Beneficiaries Equity of the Parent Company (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerator
Income (Loss) from Continuing Operations, Basic	$ 1,245	$ 9,310	$ (992)	$ 7,065
Income (Loss) From Continuing Operations, Diluted	1,245	9,310	(992)	7,065
Net Income (Loss) From Continuing Operations Attributable to Non controlling interests, Basic	5	(87)	49	(37)
Net Income (Loss) From Continuing Operations Attributable To Non Controlling Interests, Diluted	5	(87)	49	(37)
Net income attributable to non-controlling interest — partners' share of consolidated real estate ventures	24	0	12	0
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Redeemable, Diluted	24	0	12	0
Amount allocated to unvested restricted shareholders/unitholders, Basic	(83)	(85)	(186)	(193)
Amount allocated to unvested restricted shareholders/unitholders, Diluted	(83)	(85)	(186)	(193)
Preferred share/unit dividends, Basic	(1,725)	(1,725)	(3,450)	(3,450)
Preferred share/unit dividends, Diluted	(1,725)	(1,725)	(3,450)	(3,450)
Income (Loss) from continuing operations available to common unitholders, Basic	(534)	7,413	(4,567)	3,385
Income (Loss) from continuing operations available to common unitholders, Diluted	(534)	7,413	(4,567)	3,385
Income (Loss) from Discontinued Operations	929	(2,130)	921	4,034
Income (Loss) From Discontinued Operations, Diluted	929	(2,130)	921	4,034
Discontinued operations attributable to non-controlling interests, Basic	(10)	25	(10)	(53)
Discontinued Operations Attributable to Noncontrolling Interests- Diluted	(10)	25	(10)	(53)
Discontinued operations attributable to common shareholders, Basic	919	(2,105)	911	3,981
Discontinued operations attributable to common shareholders, Diluted	919	(2,105)	911	3,981
Net income (loss) attributable to Common Shareholders of Brandywine Realty Trust	385	5,308	(3,656)	7,366
Net Income (Loss) Available to Common Shareholders/unitholders, Diluted	$ 385	$ 5,308	$ (3,656)	$ 7,366
Denominator
Weighted Average Number of Shares Outstanding, Basic	157,037,348	155,347,384	156,916,356	149,508,957
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	1,343,817	0	1,157,288
Weighted Average Number of Shares Outstanding, Diluted	157,037,348	156,691,201	156,916,356	150,666,245
Earnings per common share from continuing operations Abstract
Income (Loss) from Continuing Operations Attributable to Common Shareholders/unitholders, Per Basic Share	$ 0.00	$ 0.05	$ (0.03)	$ 0.02
Income (Loss) from Continuing Operations Attributable to Common Shareholders/unitholders, Per Diluted Share	$ 0.00	$ 0.05	$ (0.03)	$ 0.02
Discontinued Operations attributable to common shareholders/unitholders, Basic	$ 0.00	$ (0.02)	$ 0.01	$ 0.03
Discontinued Operations attributable to common shareholders/unitholders, Diluted	$ 0.00	$ (0.02)	$ 0.01	$ 0.03
Net income (loss) attributable to common shareholders/unitholders, Basic	$ 0.00	$ 0.03	$ (0.02)	$ 0.05
Net income attributable to common shareholders/unitholders, Diluted	$ 0.00	$ 0.03	$ (0.02)	$ 0.05