Partners Equity of The Operating Partnership (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator
Income (loss) from continuing operations, Basic									$ 38,982	$ (37,309)	$ (24,556)
Income (loss) from continuing operations, Diluted									38,982	(37,309)	(24,556)
Amount allocated to unvested restricted shareholders/unitholders, Basic									(363)	(376)	(505)
Amount allocable to unvested restricted unitholders, Diluted									(363)	(376)	(505)
Preferred share/unit dividends, Basic									(6,900)	(10,405)	(7,992)
Preferred share/unit dividends, Diluted									(6,900)	(10,405)	(7,992)
Redemption Premium									0	4,052	0
Preferred share/unit redemption Premium, Diluted									0	(4,052)	0
Income Loss from continuing operations available to common shareholders/unitholders, Basic									31,362	(51,279)	(32,059)
Income (loss) from continuing operations available to common unit holders, Diluted									31,362	(51,279)	(32,059)
Discontinued operations attributable to common unitholders									4,207	43,838	19,841
Net income (loss) attributable to Common Shareholders/Unitholders									35,514	(8,238)	(12,996)
Net income (loss) available to common shareholders/unitholders, Diluted									35,514	(8,238)	(12,996)
Denominator
Weighted-average shares/units outstanding, Basic									153,140,458	143,257,097	135,444,424
Contingent securities/Stock based compensation									1,273,853	0	0
Weighted-average shares/units outstanding, Diluted									154,414,311	143,257,097	135,444,424
Income per Common Partnership Unit:
Income (Loss) from continuing operations attributable to common shareholders/unitholders, Basic									$ 0.20	$ (0.36)	$ (0.24)
Income (Loss) from continuing operations attributable to common shareholders/unitholders, Diluted									$ 0.20	$ (0.36)	$ (0.24)
Discontinued operations attributable to common shareholders/unitholders, Basic									$ 0.03	$ 0.30	$ 0.14
Discontinued operations attributable to common shareholders, Diluted									$ 0.03	$ 0.30	$ 0.14
Net income (loss) attributable to common shareholders/unitholders, Basic	$ 0.12	$ 0.06	$ 0.03	$ 0.01	$ (0.21)	$ 0.10	$ 0.01	$ 0.05	$ 0.23	$ (0.06)	$ (0.10)
Net income (loss) attributable to common shareholders/unitholders, Diluted	$ 0.12	$ 0.06	$ 0.03	$ 0.01	$ (0.21)	$ 0.10	$ 0.01	$ 0.05	$ 0.23	$ (0.06)	$ (0.10)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Income (loss) from continuing operations, Basic									38,982	(37,309)	(24,556)
Income (loss) from continuing operations, Diluted									38,982	(37,309)	(24,556)
Amount allocated to unvested restricted shareholders/unitholders, Basic									(363)	(376)	(505)
Amount allocable to unvested restricted unitholders, Diluted									(363)	(376)	(505)
Preferred share/unit dividends, Basic									(6,900)	(10,405)	(7,992)
Preferred share/unit dividends, Diluted									(6,900)	(10,405)	(7,992)
Redemption Premium									0	4,052	0
Preferred share/unit redemption Premium, Diluted									0	(4,052)	0
Income Loss from continuing operations available to common shareholders/unitholders, Basic									31,719	(52,142)	(33,053)
Income (loss) from continuing operations available to common unit holders, Diluted									31,719	(52,142)	(33,053)
Discontinued operations attributable to common unitholders									4,207	43,838	19,841
Discontinued operations attributable to common unitholders, Diluted									4,207	43,838	19,841
Net income (loss) attributable to Common Shareholders/Unitholders									35,926	(8,304)	(13,212)
Net income (loss) available to common shareholders/unitholders, Diluted									$ 35,926	$ (8,304)	$ (13,212)
Denominator
Weighted-average shares/units outstanding, Basic									154,929,545	145,883,217	145,118,841
Contingent securities/Stock based compensation									1,273,853	0	0
Weighted-average shares/units outstanding, Diluted									156,203,398	145,883,217	145,118,841
Income per Common Partnership Unit:
Income (Loss) from continuing operations attributable to common shareholders/unitholders, Basic									$ 0.20	$ (0.36)	$ (0.23)
Income (Loss) from continuing operations attributable to common shareholders/unitholders, Diluted									$ 0.20	$ (0.36)	$ (0.23)
Discontinued operations attributable to common shareholders/unitholders, Basic									$ 0.03	$ 0.30	$ 0.14
Discontinued operations attributable to common shareholders, Diluted									$ 0.03	$ 0.30	$ 0.14
Net income (loss) attributable to common shareholders/unitholders, Basic									$ 0.23	$ (0.06)	$ (0.09)
Net income (loss) attributable to common shareholders/unitholders, Diluted									$ 0.23	$ (0.06)	$ (0.09)