Partners Equity of the Operating Partnership (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)
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)
Net loss attributable to non-controlling interest — partners' share of consolidated real estate ventures	5	24	5	12
Net loss attributable to non-controlling interest — partners' share of consolidated real estate ventures, Diluted	5	24	5	12
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
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
Weighted-average units outstanding, Basic (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 Partnership Unit:
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)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
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)
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)
Net loss attributable to non-controlling interest — partners' share of consolidated real estate ventures	5	24	5	12
Net loss attributable to non-controlling interest — partners' share of consolidated real estate ventures, Diluted	5	24	5	12
Income (Loss) from continuing operations available to common unitholders, Basic	1,262	(539)	8,030	(4,616)
Income (Loss) from continuing operations available to common unitholders, Diluted	1,262	(539)	8,030	(4,616)
Income (loss) from discontinued operations, Basic	0	929	0	921
Income (Loss) From Discontinued Operations, Diluted	0	929	0	921
Net income (loss) attributable to Common Shareholders of Brandywine Realty Trust	1,262	390	8,030	(3,695)
Net Income (Loss) Available to Common Shareholders/unitholders, Diluted	$ 1,262	$ 390	$ 8,030	$ (3,695)
Denominator
Weighted-average units outstanding, Basic (in shares)	181,395,386	158,801,087	181,247,530	158,680,095
Contingent securities/Share based compensation (in shares)	678,603	0	886,837	0
Diluted weighted average shares outstanding (in shares)	182,073,989	158,801,087	182,134,367	158,680,095
Earnings per Common Partnership Unit:
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)