XML 85 R70.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Segment Information (Textual) (Details) |  | 9 Months Ended
--- | --- | ---
Feb. 02, 2017 property | Sep. 30, 2017 property segment
Segment Reporting Information [Line Items] |  |
Number of Reportable Segments | segment |  | 5
Office Properties [Member] |  |
Segment Reporting Information [Line Items] |  |
Number of Properties Sold |  | 12
Office Properties [Member] | 1200 & 1220 Concord Avenue (Concord Airport Plaza) [Member] |  |
Segment Reporting Information [Line Items] |  |
Number of Properties Sold | 2 | 2

X
- Definition The number of real estate properties sold during the period. + References No definition available. + Details
Name: | bdn_NumberOfRealEstatePropertiesSold
Namespace Prefix: | bdn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_OfficeBuildingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bdn_A1200And1220ConcordAvenueInConcordMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |