XML 55 R40.htm IDEA: XBRL DOCUMENT
v3.20.2

Organization of The Parent Company and The Operating Partnership - Summary of Core Portfolio of Operating Properties and Excludes Development, Redevelopment and Held for Sale (Details) | Sep. 30, 2020 ft² property
--- | ---
Real Estate Properties [Line Items] |
Number of properties | property | 92
Net rentable area (in square feet) | ft² | 14,691,346
Office properties |
Real Estate Properties [Line Items] |
Number of properties | property | 84
Net rentable area (in square feet) | ft² | 13,641,289
Mixed-use properties |
Real Estate Properties [Line Items] |
Number of properties | property | 5
Net rentable area (in square feet) | ft² | 780,184
Core Properties |
Real Estate Properties [Line Items] |
Number of properties | property | 89
Net rentable area (in square feet) | ft² | 14,421,473
Development property |
Real Estate Properties [Line Items] |
Number of properties | property | 1
Net rentable area (in square feet) | ft² | 205,803
Redevelopment properties |
Real Estate Properties [Line Items] |
Number of properties | property | 2
Net rentable area (in square feet) | ft² | 64,070

X
- Definition Area of a real estate property. + References No definition available. + Details
Name: | us-gaap_AreaOfRealEstateProperty
Namespace Prefix: | us-gaap_
Data Type: | num:areaItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of real estate properties owned as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfRealEstateProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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_RealEstatePropertiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=bdn_OfficePropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=bdn_MixedUsePropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=bdn_CorePropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=bdn_DevelopmentProjectsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=bdn_RedevelopmentProjectsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |