Investments in real estate Real estate asset sales (Details) (USD $)
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12 Months Ended |
36 Months Ended |
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Dec. 31, 2014
property
sqft
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Dec. 31, 2013
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Dec. 31, 2012
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Dec. 31, 2014
property
sqft
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Sep. 30, 2014
sqft
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Real Estate Properties [Line Items] |
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Number of properties sold |
3are_DisposalGroupIncludingDiscontinuedOperationPropertiesSoldNumber |
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16are_DisposalGroupIncludingDiscontinuedOperationPropertiesSoldNumber |
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Area of Real Estate Property |
18,729,282us-gaap_AreaOfRealEstateProperty |
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18,729,282us-gaap_AreaOfRealEstateProperty |
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Impairment of real estate |
$ 51,675,000us-gaap_ImpairmentOfRealEstate |
$ 0us-gaap_ImpairmentOfRealEstate |
$ 13,450,000us-gaap_ImpairmentOfRealEstate |
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Gain on sales of real estate - land parcels |
6,403,000us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes |
4,824,000us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes |
1,864,000us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes |
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Various |
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Real Estate Properties [Line Items] |
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Number of Land Parcels Sold |
6are_NumberofLandParcelsSold / us-gaap_StatementGeographicalAxis = are_VariousMember |
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San Francisco, California |
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Real Estate Properties [Line Items] |
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Number of Land Parcels Sold |
9are_NumberofLandParcelsSold / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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Number of Industrial Buildings Sold |
7are_NumberofIndustrialBuildingsSold / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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Impairment of land parcels |
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Real Estate Properties [Line Items] |
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Impairment of real estate |
24,700,000us-gaap_ImpairmentOfRealEstate / are_ImpairmentTypeAxis = are_ImpairmentoflandparcelsMember |
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661 University Avenue | CANADA |
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Real Estate Properties [Line Items] |
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Area of Real Estate Property |
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780,540us-gaap_AreaOfRealEstateProperty / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_A661UniversityAvenueMember / us-gaap_StatementGeographicalAxis = country_CA |
661 University Avenue | Impairment of real estate | CANADA |
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Real Estate Properties [Line Items] |
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Impairment of real estate |
16,600,000us-gaap_ImpairmentOfRealEstate / are_ImpairmentTypeAxis = are_ImpairmentofrealestateMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_A661UniversityAvenueMember / us-gaap_StatementGeographicalAxis = country_CA |
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Percentage of Impairment of Real Estate related to Foreign Exchange Rate, Estimated Transfer Taxes, and Closing Costs |
75.00%are_PercentageofImpairmentofRealEstaterelatedtoForeignExchangeRateEstimatedTransferTaxesandClosingCosts / are_ImpairmentTypeAxis = are_ImpairmentofrealestateMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_A661UniversityAvenueMember / us-gaap_StatementGeographicalAxis = country_CA |
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500 Forbes Boulevard | San Francisco, California |
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Real Estate Properties [Line Items] |
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Area of Real Estate Property |
155,685us-gaap_AreaOfRealEstateProperty / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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155,685us-gaap_AreaOfRealEstateProperty / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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Annualized Revenues minus Operating Expenses |
5,500,000are_AnnualizedRevenuesminusOperatingExpenses / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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Real Estate Project Yield |
5.10%are_RealEstateProjectYield / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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5.10%are_RealEstateProjectYield / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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500 Forbes Boulevard | Impairment of real estate | San Francisco, California |
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Real Estate Properties [Line Items] |
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Impairment of real estate |
9,600,000us-gaap_ImpairmentOfRealEstate / are_ImpairmentTypeAxis = are_ImpairmentofrealestateMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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Estimated Fair Value of Property, Less Cost to Sell |
107,800,000are_FairValueofPropertyLessCosttoSell / are_ImpairmentTypeAxis = are_ImpairmentofrealestateMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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107,800,000are_FairValueofPropertyLessCosttoSell / are_ImpairmentTypeAxis = are_ImpairmentofrealestateMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = are_Number500ForbesBoulevardMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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Income-producing assets | San Diego, California |
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Real Estate Properties [Line Items] |
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Number of properties sold |
3are_DisposalGroupIncludingDiscontinuedOperationPropertiesSoldNumber / are_DispositionsAxis = are_IncomeproducingassetsMember / us-gaap_StatementGeographicalAxis = are_SanDiegoCaliforniaMember |
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Proceeds from sale of real estate |
7,400,000us-gaap_ProceedsFromSaleOfRealEstate / are_DispositionsAxis = are_IncomeproducingassetsMember / us-gaap_StatementGeographicalAxis = are_SanDiegoCaliforniaMember |
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Gain (loss) on disposal of properties recognized |
1,800,000us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax / are_DispositionsAxis = are_IncomeproducingassetsMember / us-gaap_StatementGeographicalAxis = are_SanDiegoCaliforniaMember |
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Area of Real Estate Property |
62,346us-gaap_AreaOfRealEstateProperty / are_DispositionsAxis = are_IncomeproducingassetsMember / us-gaap_StatementGeographicalAxis = are_SanDiegoCaliforniaMember |
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62,346us-gaap_AreaOfRealEstateProperty / are_DispositionsAxis = are_IncomeproducingassetsMember / us-gaap_StatementGeographicalAxis = are_SanDiegoCaliforniaMember |
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Land parcels | Various |
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Real Estate Properties [Line Items] |
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Proceeds from sale of real estate |
48,400,000us-gaap_ProceedsFromSaleOfRealEstate / are_DispositionsAxis = are_LandparcelsMember / us-gaap_StatementGeographicalAxis = are_VariousMember |
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Area of Real Estate Property |
662,950us-gaap_AreaOfRealEstateProperty / are_DispositionsAxis = are_LandparcelsMember / us-gaap_StatementGeographicalAxis = are_VariousMember |
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662,950us-gaap_AreaOfRealEstateProperty / are_DispositionsAxis = are_LandparcelsMember / us-gaap_StatementGeographicalAxis = are_VariousMember |
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Gain on sales of real estate - land parcels |
6,400,000us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes / are_DispositionsAxis = are_LandparcelsMember / us-gaap_StatementGeographicalAxis = are_VariousMember |
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Land parcels | San Francisco, California |
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Real Estate Properties [Line Items] |
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Proceeds from sale of real estate |
$ 31,000,000us-gaap_ProceedsFromSaleOfRealEstate / are_DispositionsAxis = are_LandparcelsMember / us-gaap_StatementGeographicalAxis = are_SanFranciscoCaliforniaMember |
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