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, 2025	Mar. 31, 2024
Numerator
Net loss	$ (27,056)	$ (16,414)
Basic
Nonforfeitable dividends allocated to unvested restricted shareholders	(429)	(336)
Diluted
Nonforfeitable dividends allocated to unvested restricted unitholders, Diluted	$ (429)	$ (336)
Denominator
Weighted average units outstanding, basic (in shares)	172,915,482	172,207,037
Weighted average shares outstanding, diluted (in shares)	172,915,482	172,207,037
Loss per Common Partnership Unit:
Net loss attributable to common shareholders, basic (in dollars per share)	$ (0.16)	$ (0.10)
Net loss attributable to common shareholders, diluted (in dollars per share)	$ (0.16)	$ (0.10)
Brandywine Operating Partnership, L.P.
Numerator
Net loss	$ (27,056)	$ (16,414)
Basic
Net income attributable to noncontrolling interests	0	(3)
Nonforfeitable dividends allocated to unvested restricted shareholders	(429)	(336)
Net loss attributable to common unitholders	(27,485)	(16,753)
Diluted
Nonforfeitable dividends allocated to unvested restricted unitholders, Diluted	(429)	(336)
Net loss attributable to common unitholders	$ (27,485)	$ (16,753)
Denominator
Weighted average units outstanding, basic (in shares)	173,431,077	172,722,632
Weighted average shares outstanding, diluted (in shares)	173,431,077	172,722,632
Loss per Common Partnership Unit:
Net loss attributable to common shareholders, basic (in dollars per share)	$ (0.16)	$ (0.10)
Net loss attributable to common shareholders, diluted (in dollars per share)	$ (0.16)	$ (0.10)