Partners Equity of The Operating Partnership (DetailsTextuals) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 05, 2013
Earnings per Common Partnership Unit [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									$ 6,024,000	$ 38,982,000	$ (37,309,000)
Income Loss From Continuing Operations Including Portion Attributable To Non controlling Interest Diluted									6,024,000	38,982,000	(37,309,000)
Amount allocated to unvested restricted shareholders									349,000	363,000	376,000
Amount allocated to unvested restricted shareholders, Diluted									(349,000)	(363,000)	(376,000)
Preferred share/unit dividends, Basic									(6,900,000)	(6,900,000)	(10,405,000)
Preferred share/unit dividends, Diluted									(6,900,000)	(6,900,000)	(10,405,000)
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Redeemable									(44,000)	0	0
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Redeemable, Diluted									(44,000)	0	0
Preferred share/unit redemption premium, basic									0	0	(4,052,000)
Preferred share/unit redemption Premium, Diluted									0	0	(4,052,000)
Income Loss from continuing operations available to common shareholders/unitholders, Basic									(1,182,000)	31,362,000	(51,279,000)
Income Loss from continuing operations available to common shareholders Diluted									(1,182,000)	31,362,000	(51,279,000)
Discontinued operations attributable to common unitholders									918,000	4,207,000	43,838,000
Net Income (Loss) Available to Common Stockholders, Basic									(274,000)	35,514,000	(8,238,000)
Net Income (Loss) Available to Common Stockholders, Diluted									(274,000)	35,514,000	(8,238,000)
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									0	1,273,853	0
Income (Loss) from continuing operations attributable to common shareholders/unitholders, Basic									$ (0.01)	$ 0.20	$ (0.36)
Income (Loss) from Continuing Operations, Per Diluted Share									$ (0.01)	$ 0.20	$ (0.36)
Discontinued operations attributable to common shareholders/unitholders, Basic									$ 0.01	$ 0.03	$ 0.30
Discontinued operations attributable to common shareholders, Diluted									$ 0.01	$ 0.03	$ 0.30
Net income (loss) attributable to common shareholders/unitholders, Basic	$ (0.02)	$ 0.04	$ 0.00	$ (0.03)	$ 0.12	$ 0.06	$ 0.03	$ 0.01	$ 0.00	$ 0.23	$ (0.06)
Net income (loss) attributable to common shareholders/unitholders, Diluted	$ (0.02)	$ 0.04	$ 0.00	$ (0.03)	$ 0.12	$ 0.06	$ 0.03	$ 0.01	$ 0.00	$ 0.23	$ (0.06)
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Dividends Payable, Amount	28,871,000				25,584,000				28,871,000	25,584,000
Percentage of Preferential return									6.90%	6.90%
Dividends, Preferred Stock, Cash									(6,900,000)	(6,900,000)	(10,405,000)
Partners' Capital Account, Redemptions											9,741,000
Weighted-average shares/units outstanding, Basic									166,202,649	153,140,458	143,257,097
Weighted-average shares/units outstanding, Diluted									166,202,649	154,414,311	143,257,097
Series E Preferred Stock [Member]
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Percentage of Preferential return									6.90%
Preferred Stock, Liquidation Preference Per Share	$ 25.00								$ 25.00
Class A Units [Member]
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Redeemable Limited Partnership Units Potential Cash Redemption Value Closing Market Price	$ 15.98				$ 14.09				$ 15.98	$ 14.09	$ 12.19
Limited Partners' Capital Account, Units Outstanding	1,535,102				1,763,739				1,535,102	1,763,739
Offering Program [Member]
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Shares Authorized For Equity Offering Program												16,000,000
Remaining Shares Available For Sales	16,000,000								16,000,000
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Earnings per Common Partnership Unit [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									6,024,000	38,982,000	(37,309,000)
Income Loss From Continuing Operations Including Portion Attributable To Non controlling Interest Diluted									6,024,000	38,982,000	(37,309,000)
Amount allocated to unvested restricted shareholders									349,000	363,000	376,000
Amount allocated to unvested restricted shareholders, Diluted									(349,000)	(363,000)	(376,000)
Preferred share/unit dividends, Basic									(6,900,000)	(6,900,000)	(10,405,000)
Preferred share/unit dividends, Diluted									(6,900,000)	(6,900,000)	(10,405,000)
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Redeemable									(44,000)	0	0
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Redeemable, Diluted									(44,000)	0	0
Preferred share/unit redemption premium, basic									0	0	(4,052,000)
Preferred share/unit redemption Premium, Diluted									0	0	(4,052,000)
Income Loss from continuing operations available to common shareholders/unitholders, Basic									(1,181,000)	31,719,000	(52,142,000)
Income Loss from continuing operations available to common shareholders Diluted									(1,181,000)	31,719,000	(52,142,000)
Discontinued operations attributable to common unitholders									918,000	4,207,000	43,838,000
Discontinued operations attributable to common unitholders, Diluted									918,000	4,207,000	43,838,000
Net Income (Loss) Available to Common Stockholders, Basic									(263,000)	35,926,000	(8,304,000)
Net Income (Loss) Available to Common Stockholders, Diluted									(263,000)	35,926,000	(8,304,000)
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									0	1,273,853	0
Income (Loss) from continuing operations attributable to common shareholders/unitholders, Basic									$ (0.01)	$ 0.20	$ (0.36)
Income (Loss) from Continuing Operations, Per Diluted Share									$ (0.01)	$ 0.20	$ (0.36)
Discontinued operations attributable to common shareholders/unitholders, Basic									$ 0.01	$ 0.03	$ 0.30
Discontinued operations attributable to common shareholders, Diluted									$ 0.01	$ 0.03	$ 0.30
Net income (loss) attributable to common shareholders/unitholders, Basic									$ 0.00	$ 0.23	$ (0.06)
Net income (loss) attributable to common shareholders/unitholders, Diluted									$ 0.00	$ 0.23	$ (0.06)
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Dividends Payable, Amount	28,871,000				25,584,000				28,871,000	25,584,000
Percentage of Preferential return									6.90%	6.90%
Weighted-average shares/units outstanding, Basic									167,942,246	154,929,545	145,883,217
Weighted-average shares/units outstanding, Diluted									167,942,246	156,203,398	145,883,217
Maximum [Member]
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Fees and Commissions									$ 0.02