Partners Equity of the Operating Partnership (Textual) (Details) $ / shares in Units, $ in Millions	Feb. 28, 2018 USD ($) $ / shares
Earnings Per Common Partnership Unit [Line Items]
Dividends, Common Stock | $	$ 32.5
Dividends payable, date to be paid	Apr. 18, 2018
Dividends payable, date of record	Apr. 04, 2018
Dividend Declared [Member]
Earnings Per Common Partnership Unit [Line Items]
Dividends Payable, Amount Per Share | $ / shares	$ 0.18
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Earnings Per Common Partnership Unit [Line Items]
Dividends, Common Stock | $	$ 32.5
Dividends payable, date to be paid	Apr. 18, 2018
Dividends payable, date of record	Apr. 04, 2018
BRANDYWINE OPERATING PARTNERSHIP, L.P. | Dividend Declared [Member]
Earnings Per Common Partnership Unit [Line Items]
Dividends Payable, Amount Per Share | $ / shares	$ 0.18