<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.3.0.11</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ReportType />
  <ContextCount>333</ContextCount>
  <ElementCount>524</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>92</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>true</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0110 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/BalanceSheet</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0111 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/BalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0120 - Statement - Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/StatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0130 - Statement - Consolidated Statements of Comprehensive Income (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/StatementsOfOtherComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0140 - Statement - Consolidated Statements of Beneficiaries' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/StatementsOfEquity</Role>
      <ShortName>Consolidated Statements of Beneficiaries' Equity (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0141 - Statement - Consolidated Statements of Beneficiaries' Equity (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/StatementsOfShareholdersEquityParenthetical</Role>
      <ShortName>Consolidated Statements of Beneficiaries' Equity (Unaudited) (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>0150 - Statement - Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/StatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>0151 - Statement - Consolidated Statements of Cash Flows (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/StatementsOfCashFlowsParenthetical</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited) (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>0201 - Disclosure - Organization of The Parent Company and The Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/OrganizationOfParentCompanyAndOperatingPartnership</Role>
      <ShortName>Organization of The Parent Company and The Operating Partnership</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>0202 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>0203 - Disclosure - Real Estate Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestments</Role>
      <ShortName>Real Estate Investments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>0204 - Disclosure - Investment in Unconsolidated Ventures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/InvestmentInUnconsolidatedVentures</Role>
      <ShortName>Investment in Unconsolidated Ventures</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>0205 - Disclosure - Deferred Costs</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DeferredCosts</Role>
      <ShortName>Deferred Costs</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>0206 - Disclosure - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/IntangibleAssets</Role>
      <ShortName>Intangible Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>0207 - Disclosure - Debt Obligations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligations</Role>
      <ShortName>Debt Obligations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>0208 - Disclosure - Fair Value of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/FairValueOfFinancialInstruments</Role>
      <ShortName>Fair Value of Financial Instruments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>0209 - Disclosure - Risk Management and Use of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RiskManagementAndUseOfFinancialInstruments</Role>
      <ShortName>Risk Management and Use of Financial Instruments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>0210 - Disclosure - Discontinued Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DiscontinuedOperations</Role>
      <ShortName>Discontinued Operations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>0211 - Disclosure - Non Controlling Interests in The Parent Company</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/NonControllingInterestsInParentCompany</Role>
      <ShortName>Non Controlling Interests in The Parent Company</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>0212 - Disclosure - Beneficiaries Equity of the Parent Company</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/BeneficiariesEquityOfParentCompany</Role>
      <ShortName>Beneficiaries Equity of the Parent Company</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>0213 - Disclosure - Partners Equity of The Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/PartnersEquityOfOperatingPartnership</Role>
      <ShortName>Partners Equity of The Operating Partnership</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>0214 - Disclosure - Share Based and Deferred Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/ShareBasedAndDeferredCompensation</Role>
      <ShortName>Share Based and Deferred Compensation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>0215 - Disclosure - Tax Credit Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/TaxCreditTransactions</Role>
      <ShortName>Tax Credit Transactions</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>0216 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>0217 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>0218 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>0402 - Disclosure - Summary of Significant Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SummaryOfSignificantPoliciesPolicies</Role>
      <ShortName>Summary of Significant Policies (Policies)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>0502 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>0503 - Disclosure - Real Estate Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsTables</Role>
      <ShortName>Real Estate Investments (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>0504 - Disclosure - Investment in Unconsolidated Ventures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/InvestmentInUnconsolidatedVenturesTables</Role>
      <ShortName>Investment in Unconsolidated Ventures (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>0505 - Disclosure - Deferred Costs (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DeferredCostsTables</Role>
      <ShortName>Deferred Costs (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>0506 - Disclosure - Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/IntangibleAssetsTables</Role>
      <ShortName>Intangible Assets (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>0507 - Disclosure - Debt Obligations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligationsTables</Role>
      <ShortName>Debt Obligations (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>0508 - Disclosure - Fair Value of Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/FairValueOfFinancialInstrumentsTables</Role>
      <ShortName>Fair Value of Financial Instruments (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>0510 - Disclosure - Discontinued Operations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DiscontinuedOperationsTables</Role>
      <ShortName>Discontinued Operations (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>0512 - Disclosure - Beneficiaries Equity of The Parent Company (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/BeneficiariesEquityOfParentCompanyTables</Role>
      <ShortName>Beneficiaries Equity of The Parent Company (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>0513 - Disclosure - Partners Equity of The Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/PartnersEquityOfOperatingPartnershipTables</Role>
      <ShortName>Partners Equity of The Operating Partnership (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>0515 - Disclosure - Share Based and Deferred Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/ShareBasedAndDeferredCompensationTables</Role>
      <ShortName>Share Based and Deferred Compensation (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>0516 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>0517 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/CommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>0601 - Disclosure - Organization of The Parent Company and The Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/OrganizationOfParentCompanyAndOperatingPartnershipDetails</Role>
      <ShortName>Organization of The Parent Company and The Operating Partnership (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>0602 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>06021 - Disclosure - Summary of Significant Accounting Policies (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SummaryOfSignificantAccountingPoliciesDetailsTextuals</Role>
      <ShortName>Summary of Significant Accounting Policies (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>06022 - Disclosure - Summary of Significant Accounting Policies (Details Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SummaryOfSignificantAccountingPoliciesDetailsTextuals1</Role>
      <ShortName>Summary of Significant Accounting Policies (Details Textuals 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>0603 - Disclosure - Real Estate Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsDetails</Role>
      <ShortName>Real Estate Investments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>06031 - Disclosure - Real Estate Investments (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsDetails1</Role>
      <ShortName>Real Estate Investments (Details 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>06032 - Disclosure - Real Estate Investments (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsDetails2</Role>
      <ShortName>Real Estate Investments (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>06033 - Disclosure - Real Estate Investments (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsDetails3</Role>
      <ShortName>Real Estate Investments (Details 3)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>06035 - Disclosure - Real Estate Investments (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsDetailsTextuals</Role>
      <ShortName>Real Estate Investments (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>06036 - Disclosure - Real Estate Investments (Details Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RealEstateInvestmentsDetailsTextuals1</Role>
      <ShortName>Real Estate Investments (Details Textuals 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>0604 - Disclosure - Investment in Unconsolidated Ventures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/InvestmentInUnconsolidatedVenturesDetails</Role>
      <ShortName>Investment in Unconsolidated Ventures (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>06041 - Disclosure - Investment in Unconsolidated Ventures (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/InvestmentInUnconsolidatedVenturesDetails1</Role>
      <ShortName>Investment in Unconsolidated Ventures (Details 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>06042 - Disclosure - Investment in Unconsolidated Ventures (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/InvestmentInUnconsolidatedVenturesDetailsTextuals</Role>
      <ShortName>Investment in Unconsolidated Ventures (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>06043 - Disclosure - Investment in Unconsolidated Ventures (Details Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/InvestmentInUnconsolidatedVenturesDetailsTextuals1</Role>
      <ShortName>Investment in Unconsolidated Ventures (Details Textuals 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>0605 - Disclosure - Deferred Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DeferredCostsDetails</Role>
      <ShortName>Deferred Costs (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>06051 - Disclosure - Deferred Costs (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DeferredCostsDetailsTextuals</Role>
      <ShortName>Deferred Costs (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>0606 - Disclosure - Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/IntangibleAssetsDetails</Role>
      <ShortName>Intangible Assets (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>06061 - Disclosure - Intangible Assets (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/IntangibleAssetsDetails1</Role>
      <ShortName>Intangible Assets (Details 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>0607 - Disclosure - Debt Obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligationsDetails</Role>
      <ShortName>Debt Obligations (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>06071 - Disclosure - Debt Obligations (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligationsDetails1</Role>
      <ShortName>Debt Obligations (Details 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>06072 - Disclosure - Debt Obligations (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligationsDetails2</Role>
      <ShortName>Debt Obligations (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>06073 - Disclosure - Debt Obligations (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligationsDetailsTextuals</Role>
      <ShortName>Debt Obligations (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>06074 - Disclosure - Debt Obligations (Details Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DebtObligationsDetailsTextuals1</Role>
      <ShortName>Debt Obligations (Details Textuals 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>0608 - Disclosure - Fair Value of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/FairValueOfFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value of Financial Instruments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>06081 - Disclosure - Fair Value of Financial Instruments (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/FairValueOfFinancialInstrumentsDetailsTextuals</Role>
      <ShortName>Fair Value of Financial Instruments (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>0609 - Disclosure - Risk Management and Use of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/RiskManagementAndUseOfFinancialInstrumentsDetails</Role>
      <ShortName>Risk Management and Use of Financial Instruments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>0610 - Disclosure - Discontinued Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DiscontinuedOperationsDetails</Role>
      <ShortName>Discontinued Operations (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>06101 - Disclosure - Discontinued Operations (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/DiscontinuedOperationsDetailsTextuals</Role>
      <ShortName>Discontinued Operations (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>0611 - Disclosure - Non-Controlling Interests in The Parent Company (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/NonControllingInterestsInParentCompanyDetails</Role>
      <ShortName>Non-Controlling Interests in The Parent Company (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>0612 - Disclosure - Beneficiaries Equity of The Parent Company (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/BeneficiariesEquityOfParentCompanyDetails</Role>
      <ShortName>Beneficiaries Equity of The Parent Company (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>06121 - Disclosure - Beneficiaries Equity of The Parent Company (DetailsTextuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/BeneficiariesEquityOfParentCompanyDetails1</Role>
      <ShortName>Beneficiaries Equity of The Parent Company (DetailsTextuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>0613 - Disclosure - Partners Equity of The Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/PartnersEquityOfOperatingPartnershipDetails</Role>
      <ShortName>Partners Equity of The Operating Partnership (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>06131 - Disclosure - Partners Equity of The Operating Partnership (DetailsTextuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/PartnersEquityOfOperatingPartnershipDetails1</Role>
      <ShortName>Partners Equity of The Operating Partnership (DetailsTextuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>0614 - Disclosure - Share Based and Deferred Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/ShareBasedAndDeferredCompensationDetails</Role>
      <ShortName>Share Based and Deferred Compensation (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>06141 - Disclosure - Share Based and Deferred Compensation (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/ShareBasedAndDeferredCompensationDetails1</Role>
      <ShortName>Share Based and Deferred Compensation (Details 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>06142 - Disclosure - Share Based and Deferred Compensation (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/ShareBasedAndDeferredCompensationDetailsTextual</Role>
      <ShortName>Share Based and Deferred Compensation (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>0615 - Disclosure - Tax Credit Transactions (DetailsTextuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/TaxCreditTransactionsDetails</Role>
      <ShortName>Tax Credit Transactions (DetailsTextuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>0616 - Disclosure - Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SegmentInformationDetails</Role>
      <ShortName>Segment Information (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>06161 - Disclosure - Segment Information (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SegmentInformationDetails1</Role>
      <ShortName>Segment Information (Details 1)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>0617 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/CommitmentsAndContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>06171 - Disclosure - Commitments and Contingencies (Details Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/CommitmentsAndContingenciesDetailsTextuals</Role>
      <ShortName>Commitments and Contingencies (Details Textuals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>0618 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://brandywinerealty.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Element bdn_NetRentableSpace had a mix of decimals attribute values: 0 -5.</Log>
    <Log type="Info">Element bdn_NetRentableSpace had a mix of decimals attribute values: 0 -5.</Log>
    <Log type="Info">Element bdn_LeasePercentageOfAcquiredProperty had a mix of decimals attribute values: 3 0.</Log>
    <Log type="Info">Element us-gaap_DebtInstrumentCarryingAmount had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">Element bdn_UnamortizedExchangeableDebtDiscount had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">Element us-gaap_DebtInstrumentInterestRateEffectivePercentageRateRangeMinimum had a mix of decimals attribute values: 4 3.</Log>
    <Log type="Info">Element us-gaap_DebtInstrumentInterestRateStatedPercentage had a mix of decimals attribute values: 5 4.</Log>
    <Log type="Info">Element us-gaap_DebtInstrumentCarryingAmount had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">Element bdn_UnamortizedExchangeableDebtDiscount had a mix of decimals attribute values: -3 -5.</Log>
    <Log type="Info">Element us-gaap_DebtInstrumentInterestRateStatedPercentage had a mix of decimals attribute values: 5 4.</Log>
    <Log type="Info">Element bdn_NetRentableSpace had a mix of decimals attribute values: 0 -5.</Log>
    <Log type="Info">'Monetary' elements on report '06035 - Disclosure - Real Estate Investments (Details Textuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '06042 - Disclosure - Investment in Unconsolidated Ventures (Details Textuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '06073 - Disclosure - Debt Obligations (Details Textuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '06121 - Disclosure - Beneficiaries Equity of The Parent Company (DetailsTextuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '06131 - Disclosure - Partners Equity of The Operating Partnership (DetailsTextuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '0615 - Disclosure - Tax Credit Transactions (DetailsTextuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '06171 - Disclosure - Commitments and Contingencies (Details Textuals)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 0110 - Statement - Consolidated Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Jun. 30, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 0111 - Statement - Consolidated Balance Sheets (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 0120 - Statement - Consolidated Statements of Operations (Unaudited)</Log>
    <Log type="Info">	Process Flow-Through: Removing column '9 Months Ended
Sep. 30, 2009'</Log>
    <Log type="Info">Process Flow-Through: 0130 - Statement - Consolidated Statements of Comprehensive Income (Unaudited)</Log>
    <Log type="Info">	Process Flow-Through: Removing column '9 Months Ended
Sep. 30, 2009'</Log>
    <Log type="Info">Process Flow-Through: 0141 - Statement - Consolidated Statements of Beneficiaries' Equity (Unaudited) (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 0150 - Statement - Consolidated Statements of Cash Flows (Unaudited)</Log>
    <Log type="Info">	Process Flow-Through: Removing column '9 Months Ended
Sep. 30, 2009'</Log>
    <Log type="Info">Process Flow-Through: 0151 - Statement - Consolidated Statements of Cash Flows (Unaudited) (Parenthetical)</Log>
  </Logs>
  <InputFiles>
    <File>bdn-20110630.xml</File>
    <File>bdn-20110630.xsd</File>
    <File>bdn-20110630_cal.xml</File>
    <File>bdn-20110630_def.xml</File>
    <File>bdn-20110630_lab.xml</File>
    <File>bdn-20110630_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
