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				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Numerator
Net loss	$ 30,267	$ (16,414)	$ (12,737)	$ (5,276)	$ 13,853	$ (18,013)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(277)		(204)		(613)	(274)
Nonforfeitable dividends allocated to unvested restricted unitholders, Diluted	$ (277)		$ (204)		$ (613)	$ (274)
Denominator
Weighted average units outstanding, basic (in shares)	172,563,136		171,962,162		172,385,087	171,818,463
Contingent securities/Share based compensation (in shares)	2,132,515		0		1,957,064	0
Weighted average shares outstanding, diluted (in shares)	174,695,651		171,962,162		174,342,151	171,818,463
Earnings (loss) per Common Partnership Unit:
Net income (loss) attributable to common shareholders, basic (in dollars per share)	$ 0.17		$ (0.08)		$ 0.08	$ (0.11)
Net income (loss) attributable to common shareholders, diluted (in dollars per share)	$ 0.17		$ (0.08)		$ 0.08	$ (0.11)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Net loss	$ 30,267	$ (16,414)	$ (12,737)	$ (5,276)	$ 13,853	$ (18,013)
Net income attributable to noncontrolling interests	(3)		0		(6)	1
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(277)		(204)		(613)	(274)
Nonforfeitable dividends allocated to unvested restricted unitholders, Diluted	(277)		(204)		(613)	(274)
Net income (loss) attributable to common unitholders, basic	29,987		(12,941)		13,234	(18,286)
Net income (loss) attributable to common unitholders, diluted	$ 29,987		$ (12,941)		$ 13,234	$ (18,286)
Denominator
Weighted average units outstanding, basic (in shares)	173,078,731		172,478,629		172,900,681	172,334,930
Contingent securities/Share based compensation (in shares)					1,957,064	0
Weighted average shares outstanding, diluted (in shares)	175,211,246		172,478,629		174,857,745	172,334,930
Earnings (loss) per Common Partnership Unit:
Net income (loss) attributable to common shareholders, basic (in dollars per share)	$ 0.17		$ (0.08)		$ 0.08	$ (0.11)
Net income (loss) attributable to common shareholders, diluted (in dollars per share)	$ 0.17		$ (0.08)		$ 0.08	$ (0.11)