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Organization of The Parent Company and The Operating Partnership (Textual) (Details) | 12 Months Ended
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Dec. 31, 2018 ft² a property Parcel
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of Properties | property | 97
Net Rentable Square Feet | 16,777,249
Land Parcel One [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Lease agreement term | 99 years
Land Parcel Two [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Lease agreement term | 99 years
Parent Company |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Undeveloped Parcels of Land | a | 237.4
Undeveloped Land Held for Sale | a | 37.9
Area of Additional Undeveloped Parcels of Land With Option to Purchase | a | 55.5
Total Potential Development Capacity | 14,300,000
Parent Company | Land Parcel One [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Lease agreement term | 99 years
Parent Company | Land Parcel Two [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Lease agreement term | 99 years
Parent Company | Held for Sale Properties Included in Continuing Operations [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Total Potential Development Capacity | 400,000
Wholly-owned Management Company Subsidiaries [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Net Rentable Square Feet | 24,800,000
Wholly-owned Management Company Subsidiaries [Member] | Wholly Owned Properties [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Net Rentable Square Feet | 16,800,000
Wholly-owned Management Company Subsidiaries [Member] | Partially Owned Properties [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Net Rentable Square Feet | 8,000,000.0
Development Property [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of Properties | property | 1
Redevelopment Properties [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of Properties | property | 3
Leashold Interest Land [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of Parcels | Parcel | 2
Leashold Interest Land [Member] | Parent Company |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of Parcels | Parcel | 2
Undeveloped Parcels of Land Held | a | 1.8
Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 99.40%
BRSCO [Member] | Subsidiaries [Member] | Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 100.00%
BMH [Member] | Subsidiaries [Member] | Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 100.00%
BPI [Member] | Subsidiaries [Member] | Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 100.00%
BBL [Member] | Subsidiaries [Member] | Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 100.00%
BPM [Member] | Subsidiaries [Member] | Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 100.00%
BBS [Member] | Subsidiaries [Member] | Brandywine Operating Partnership LP [Member] |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the Operating Partnership | 100.00%

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