Partners Equity of the Operating Partnership (Textual) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 13, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Class of Stock [Line Items]
Dividends, Common Stock	$ 28,300
Preferred Stock, Dividend Rate, Percentage				6.90%		6.90%
Dividends, Preferred Stock		$ 1,725	$ 1,725	$ 5,175	$ 5,175
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Dividends, Common Stock	$ 28,300
Preferred Stock, Dividend Rate, Percentage				6.90%		6.90%
Dividends, Preferred Stock		$ 1,725	$ 1,725	$ 5,175	$ 5,175
Dividend Declared [Member]
Class of Stock [Line Items]
Dividends Payable, Amount Per Share	$ 0.16
Dividend Declared [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Dividends Payable, Amount Per Share	$ 0.16
6.90% Series E-linked Preferred Units [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage				6.90%
Preferred Stock, Liquidation Preference Per Share		$ 25.00		$ 25.00
Dividends, Preferred Stock	$ 1,700