BENEFICIARIES' EQUITY OF THE PARENT COMPANY - Schedule of Earnings Per Share, Basic and Diluted (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)
Net (income) loss attributable to noncontrolling interests, Basic	(94)		41		(48)	58
Net (income) loss attributable to noncontrolling interests, Diluted	(94)		41		(48)	58
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(277)		(204)		(613)	(274)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(277)		(204)		(613)	(274)
Net income (loss) attributable to Common Shareholders of Brandywine Realty Trust	29,896		(12,900)		13,192	(18,229)
Net income (loss) attributable to common shareholders, diluted	$ 29,896		$ (12,900)		$ 13,192	$ (18,229)
Denominator
Basic weighted average shares outstanding (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 Share:
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)