Beneficiaries Equity of the Parent Company - Number of Shares and Net Income Used to Calculate Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator
Income (loss) from continuing operations, Basic	$ 7,698	$ (1,323)	$ 28,969	$ 44,987
Net (income) loss from continuing operations attributable to non-controlling interests, Basic	(45)	22	(214)	(367)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(73)	(79)	(172)	(184)
Distribution to preferred shareholders	(307)	(1,725)	(2,032)	(3,450)
Preferred share redemption charge	(3,181)	0	(3,181)	0
Net income (loss) attributable to Common Shareholders of Brandywine Realty Trust	4,092	(3,105)	23,370	40,986
Net (income) loss from continuing operations attributable to non-controlling interests, Diluted	(45)	22	(214)	(367)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(73)	(79)	(172)	(184)
Net income (loss) attributable to common shareholders, Diluted	$ 4,092	$ (3,105)	$ 23,370	$ 40,986
Denominator
Basic weighted average shares outstanding (in shares)	175,333,300	175,013,291	175,255,564	174,901,118
Contingent securities/Share based compensation (in shares)	1,423,298	0	1,224,816	922,852
Diluted weighted average shares outstanding (in shares)	176,756,598	175,013,291	176,480,380	175,823,970
Earnings per Common Share:
Net income (loss) attributable to common shareholders, Basic (USD per share)	$ 0.02	$ (0.02)	$ 0.13	$ 0.23
Net income (loss) attributable to common shareholders, Diluted (USD per share)	$ 0.02	$ (0.02)	$ 0.13	$ 0.23