PARTNERS' EQUITY OF THE PARENT COMPANY - Schedule of Number of Units and Net Income Used to Calculate Basic and Diluted Earnings Per Common Partnership Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator
Net loss	$ (16,414)	$ (5,276)
Nonforfeitable dividends allocated to unvested restricted unitholders, Basic	(336)	(70)
Nonforfeitable dividends allocated to unvested restricted unitholders, Diluted	$ (336)	$ (70)
Denominator
Weighted average units outstanding, basic (in shares)	172,207,037	171,673,167
Weighted average shares outstanding, diluted (in shares)	172,207,037	171,673,167
Loss per Common Partnership Unit:
Net loss attributable to common shareholders, Basic (in dollars per share)	$ (0.10)	$ (0.03)
Net loss attributable to common shareholders, Diluted (in dollars per share)	$ (0.10)	$ (0.03)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Net loss	$ (16,414)	$ (5,276)
Net (income) loss attributable to noncontrolling interests	(3)	1
Nonforfeitable dividends allocated to unvested restricted unitholders, Basic	(336)	(70)
Nonforfeitable dividends allocated to unvested restricted unitholders, Diluted	(336)	(70)
Net loss attributable to common unitholders, Basic	(16,753)	(5,345)
Net loss attributable to common unitholders, Diluted	$ (16,753)	$ (5,345)
Denominator
Weighted average units outstanding, basic (in shares)	172,722,632	172,189,634
Weighted average shares outstanding, diluted (in shares)	172,722,632	172,189,634
Loss per Common Partnership Unit:
Net loss attributable to common shareholders, Basic (in dollars per share)	$ (0.10)	$ (0.03)
Net loss attributable to common shareholders, Diluted (in dollars per share)	$ (0.10)	$ (0.03)