Partners Equity of the Operating Partnership (Textual) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
Feb. 21, 2019	Mar. 31, 2019
Earnings Per Common Partnership Unit [Line Items]
Dividends, Common Stock	$ 33,700
Dividends payable, date to be paid	Apr. 18, 2019
Dividends payable, date of record	Apr. 04, 2019
Repurchased and Retired, Shares		1,337,169
Share Price		$ 12.92
Repurchased and Retired, Value		$ 17,281
Dividend Declared [Member]
Earnings Per Common Partnership Unit [Line Items]
Dividends Payable, Amount Per Share	$ 0.19
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Earnings Per Common Partnership Unit [Line Items]
Dividends, Common Stock	$ 33,700
Dividends payable, date to be paid	Apr. 18, 2019
Dividends payable, date of record	Apr. 04, 2019
Repurchase program, number of mirror unit of operating partnership retired for each common share repurchased		1
BRANDYWINE OPERATING PARTNERSHIP, L.P. \| Dividend Declared [Member]
Earnings Per Common Partnership Unit [Line Items]
Dividends Payable, Amount Per Share	$ 0.19

Earnings per common partnership unit line items.

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Repurchase program number of mirror unit of operating partnership retired for each common share repurchased.

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Date the declared dividend will be paid, in CCYY-MM-DD format.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

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The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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Number of shares that have been repurchased and retired during the period.

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Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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