PARTNERS' EQUITY OF THE PARENT COMPANY- 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, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator
Net income (loss)	$ 4,651	$ 6,101	$ (175)	$ 6,964	$ 10,752	$ 6,789
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(98)		(94)		(246)	(240)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	$ (98)		$ (94)		$ (246)	$ (240)
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 Partnership Unit:
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
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Net income (loss)	$ 4,651	$ 6,101	$ (175)	$ 6,964	$ 10,752	$ 6,789
Net loss attributable to noncontrolling interests	2		1		4	2
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 unitholders, Basic	4,555		(268)		10,510	6,551
Net income (loss) attributable to common unitholders, Diluted	$ 4,555		$ (268)		$ 10,510	$ 6,551
Denominator
Weighted average units outstanding, basic (in shares)	172,043,498		171,792,415		171,985,863	171,699,909
Contingent securities/Share based compensation (in shares)	733,398		0		1,163,777	1,258,682
Weighted average units outstanding, diluted (in shares)	172,776,896		171,792,415		173,149,640	172,958,591
Earnings per Common Partnership Unit:
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