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Organization of The Parent Company and The Operating Partnership - Narrative (Details) | 9 Months Ended
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Sep. 30, 2021 ft² a property parcel
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of real estate properties | property | 81
Rentable Square Feet | 13,651,650
Unconsolidated Properties | Unconsolidated Real Estate Ventures |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Number of real estate properties | property | 10
Parent Company |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Areas of land held for development (in acres) | a | 176.1
Area of land held for sale | a | 10.0
Lease agreement term | 99 years
Area of additional undeveloped parcels of land with option to purchase (in acres) | a | 55.5
Total potential development capacity (in square feet) | 13,400,000
Parent Company | Land Parcel One |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Lease agreement term | 99 years
Parent Company | Held-for-sale |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Total potential development capacity (in square feet) | 100,000
Parent Company | Leashold Interest Land |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Areas of land held for development (in acres) | a | 0.8
Number of parcels of land | parcel | 1
Wholly-owned Management Company Subsidiaries |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Rentable Square Feet | 24,400,000
Wholly-owned Management Company Subsidiaries | Wholly Owned Properties |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Rentable Square Feet | 13,700,000
Wholly-owned Management Company Subsidiaries | Partially Owned Properties |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Rentable Square Feet | 10,700,000
Brandywine Operating Partnership LP |
Organization of The Parent Company and The Operating Partnership [Line Items] |
Ownership in the operating partnership | 99.50%

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