PARTNERS' EQUITY OF THE PARENT COMPANY - Narrative (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Dec. 06, 2022 USD ($) $ / shares	Dec. 31, 2022 class_of_units $ / shares shares	Dec. 31, 2021 $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Earnings Per Common Partnership Unit [Line Items]
Number of classes of partnership units | class_of_units		2
Amount of dividend declared | $	$ 32,800
Repurchased and retired (in shares)		0	0	6,248,483	1,337,169
Share price (in usd per share) | $ / shares				$ 9.60	$ 12.92
Repurchased and retired, value | $				$ 59,999	$ 17,300
Common stock, par or stated value per share (in usd per share) | $ / shares		$ 0.01	$ 0.01
Commerce Square
Earnings Per Common Partnership Unit [Line Items]
Percent of noncontrolling interest acquired			1.00%
Shelf Registration
Earnings Per Common Partnership Unit [Line Items]
Number of shares issued (in shares)			226,695
Dividend Declared
Earnings Per Common Partnership Unit [Line Items]
Dividends payable (in dollars per share) | $ / shares	$ 0.19
Class A Units
Earnings Per Common Partnership Unit [Line Items]
Redeemable limited partnership unit price (in dollars per share) | $ / shares		$ 6.15	$ 13.42	$ 11.91
Limited partners' capital account, units outstanding (in units)		516,467	823,983	981,634
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Earnings Per Common Partnership Unit [Line Items]
Preferred units, outstanding (in units)		0	0
Repurchase program, number of mirror unit of operating partnership retired for each common share repurchased		1