Partners Equity of the Operating Partnership (Textual) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	12 Months Ended
	Mar. 09, 2016	Mar. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Distributions payable		$ 28,295	$ 28,249
Preferred Stock, Dividend Rate, Percentage		6.90%	6.90%
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Distributions payable		$ 28,295	$ 28,249
Preferred Stock, Dividend Rate, Percentage		6.90%	6.90%
Dividend Declared [Member]
Class of Stock [Line Items]
Dividends Payable, Amount Per Share	$ 0.15
Dividend Declared [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Dividends Payable, Amount Per Share	$ 0.15
Dividend Paid [Member]
Class of Stock [Line Items]
Distributions payable		$ 26,600
Dividend Paid [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Distributions payable		$ 26,600
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
6.90% Series E-linked Preferred Units [Member] | Dividend Paid [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Class of Stock [Line Items]
Dividends, Preferred Stock, Cash	$ 1,700