BENEFICIARIES' EQUITY OF THE PARENT COMPANY - 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				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator
Net income	$ 4,651	$ 6,101	$ (175)	$ 6,964	$ 10,752	$ 6,789
Net (income) loss attributable to noncontrolling interests, Basic	(14)		8		(22)	(35)
Net (income) loss attributable to noncontrolling interests, Diluted	(14)		8		(22)	(35)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(98)		(94)		(246)	(240)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(98)		(94)		(246)	(240)
Net income (loss) attributable to Common Partnership Unitholders of Brandywine Operating Partnership, L.P.	4,539		(261)		10,484	6,514
Net income (loss) attributable to common shareholders, diluted	$ 4,539		$ (261)		$ 10,484	$ 6,514
Denominator
Weighted average units outstanding, basic (in shares)	171,527,031		170,848,894		171,411,631	170,737,437
Contingent securities/Share based compensation (in shares)	733,398		0		1,163,777	1,258,682
Weighted average units outstanding, diluted (in shares)	172,260,429		170,848,894		172,575,408	171,996,119
Earnings per Common Share:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.03		$ 0		$ 0.06	$ 0.04
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.03		$ 0		$ 0.06	$ 0.04