Partners Equity of the Operating Partnership - Number of Units and Net Income Used to Calculate Basic and Diluted Earnings Per Common Partnership Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator
Income (loss) from continuing operations	$ (1,323)	$ 3,058	$ 44,987	$ 11,652
Nonforfeitable dividends allocated to unvested restricted shareholders	(79)	(76)	(184)	(177)
Distribution to preferred shareholders	(1,725)	(1,725)	(3,450)	(3,450)
Net income (loss) attributable to Common Share/Unit holders of entity	(3,105)	1,255	40,986	7,965
Net income (loss) attributable to common share/unit holders, Diluted	$ (3,105)	$ 1,255	$ 40,986	$ 7,965
Denominator
Basic weighted average shares outstanding (in shares)	175,013,291	179,860,284	174,901,118	179,712,428
Contingent securities/Share based compensation (in shares)	0	678,603	922,852	886,837
Diluted weighted average shares outstanding (in shares)	175,013,291	180,538,887	175,823,970	180,599,265
Earnings per Common Partnership Unit:
Net income (loss) attributable to common shareholders, Basic (USD per share)	$ (0.02)	$ 0.01	$ 0.23	$ 0.04
Net income (loss) attributable to common shareholders, Diluted (USD per share)	$ (0.02)	$ 0.01	$ 0.23	$ 0.04
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Income (loss) from continuing operations	$ (1,323)	$ 3,058	$ 44,987	$ 11,652
Nonforfeitable dividends allocated to unvested restricted shareholders	(79)	(76)	(184)	(177)
Distribution to preferred shareholders	(1,725)	(1,725)	(3,450)	(3,450)
Net (income) loss attributable to non-controlling interests	(4)	5	(6)	5
Net income (loss) attributable to Common Share/Unit holders of entity	(3,131)	1,262	41,347	8,030
Net income (loss) attributable to common share/unit holders, Diluted	$ (3,131)	$ 1,262	$ 41,347	$ 8,030
Denominator
Basic weighted average shares outstanding (in shares)	176,541,708	181,395,386	176,432,877	181,247,530
Contingent securities/Share based compensation (in shares)	0	678,603	922,853	886,837
Diluted weighted average shares outstanding (in shares)	176,541,708	182,073,989	177,355,730	182,134,367
Earnings per Common Partnership Unit:
Net income (loss) attributable to common shareholders, Basic (USD per share)	$ (0.02)	$ 0.01	$ 0.23	$ 0.04
Net income (loss) attributable to common shareholders, Diluted (USD per share)	$ (0.02)	$ 0.01	$ 0.23	$ 0.04