-11.11%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$441.0M	$331.0M	$367.0M
YoY Change	20.16%	3.76%	7.94%
LONG-TERM LIABILITIES
Long-Term Debt	$8.529B	$9.413B	$9.721B
YoY Change	-12.26%	-2.73%	-2.28%
Other Long-Term Liabilities	$305.0M	$261.0M	$291.0M
YoY Change	4.81%	0.0%	-4.28%
Total Long-Term Liabilities	$8.834B	$9.674B	$10.01B
YoY Change	-11.77%	-2.66%	-2.34%
TOTAL LIABILITIES
Total Short-Term Liabilities	$441.0M	$331.0M	$367.0M
Total Long-Term Liabilities	$8.834B	$9.674B	$10.01B
Total Liabilities	$9.276B	$10.01B	$10.38B
YoY Change	-10.64%	-7.33%	-2.0%
SHAREHOLDERS EQUITY
Retained Earnings	$887.4M	$656.0M	$615.6M
YoY Change	44.15%		202.37%
Common Stock	$3.251M	$3.005M	$2.975M
YoY Change	9.28%		2.52%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$7.290B	$5.822B	$5.669B
YoY Change
Total Liabilities & Shareholders Equity	$17.20B	$16.48B	$16.66B
YoY Change	3.25%	2.53%	2.94%

Cashflow Statement

Concept	2012 Q4	2012 Q1	2011 Q4
OPERATING ACTIVITIES
Net Income	$384.4M	$145.3M	$107.4M
YoY Change	257.91%	14.11%	-45.82%
Depreciation, Depletion And Amortization	$168.1M	$148.2M	$167.2M
YoY Change	0.54%	-6.44%	-2.62%
Cash From Operating Activities	$184.3M	$234.2M	$186.4M
YoY Change	-1.13%	24.91%	12.76%
INVESTING ACTIVITIES
Capital Expenditures	-$183.2M	-$251.4M	-$874.6M
YoY Change	-79.05%	34.94%	462.81%
Acquisitions		$0.00
YoY Change
Other Investing Activities	$302.7M	$169.6M	$309.2M
YoY Change	-2.1%	14.36%	-27.86%
Cash From Investing Activities	$119.4M	-$81.87M	-$565.4M
YoY Change	-121.12%	115.4%	-307.11%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$152.1M
YoY Change		-1.59%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	263.2M	-$316.7M	717.0M
YoY Change	-63.29%	15.21%	-1514.2%
NET CHANGE
Cash From Operating Activities	184.3M	$234.2M	186.4M
Cash From Investing Activities	119.4M	-$81.87M	-565.4M
Cash From Financing Activities	263.2M	-$316.7M	717.0M
Net Change In Cash	566.9M	-$164.3M	338.0M
YoY Change	67.72%	31.08%	-12.8%
FREE CASH FLOW
Cash From Operating Activities	$184.3M	$234.2M	$186.4M
Capital Expenditures	-$183.2M	-$251.4M	-$874.6M
Free Cash Flow	$367.5M	$485.6M	$1.061B
YoY Change	-65.36%	29.91%	230.84%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2011	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	23482000	USD
CY2012	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	26960000	USD
CY2010	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	21016000	USD
CY2011	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	21177000	USD
CY2012	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	24832000	USD
CY2010	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	18875000	USD
CY2012	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	-8181000	USD
CY2011	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	-1478000	USD
CY2011Q4	us-gaap	Accumulated Amortization Deferred Finance Costs AccumulatedAmortizationDeferredFinanceCosts	37700000	USD
CY2012Q4	us-gaap	Accumulated Amortization Deferred Finance Costs AccumulatedAmortizationDeferredFinanceCosts	32200000	USD
CY2012Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-193148000	USD
CY2011Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-196718000	USD
CY2012Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	6542355000	USD
CY2011Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	5047186000	USD
CY2012	us-gaap	Additions To Noncurrent Assets AdditionsToNoncurrentAssets	152828000	USD
CY2011	us-gaap	Additions To Noncurrent Assets AdditionsToNoncurrentAssets	144452000	USD
CY2010	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	-471000	USD
CY2012	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	14144000	USD
CY2011	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	3808000	USD
CY2010	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	2804000	USD
CY2010	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	9453000	USD
CY2011	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	16651000	USD
CY2012	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	21320000	USD
CY2010	us-gaap	Asset Impairment Charges AssetImpairmentCharges	45380000	USD
CY2012	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2011	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2011Q4	us-gaap	Assets Assets	16659303000	USD
CY2012Q4	us-gaap	Assets Assets	17201000000	USD
CY2012Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	74393000	USD
CY2011Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	81948000	USD
CY2012Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	675000	USD
CY2011Q4	us-gaap	Available For Sale Securities Amortized Cost AvailableForSaleSecuritiesAmortizedCost	675000	USD
CY2012Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2214000	USD
CY2011Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1550000	USD
CY2012Q4	us-gaap	Available For Sale Securities Gross Unrealized Losses1 AvailableForSaleSecuritiesGrossUnrealizedLosses1	0	USD
CY2011Q4	us-gaap	Available For Sale Securities Gross Unrealized Losses1 AvailableForSaleSecuritiesGrossUnrealizedLosses1	0	USD
CY2012Q4	us-gaap	Availableforsale Securities Gross Unrealized Gain AvailableforsaleSecuritiesGrossUnrealizedGain	1539000	USD
CY2011Q4	us-gaap	Availableforsale Securities Gross Unrealized Gain AvailableforsaleSecuritiesGrossUnrealizedGain	875000	USD
CY2011Q4	us-gaap	Business Acquisition Cost Of Acquired Entity Purchase Price BusinessAcquisitionCostOfAcquiredEntityPurchasePrice	1597111000	USD
CY2012Q4	us-gaap	Business Acquisition Cost Of Acquired Entity Purchase Price BusinessAcquisitionCostOfAcquiredEntityPurchasePrice	1047545000	USD
CY2012	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	12600000	USD
CY2010	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	6600000	USD
CY2011	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	9500000	USD
CY2012Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	612590000	USD
CY2011Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	383921000	USD
CY2010Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	431408000	USD
CY2009Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	193288000	USD
CY2011	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-47487000	USD
CY2010	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	238120000	USD
CY2012	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	228669000	USD
CY2012Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2011Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2011	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.580
CY2010	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.470
CY2012	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.780
CY2010Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	290197242	shares
CY2009Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	279959048	shares
CY2011Q4	us-gaap	Common Stock Value CommonStockValue	2975000	USD
CY2012Q4	us-gaap	Common Stock Value CommonStockValue	3251000	USD
CY2012	us-gaap	Comparability Of Prior Year Financial Data ComparabilityOfPriorYearFinancialData	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;text-align:left;text-indent:24px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div><div style="line-height:120%;text-align:left;text-indent:24px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;">Reclassifications</font></div><div style="line-height:120%;text-align:left;text-indent:24px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div><div style="line-height:120%;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">Certain reclassifications considered necessary for a fair presentation have been made to the prior period financial statements in order to conform to the current year presentation. These reclassifications have not changed the results of operations or equity/capital. </font></div></div>
CY2011	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	754685000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	221111000	USD
CY2012	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	845289000	USD
CY2012	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	39485000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	12373000	USD
CY2011	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	41612000	USD
CY2010	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	233484000	USD
CY2012	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	884774000	USD
CY2011	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	796297000	USD
CY2006Q3	us-gaap	Convertible Debt ConvertibleDebt	650000000	USD
CY2011Q3	us-gaap	Convertible Debt ConvertibleDebt	482500000	USD
CY2010	us-gaap	Cost Of Property Repairs And Maintenance CostOfPropertyRepairsAndMaintenance	323743000	USD
CY2011	us-gaap	Cost Of Property Repairs And Maintenance CostOfPropertyRepairsAndMaintenance	337419000	USD
CY2012	us-gaap	Cost Of Property Repairs And Maintenance CostOfPropertyRepairsAndMaintenance	365778000	USD
CY2011	us-gaap	Costs And Expenses CostsAndExpenses	1197354000	USD
CY2012	us-gaap	Costs And Expenses CostsAndExpenses	1313440000	USD
CY2010	us-gaap	Costs And Expenses CostsAndExpenses	1171906000	USD
CY2006Q3	us-gaap	Debt Instrument Convertible Carrying Amount Of The Equity Component DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent	44300000	USD
CY2011Q4	us-gaap	Debt Instrument Convertible Carrying Amount Of The Equity Component DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent	44300000	USD
CY2008Q4	us-gaap	Debt Instrument Convertible Carrying Amount Of The Equity Component DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent	44300000	USD
CY2006Q3	us-gaap	Debt Instrument Convertible Effective Interest Rate DebtInstrumentConvertibleEffectiveInterestRate	0.0580
CY2011	us-gaap	Debt Instrument Convertible Interest Expense DebtInstrumentConvertibleInterestExpense	11800000	USD
CY2010	us-gaap	Debt Instrument Convertible Interest Expense DebtInstrumentConvertibleInterestExpense	18600000	USD
CY2010Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	600000000	USD
CY2011Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	1000000000	USD
CY2006Q3	us-gaap	Debt Instrument Interest Rate Stated Percentage DebtInstrumentInterestRateStatedPercentage	0.0385
CY2012	us-gaap	Debt Instrument Interest Rate Stated Percentage Rate Range Maximum DebtInstrumentInterestRateStatedPercentageRateRangeMaximum	0.1125
CY2011	us-gaap	Debt Instrument Interest Rate Stated Percentage Rate Range Maximum DebtInstrumentInterestRateStatedPercentageRateRangeMaximum	0.1125
CY2012	us-gaap	Debt Instrument Interest Rate Stated Percentage Rate Range Minimum DebtInstrumentInterestRateStatedPercentageRateRangeMinimum	0.0011
CY2011	us-gaap	Debt Instrument Interest Rate Stated Percentage Rate Range Minimum DebtInstrumentInterestRateStatedPercentageRateRangeMinimum	0.0005
CY2012Q4	us-gaap	Debt Instrument Unamortized Premium DebtInstrumentUnamortizedPremium	20584000	USD
CY2011Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	44608000	USD
CY2012Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	44382000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	36100000	USD
CY2012Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	1179000	USD
CY2012Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	1692000	USD
CY2012Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	1691000	USD
CY2012Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	1691000	USD
CY2012Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	1691000	USD
CY2012	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	4400000	USD
CY2011	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3700000	USD
CY2010	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	4000000	USD
CY2010	us-gaap	Depreciation Depreciation	505516000	USD
CY2011	us-gaap	Depreciation Depreciation	539351000	USD
CY2012	us-gaap	Depreciation Depreciation	593884000	USD
CY2012Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	1524000	USD
CY2011Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	8972000	USD
CY2012Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	44050000	USD
CY2011Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	32278000	USD
CY2011	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	-170000	USD
CY2012	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	0	USD
CY2010	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	0	USD
CY2011	us-gaap	Derivative Instruments Gain Recognized In Other Comprehensive Income Effective Portion DerivativeInstrumentsGainRecognizedInOtherComprehensiveIncomeEffectivePortion	-143768000	USD
CY2012	us-gaap	Derivative Instruments Gain Recognized In Other Comprehensive Income Effective Portion DerivativeInstrumentsGainRecognizedInOtherComprehensiveIncomeEffectivePortion	-11772000	USD
CY2010	us-gaap	Derivative Instruments Gain Recognized In Other Comprehensive Income Effective Portion DerivativeInstrumentsGainRecognizedInOtherComprehensiveIncomeEffectivePortion	-65894000	USD
CY2011	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	-4343000	USD
CY2012	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	-14678000	USD
CY2010	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	-3338000	USD
CY2011Q4	us-gaap	Development In Process DevelopmentInProcess	160190000	USD
CY2012Q4	us-gaap	Development In Process DevelopmentInProcess	387750000	USD
CY2011	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	826489000	USD
CY2010	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	297956000	USD
CY2012	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	548278000	USD
CY2012	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	32000	USD
CY2011	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	-223000	USD
CY2010	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	108000	USD
CY2011	us-gaap	Disposal Group Including Discontinued Operation Interest Expense DisposalGroupIncludingDiscontinuedOperationInterestExpense	7686000	USD
CY2012	us-gaap	Disposal Group Including Discontinued Operation Interest Expense DisposalGroupIncludingDiscontinuedOperationInterestExpense	2284000	USD
CY2010	us-gaap	Disposal Group Including Discontinued Operation Interest Expense DisposalGroupIncludingDiscontinuedOperationInterestExpense	20763000	USD
CY2011	us-gaap	Disposal Group Including Discontinued Operation Operating Expense DisposalGroupIncludingDiscontinuedOperationOperatingExpense	289607000	USD
CY2010	us-gaap	Disposal Group Including Discontinued Operation Operating Expense DisposalGroupIncludingDiscontinuedOperationOperatingExpense	424105000	USD
CY2012	us-gaap	Disposal Group Including Discontinued Operation Operating Expense DisposalGroupIncludingDiscontinuedOperationOperatingExpense	189145000	USD
CY2011	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	142344000	USD
CY2010	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	182827000	USD
CY2012	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	124307000	USD
CY2011Q4	us-gaap	Disposal Group Including Discontinued Operation Property Plant And Equipment Net DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet	2000000000	USD
CY2012Q4	us-gaap	Disposal Group Including Discontinued Operation Property Plant And Equipment Net DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet	1400000000	USD
CY2010	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	606932000	USD
CY2012	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	313452000	USD
CY2011	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	431951000	USD
CY2012	us-gaap	Distributions Per Limited Partnership And General Partnership Unit Outstanding Basic DistributionsPerLimitedPartnershipAndGeneralPartnershipUnitOutstandingBasic	1.78
CY2010	us-gaap	Distributions Per Limited Partnership And General Partnership Unit Outstanding Basic DistributionsPerLimitedPartnershipAndGeneralPartnershipUnitOutstandingBasic	1.47
CY2011	us-gaap	Distributions Per Limited Partnership And General Partnership Unit Outstanding Basic DistributionsPerLimitedPartnershipAndGeneralPartnershipUnitOutstandingBasic	1.58
CY2011Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	179079000	USD
CY2012Q4	us-gaap	Dividends Payable Current And Noncurrent DividendsPayableCurrentAndNoncurrent	260176000	USD
CY2011	us-gaap	Dividends Preferred Stock DividendsPreferredStock	13865000	USD
CY2012	us-gaap	Dividends Preferred Stock DividendsPreferredStock	10355000	USD
CY2010	us-gaap	Dividends Preferred Stock DividendsPreferredStock	14368000	USD
CY2011	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.984
CY2010	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.952
CY2012	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.729
CY2011Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.42
CY2011Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.35
CY2011Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.33
CY2011Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.88
CY2012Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.47
CY2012Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.73
CY2012Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.18
CY2012Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.33
CY2010	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.952
CY2011	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.984
CY2012	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.705
CY2011Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.35
CY2011Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.88
CY2011Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.42
CY2011Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.33
CY2012Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.47
CY2012Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.33
CY2012Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.17
CY2012Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.72
CY2011	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	2305000	USD
CY2012	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	2128000	USD
CY2010	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	2141000	USD
CY2012Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	18600000	USD
CY2012	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P2Y1M13D
CY2012	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	575000	USD
CY2010	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	61000	USD
CY2011	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	319000	USD
CY2012Q4	us-gaap	Equity Method Investment Ownership Percentage EquityMethodInvestmentOwnershipPercentage	0.20
CY2011	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	0	USD
CY2012	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	0	USD
CY2010	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	28101000	USD
CY2011Q4	us-gaap	Fixtures And Equipment Gross FixturesAndEquipmentGross	1292124000	USD
CY2012Q4	us-gaap	Fixtures And Equipment Gross FixturesAndEquipmentGross	1343765000	USD
CY2012	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	272000	USD
CY2011	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2010	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	2457000	USD
CY2010	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	39881000	USD
CY2011	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	43604000	USD
CY2012	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	47238000	USD
CY2010	us-gaap	Income Loss Attributable To Noncontrolling Interest IncomeLossAttributableToNoncontrollingInterest	-8250000	USD
CY2011Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	105488000	USD
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	640193000	USD
CY2010	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	438769000	USD
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	917494000	USD
CY2010	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	1.551
CY2012	us-gaap	Income Loss Attributable To Noncontrolling Interest IncomeLossAttributableToNoncontrollingInterest	8685000	USD
CY2011	us-gaap	Income Loss Attributable To Noncontrolling Interest IncomeLossAttributableToNoncontrollingInterest	-1749000	USD
CY2011	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-37774000	USD
CY2012	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	186019000	USD
CY2010	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-169527000	USD
CY2011	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-28335000	USD
CY2012	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	211585000	USD
CY2010	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-189836000	USD
CY2010	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-164135000	USD
CY2011	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-24826000	USD
CY2012	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	211055000	USD
CY2012Q2	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	6222000	USD
CY2012Q3	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	104020000	USD
CY2012Q4	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	114239000	USD
CY2012Q1	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-13426000	USD
CY2011Q4	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	7496000	USD
CY2011Q3	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	7489000	USD
CY2011Q1	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-31876000	USD
CY2011Q2	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-7935000	USD
CY2011	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.128
CY2012	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.614
CY2010	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.599
CY2010	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.599
CY2011	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.128
CY2012	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.609
CY2010	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	460118000	USD
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	960023000	USD
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	670149000	USD
CY2012Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	270160000	USD
CY2012Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	165593000	USD
CY2012Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	132303000	USD
CY2012Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	102093000	USD
CY2011Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	99905000	USD
CY2011Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	164942000	USD
CY2011Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	589688000	USD
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	3.112
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	2.115
CY2010	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	1.551
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	2.096
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	3.112
CY2012	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-14000	USD
CY2011	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	0	USD
CY2010	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-735000	USD
CY2010	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	270000	USD
CY2011	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	708000	USD
CY2012	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	516000	USD
CY2010	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-2740000	USD
CY2012	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	673000	USD
CY2011	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	645000	USD
CY2012	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-2102000	USD
CY2011	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	332000	USD
CY2010	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-5454000	USD
CY2010	us-gaap	Increase Decrease In Fair Value Of Hedged Item In Interest Rate Fair Value Hedge1 IncreaseDecreaseInFairValueOfHedgedItemInInterestRateFairValueHedge1	-7335000	USD
CY2011	us-gaap	Increase Decrease In Fair Value Of Hedged Item In Interest Rate Fair Value Hedge1 IncreaseDecreaseInFairValueOfHedgedItemInInterestRateFairValueHedge1	3549000	USD
CY2012	us-gaap	Increase Decrease In Fair Value Of Hedged Item In Interest Rate Fair Value Hedge1 IncreaseDecreaseInFairValueOfHedgedItemInInterestRateFairValueHedge1	7448000	USD
CY2010	us-gaap	Increase Decrease In Fair Value Of Interest Rate Fair Value Hedging Instruments1 IncreaseDecreaseInFairValueOfInterestRateFairValueHedgingInstruments1	7335000	USD
CY2011	us-gaap	Increase Decrease In Fair Value Of Interest Rate Fair Value Hedging Instruments1 IncreaseDecreaseInFairValueOfInterestRateFairValueHedgingInstruments1	-3549000	USD
CY2012	us-gaap	Increase Decrease In Fair Value Of Interest Rate Fair Value Hedging Instruments1 IncreaseDecreaseInFairValueOfInterestRateFairValueHedgingInstruments1	-7448000	USD
CY2010	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-4000000	USD
CY2011	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-10510000	USD
CY2012	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-11898000	USD
CY2011	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-2743000	USD
CY2012	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-20411000	USD
CY2010	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-9048000	USD
CY2012	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	2987000	USD
CY2011	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-8245000	USD
CY2010	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	9972000	USD
CY2010	us-gaap	Increase Decrease In Restricted Cash For Operating Activities IncreaseDecreaseInRestrictedCashForOperatingActivities	3316000	USD
CY2012	us-gaap	Increase Decrease In Restricted Cash For Operating Activities IncreaseDecreaseInRestrictedCashForOperatingActivities	-4091000	USD
CY2011	us-gaap	Increase Decrease In Restricted Cash For Operating Activities IncreaseDecreaseInRestrictedCashForOperatingActivities	4523000	USD
CY2011	us-gaap	Increase Decrease In Security Deposits IncreaseDecreaseInSecurityDeposits	4474000	USD
CY2012	us-gaap	Increase Decrease In Security Deposits IncreaseDecreaseInSecurityDeposits	1702000	USD
CY2010	us-gaap	Increase Decrease In Security Deposits IncreaseDecreaseInSecurityDeposits	1007000	USD
CY2012	us-gaap	Interest And Dividend Income Securities Available For Sale InterestAndDividendIncomeSecuritiesAvailableForSale	0	USD
CY2011	us-gaap	Interest And Dividend Income Securities Available For Sale InterestAndDividendIncomeSecuritiesAvailableForSale	0	USD
CY2010	us-gaap	Interest And Other Income InterestAndOtherIncome	4476000	USD
CY2012	us-gaap	Interest And Other Income InterestAndOtherIncome	150546000	USD
CY2011	us-gaap	Interest And Other Income InterestAndOtherIncome	7965000	USD
CY2012	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	-22509000	USD
CY2010	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	-13008000	USD
CY2011	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	-9108000	USD
CY2012	us-gaap	Interest Expense Debt InterestExpenseDebt	456763000	USD
CY2011	us-gaap	Interest Expense Debt InterestExpenseDebt	461754000	USD
CY2010	us-gaap	Interest Expense Debt InterestExpenseDebt	457613000	USD
CY2012	us-gaap	Interest Paid Net InterestPaidNet	464937000	USD
CY2011	us-gaap	Interest Paid Net InterestPaidNet	477434000	USD
CY2010	us-gaap	Interest Paid Net InterestPaidNet	475374000	USD
CY2011Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	88121000	USD
CY2012Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	76223000	USD
CY2012Q4	us-gaap	Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Net InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet	18900000	USD
CY2012Q4	us-gaap	Investment Building And Building Improvements InvestmentBuildingAndBuildingImprovements	14368179000	USD
CY2011Q4	us-gaap	Investment Building And Building Improvements InvestmentBuildingAndBuildingImprovements	14262616000	USD
CY2012Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	17877000	USD
CY2011Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	12327000	USD
CY2011Q4	us-gaap	Land Land	4367816000	USD
CY2012Q4	us-gaap	Land Land	4554912000	USD
CY2012Q4	us-gaap	Land Available For Development LandAvailableForDevelopment	353823000	USD
CY2011Q4	us-gaap	Land Available For Development LandAvailableForDevelopment	325200000	USD
CY2011Q4	us-gaap	Liabilities Liabilities	10380042000	USD
CY2012Q4	us-gaap	Liabilities Liabilities	9275521000	USD
CY2012Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	17201000000	USD
CY2011Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	16659303000	USD
CY2012Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	114705000	USD
CY2011Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	103704000	USD
CY2012Q4	us-gaap	Line Of Credit LineOfCredit	0	USD
CY2011Q4	us-gaap	Line Of Credit LineOfCredit	0	USD
CY2012Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	1750000000	USD
CY2013Q1	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	2500000000	USD
CY2011	us-gaap	Loans Assumed1 LoansAssumed1	158240000	USD
CY2012	us-gaap	Loans Assumed1 LoansAssumed1	137644000	USD
CY2010	us-gaap	Loans Assumed1 LoansAssumed1	359082000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	4341101000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	526310000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	1446576000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	1190538000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	417812000	USD
CY2012Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	586323000	USD
CY2010	us-gaap	Management Fees Revenue ManagementFeesRevenue	9476000	USD
CY2011	us-gaap	Management Fees Revenue ManagementFeesRevenue	9026000	USD
CY2012	us-gaap	Management Fees Revenue ManagementFeesRevenue	9573000	USD
CY2011Q4	us-gaap	Minority Interest MinorityInterest	193842000	USD
CY2012Q4	us-gaap	Minority Interest MinorityInterest	237294000	USD
CY2010	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	129918000	USD
CY2011	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	22714000	USD
CY2011Q4	us-gaap	Minority Interest In Operating Partnerships MinorityInterestInOperatingPartnerships	119536000	USD
CY2012	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	-38734000	USD
CY2011	us-gaap	Minority Interest In Net Income Loss Operating Partnerships MinorityInterestInNetIncomeLossOperatingPartnerships	40780000	USD
CY2010	us-gaap	Minority Interest In Net Income Loss Operating Partnerships MinorityInterestInNetIncomeLossOperatingPartnerships	13099000	USD
CY2012	us-gaap	Minority Interest In Net Income Loss Operating Partnerships MinorityInterestInNetIncomeLossOperatingPartnerships	38641000	USD
CY2012	us-gaap	Operating Income Loss OperatingIncomeLoss	566442000	USD
CY2010	us-gaap	Operating Income Loss OperatingIncomeLoss	284351000	USD
CY2012Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	134698000	USD
CY2012Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	155159000	USD
CY2012Q4	us-gaap	Minority Interest In Operating Partnerships MinorityInterestInOperatingPartnerships	159606000	USD
CY2010Q4	us-gaap	Minority Interest Ownership Percentage By Noncontrolling Owners MinorityInterestOwnershipPercentageByNoncontrollingOwners	0.045
CY2012Q4	us-gaap	Minority Interest Ownership Percentage By Noncontrolling Owners MinorityInterestOwnershipPercentageByNoncontrollingOwners	0.041
CY2011Q4	us-gaap	Minority Interest Ownership Percentage By Noncontrolling Owners MinorityInterestOwnershipPercentageByNoncontrollingOwners	0.043
CY2012Q4	us-gaap	Minority Interest Ownership Percentage By Parent MinorityInterestOwnershipPercentageByParent	0.959
CY2011	us-gaap	Mortgage Loans On Real Estate New Mortgage Loans MortgageLoansOnRealEstateNewMortgageLoans	190900000	USD
CY2012	us-gaap	Mortgage Loans On Real Estate New Mortgage Loans MortgageLoansOnRealEstateNewMortgageLoans	26500000	USD
CY2011	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-650993000	USD
CY2012	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-556533000	USD
CY2010	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	151541000	USD
CY2010	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-639458000	USD
CY2012	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-261049000	USD
CY2011	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-194828000	USD
CY2012	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1046251000	USD
CY2010	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	726037000	USD
CY2011	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	798334000	USD
CY2012	us-gaap	Net Income Loss NetIncomeLoss	841719000	USD
CY2011	us-gaap	Net Income Loss NetIncomeLoss	893585000	USD
CY2010	us-gaap	Net Income Loss NetIncomeLoss	283610000	USD
CY2012	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	826212000	USD
CY2011	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	879720000	USD
CY2010	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	269242000	USD
CY2011Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	123865000	USD
CY2011Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	99016000	USD
CY2011Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	552457000	USD
CY2011Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	104382000	USD
CY2012Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	141833000	USD
CY2012Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	365979000	USD
CY2012Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	99797000	USD
CY2012Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	218603000	USD
CY2012	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	864853000	USD
CY2011	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	879720000	USD
CY2010	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	269242000	USD
CY2012	us-gaap	Noncash Or Part Noncash Acquisition Debt Assumed1 NoncashOrPartNoncashAcquisitionDebtAssumed1	137600000	USD
CY2011	us-gaap	Noncash Or Part Noncash Acquisition Debt Assumed1 NoncashOrPartNoncashAcquisitionDebtAssumed1	158200000	USD
CY2010	us-gaap	Noncash Project Abandonment Costs NoncashProjectAbandonmentCosts	5272000	USD
CY2011	us-gaap	Noncash Project Abandonment Costs NoncashProjectAbandonmentCosts	5075000	USD
CY2012	us-gaap	Noncash Project Abandonment Costs NoncashProjectAbandonmentCosts	9056000	USD
CY2011Q4	us-gaap	Notes Payable NotesPayable	5609574000	USD
CY2012Q4	us-gaap	Notes Payable NotesPayable	4630875000	USD
CY2012Q4	us-gaap	Notional Amount Of Interest Rate Derivatives NotionalAmountOfInterestRateDerivatives	300000000	USD
CY2012Q4	us-gaap	Number Of Real Estate Properties NumberOfRealEstateProperties	403
CY2012Q4	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	13
CY2012Q4	us-gaap	Number Of Units In Real Estate Property NumberOfUnitsInRealEstateProperty	115370
CY2011	us-gaap	Operating Income Loss OperatingIncomeLoss	456314000	USD
CY2012Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	162109000	USD
CY2012Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	114476000	USD
CY2011Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	121285000	USD
CY2011Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	115234000	USD
CY2011Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	128994000	USD
CY2011Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	90801000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	736006000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	7462000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	9415000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	9462000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	9501000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	8862000	USD
CY2012Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	691304000	USD
CY2012	us-gaap	Operating Leases Income Statement Lease Revenue OperatingLeasesIncomeStatementLeaseRevenue	1870309000	USD
CY2010	us-gaap	Operating Leases Income Statement Lease Revenue OperatingLeasesIncomeStatementLeaseRevenue	1446781000	USD
CY2011	us-gaap	Operating Leases Income Statement Lease Revenue OperatingLeasesIncomeStatementLeaseRevenue	1644642000	USD
CY2012Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	76400000	USD
CY2012	us-gaap	Operating Loss Carryforwards Expiration Dates OperatingLossCarryforwardsExpirationDates	2028 and 2031
CY2012Q4	us-gaap	Other Assets OtherAssets	170372000	USD
CY2011Q4	us-gaap	Other Assets OtherAssets	187155000	USD
CY2012Q4	us-gaap	Other Assets Fair Value Disclosure OtherAssetsFairValueDisclosure	2214000	USD
CY2011Q4	us-gaap	Other Assets Fair Value Disclosure OtherAssetsFairValueDisclosure	1550000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-138900000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	3570000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-62499000	USD
CY2011	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax	4343000	USD
CY2012	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax	14678000	USD
CY2010	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax	3338000	USD
CY2011	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-143598000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-65894000	USD
CY2012	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-11772000	USD
CY2012	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	664000	USD
CY2010	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	57000	USD
CY2011	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	355000	USD
CY2012	us-gaap	Other Expenses OtherExpenses	21600000	USD
CY2011	us-gaap	Other Expenses OtherExpenses	14600000	USD
CY2010	us-gaap	Other Expenses OtherExpenses	11900000	USD
CY2012Q4	us-gaap	Other Liabilities OtherLiabilities	304518000	USD
CY2011Q4	us-gaap	Other Liabilities OtherLiabilities	291289000	USD
CY2012Q4	us-gaap	Other Liabilities Fair Value Disclosure OtherLiabilitiesFairValueDisclosure	70655000	USD
CY2011Q4	us-gaap	Other Liabilities Fair Value Disclosure OtherLiabilitiesFairValueDisclosure	71426000	USD
CY2010	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	11597000	USD
CY2011	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	14209000	USD
CY2012	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	27320000	USD
CY2011	us-gaap	Owned Property Management Costs OwnedPropertyManagementCosts	81867000	USD
CY2010	us-gaap	Owned Property Management Costs OwnedPropertyManagementCosts	79857000	USD
CY2012	us-gaap	Owned Property Management Costs OwnedPropertyManagementCosts	81902000	USD
CY2010	us-gaap	Payments For Capital Improvements PaymentsForCapitalImprovements	138208000	USD
CY2011	us-gaap	Payments For Capital Improvements PaymentsForCapitalImprovements	144452000	USD
CY2012	us-gaap	Payments For Capital Improvements PaymentsForCapitalImprovements	152828000	USD
CY2012	us-gaap	Payments For Proceeds From Deposits On Real Estate Acquisitions PaymentsForProceedsFromDepositsOnRealEstateAcquisitions	97984000	USD
CY2011	us-gaap	Payments For Proceeds From Deposits On Real Estate Acquisitions PaymentsForProceedsFromDepositsOnRealEstateAcquisitions	-7631000	USD
CY2010	us-gaap	Payments For Proceeds From Deposits On Real Estate Acquisitions PaymentsForProceedsFromDepositsOnRealEstateAcquisitions	-137106000	USD
CY2010	us-gaap	Payments For Proceeds From Hedge Financing Activities PaymentsForProceedsFromHedgeFinancingActivities	10040000	USD
CY2012	us-gaap	Payments For Proceeds From Hedge Financing Activities PaymentsForProceedsFromHedgeFinancingActivities	0	USD
CY2011	us-gaap	Payments For Proceeds From Hedge Financing Activities PaymentsForProceedsFromHedgeFinancingActivities	147306000	USD
CY2011	us-gaap	Payments For Proceeds From Mortgage Deposits PaymentsForProceedsFromMortgageDeposits	-16596000	USD
CY2012	us-gaap	Payments For Proceeds From Mortgage Deposits PaymentsForProceedsFromMortgageDeposits	-2370000	USD
CY2010	us-gaap	Payments For Proceeds From Mortgage Deposits PaymentsForProceedsFromMortgageDeposits	-73232000	USD
CY2010	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1887000	USD
CY2011	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2012	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2010	us-gaap	Payments For Repurchase Of Preferred Stock And Preference Stock PaymentsForRepurchaseOfPreferredStockAndPreferenceStock	877000	USD
CY2012	us-gaap	Payments For Repurchase Of Preferred Stock And Preference Stock PaymentsForRepurchaseOfPreferredStockAndPreferenceStock	150000000	USD
CY2011	us-gaap	Payments For Repurchase Of Preferred Stock And Preference Stock PaymentsForRepurchaseOfPreferredStockAndPreferenceStock	0	USD
CY2011	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	432023000	USD
CY2012	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	473451000	USD
CY2010	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	379969000	USD
CY2012	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	21915000	USD
CY2010	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	18867000	USD
CY2011	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	20002000	USD
CY2012	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	13416000	USD
CY2010	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	14471000	USD
CY2011	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	12829000	USD
CY2010	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	8811000	USD
CY2012	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	21209000	USD
CY2011	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	20421000	USD
CY2011	us-gaap	Payments Of Stock Issuance Costs PaymentsOfStockIssuanceCosts	3596000	USD
CY2012	us-gaap	Payments Of Stock Issuance Costs PaymentsOfStockIssuanceCosts	39359000	USD
CY2010	us-gaap	Payments Of Stock Issuance Costs PaymentsOfStockIssuanceCosts	4657000	USD
CY2010	us-gaap	Payments To Acquire Additional Interest In Subsidiaries PaymentsToAcquireAdditionalInterestInSubsidiaries	16023000	USD
CY2012	us-gaap	Payments To Acquire Additional Interest In Subsidiaries PaymentsToAcquireAdditionalInterestInSubsidiaries	13000	USD
CY2011	us-gaap	Payments To Acquire Additional Interest In Subsidiaries PaymentsToAcquireAdditionalInterestInSubsidiaries	12809000	USD
CY2010	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	26854000	USD
CY2012	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2011	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2012	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	5291000	USD
CY2010	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	0	USD
CY2011	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	2021000	USD
CY2011	us-gaap	Payments To Acquire Real Estate PaymentsToAcquireRealEstate	1441599000	USD
CY2012	us-gaap	Payments To Acquire Real Estate PaymentsToAcquireRealEstate	843976000	USD
CY2010	us-gaap	Payments To Acquire Real Estate PaymentsToAcquireRealEstate	1189210000	USD
CY2012	us-gaap	Payments To Develop Real Estate Assets PaymentsToDevelopRealEstateAssets	180409000	USD
CY2010	us-gaap	Payments To Develop Real Estate Assets PaymentsToDevelopRealEstateAssets	131301000	USD
CY2011	us-gaap	Payments To Develop Real Estate Assets PaymentsToDevelopRealEstateAssets	120741000	USD
CY2011Q4	us-gaap	Preferred Stock Value PreferredStockValue	200000000	USD
CY2012Q4	us-gaap	Preferred Stock Value PreferredStockValue	50000000	USD
CY2012Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	50000000	USD
CY2011Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	200000000	USD
CY2012	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	1417040000	USD
CY2011	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	173484000	USD
CY2010	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	329452000	USD
CY2012	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	26495000	USD
CY2011	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	190905000	USD
CY2010	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	173561000	USD
CY2010	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	5112000	USD
CY2011	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	5262000	USD
CY2012	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	5399000	USD
CY2012	us-gaap	Proceeds From Minority Shareholders ProceedsFromMinorityShareholders	8221000	USD
CY2010	us-gaap	Proceeds From Minority Shareholders ProceedsFromMinorityShareholders	222000	USD
CY2011	us-gaap	Proceeds From Minority Shareholders ProceedsFromMinorityShareholders	75911000	USD
CY2011	us-gaap	Proceeds From Notes Payable ProceedsFromNotesPayable	996190000	USD
CY2012	us-gaap	Proceeds From Notes Payable ProceedsFromNotesPayable	0	USD
CY2010	us-gaap	Proceeds From Notes Payable ProceedsFromNotesPayable	595422000	USD
CY2012	us-gaap	Proceeds From Partnership Contribution ProceedsFromPartnershipContribution	5000	USD
CY2010	us-gaap	Proceeds From Partnership Contribution ProceedsFromPartnershipContribution	0	USD
CY2011	us-gaap	Proceeds From Partnership Contribution ProceedsFromPartnershipContribution	0	USD
CY2012	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-48000	USD
CY2011	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-48000	USD
CY2010	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-48000	USD
CY2012	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	364300000	USD
CY2011	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	991700000	USD
CY2012	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	0	USD
CY2010	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	25000000	USD
CY2011	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	0	USD
CY2012	us-gaap	Proceeds From Sale Of Real Estate Heldforinvestment ProceedsFromSaleOfRealEstateHeldforinvestment	1049219000	USD
CY2010	us-gaap	Proceeds From Sale Of Real Estate Heldforinvestment ProceedsFromSaleOfRealEstateHeldforinvestment	672700000	USD
CY2011	us-gaap	Proceeds From Sale Of Real Estate Heldforinvestment ProceedsFromSaleOfRealEstateHeldforinvestment	1500583000	USD
CY2011	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	95322000	USD
CY2012	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	49039000	USD
CY2010	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	71596000	USD
CY2011	us-gaap	Profit Loss ProfitLoss	935197000	USD
CY2012	us-gaap	Profit Loss ProfitLoss	881204000	USD
CY2010	us-gaap	Profit Loss ProfitLoss	295983000	USD
CY2011Q3	us-gaap	Profit Loss ProfitLoss	112977000	USD
CY2011Q4	us-gaap	Profit Loss ProfitLoss	107401000	USD
CY2011Q1	us-gaap	Profit Loss ProfitLoss	133066000	USD
CY2011Q2	us-gaap	Profit Loss ProfitLoss	581753000	USD
CY2012Q2	us-gaap	Profit Loss ProfitLoss	108315000	USD
CY2012Q4	us-gaap	Profit Loss ProfitLoss	384399000	USD
CY2012Q1	us-gaap	Profit Loss ProfitLoss	152167000	USD
CY2012Q3	us-gaap	Profit Loss ProfitLoss	236323000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	15711944000	USD
CY2011Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	15554740000	USD
CY2010Q4	us-gaap	Real Estate Accumulated Depreciation RealEstateAccumulatedDepreciation	4337357000	USD
CY2011Q4	us-gaap	Real Estate Accumulated Depreciation RealEstateAccumulatedDepreciation	4539583000	USD
CY2012Q4	us-gaap	Real Estate Accumulated Depreciation RealEstateAccumulatedDepreciation	4912221000	USD
CY2009Q4	us-gaap	Real Estate Accumulated Depreciation RealEstateAccumulatedDepreciation	3877564000	USD
CY2011	us-gaap	Real Estate Accumulated Depreciation Depreciation Expense RealEstateAccumulatedDepreciationDepreciationExpense	663616000	USD
CY2010	us-gaap	Real Estate Accumulated Depreciation Depreciation Expense RealEstateAccumulatedDepreciationDepreciationExpense	673403000	USD
CY2012	us-gaap	Real Estate Accumulated Depreciation Depreciation Expense RealEstateAccumulatedDepreciationDepreciationExpense	684992000	USD
CY2010Q4	us-gaap	Real Estate Gross At Carrying Value RealEstateGrossAtCarryingValue	19702371000	USD
CY2011Q4	us-gaap	Real Estate Gross At Carrying Value RealEstateGrossAtCarryingValue	20407946000	USD
CY2009Q4	us-gaap	Real Estate Gross At Carrying Value RealEstateGrossAtCarryingValue	18465144000	USD
CY2012Q4	us-gaap	Real Estate Gross At Carrying Value RealEstateGrossAtCarryingValue	21008429000	USD
CY2010	us-gaap	Real Estate Improvements RealEstateImprovements	141199000	USD
CY2011	us-gaap	Real Estate Improvements RealEstateImprovements	151476000	USD
CY2012	us-gaap	Real Estate Improvements RealEstateImprovements	161460000	USD
CY2012Q4	us-gaap	Real Estate Investment Property Accumulated Depreciation RealEstateInvestmentPropertyAccumulatedDepreciation	4912221000	USD
CY2011Q4	us-gaap	Real Estate Investment Property Accumulated Depreciation RealEstateInvestmentPropertyAccumulatedDepreciation	4539583000	USD
CY2012Q4	us-gaap	Real Estate Investment Property At Cost RealEstateInvestmentPropertyAtCost	21008429000	USD
CY2011Q4	us-gaap	Real Estate Investment Property At Cost RealEstateInvestmentPropertyAtCost	20407946000	USD
CY2011Q4	us-gaap	Real Estate Investment Property Net RealEstateInvestmentPropertyNet	15868363000	USD
CY2012Q4	us-gaap	Real Estate Investment Property Net RealEstateInvestmentPropertyNet	16096208000	USD
CY2012	us-gaap	Real Estate Taxes And Insurance RealEstateTaxesAndInsurance	219975000	USD
CY2010	us-gaap	Real Estate Taxes And Insurance RealEstateTaxesAndInsurance	172531000	USD
CY2011	us-gaap	Real Estate Taxes And Insurance RealEstateTaxesAndInsurance	190834000	USD
CY2011Q3	us-gaap	Revenues Revenues	424300000	USD
CY2012	us-gaap	Redemption Premium RedemptionPremium	5152000	USD
CY2010	us-gaap	Redemption Premium RedemptionPremium	0	USD
CY2011	us-gaap	Redemption Premium RedemptionPremium	0	USD
CY2012	us-gaap	Related Party Transaction Expenses From Transactions With Related Party RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty	1300000	USD
CY2011	us-gaap	Related Party Transaction Expenses From Transactions With Related Party RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty	2200000	USD
CY2010	us-gaap	Related Party Transaction Expenses From Transactions With Related Party RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty	2700000	USD
CY2010	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	5513125000	USD
CY2011	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	1455000000	USD
CY2012	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	5876000000	USD
CY2010	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	0	USD
CY2012	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	975991000	USD
CY2011	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	575641000	USD
CY2012Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	250442000	USD
CY2011Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	152237000	USD
CY2012Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	887355000	USD
CY2011Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	615572000	USD
CY2012	us-gaap	Revenues Revenues	1879882000	USD
CY2011	us-gaap	Revenues Revenues	1653668000	USD
CY2010	us-gaap	Revenues Revenues	1456257000	USD
CY2012Q4	us-gaap	Revenues Revenues	485868000	USD
CY2012Q2	us-gaap	Revenues Revenues	464918000	USD
CY2012Q3	us-gaap	Revenues Revenues	482648000	USD
CY2012Q1	us-gaap	Revenues Revenues	446448000	USD
CY2011Q1	us-gaap	Revenues Revenues	389708000	USD
CY2011Q2	us-gaap	Revenues Revenues	405975000	USD
CY2011Q4	us-gaap	Revenues Revenues	433685000	USD
CY2012Q4	us-gaap	Secured Debt SecuredDebt	3898369000	USD
CY2011Q4	us-gaap	Secured Debt SecuredDebt	4111487000	USD
CY2011Q4	us-gaap	Security Deposit Liability SecurityDepositLiability	65286000	USD
CY2012Q4	us-gaap	Security Deposit Liability SecurityDepositLiability	66988000	USD
CY2012	us-gaap	Segment Reporting Information Revenue SegmentReportingInformationRevenue	1870309000	USD
CY2011	us-gaap	Segment Reporting Information Revenue SegmentReportingInformationRevenue	1644642000	USD
CY2010	us-gaap	Segment Reporting Information Revenue SegmentReportingInformationRevenue	1446781000	USD
CY2010	us-gaap	Service Management Costs ServiceManagementCosts	4998000	USD
CY2012	us-gaap	Service Management Costs ServiceManagementCosts	4663000	USD
CY2011	us-gaap	Service Management Costs ServiceManagementCosts	4279000	USD
CY2011	us-gaap	Share Based Compensation ShareBasedCompensation	21177000	USD
CY2010	us-gaap	Share Based Compensation ShareBasedCompensation	18875000	USD
CY2012	us-gaap	Share Based Compensation ShareBasedCompensation	24832000	USD
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Discount From Market Price Purchase Date ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate	0.85
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	-126960	shares
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	-12728	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	-35038	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	37.19
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	46.25
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	30.84
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	170588	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	270805	shares
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	140980	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	53.99
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	60.20
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	34.85
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	911950	shares
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	954366	shares
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	524953	shares
CY2011Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	697510	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	32.05
CY2011Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	34.17
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	37.10
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	46.81
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	-300809	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	-258068	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	-278183	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	9100000	USD
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	18000000	USD
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	14000000	USD
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	23.79
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	52.25
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	38.32
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0485
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0456
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0435
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.274
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.271
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.324
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0227
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0229
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0071
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	11097881	shares
CY2011Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	5415550	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	6786651	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	34.89
CY2011Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	34.64
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	74800000	USD
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	46700000	USD
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	39600000	USD
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	-11029	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	-96457	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	-16270	shares
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	-76275	shares
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	-23795	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	-41559	shares
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	1164484	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	1491311	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	8.36
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod	1436115	shares
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	8.54
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	6.18
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	8115255	shares
CY2011Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	8594020	shares
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	10106488	shares
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	11349750	shares
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	41.31
CY2010Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	33.00
CY2011Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	36.81
CY2009Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	32.03
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue	128400000	USD
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber	7801412	shares
CY2012Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice	40.66
CY2010	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Issued In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod	157363	shares
CY2012	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Issued In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod	110054	shares
CY2011	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Issued In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod	113107	shares
CY2012	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	30.87
CY2010	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	28.68
CY2011	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	32.27
CY2010	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	42.69
CY2012	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	35.53
CY2011	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	44.13
CY2011	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	35.14
CY2010	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	29.43
CY2012	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	51.55
CY2012	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	60.22
CY2011	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	53.70
CY2010	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	33.59
CY2012Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Exercisable Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions	5385907	shares
CY2012Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Outstanding Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions	8115255	shares
CY2012Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	114700000	USD
CY2012	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y7M6D
CY2012	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1	P5Y9M25D
CY2012Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Exercise Price1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1	35.40
CY2012Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Exercise Price Beginning Balance1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1	41.31
CY2012	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Term2 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2	P5Y11M1D
CY2012	us-gaap	Stock Issued During Period Shares Conversion Of Units StockIssuedDuringPeriodSharesConversionOfUnits	675817	shares
CY2011	us-gaap	Stock Issued During Period Shares Conversion Of Units StockIssuedDuringPeriodSharesConversionOfUnits	341594	shares
CY2010	us-gaap	Stock Issued During Period Shares Conversion Of Units StockIssuedDuringPeriodSharesConversionOfUnits	884472	shares
CY2012	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	110054	shares
CY2010	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	157363	shares
CY2011	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	113107	shares
CY2012	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1608427	shares
CY2011	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	2945948	shares
CY2010	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	2506645	shares
CY2011Q4	us-gaap	Stockholders Equity StockholdersEquity	5669015000	USD
CY2012Q4	us-gaap	Stockholders Equity StockholdersEquity	7289813000	USD
CY2011Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5862857000	USD
CY2012Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	7527107000	USD
CY2012	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	-1000	USD
CY2010	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	1000	USD
CY2011	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	186000	USD
CY2011	us-gaap	Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss	197600000	USD
CY2012	us-gaap	Unrealized Gain Loss On Interest Rate Cash Flow Hedges Pretax Accumulated Other Comprehensive Income Loss UnrealizedGainLossOnInterestRateCashFlowHedgesPretaxAccumulatedOtherComprehensiveIncomeLoss	194700000	USD
CY2012	us-gaap	Use Of Estimates UseOfEstimates	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-top:17px;text-align:left;text-indent:24px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-style:italic;">Use of Estimates</font></div><div style="line-height:120%;padding-top:9px;text-align:justify;text-indent:48px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">In preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.</font></div><div style="line-height:120%;text-align:left;text-indent:24px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div></div>
CY2012Q4	us-gaap	Variable Interest Entity Consolidated Carrying Amount Assets VariableInterestEntityConsolidatedCarryingAmountAssets	5000000	USD
CY2011	us-gaap	Weighted Average Limited Partnership And General Partnership Units Outstanding Basic WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic	308062000	shares
CY2010	us-gaap	Weighted Average Limited Partnership And General Partnership Units Outstanding Basic WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic	296527000	shares
CY2012	us-gaap	Weighted Average Limited Partnership And General Partnership Units Outstanding Basic WeightedAverageLimitedPartnershipAndGeneralPartnershipUnitsOutstandingBasic	316554000	shares
CY2012	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	319766000	shares
CY2010	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	282888000	shares
CY2011	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	294856000	shares
CY2011Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	312844000	shares
CY2011Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	292895000	shares
CY2011Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	312731000	shares
CY2011Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	294663000	shares
CY2012Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	318773000	shares
CY2012Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	327108000	shares
CY2012Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	298805000	shares
CY2012Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	317648000	shares
CY2012	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	302701000	shares
CY2011	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	294856000	shares
CY2010	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	282888000	shares
CY2011Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	295990000	shares
CY2011Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	295831000	shares
CY2011Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	294663000	shares
CY2011Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	292895000	shares
CY2012Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	310398000	shares
CY2012Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	298805000	shares
CY2012Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	300193000	shares
CY2012Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	301336000	shares
CY2013Q1	eqr	Ability To Increase Line Of Credit AbilityToIncreaseLineOfCredit	500000000	USD
CY2011Q4	eqr	Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrentOtherThanInterestAndDividendPayable	35206000	USD
CY2012Q4	eqr	Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrentOtherThanInterestAndDividendPayable	38372000	USD
CY2010	eqr	Adjustment Depreciation AdjustmentDepreciation	673403000	USD
CY2011	eqr	Adjustment Depreciation AdjustmentDepreciation	663616000	USD
CY2012	eqr	Adjustment Depreciation AdjustmentDepreciation	684992000	USD
CY2011	eqr	Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties AllocationOfNetIncomeLossToNoncontrollingInterestsPartiallyOwnedProperties	832000	USD
CY2010	eqr	Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties AllocationOfNetIncomeLossToNoncontrollingInterestsPartiallyOwnedProperties	-726000	USD
CY2012	eqr	Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties AllocationOfNetIncomeLossToNoncontrollingInterestsPartiallyOwnedProperties	844000	USD
CY2012	eqr	Amortization Of Deferred Financing Costs AmortizationOfDeferredFinancingCosts	21435000	USD
CY2011	eqr	Amortization Of Deferred Financing Costs AmortizationOfDeferredFinancingCosts	17846000	USD
CY2010	eqr	Amortization Of Deferred Financing Costs AmortizationOfDeferredFinancingCosts	10406000	USD
CY2010	eqr	Amortization Of Deferred Financing Costs Deferred Financing Costs Net AmortizationOfDeferredFinancingCostsDeferredFinancingCostsNet	13174000	USD
CY2011	eqr	Amortization Of Deferred Financing Costs Deferred Financing Costs Net AmortizationOfDeferredFinancingCostsDeferredFinancingCostsNet	17846000	USD
CY2012	eqr	Amortization Of Deferred Financing Costs Deferred Financing Costs Net AmortizationOfDeferredFinancingCostsDeferredFinancingCostsNet	21435000	USD
CY2012	eqr	Amortization Of Deferred Financing Costs Investment In Real Estate Net AmortizationOfDeferredFinancingCostsInvestmentInRealEstateNet	0	USD
CY2010	eqr	Amortization Of Deferred Financing Costs Investment In Real Estate Net AmortizationOfDeferredFinancingCostsInvestmentInRealEstateNet	-2768000	USD
CY2011	eqr	Amortization Of Deferred Financing Costs Investment In Real Estate Net AmortizationOfDeferredFinancingCostsInvestmentInRealEstateNet	0	USD
CY2012	eqr	Amortization Of Deferred Settlements On Derivative Instruments Other Liabilities AmortizationOfDeferredSettlementsOnDerivativeInstrumentsOtherLiabilities	-534000	USD
CY2010	eqr	Amortization Of Deferred Settlements On Derivative Instruments Other Liabilities AmortizationOfDeferredSettlementsOnDerivativeInstrumentsOtherLiabilities	-534000	USD
CY2011	eqr	Amortization Of Deferred Settlements On Derivative Instruments Other Liabilities AmortizationOfDeferredSettlementsOnDerivativeInstrumentsOtherLiabilities	-535000	USD
CY2011	eqr	Amortization Of Discounts And Premiums On Debt Mortgage Notes Payable AmortizationOfDiscountsAndPremiumsOnDebtMortgageNotesPayable	-8260000	USD
CY2012	eqr	Amortization Of Discounts And Premiums On Debt Mortgage Notes Payable AmortizationOfDiscountsAndPremiumsOnDebtMortgageNotesPayable	-10333000	USD
CY2010	eqr	Amortization Of Discounts And Premiums On Debt Mortgage Notes Payable AmortizationOfDiscountsAndPremiumsOnDebtMortgageNotesPayable	-9208000	USD
CY2012	eqr	Amortization Of Discounts And Premiums On Debt Notes Net AmortizationOfDiscountsAndPremiumsOnDebtNotesNet	2152000	USD
CY2010	eqr	Amortization Of Discounts And Premiums On Debt Notes Net AmortizationOfDiscountsAndPremiumsOnDebtNotesNet	8737000	USD
CY2011	eqr	Amortization Of Discounts And Premiums On Debt Notes Net AmortizationOfDiscountsAndPremiumsOnDebtNotesNet	6782000	USD
CY2012	eqr	Annual Dividend Per Depositary Share AnnualDividendPerDepositaryShare	1.62
CY2011	eqr	Capitalized Costs Development And Renovation CapitalizedCostsDevelopmentAndRenovation	11600000	USD
CY2012	eqr	Capitalized Costs Development And Renovation CapitalizedCostsDevelopmentAndRenovation	14300000	USD
CY2010	eqr	Capitalized Costs Development And Renovation CapitalizedCostsDevelopmentAndRenovation	10700000	USD
CY2010Q4	eqr	Common Shares And Units Outstanding CommonSharesAndUnitsOutstanding	303809279	shares
CY2011Q4	eqr	Common Shares And Units Outstanding CommonSharesAndUnitsOutstanding	311000728	shares
CY2012Q4	eqr	Common Shares And Units Outstanding CommonSharesAndUnitsOutstanding	339023412	shares
CY2013Q1	eqr	Consolidated Properties Portfolio Sale In Units ConsolidatedPropertiesPortfolioSaleInUnits	8010
CY2011	eqr	Consolidation Of Previously Unconsolidated Properties Deposits Restricted ConsolidationOfPreviouslyUnconsolidatedPropertiesDepositsRestricted	0	USD
CY2012	eqr	Consolidation Of Previously Unconsolidated Properties Deposits Restricted ConsolidationOfPreviouslyUnconsolidatedPropertiesDepositsRestricted	0	USD
CY2010	eqr	Consolidation Of Previously Unconsolidated Properties Deposits Restricted ConsolidationOfPreviouslyUnconsolidatedPropertiesDepositsRestricted	-42633000	USD
CY2012	eqr	Consolidation Of Previously Unconsolidated Properties Investment In Real Estate Net ConsolidationOfPreviouslyUnconsolidatedPropertiesInvestmentInRealEstateNet	0	USD
CY2010	eqr	Consolidation Of Previously Unconsolidated Properties Investment In Real Estate Net ConsolidationOfPreviouslyUnconsolidatedPropertiesInvestmentInRealEstateNet	-105065000	USD
CY2011	eqr	Consolidation Of Previously Unconsolidated Properties Investment In Real Estate Net ConsolidationOfPreviouslyUnconsolidatedPropertiesInvestmentInRealEstateNet	0	USD
CY2012	eqr	Consolidation Of Previously Unconsolidated Properties Investments In Unconsolidated Entities ConsolidationOfPreviouslyUnconsolidatedPropertiesInvestmentsInUnconsolidatedEntities	0	USD
CY2010	eqr	Consolidation Of Previously Unconsolidated Properties Investments In Unconsolidated Entities ConsolidationOfPreviouslyUnconsolidatedPropertiesInvestmentsInUnconsolidatedEntities	7376000	USD
CY2011	eqr	Consolidation Of Previously Unconsolidated Properties Investments In Unconsolidated Entities ConsolidationOfPreviouslyUnconsolidatedPropertiesInvestmentsInUnconsolidatedEntities	0	USD
CY2012	eqr	Consolidation Of Previously Unconsolidated Properties Mortgage Notes Payable ConsolidationOfPreviouslyUnconsolidatedPropertiesMortgageNotesPayable	0	USD
CY2011	eqr	Consolidation Of Previously Unconsolidated Properties Mortgage Notes Payable ConsolidationOfPreviouslyUnconsolidatedPropertiesMortgageNotesPayable	0	USD
CY2010	eqr	Consolidation Of Previously Unconsolidated Properties Mortgage Notes Payable ConsolidationOfPreviouslyUnconsolidatedPropertiesMortgageNotesPayable	112631000	USD
CY2010	eqr	Consolidation Of Previously Unconsolidated Properties Net Other Assets ConsolidationOfPreviouslyUnconsolidatedPropertiesNetOtherAssets	837000	USD
CY2012	eqr	Consolidation Of Previously Unconsolidated Properties Net Other Assets ConsolidationOfPreviouslyUnconsolidatedPropertiesNetOtherAssets	0	USD
CY2011	eqr	Consolidation Of Previously Unconsolidated Properties Net Other Assets ConsolidationOfPreviouslyUnconsolidatedPropertiesNetOtherAssets	0	USD
CY2010	eqr	Conversion Of Restricted Shares To Ltip Units Shares ConversionOfRestrictedSharesToLtipUnitsShares	0	shares
CY2011	eqr	Conversion Of Restricted Shares To Ltip Units Shares ConversionOfRestrictedSharesToLtipUnitsShares	-101988	shares
CY2012	eqr	Conversion Of Restricted Shares To Ltip Units Shares ConversionOfRestrictedSharesToLtipUnitsShares	0	shares
CY2008Q4	eqr	Cumulative Effect On Notes From Adoption Of Accounting Principle CumulativeEffectOnNotesFromAdoptionOfAccountingPrinciple	17300000	USD
CY2011	eqr	Deconsolidation Of Previously Consolidated Properties Investments In Unconsolidated Entities DeconsolidationOfPreviouslyConsolidatedPropertiesInvestmentsInUnconsolidatedEntities	-7135000	USD
CY2010	eqr	Deconsolidation Of Previously Consolidated Properties Investments In Unconsolidated Entities DeconsolidationOfPreviouslyConsolidatedPropertiesInvestmentsInUnconsolidatedEntities	-3167000	USD
CY2012	eqr	Deconsolidation Of Previously Consolidated Properties Investments In Unconsolidated Entities DeconsolidationOfPreviouslyConsolidatedPropertiesInvestmentsInUnconsolidatedEntities	0	USD
CY2012	eqr	Deconsolidationofpreviouslyconsolidatedpropertiesinvestmentinrealestatenet Deconsolidationofpreviouslyconsolidatedpropertiesinvestmentinrealestatenet	0	USD
CY2011	eqr	Deconsolidationofpreviouslyconsolidatedpropertiesinvestmentinrealestatenet Deconsolidationofpreviouslyconsolidatedpropertiesinvestmentinrealestatenet	35495000	USD
CY2010	eqr	Deconsolidationofpreviouslyconsolidatedpropertiesinvestmentinrealestatenet Deconsolidationofpreviouslyconsolidatedpropertiesinvestmentinrealestatenet	14875000	USD
CY2012Q4	eqr	Defined Benefit Plan Expected Future Benefit Payments DefinedBenefitPlanExpectedFutureBenefitPayments	14473000	USD
CY2012Q4	eqr	Defined Benefit Plan Expected Future Benefit Payments Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsThereafter	6529000	USD
CY2012	eqr	Defined Contribution Plan Vesting Period DefinedContributionPlanVestingPeriod	5
CY2012	eqr	Dilutive Op Units DilutiveOpUnits	13853000	shares
CY2011	eqr	Dilutive Op Units DilutiveOpUnits		shares
CY2011	eqr	Dilutive Securities Options DilutiveSecuritiesOptions		shares
CY2012	eqr	Dilutive Securities Options DilutiveSecuritiesOptions	3212000	shares
	eqr	Discontinued Operation Corporate Housing Business Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationCorporateHousingBusinessGainLossOnDisposalOfDiscontinuedOperationNetOfTax	1400000	USD
CY2012Q1	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	26080000	USD
CY2012Q2	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	23991000	USD
CY2012Q3	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	24413000	USD
CY2012Q4	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	26016000	USD
CY2011Q3	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	20785000	USD
CY2011Q1	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	18554000	USD
CY2011Q2	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	18271000	USD
CY2011Q4	eqr	Discontinued Operations For Properties Sold DiscontinuedOperationsForPropertiesSold	25010000	USD
CY2011	eqr	Disposal Group Corporate Housing Business Sale DisposalGroupCorporateHousingBusinessSale	4000000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Amortization Of Deferred Financing Costs DisposalGroupIncludingDiscontinuedOperationAmortizationOfDeferredFinancingCosts	115000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Amortization Of Deferred Financing Costs DisposalGroupIncludingDiscontinuedOperationAmortizationOfDeferredFinancingCosts	953000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Amortization Of Deferred Financing Costs DisposalGroupIncludingDiscontinuedOperationAmortizationOfDeferredFinancingCosts	1195000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Depreciation DisposalGroupIncludingDiscontinuedOperationDepreciation	124265000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Depreciation DisposalGroupIncludingDiscontinuedOperationDepreciation	167887000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Depreciation DisposalGroupIncludingDiscontinuedOperationDepreciation	91108000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation General And Administrative DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrative	55000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation General And Administrative DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrative	42000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation General And Administrative DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrative	87000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Interest And Other Income DisposalGroupIncludingDiscontinuedOperationInterestAndOtherIncome	196000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Interest And Other Income DisposalGroupIncludingDiscontinuedOperationInterestAndOtherIncome	1490000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Interest And Other Income DisposalGroupIncludingDiscontinuedOperationInterestAndOtherIncome	156000	USD
CY2011Q4	eqr	Disposal Group Including Discontinued Operation Mortgage Notes Payable DisposalGroupIncludingDiscontinuedOperationMortgageNotesPayable	147600000	USD
CY2012Q4	eqr	Disposal Group Including Discontinued Operation Mortgage Notes Payable DisposalGroupIncludingDiscontinuedOperationMortgageNotesPayable	8355000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Other Expenses DisposalGroupIncludingDiscontinuedOperationOtherExpenses	161000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Other Expenses DisposalGroupIncludingDiscontinuedOperationOtherExpenses	348000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Other Expenses DisposalGroupIncludingDiscontinuedOperationOtherExpenses	331000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Property And Maintenance DisposalGroupIncludingDiscontinuedOperationPropertyAndMaintenance	193550000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Property And Maintenance DisposalGroupIncludingDiscontinuedOperationPropertyAndMaintenance	69783000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Property And Maintenance DisposalGroupIncludingDiscontinuedOperationPropertyAndMaintenance	127276000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Real Estate Taxes And Insurance DisposalGroupIncludingDiscontinuedOperationRealEstateTaxesAndInsurance	27956000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Real Estate Taxes And Insurance DisposalGroupIncludingDiscontinuedOperationRealEstateTaxesAndInsurance	62396000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Real Estate Taxes And Insurance DisposalGroupIncludingDiscontinuedOperationRealEstateTaxesAndInsurance	37745000	USD
CY2012	eqr	Disposal Group Including Discontinued Operation Rental Revenue DisposalGroupIncludingDiscontinuedOperationRentalRevenue	313452000	USD
CY2011	eqr	Disposal Group Including Discontinued Operation Rental Revenue DisposalGroupIncludingDiscontinuedOperationRentalRevenue	431951000	USD
CY2010	eqr	Disposal Group Including Discontinued Operation Rental Revenue DisposalGroupIncludingDiscontinuedOperationRentalRevenue	606932000	USD
CY2011	eqr	Disposal Group Including Discontinued Operations Property Management DisposalGroupIncludingDiscontinuedOperationsPropertyManagement	266000	USD
CY2012	eqr	Disposal Group Including Discontinued Operations Property Management DisposalGroupIncludingDiscontinuedOperationsPropertyManagement	211000	USD
CY2010	eqr	Disposal Group Including Discontinued Operations Property Management DisposalGroupIncludingDiscontinuedOperationsPropertyManagement	230000	USD
CY2012	eqr	Disposed Properties DisposedProperties	35
CY2011	eqr	Disposed Properties DisposedProperties	47
CY2012	eqr	Disposed Units DisposedUnits	9012
CY2011	eqr	Disposed Units DisposedUnits	14345
CY2010	eqr	Distributions Minority Interest Partially Owned Properties DistributionsMinorityInterestPartiallyOwnedProperties	2918000	USD
CY2011	eqr	Distributions Minority Interest Partially Owned Properties DistributionsMinorityInterestPartiallyOwnedProperties	1115000	USD
CY2012	eqr	Distributions Minority Interest Partially Owned Properties DistributionsMinorityInterestPartiallyOwnedProperties	5083000	USD
CY2012	eqr	Dividend Preference Units DividendPreferenceUnits	10355000	USD
CY2011	eqr	Dividend Preference Units DividendPreferenceUnits	13865000	USD
CY2010	eqr	Dividend Preference Units DividendPreferenceUnits	14368000	USD
CY2011Q4	eqr	Earnest Money On Acquisitions EarnestMoneyOnAcquisitions	7882000	USD
CY2012Q4	eqr	Earnest Money On Acquisitions EarnestMoneyOnAcquisitions	5613000	USD
CY2011	eqr	Effect Of Change In Accounting Principle On Earnings Net Of Tax EffectOfChangeInAccountingPrincipleOnEarningsNetOfTax	5000000	USD
CY2010	eqr	Effect Of Change In Accounting Principle On Earnings Net Of Tax EffectOfChangeInAccountingPrincipleOnEarningsNetOfTax	7800000	USD
CY2010	eqr	Effect Of Change In Accounting Principle On Earnings Per Share EffectOfChangeInAccountingPrincipleOnEarningsPerShare	0.03
CY2011	eqr	Effect Of Change In Accounting Principle On Earnings Per Share EffectOfChangeInAccountingPrincipleOnEarningsPerShare	0.02
CY2011Q4	eqr	Escrow Deposits For Mortgage And Replacement Reserves EscrowDepositsForMortgageAndReplacementReserves	10692000	USD
CY2012Q4	eqr	Escrow Deposits For Mortgage And Replacement Reserves EscrowDepositsForMortgageAndReplacementReserves	9129000	USD
CY2012	eqr	Estimates Of Lost Revenue And Garage Reconstruction EstimatesOfLostRevenueAndGarageReconstruction	22800000	USD
CY2011	eqr	Expenses Related To Garage Collapse ExpensesRelatedToGarageCollapse	1700000	USD
CY2010	eqr	Expenses Related To Garage Collapse ExpensesRelatedToGarageCollapse	5500000	USD
CY2012Q4	eqr	Fair Value Of Serp Investments FairValueOfSerpInvestments	70655000	USD
CY2011Q4	eqr	Fair Value Of Serp Investments FairValueOfSerpInvestments	71426000	USD
CY2012	eqr	Gain Loss On Debt Extinguishments Mortgage Notes Payable GainLossOnDebtExtinguishmentsMortgageNotesPayable	272000	USD
CY2011	eqr	Gain Loss On Debt Extinguishments Mortgage Notes Payable GainLossOnDebtExtinguishmentsMortgageNotesPayable	0	USD
CY2010	eqr	Gain Loss On Debt Extinguishments Mortgage Notes Payable GainLossOnDebtExtinguishmentsMortgageNotesPayable	2457000	USD
CY2010	eqr	Gain Loss On Sale Of Land Parcels GainLossOnSaleOfLandParcels	-1395000	USD
CY2011	eqr	Gain Loss On Sale Of Land Parcels GainLossOnSaleOfLandParcels	4217000	USD
CY2012	eqr	Gain Loss On Sale Of Land Parcels GainLossOnSaleOfLandParcels	0	USD
CY2011	eqr	Gain Loss On Sales Of Land Parcels GainLossOnSalesOfLandParcels	-4217000	USD
CY2012	eqr	Gain Loss On Sales Of Land Parcels GainLossOnSalesOfLandParcels	0	USD
CY2010	eqr	Gain Loss On Sales Of Land Parcels GainLossOnSalesOfLandParcels	1395000	USD
CY2011Q4	eqr	Historical Cost Of Encumbered Properties HistoricalCostOfEncumberedProperties	4900000000	USD
CY2012Q4	eqr	Historical Cost Of Encumbered Properties HistoricalCostOfEncumberedProperties	4400000000	USD
CY2012	eqr	Income From Continuing Operations Available To Common Shares IncomeFromContinuingOperationsAvailableToCommonShares	194704000	USD
CY2012Q3	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-24413000	USD
CY2012Q1	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-26080000	USD
CY2012Q2	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-23991000	USD
CY2012Q4	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-26016000	USD
CY2011Q1	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-18554000	USD
CY2011Q3	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-20785000	USD
CY2011Q2	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-18271000	USD
CY2011Q4	eqr	Income Loss From Continuing Operations Adjusted To Discontinued Operations IncomeLossFromContinuingOperationsAdjustedToDiscontinuedOperations	-25010000	USD
CY2010	eqr	Income Loss From Continuing Operations Available To Units IncomeLossFromContinuingOperationsAvailableToUnits	-177777000	USD
CY2012	eqr	Income Loss From Continuing Operations Available To Units IncomeLossFromContinuingOperationsAvailableToUnits	194704000	USD
CY2011	eqr	Income Loss From Continuing Operations Available To Units IncomeLossFromContinuingOperationsAvailableToUnits	-39523000	USD
CY2012	eqr	Income Loss From Discontinued Operations IncomeLossFromDiscontinuedOperations	121871000	USD
CY2011	eqr	Income Loss From Discontinued Operations IncomeLossFromDiscontinuedOperations	133534000	USD
CY2010	eqr	Income Loss From Discontinued Operations IncomeLossFromDiscontinuedOperations	162162000	USD
CY2012	eqr	Incomefromtechnologyinvestments Incomefromtechnologyinvestments	0	USD
CY2010	eqr	Incomefromtechnologyinvestments Incomefromtechnologyinvestments	0	USD
CY2011	eqr	Incomefromtechnologyinvestments Incomefromtechnologyinvestments	-4537000	USD
CY2012Q4	eqr	Indirect Ownership Interest Percentage IndirectOwnershipInterestPercentage	0.01
CY2010	eqr	Initial Insurance Proceeds InitialInsuranceProceeds	4000000	USD
CY2010	eqr	Insurance Litigation Expenses InsuranceLitigationExpenses	1700000	USD
CY2011	eqr	Insurance Litigation Settlement Proceeds InsuranceLitigationSettlementProceeds	800000	USD
CY2010	eqr	Insurance Litigation Settlement Proceeds InsuranceLitigationSettlementProceeds	5200000	USD
CY2011	eqr	Insurance Proceeds InsuranceProceeds	6100000	USD
CY2012	eqr	Interest Capitalized For Real Estate Under Development InterestCapitalizedForRealEstateUnderDevelopment	-21661000	USD
CY2010	eqr	Interest Capitalized For Real Estate Under Development InterestCapitalizedForRealEstateUnderDevelopment	-13008000	USD
CY2011	eqr	Interest Capitalized For Real Estate Under Development InterestCapitalizedForRealEstateUnderDevelopment	-8785000	USD
CY2010	eqr	Interest Capitalized For Unconsolidated Entities Under Development InterestCapitalizedForUnconsolidatedEntitiesUnderDevelopment	0	USD
CY2011	eqr	Interest Capitalized For Unconsolidated Entities Under Development InterestCapitalizedForUnconsolidatedEntitiesUnderDevelopment	-323000	USD
CY2012	eqr	Interest Capitalized For Unconsolidated Entities Under Development InterestCapitalizedForUnconsolidatedEntitiesUnderDevelopment	-848000	USD
CY2012Q4	eqr	Investment In Joint Venture InvestmentInJointVenture	203500000	USD
CY2011	eqr	Issue Price Op Unit IssuePriceOpUnit	0
CY2010	eqr	Issue Price Op Unit IssuePriceOpUnit	40.09
CY2012	eqr	Issue Price Op Unit IssuePriceOpUnit	61.57
CY2012Q4	eqr	Joint Venture Partner Ownership Percentage JointVenturePartnerOwnershipPercentage	0.80
CY2011Q4	eqr	Land And Depreciable Property Net LandAndDepreciablePropertyNet	11400000000	USD
CY2012Q4	eqr	Land And Depreciable Property Net LandAndDepreciablePropertyNet	11200000000	USD
CY2010	eqr	Limited Partners Change In Carrying Value LimitedPartnersChangeInCarryingValue	-4658000	USD
CY2012	eqr	Limited Partners Change In Carrying Value LimitedPartnersChangeInCarryingValue	20702000	USD
CY2011	eqr	Limited Partners Change In Carrying Value LimitedPartnersChangeInCarryingValue	10150000	USD
CY2011	eqr	Limited Partners Change In Redemption Value LimitedPartnersChangeInRedemptionValue	22714000	USD
CY2012	eqr	Limited Partners Change In Redemption Value LimitedPartnersChangeInRedemptionValue	-38734000	USD
CY2010	eqr	Limited Partners Change In Redemption Value LimitedPartnersChangeInRedemptionValue	129918000	USD
CY2012Q4	eqr	Market Value Of Common Shares MarketValueOfCommonShares	56.67
CY2012	eqr	Maximum Eligible Compensation Percentage For Defined Contribution Plan By Employer MaximumEligibleCompensationPercentageForDefinedContributionPlanByEmployer	0.03
CY2012Q4	eqr	Military Housing Properties MilitaryHousingProperties	2
CY2012Q4	eqr	Military Housing Units MilitaryHousingUnits	5039
CY2012	eqr	Minority Interest Change In Carrying Value MinorityInterestChangeInCarryingValue	20702000	USD
CY2011	eqr	Minority Interest Change In Carrying Value MinorityInterestChangeInCarryingValue	10150000	USD
CY2010	eqr	Minority Interest Change In Carrying Value MinorityInterestChangeInCarryingValue	-4658000	USD
CY2012	eqr	Mortgage Deposits Investing Activities MortgageDepositsInvestingActivities	-1563000	USD
CY2010	eqr	Mortgage Deposits Investing Activities MortgageDepositsInvestingActivities	-4699000	USD
CY2011	eqr	Mortgage Deposits Investing Activities MortgageDepositsInvestingActivities	-1901000	USD
CY2010	eqr	Mortgage Loans Assumed By Purchaser MortgageLoansAssumedByPurchaser	-39999000	USD
CY2011	eqr	Mortgage Loans Assumed By Purchaser MortgageLoansAssumedByPurchaser	0	USD
CY2012	eqr	Mortgage Loans Assumed By Purchaser MortgageLoansAssumedByPurchaser	0	USD
CY2011	eqr	Mortgage Notes Payable Lump Sum Payoffs MortgageNotesPayableLumpSumPayoffs	974956000	USD
CY2010	eqr	Mortgage Notes Payable Lump Sum Payoffs MortgageNotesPayableLumpSumPayoffs	635285000	USD
CY2012	eqr	Mortgage Notes Payable Lump Sum Payoffs MortgageNotesPayableLumpSumPayoffs	350247000	USD
CY2012	eqr	Net Income Loss Available To Common Stockholder Basic NetIncomeLossAvailableToCommonStockholderBasic	826212000	USD
CY2011	eqr	Net Income Loss Available To Common Stockholder Basic NetIncomeLossAvailableToCommonStockholderBasic	879720000	USD
CY2010	eqr	Net Income Loss Available To Common Stockholder Basic NetIncomeLossAvailableToCommonStockholderBasic	269242000	USD
CY2011	eqr	Net Income Loss Available To Op Unitholders Basic Diluted Numerator NetIncomeLossAvailableToOpUnitholdersBasicDilutedNumerator	920500000	USD
CY2012	eqr	Net Income Loss Available To Op Unitholders Basic Diluted Numerator NetIncomeLossAvailableToOpUnitholdersBasicDilutedNumerator	864853000	USD
CY2010	eqr	Net Income Loss Available To Op Unitholders Basic Diluted Numerator NetIncomeLossAvailableToOpUnitholdersBasicDilutedNumerator	282341000	USD
CY2011Q4	eqr	Noncontrolling Interests Partially Owned Properties NoncontrollingInterestsPartiallyOwnedProperties	74306000	USD
CY2012Q4	eqr	Noncontrolling Interests Partially Owned Properties NoncontrollingInterestsPartiallyOwnedProperties	77688000	USD
CY2012Q4	eqr	Noncontrolling Interests Settlement Value NoncontrollingInterestsSettlementValue	34200000	USD
CY2013Q1	eqr	Number Of Consolidated Apartment Units Disposed NumberOfConsolidatedApartmentUnitsDisposed	4798
CY2013Q1	eqr	Number Of Consolidated Properties Disposed Of NumberOfConsolidatedPropertiesDisposedOf	16
CY2012Q4	eqr	Number Of Joint Ventures NumberOfJointVentures	2
CY2012Q4	eqr	Number Of Land Parcels Under Long Term Ground Leases NumberOfLandParcelsUnderLongTermGroundLeases	1
CY2012Q4	eqr	Number Of Operating Properties And Land Parcels Under Long Term Ground Leases NumberOfOperatingPropertiesAndLandParcelsUnderLongTermGroundLeases	5
CY2012Q4	eqr	Number Of Operating Properties Under Long Term Ground Leases NumberOfOperatingPropertiesUnderLongTermGroundLeases	4
CY2010	eqr	Number Of Potential Condo Sales NumberOfPotentialCondoSales	38
CY2012Q4	eqr	Number Of Properties Encumbered NumberOfPropertiesEncumbered	37
CY2012Q4	eqr	Number Of Shares Available For Issuance NumberOfSharesAvailableForIssuance	4833763	shares
CY2012Q4	eqr	Number Of Unconsolidated Projects NumberOfUnconsolidatedProjects	2
CY2011	eqr	Number Of Units In Same Store Properties NumberOfUnitsInSameStoreProperties	98577
CY2012	eqr	Number Of Units In Same Store Properties NumberOfUnitsInSameStoreProperties	98577
CY2010	eqr	Number Of Units In Same Store Properties NumberOfUnitsInSameStoreProperties	101312
CY2012Q1	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-26413000	USD
CY2012Q3	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-24708000	USD
CY2012Q2	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-24290000	USD
CY2012Q4	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-26105000	USD
CY2011Q3	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-21496000	USD
CY2011Q1	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-19241000	USD
CY2011Q4	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-25728000	USD
CY2011Q2	eqr	Operating Income Loss Adjusted To Discountinued Operations OperatingIncomeLossAdjustedToDiscountinuedOperations	-18896000	USD
CY2011Q4	eqr	Other Restricted Cash OtherRestrictedCash	3944000	USD
CY2012Q4	eqr	Other Restricted Cash OtherRestrictedCash	4239000	USD
CY2010	eqr	Overhead Costs OverheadCosts	600000	USD
CY2011	eqr	Overhead Costs OverheadCosts	400000	USD
CY2012Q4	eqr	Partially Owned Consolidated Properties PartiallyOwnedConsolidatedProperties	19
CY2012Q4	eqr	Partially Owned Consolidated Units PartiallyOwnedConsolidatedUnits	3475
CY2012	eqr	Partners Payments To Acquire Equity Method Investments PartnersPaymentsToAcquireEquityMethodInvestments	40100000	USD
CY2011	eqr	Payments To Acquire Other Capital Assets PaymentsToAcquireOtherCapitalAssets	7110000	USD
CY2012	eqr	Payments To Acquire Other Capital Assets PaymentsToAcquireOtherCapitalAssets	8821000	USD
CY2010	eqr	Payments To Acquire Other Capital Assets PaymentsToAcquireOtherCapitalAssets	2991000	USD
CY2011Q4	eqr	Preferred Units Value Outstanding PreferredUnitsValueOutstanding	200000000	USD
CY2012Q4	eqr	Preferred Units Value Outstanding PreferredUnitsValueOutstanding	50000000	USD
CY2011	eqr	Premium On Redemption Of Preferred Shares Cash PremiumOnRedemptionOfPreferredSharesCash	0	USD
CY2012	eqr	Premium On Redemption Of Preferred Shares Cash PremiumOnRedemptionOfPreferredSharesCash	23000	USD
CY2010	eqr	Premium On Redemption Of Preferred Shares Cash PremiumOnRedemptionOfPreferredSharesCash	0	USD
CY2012	eqr	Prepayment Penalty Charges PrepaymentPenaltyCharges	300000	USD
CY2012	eqr	Proceeds From Distributions Received From Unconsolidated Subsidiaries ProceedsFromDistributionsReceivedFromUnconsolidatedSubsidiaries	0	USD
CY2010	eqr	Proceeds From Distributions Received From Unconsolidated Subsidiaries ProceedsFromDistributionsReceivedFromUnconsolidatedSubsidiaries	26924000	USD
CY2011	eqr	Proceeds From Distributions Received From Unconsolidated Subsidiaries ProceedsFromDistributionsReceivedFromUnconsolidatedSubsidiaries	0	USD
CY2010	eqr	Proceeds From Payments On Settlement Of Derivative Instruments Other Liabilities ProceedsFromPaymentsOnSettlementOfDerivativeInstrumentsOtherLiabilities	-10040000	USD
CY2012	eqr	Proceeds From Payments On Settlement Of Derivative Instruments Other Liabilities ProceedsFromPaymentsOnSettlementOfDerivativeInstrumentsOtherLiabilities	0	USD
CY2011	eqr	Proceeds From Payments On Settlement Of Derivative Instruments Other Liabilities ProceedsFromPaymentsOnSettlementOfDerivativeInstrumentsOtherLiabilities	-147306000	USD
CY2011	eqr	Proceeds From Royalty Termination ProceedsFromRoyaltyTermination	4500000	USD
CY2012	eqr	Proceeds From Sale Of Property ProceedsFromSaleOfProperty	1061334000	USD
CY2011	eqr	Proceeds From Sale Of Property ProceedsFromSaleOfProperty	1505025000	USD
CY2012	eqr	Proceeds From Unsecured Line Of Credit ProceedsFromUnsecuredLineOfCredit	5876000000	USD
CY2011	eqr	Proceeds From Unsecured Line Of Credit ProceedsFromUnsecuredLineOfCredit	1455000000	USD
CY2010	eqr	Proceeds From Unsecured Line Of Credit ProceedsFromUnsecuredLineOfCredit	5513125000	USD
CY2011	eqr	Proceeds Received From Seller Provided Finanacing ProceedsReceivedFromSellerProvidedFinanacing	200000	USD
CY2012	eqr	Proceedsfromsaleofequityinterest Proceedsfromsaleofequityinterest	0	USD
CY2010	eqr	Proceedsfromsaleofequityinterest Proceedsfromsaleofequityinterest	-11708000	USD
CY2011	eqr	Proceedsfromsaleofequityinterest Proceedsfromsaleofequityinterest	-28360000	USD
CY2012	eqr	Proceedsfromtechnologyinvestments Proceedsfromtechnologyinvestments	0	USD
CY2010	eqr	Proceedsfromtechnologyinvestments Proceedsfromtechnologyinvestments	0	USD
CY2011	eqr	Proceedsfromtechnologyinvestments Proceedsfromtechnologyinvestments	4537000	USD
CY2012Q4	eqr	Project Cost ProjectCost	232800000	USD
CY2011	eqr	Properties Acquired PropertiesAcquired	21
CY2012Q4	eqr	Properties Contracted To Be Acquired PropertiesContractedToBeAcquired	0
CY2012Q4	eqr	Properties Contracted To Be Disposed PropertiesContractedToBeDisposed	50
CY2012Q4	eqr	Properties Having Fee Simple Title PropertiesHavingFeeSimpleTitle	378
CY2012Q4	eqr	Properties Having Less Than Hundred Percent Fee Simple Title PropertiesHavingLessThanHundredPercentFeeSimpleTitle	1
CY2011	eqr	Property Units Acquired PropertyUnitsAcquired	6198
CY2012	eqr	Property Units Acquired PropertyUnitsAcquired	1896
CY2012	eqr	Provision For Income Franchise And Excise Taxes ProvisionForIncomeFranchiseAndExciseTaxes	548000	USD
CY2010	eqr	Provision For Income Franchise And Excise Taxes ProvisionForIncomeFranchiseAndExciseTaxes	378000	USD
CY2011	eqr	Provision For Income Franchise And Excise Taxes ProvisionForIncomeFranchiseAndExciseTaxes	485000	USD
CY2012Q4	eqr	Purchase Price For Commitments To Acquire PurchasePriceForCommitmentsToAcquire	45500000	USD
CY2011	eqr	Real Estate Accumulated Depreciation Dispositions And Other RealEstateAccumulatedDepreciationDispositionsAndOther	-461390000	USD
CY2010	eqr	Real Estate Accumulated Depreciation Dispositions And Other RealEstateAccumulatedDepreciationDispositionsAndOther	-213610000	USD
CY2012	eqr	Real Estate Accumulated Depreciation Dispositions And Other RealEstateAccumulatedDepreciationDispositionsAndOther	-312354000	USD
CY2012	eqr	Real Estate Acquisitions And Development RealEstateAcquisitionsAndDevelopment	1250633000	USD
CY2011	eqr	Real Estate Acquisitions And Development RealEstateAcquisitionsAndDevelopment	1721895000	USD
CY2010	eqr	Real Estate Acquisitions And Development RealEstateAcquisitionsAndDevelopment	1789948000	USD
CY2010	eqr	Real Estate Dispositions And Other RealEstateDispositionsAndOther	-693920000	USD
CY2011	eqr	Real Estate Dispositions And Other RealEstateDispositionsAndOther	-1167796000	USD
CY2012	eqr	Real Estate Dispositions And Other RealEstateDispositionsAndOther	-811610000	USD
CY2012	eqr	Receivable For Common Shares Op Units Issued ReceivableForCommonSharesOpUnitsIssued	28457000	USD
CY2011	eqr	Receivable For Common Shares Op Units Issued ReceivableForCommonSharesOpUnitsIssued	0	USD
CY2010	eqr	Receivable For Common Shares Op Units Issued ReceivableForCommonSharesOpUnitsIssued	37550000	USD
CY2012	eqr	Restricted Share Grants Net RestrictedShareGrantsNet	128252	shares
CY2008Q4	eqr	Retained Earnings Decrease RetainedEarningsDecrease	27000000	USD
CY2012Q3	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-62026000	USD
CY2012Q4	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-61782000	USD
CY2012Q1	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-59313000	USD
CY2012Q4	eqr	Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure RedeemableNoncontrollingInterestOperatingPartnershipFairValueDisclosure	398372000	USD
CY2011Q4	eqr	Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure RedeemableNoncontrollingInterestOperatingPartnershipFairValueDisclosure	416404000	USD
CY2011Q4	eqr	Redeemable Noncontrolling Interests Operating Partnership RedeemableNoncontrollingInterestsOperatingPartnership	416404000	USD
CY2012Q4	eqr	Redeemable Noncontrolling Interests Operating Partnership RedeemableNoncontrollingInterestsOperatingPartnership	398372000	USD
CY2010Q4	eqr	Redeemable Noncontrolling Interests Operating Partnership RedeemableNoncontrollingInterestsOperatingPartnership	383540000	USD
CY2009Q4	eqr	Redeemable Noncontrolling Interests Operating Partnership RedeemableNoncontrollingInterestsOperatingPartnership	258280000	USD
CY2011Q4	eqr	Redemption Value Limited Partners RedemptionValueLimitedPartners	416404000	USD
CY2012Q4	eqr	Redemption Value Limited Partners RedemptionValueLimitedPartners	398372000	USD
CY2009Q4	eqr	Redemption Value Limited Partners RedemptionValueLimitedPartners	258280000	USD
CY2010Q4	eqr	Redemption Value Limited Partners RedemptionValueLimitedPartners	383540000	USD
CY2011	eqr	Repayments Of Mortgage Notes Payable RepaymentsOfMortgageNotesPayable	16726000	USD
CY2010	eqr	Repayments Of Mortgage Notes Payable RepaymentsOfMortgageNotesPayable	16769000	USD
CY2012	eqr	Repayments Of Mortgage Notes Payable RepaymentsOfMortgageNotesPayable	14088000	USD
CY2012Q4	eqr	Resident Security And Utility Deposits ResidentSecurityAndUtilityDeposits	44199000	USD
CY2011Q4	eqr	Resident Security And Utility Deposits ResidentSecurityAndUtilityDeposits	40403000	USD
CY2012Q4	eqr	Restricted Deposits On Debt RestrictedDepositsOnDebt	0	USD
CY2011Q4	eqr	Restricted Deposits On Debt RestrictedDepositsOnDebt	2370000	USD
CY2012Q4	eqr	Restricted Deposits On Real Estate Investments RestrictedDepositsOnRealEstateInvestments	44209000	USD
CY2011Q4	eqr	Restricted Deposits On Real Estate Investments RestrictedDepositsOnRealEstateInvestments	43970000	USD
CY2011	eqr	Restricted Share Grants Net RestrictedShareGrantsNet	145616	shares
CY2010	eqr	Restricted Share Grants Net RestrictedShareGrantsNet	235767	shares
CY2012Q2	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-60712000	USD
CY2011Q2	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-56906000	USD
CY2011Q3	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-58552000	USD
CY2011Q1	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-55700000	USD
CY2011Q4	eqr	Revenue Adjusted To Discontinued Operations RevenueAdjustedToDiscontinuedOperations	-58665000	USD
CY2012Q4	eqr	Sales Price For Commitments To Dispose SalesPriceForCommitmentsToDispose	2012960000	USD
CY2011Q4	eqr	Secured Debt Instrument Fair Value SecuredDebtInstrumentFairValue	4300000000	USD
CY2012Q4	eqr	Secured Debt Instrument Fair Value SecuredDebtInstrumentFairValue	4300000000	USD
CY2012	eqr	Segment Reporting Information Net Operating Income SegmentReportingInformationNetOperatingIncome	1202654000	USD
CY2011	eqr	Segment Reporting Information Net Operating Income SegmentReportingInformationNetOperatingIncome	1034522000	USD
CY2010	eqr	Segment Reporting Information Net Operating Income SegmentReportingInformationNetOperatingIncome	870650000	USD
CY2012	eqr	Segment Reporting Information Non Same Store Net Operating Income SegmentReportingInformationNonSameStoreNetOperatingIncome	155374000	USD
CY2011	eqr	Segment Reporting Information Non Same Store Net Operating Income SegmentReportingInformationNonSameStoreNetOperatingIncome	60334000	USD
CY2010	eqr	Segment Reporting Information Non Same Store Net Operating Income SegmentReportingInformationNonSameStoreNetOperatingIncome	53734000	USD
CY2012	eqr	Segment Reporting Information Same Store Net Operating Income SegmentReportingInformationSameStoreNetOperatingIncome	1219004000	USD
CY2011	eqr	Segment Reporting Information Same Store Net Operating Income SegmentReportingInformationSameStoreNetOperatingIncome	1132778000	USD
CY2010	eqr	Segment Reporting Information Same Store Net Operating Income SegmentReportingInformationSameStoreNetOperatingIncome	1016272000	USD
CY2012	eqr	Segment Reporting Segment Non Same Store Operating Expenses SegmentReportingSegmentNonSameStoreOperatingExpenses	89850000	USD
CY2011	eqr	Segment Reporting Segment Non Same Store Operating Expenses SegmentReportingSegmentNonSameStoreOperatingExpenses	42682000	USD
CY2010	eqr	Segment Reporting Segment Non Same Store Operating Expenses SegmentReportingSegmentNonSameStoreOperatingExpenses	79576000	USD
CY2012	eqr	Segment Reporting Segment Non Same Store Rental Income SegmentReportingSegmentNonSameStoreRentalIncome	245224000	USD
CY2011	eqr	Segment Reporting Segment Non Same Store Rental Income SegmentReportingSegmentNonSameStoreRentalIncome	103016000	USD
CY2010	eqr	Segment Reporting Segment Non Same Store Rental Income SegmentReportingSegmentNonSameStoreRentalIncome	133310000	USD
CY2012	eqr	Segment Reporting Segment Operating Expenses SegmentReportingSegmentOperatingExpenses	667655000	USD
CY2011	eqr	Segment Reporting Segment Operating Expenses SegmentReportingSegmentOperatingExpenses	610120000	USD
CY2010	eqr	Segment Reporting Segment Operating Expenses SegmentReportingSegmentOperatingExpenses	576131000	USD
CY2010	eqr	Segment Reporting Segment Properties Sold Net Operating Income SegmentReportingSegmentPropertiesSoldNetOperatingIncome	-59544000	USD
CY2010	eqr	Segment Reporting Segment Properties Sold Operating Expenses SegmentReportingSegmentPropertiesSoldOperatingExpenses	-39015000	USD
CY2010	eqr	Segment Reporting Segment Properties Sold Rental Income SegmentReportingSegmentPropertiesSoldRentalIncome	-98559000	USD
CY2012	eqr	Segment Reporting Segment Same Store Operating Expenses SegmentReportingSegmentSameStoreOperatingExpenses	649914000	USD
CY2011	eqr	Segment Reporting Segment Same Store Operating Expenses SegmentReportingSegmentSameStoreOperatingExpenses	638671000	USD
CY2010	eqr	Segment Reporting Segment Same Store Operating Expenses SegmentReportingSegmentSameStoreOperatingExpenses	614210000	USD
CY2012	eqr	Segment Reporting Segment Same Store Rental Income SegmentReportingSegmentSameStoreRentalIncome	1868918000	USD
CY2011	eqr	Segment Reporting Segment Same Store Rental Income SegmentReportingSegmentSameStoreRentalIncome	1771449000	USD
CY2010	eqr	Segment Reporting Segment Same Store Rental Income SegmentReportingSegmentSameStoreRentalIncome	1630482000	USD
CY2012	eqr	Segmentreportingsegmentpropertiessoldnetoperatingincomeyeartodate Segmentreportingsegmentpropertiessoldnetoperatingincomeyeartodate	-171724000	USD
CY2011	eqr	Segmentreportingsegmentpropertiessoldnetoperatingincomeyeartodate Segmentreportingsegmentpropertiessoldnetoperatingincomeyeartodate	-158590000	USD
CY2010	eqr	Segmentreportingsegmentpropertiessoldnetoperatingincomeyeartodate Segmentreportingsegmentpropertiessoldnetoperatingincomeyeartodate	-139812000	USD
CY2012	eqr	Segmentreportingsegmentpropertiessoldoperatingexpensesyeartodate Segmentreportingsegmentpropertiessoldoperatingexpensesyeartodate	-72109000	USD
CY2011	eqr	Segmentreportingsegmentpropertiessoldoperatingexpensesyeartodate Segmentreportingsegmentpropertiessoldoperatingexpensesyeartodate	-71233000	USD
CY2010	eqr	Segmentreportingsegmentpropertiessoldoperatingexpensesyeartodate Segmentreportingsegmentpropertiessoldoperatingexpensesyeartodate	-78640000	USD
CY2012	eqr	Segmentreportingsegmentpropertiessoldrentalincomeyeartodate Segmentreportingsegmentpropertiessoldrentalincomeyeartodate	-243833000	USD
CY2011	eqr	Segmentreportingsegmentpropertiessoldrentalincomeyeartodate Segmentreportingsegmentpropertiessoldrentalincomeyeartodate	-229823000	USD
CY2010	eqr	Segmentreportingsegmentpropertiessoldrentalincomeyeartodate Segmentreportingsegmentpropertiessoldrentalincomeyeartodate	-218452000	USD
CY2011	eqr	Seller Provided Financing SellerProvidedFinancing	2000000	USD
CY2010	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Forfeited ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanForfeited	-1204	shares
CY2012	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Forfeited ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanForfeited	0	shares
CY2011	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Forfeited ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanForfeited	-1352	shares
CY2012	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Forfeited Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanForfeitedWeightedAverageGrantDateFairValue	0
CY2011	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Forfeited Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanForfeitedWeightedAverageGrantDateFairValue	27.79
CY2010	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Forfeited Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanForfeitedWeightedAverageGrantDateFairValue	21.11
CY2011	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Grants ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanGrants	223452	shares
CY2012	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Grants ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanGrants	70235	shares
CY2010	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Grants ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanGrants	94096	shares
CY2010	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Grants Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanGrantsWeightedAverageGrantDateFairValue	32.97
CY2011	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Grants Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanGrantsWeightedAverageGrantDateFairValue	46.64
CY2012	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Grants Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanGrantsWeightedAverageGrantDateFairValue	57.24
CY2010Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Outstanding ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanOutstanding	247508	shares
CY2009Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Outstanding ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanOutstanding	154616	shares
CY2012Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Outstanding ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanOutstanding	285034	shares
CY2011Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Outstanding ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanOutstanding	367620	shares
CY2010Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Units Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanUnitsWeightedAverageGrantDateFairValue	25.62
CY2009Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Units Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanUnitsWeightedAverageGrantDateFairValue	21.11
CY2012Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Units Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanUnitsWeightedAverageGrantDateFairValue	48.41
CY2011Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Long Term Incentive Plan Units Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardLongTermIncentivePlanUnitsWeightedAverageGrantDateFairValue	34.80
CY2012Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized Before Amendment ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedBeforeAmendment	2000000	shares
CY2012Q4	eqr	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Purchase Under Employee Share Purchase Plan ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForPurchaseUnderEmployeeSharePurchasePlan	3180809	shares
CY2012	eqr	Share Based Compensation Arrangement By Share Based Payment Award Value Of Common Shares That Can Be Acquired By Employee And Trustees Under Employees Share Purchase Plan ShareBasedCompensationArrangementByShareBasedPaymentAwardValueOfCommonSharesThatCanBeAcquiredByEmployeeAndTrusteesUnderEmployeesSharePurchasePlan	100000	USD
CY2012	eqr	Share Based Compensation Arrangement By Share Based Payment Minimum Discount From Market Price ShareBasedCompensationArrangementByShareBasedPaymentMinimumDiscountFromMarketPrice	0
CY2011	eqr	Share Incentive Plans Dividends Incurred ShareIncentivePlansDividendsIncurred	1320000	USD
CY2012	eqr	Share Incentive Plans Dividends Incurred ShareIncentivePlansDividendsIncurred	1183000	USD
CY2010	eqr	Share Incentive Plans Dividends Incurred ShareIncentivePlansDividendsIncurred	1472000	USD
CY2011	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiod	0	shares
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiod	0	shares
CY2010	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiod	0	shares
CY2011	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiodweightedaveragegrantdatefairvalue	0.00
CY2010	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiodweightedaveragegrantdatefairvalue	0.00
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardequityinstrumentsotherthanoptionsexpiredinperiodweightedaveragegrantdatefairvalue	0
CY2010	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiod	0	shares
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiod	0	shares
CY2011	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiod	0	shares
CY2010	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiodweightedaveragegrantdatefairvalue	0
CY2011	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiodweightedaveragegrantdatefairvalue	0
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanexpiredinperiodweightedaveragegrantdatefairvalue	0
CY2010	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestedexercisedinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestedexercisedinperiodweightedaveragegrantdatefairvalue	0
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestedexercisedinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestedexercisedinperiodweightedaveragegrantdatefairvalue	21.11
CY2011	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestedexercisedinperiodweightedaveragegrantdatefairvalue Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestedexercisedinperiodweightedaveragegrantdatefairvalue	38.57
CY2011	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestexercisedinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestexercisedinperiod	-101988	shares
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestexercisedinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestexercisedinperiod	-152821	shares
CY2010	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestexercisedinperiod Sharebasedcompensationarrangementbysharebasedpaymentawardlongtermincentiveplanvestexercisedinperiod	0	shares
CY2012Q4	eqr	Sharebasedcompensationarrangementbysharebasedpaymentawardnumberofsharesauthorizedafteramendment Sharebasedcompensationarrangementbysharebasedpaymentawardnumberofsharesauthorizedafteramendment	7000000	shares
CY2012	eqr	Sharebasedcompensationarrangementbysharebasedpaymentmaximumdiscountfrommarketprice Sharebasedcompensationarrangementbysharebasedpaymentmaximumdiscountfrommarketprice	0.05
CY2012	eqr	Stock Issued During Period Shares StockIssuedDuringPeriodShares	25023919	shares
CY2011	eqr	Stock Issued During Period Shares StockIssuedDuringPeriodShares	3866666	shares
CY2010	eqr	Stock Issued During Period Shares StockIssuedDuringPeriodShares	6151198	shares
CY2010	eqr	Stock Options Exercised StockOptionsExercised	-2506645	shares
CY2012	eqr	Stock Options Exercised StockOptionsExercised	-1608425	shares
CY2011	eqr	Stock Options Exercised StockOptionsExercised	-2945950	shares
CY2008Q4	eqr	Stock Registered During Period Shares Dividend Reinvestment Plan StockRegisteredDuringPeriodSharesDividendReinvestmentPlan	5000000	shares
CY2012Q4	eqr	Stock Registered During Period Shares Dividend Reinvestment Plan StockRegisteredDuringPeriodSharesDividendReinvestmentPlan	4850000	shares
CY2011	eqr	Stock Repurchased And Retired StockRepurchasedAndRetired	0	shares
CY2012	eqr	Stock Repurchased And Retired StockRepurchasedAndRetired	0	shares
CY2013Q1	eqr	Subsequent Event Sold Consolidated Property SubsequentEventSoldConsolidatedProperty	779700000	USD
CY2011Q4	eqr	Tax Deferred Exchange Proceeds TaxDeferredExchangeProceeds	53668000	USD
CY2012Q4	eqr	Tax Deferred Exchange Proceeds TaxDeferredExchangeProceeds	152182000	USD
CY2011	eqr	Tax Treatment Of Dividends And Distributions Long Term Capital Gain TaxTreatmentOfDividendsAndDistributionsLongTermCapitalGain	0.629
CY2010	eqr	Tax Treatment Of Dividends And Distributions Long Term Capital Gain TaxTreatmentOfDividendsAndDistributionsLongTermCapitalGain	0.622
CY2012	eqr	Tax Treatment Of Dividends And Distributions Long Term Capital Gain TaxTreatmentOfDividendsAndDistributionsLongTermCapitalGain	0.253
CY2011	eqr	Tax Treatment Of Dividends And Distributions Ordinary Dividends TaxTreatmentOfDividendsAndDistributionsOrdinaryDividends	0.667
CY2010	eqr	Tax Treatment Of Dividends And Distributions Ordinary Dividends TaxTreatmentOfDividendsAndDistributionsOrdinaryDividends	0.607
CY2012	eqr	Tax Treatment Of Dividends And Distributions Ordinary Dividends TaxTreatmentOfDividendsAndDistributionsOrdinaryDividends	1.375
CY2012	eqr	Tax Treatment Of Dividends And Distributions Unrecaptured Section Twelve Hundred And Fifty Gain TaxTreatmentOfDividendsAndDistributionsUnrecapturedSectionTwelveHundredAndFiftyGain	0.152
CY2011	eqr	Tax Treatment Of Dividends And Distributions Unrecaptured Section Twelve Hundred And Fifty Gain TaxTreatmentOfDividendsAndDistributionsUnrecapturedSectionTwelveHundredAndFiftyGain	0.284
CY2010	eqr	Tax Treatment Of Dividends And Distributions Unrecaptured Section Twelve Hundred And Fifty Gain TaxTreatmentOfDividendsAndDistributionsUnrecapturedSectionTwelveHundredAndFiftyGain	0.241
CY2013Q1	eqr	Term Loan Facility Spread TermLoanFacilitySpread	0.0120
CY2013Q1	eqr	Term Loan Principal Amount TermLoanPrincipalAmount	750000000	USD
CY2012	eqr	Total Operating Expenses TotalOperatingExpenses	667655000	USD
CY2010	eqr	Total Operating Expenses TotalOperatingExpenses	576131000	USD
CY2011	eqr	Total Operating Expenses TotalOperatingExpenses	610120000	USD
CY2012Q4	eqr	Total Secured And Unsecured Debt TotalSecuredAndUnsecuredDebt	8529244000	USD
CY2010	eqr	Transfer From Notes Net To Mortgage Notes Payable TransferFromNotesNetToMortgageNotesPayable	35600000	USD
CY2012	eqr	Transfer From Notes Net To Mortgage Notes Payable TransferFromNotesNetToMortgageNotesPayable	0	USD
CY2011	eqr	Transfer From Notes Net To Mortgage Notes Payable TransferFromNotesNetToMortgageNotesPayable	0	USD
CY2012	eqr	Unamortized Deferred Financing Costs Written Off UnamortizedDeferredFinancingCostsWrittenOff	1600000	USD
CY2011	eqr	Unamortized Deferred Financing Costs Written Off UnamortizedDeferredFinancingCostsWrittenOff	4400000	USD
CY2012Q4	eqr	Units Contracted To Be Acquired UnitsContractedToBeAcquired	0
CY2012Q4	eqr	Units Contracted To Be Disposed UnitsContractedToBeDisposed	13772
CY2010Q4	eqr	Units Ownership Interest In Operating Partnership UnitsOwnershipInterestInOperatingPartnership	0.045
CY2011Q4	eqr	Units Ownership Interest In Operating Partnership UnitsOwnershipInterestInOperatingPartnership	0.043
CY2012Q4	eqr	Units Ownership Interest In Operating Partnership UnitsOwnershipInterestInOperatingPartnership	0.041
CY2011	eqr	Unrealized Gain Loss On Derivative Instruments Mortgage Notes Payable UnrealizedGainLossOnDerivativeInstrumentsMortgageNotesPayable	-612000	USD
CY2010	eqr	Unrealized Gain Loss On Derivative Instruments Mortgage Notes Payable UnrealizedGainLossOnDerivativeInstrumentsMortgageNotesPayable	-163000	USD
CY2012	eqr	Unrealized Gain Loss On Derivative Instruments Mortgage Notes Payable UnrealizedGainLossOnDerivativeInstrumentsMortgageNotesPayable	-2589000	USD
CY2011	eqr	Unrealized Gain Loss On Derivative Instruments Notes Net UnrealizedGainLossOnDerivativeInstrumentsNotesNet	-2937000	USD
CY2012	eqr	Unrealized Gain Loss On Derivative Instruments Notes Net UnrealizedGainLossOnDerivativeInstrumentsNotesNet	-4860000	USD
CY2010	eqr	Unrealized Gain Loss On Derivative Instruments Notes Net UnrealizedGainLossOnDerivativeInstrumentsNotesNet	7497000	USD
CY2012	eqr	Unrealized Gain Loss On Derivative Instruments Other Assets UnrealizedGainLossOnDerivativeInstrumentsOtherAssets	7448000	USD
CY2010	eqr	Unrealized Gain Loss On Derivative Instruments Other Assets UnrealizedGainLossOnDerivativeInstrumentsOtherAssets	13019000	USD
CY2011	eqr	Unrealized Gain Loss On Derivative Instruments Other Assets UnrealizedGainLossOnDerivativeInstrumentsOtherAssets	6826000	USD
CY2012	eqr	Unrealized Gain Loss On Derivative Instruments Other Liabilities UnrealizedGainLossOnDerivativeInstrumentsOtherLiabilities	11772000	USD
CY2011	eqr	Unrealized Gain Loss On Derivative Instruments Other Liabilities UnrealizedGainLossOnDerivativeInstrumentsOtherLiabilities	140507000	USD
CY2010	eqr	Unrealized Gain Loss On Derivative Instruments Other Liabilities UnrealizedGainLossOnDerivativeInstrumentsOtherLiabilities	45542000	USD
CY2011Q4	eqr	Unsecured Debt Instrument Fair Value UnsecuredDebtInstrumentFairValue	6000000000	USD
CY2012Q4	eqr	Unsecured Debt Instrument Fair Value UnsecuredDebtInstrumentFairValue	5200000000	USD
CY2010	eqr	Valuation Of Op Units Issued ValuationOfOPUnitsIssued	8245000	USD
CY2012	eqr	Valuation Of Op Units Issued ValuationOfOPUnitsIssued	66606000	USD
CY2011	eqr	Valuation Of Op Units Issued ValuationOfOPUnitsIssued	0	USD
CY2012	eqr	Value Of Furniture And Fixtures Maximum Range ValueOfFurnitureAndFixturesMaximumRange	13000	USD
CY2012	eqr	Value Of Furniture And Fixtures Minimum Range ValueOfFurnitureAndFixturesMinimumRange	8000	USD
CY2012	eqr	Various Period Of Outstanding Mortgage Indebtedness VariousPeriodOfOutstandingMortgageIndebtedness	June 15, 2051
CY2011	eqr	Various Period Of Outstanding Mortgage Indebtedness VariousPeriodOfOutstandingMortgageIndebtedness	September 1, 2048
CY2011	eqr	Weighted Average Mortgage Debt Interest Rate WeightedAverageMortgageDebtInterestRate	0.0484
CY2012	eqr	Weighted Average Mortgage Debt Interest Rate WeightedAverageMortgageDebtInterestRate	0.0496
CY2010	eqr	Weighted Average Number Of Limited Partnership And General Partnership Unit Outstanding Diluted WeightedAverageNumberOfLimitedPartnershipAndGeneralPartnershipUnitOutstandingDiluted	296527000	shares
CY2012	eqr	Weighted Average Number Of Limited Partnership And General Partnership Unit Outstanding Diluted WeightedAverageNumberOfLimitedPartnershipAndGeneralPartnershipUnitOutstandingDiluted	319766000	shares
CY2011	eqr	Weighted Average Number Of Limited Partnership And General Partnership Unit Outstanding Diluted WeightedAverageNumberOfLimitedPartnershipAndGeneralPartnershipUnitOutstandingDiluted	308062000	shares
CY2012Q4	eqr	Wholly Owned Properties WhollyOwnedProperties	382
CY2012Q4	eqr	Wholly Owned Units WhollyOwnedUnits	106856
CY2012	dei	Amendment Flag AmendmentFlag	false
CY2012	dei	Document Period End Date DocumentPeriodEndDate	2012-12-31
CY2012	dei	Document Type DocumentType	8-K
CY2012	dei	Entity Central Index Key EntityCentralIndexKey	0000906107
CY2012	dei	Entity Registrant Name EntityRegistrantName	EQUITY RESIDENTIAL

Files In Submission

Name	View Source	Status
0000906107-13-000021-index-headers.html	Edgar Link	pending
0000906107-13-000021-index.html	Edgar Link	pending
0000906107-13-000021.txt	Edgar Link	pending
0000906107-13-000021-xbrl.zip	Edgar Link	pending
a8-kdiscontinuedoperations.htm	Edgar Link	pending
discops8-kexhibit1220121.htm	Edgar Link	pending
discopsexhibit231-eqrconse.htm	Edgar Link	pending
discopsexhibit232-erpopcon.htm	Edgar Link	pending
discopsexhibit9918-keqrx20.htm	Edgar Link	pending
eqr-20121231.xml	Edgar Link	completed
eqr-20121231.xsd	Edgar Link	pending
eqr-20121231_cal.xml	Edgar Link	unprocessable
eqr-20121231_def.xml	Edgar Link	unprocessable
eqr-20121231_lab.xml	Edgar Link	unprocessable
eqr-20121231_pre.xml	Edgar Link	unprocessable
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xls	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
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R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

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$EQR
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2012 Q4 Form 8-K Financial Statement

#000090610713000021 Filed on June 17, 2013

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$EQR EQUITY RESIDENTIAL Stock $eqr

2012 Q4 Form 8-K Financial Statement

#000090610713000021 Filed on June 17, 2013

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$EQR
EQUITY RESIDENTIAL Stock $eqr