Beneficiaries Equity of the Parent Company (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Numerator
Income (Loss) from continuing operations, Basic	$ 3,058	$ 1,245	$ 11,652	$ (992)
Income (Loss) from continuing operations, Diluted	3,058	1,245	11,652	(992)
Net (income) loss from continuing operations attributable to non-controlling interests - LP units, basic	(7)	5	(65)	49
Net (income) loss from continuing operations attributable to non-controlling interests - LP Units, diluted	(7)	5	(65)	49
Net loss attributable to non-controlling interest — partners' share of consolidated real estate ventures, Basic	5	24	5	12
Net loss attributable to non-controlling interest — partners' share of consolidated real estate ventures, Diluted	5	24	5	12
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(76)	(83)	(177)	(186)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(76)	(83)	(177)	(186)
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	1,255	(534)	7,965	(4,567)
Income (Loss) from continuing operations available to common unitholders, Diluted	1,255	(534)	7,965	(4,567)
Income (loss) from discontinued operations, Basic	0	929	0	921
Income (loss) from discontinued operations, Diluted	0	929	0	921
Discontinued operations attributable to non-controlling interests, basic	0	(10)	0	(10)
Discontinued operations attributable to common shareholders, diluted	0	(10)	0	(10)
Discontinued operations attributable to common shareholders, Basic	0	919	0	911
Discontinued operations attributable to common shareholders, Diluted	0	919	0	911
Net income (loss) attributable to Common Shareholders of Brandywine Realty Trust	1,255	385	7,965	(3,656)
Net Income (Loss) Available to Common Shareholders/unitholders, Diluted	$ 1,255	$ 385	$ 7,965	$ (3,656)
Denominator
Basic weighted average shares outstanding (in shares)	179,860,284	157,037,348	179,712,428	156,916,356
Contingent securities/Share based compensation (in shares)	678,603	0	886,837	0
Diluted weighted average shares outstanding (in shares)	180,538,887	157,037,348	180,599,265	156,916,356
Earnings per common share from continuing operations Abstract
Income (loss) from continuing operations attributable to common shareholders, Basic (USD per share)	$ 0.01	$ 0.00	$ 0.04	$ (0.03)
Income (loss) from continuing operations attributable to common shareholders, Dilued (USD per share)	0.01	0.00	0.04	(0.03)
Discontinued operations attributable to common shareholders, Basic (USD per share)	0.00	0.00	0.00	0.01
Discontinued operations attributable to common shareholders, Diluted (USD per share)	0.00	0.00	0.00	0.01
Net income (loss) attributable to common shareholders, Basic (USD per share)	0.01	0.00	0.04	(0.02)
Net income (loss) attributable to common shareholders, Diluted (USD per share)	$ 0.01	$ 0.00	$ 0.04	$ (0.02)