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						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
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(105)			(91)			(351)	(331)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	$ (105)			$ (91)			$ (351)	$ (331)
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 Partnership Unit:
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
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Net income	$ 13,478	$ 4,651	$ 6,101	$ 974	$ (175)	$ 6,964	$ 24,230	$ 7,763
Net loss attributable to noncontrolling interests	1			2			5	4
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 (loss) attributable to common unitholders, Basic	13,374			885			23,884	7,436
Net income (loss) attributable to common unitholders, Diluted	$ 13,374			$ 885			$ 23,884	$ 7,436
Denominator
Weighted average units outstanding, basic (in shares)	172,086,274			171,731,001			172,019,701	171,710,387
Contingent securities/Share based compensation (in shares)	582,449			1,330,176			970,217	1,283,365
Weighted average units outstanding, diluted (in shares)	172,668,723			173,061,177			172,989,918	172,993,752
Earnings per Common Partnership Unit:
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