BENEFICIARIES' EQUITY OF THE PARENT COMPANY - Schedule of Number of Shares and Net Income Used to Calculate Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator
Net income	$ 13,478	$ 4,651	$ 6,101	$ 974	$ (175)	$ 6,964	$ 24,230	$ 7,763
Net (income) loss attributable to noncontrolling interests, Basic	(37)			(7)			(59)	(42)
Net (income) loss attributable to noncontrolling interests, Diluted	(37)			(7)			(59)	(42)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(105)			(91)			(351)	(331)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(105)			(91)			(351)	(331)
Net income attributable to Common Partnership Unitholders of Brandywine Operating Partnership, L.P.	13,336			876			23,820	7,390
Net income (loss) attributable to common shareholders, diluted	$ 13,336			$ 876			$ 23,820	$ 7,390
Denominator
Weighted average units outstanding, basic (in shares)	171,569,807			170,907,018			171,464,936	170,794,585
Contingent securities/Share based compensation (in shares)	582,449			1,330,176			970,217	1,283,365
Weighted average units outstanding, diluted (in shares)	172,152,256			172,237,194			172,435,153	172,077,950
Earnings per Common Share:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.08			$ 0.01			$ 0.14	$ 0.04
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.08			$ 0.01			$ 0.14	$ 0.04