Organization of the Parent Company and The Operating Partnership	12 Months Ended
Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP	1. ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP The Parent Company is a self-administered and self-managed real estate investment trust (“REIT”) that provides leasing, property management, development, redevelopment, acquisition and other tenant-related services for a portfolio of office, retail and mixed-use properties. The Parent Company owns its assets and conducts its operations through the Operating Partnership and subsidiaries of the Operating Partnership. The Parent Company is the sole general partner of the Operating Partnership and, as of December 31, 2016, owned a 99.1% interest in the Operating Partnership. The Parent Company’s common shares of beneficial interest are publicly traded on the New York Stock Exchange under the ticker symbol “BDN”. As of December 31, 2016, the Company owned 113 properties that contain an aggregate of approximately 17.6 million net rentable square feet and consist of 93 office properties, seven mixed-use properties, one retail property (101 properties, collectively the “Core Properties”), four development properties, three redevelopment properties and five properties classified as held for sale (collectively, the “Properties”). In addition, as of December 31, 2016, the Company owned economic interests in 14 unconsolidated real estate ventures (collectively, the “Real Estate Ventures”), seven of which own properties that contain approximately 8.0 million net rentable square feet of office space; two of which own 4.3 acres of undeveloped parcels of land; two of which own 1.4 acres of land under active development; two of which own residential towers that contain 345 and 321 apartment units, respectively, and one of which owns an apartment complex that contains 398 units. As of December 31, 2016, the Company also owned 317 acres of undeveloped land, of which five acres were held for sale, and held options to purchase approximately 60 additional acres of undeveloped land. As of December 31, 2016, the total potential development that these land parcels could support, including the parcels under option, under current zoning and entitlements, amounted to an estimated 12.3 million square feet. The Properties and the properties owned by the Real Estate Ventures are located in or near Philadelphia, Pennsylvania; Metropolitan Washington, D.C.; Southern New Jersey; Richmond, Virginia; Wilmington, Delaware; Austin, Texas and Concord, California. In addition to managing properties that the Company owns, as of December 31, 2016, the Company was managing approximately 10.5 million net rentable square feet of office and industrial properties for third parties and Real Estate Ventures. Prior to the MAP Venture formation on February 4, 2016 (See Note 4, “Investment in Unconsolidated Real Estate Ventures”), the Company’s consolidated portfolio included 20 industrial properties. As of December 31, 2016, the Company held four remaining industrial properties in Core Properties, which the Company reclassified as mixed-use. All references to building square footage, acres, occupancy percentage the number of buildings and tax basis are unaudited. The Company conducts its third-party real estate management services business primarily through six management companies (collectively, the “Management Companies”): Brandywine Realty Services Corporation (“BRSCO”), BTRS, Inc. (“BTRS”), Brandywine Properties I Limited, Inc. (“BPI”), BDN Brokerage, LLC (“BBL”), Brandywine Properties Management, L.P. (“BPM”) and Brandywine Brokerage Services, LLC (“BBS”). Each of BRSCO, BTRS and BPI is a taxable REIT subsidiary. As of December 31, 2016, the Operating Partnership owns, directly and indirectly, 100% of each of BRSCO, BTRS, BPI, BBL, BPM and BBS. As of December 31, 2016, the Management Companies were managing properties containing an aggregate of approximately 28.1 million net rentable square feet, of which approximately 17.6 million net rentable square feet related to Properties owned by the Company and approximately 10.5 million net rentable square feet related to properties owned by third parties and Real Estate Ventures.

1. ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP

The Parent Company is a self-administered and self-managed real estate investment trust (“REIT”) that provides leasing, property management, development, redevelopment, acquisition and other tenant-related services for a portfolio of office, retail and mixed-use properties. The Parent Company owns its assets and conducts its operations through the Operating Partnership and subsidiaries of the Operating Partnership. The Parent Company is the sole general partner of the Operating Partnership and, as of December 31, 2016, owned a 99.1% interest in the Operating Partnership. The Parent Company’s common shares of beneficial interest are publicly traded on the New York Stock Exchange under the ticker symbol “BDN”.

As of December 31, 2016, the Company owned 113 properties that contain an aggregate of approximately 17.6 million net rentable square feet and consist of 93 office properties, seven mixed-use properties, one retail property (101 properties, collectively the “Core Properties”), four development properties, three redevelopment properties and five properties classified as held for sale (collectively, the “Properties”). In addition, as of December 31, 2016, the Company owned economic interests in 14 unconsolidated real estate ventures (collectively, the “Real Estate Ventures”), seven of which own properties that contain approximately 8.0 million net rentable square feet of office space; two of which own 4.3 acres of undeveloped parcels of land; two of which own 1.4 acres of land under active development; two of which own residential towers that contain 345 and 321 apartment units, respectively, and one of which owns an apartment complex that contains 398 units. As of December 31, 2016, the Company also owned 317 acres of undeveloped land, of which five acres were held for sale, and held options to purchase approximately 60 additional acres of undeveloped land. As of December 31, 2016, the total potential development that these land parcels could support, including the parcels under option, under current zoning and entitlements, amounted to an estimated 12.3 million square feet. The Properties and the properties owned by the Real Estate Ventures are located in or near Philadelphia, Pennsylvania; Metropolitan Washington, D.C.; Southern New Jersey; Richmond, Virginia; Wilmington, Delaware; Austin, Texas and Concord, California. In addition to managing properties that the Company owns, as of December 31, 2016, the Company was managing approximately 10.5 million net rentable square feet of office and industrial properties for third parties and Real Estate Ventures.

Prior to the MAP Venture formation on February 4, 2016 (See Note 4, “Investment in Unconsolidated Real Estate Ventures”), the Company’s consolidated portfolio included 20 industrial properties. As of December 31, 2016, the Company held four remaining industrial properties in Core Properties, which the Company reclassified as mixed-use.

All references to building square footage, acres, occupancy percentage the number of buildings and tax basis are unaudited.

The Company conducts its third-party real estate management services business primarily through six management companies (collectively, the “Management Companies”): Brandywine Realty Services Corporation (“BRSCO”), BTRS, Inc. (“BTRS”), Brandywine Properties I Limited, Inc. (“BPI”), BDN Brokerage, LLC (“BBL”), Brandywine Properties Management, L.P. (“BPM”) and Brandywine Brokerage Services, LLC (“BBS”). Each of BRSCO, BTRS and BPI is a taxable REIT subsidiary. As of December 31, 2016, the Operating Partnership owns, directly and indirectly, 100% of each of BRSCO, BTRS, BPI, BBL, BPM and BBS. As of December 31, 2016, the Management Companies were managing properties containing an aggregate of approximately 28.1 million net rentable square feet, of which approximately 17.6 million net rentable square feet related to Properties owned by the Company and approximately 10.5 million net rentable square feet related to properties owned by third parties and Real Estate Ventures.