Consolidated Statements of Partners' Equity - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	BRANDYWINE OPERATING PARTNERSHIP, L.P.	BRANDYWINE OPERATING PARTNERSHIP, L.P. Accumulated Other Comprehensive Income (Loss)	BRANDYWINE OPERATING PARTNERSHIP, L.P. Noncontrolling Interests	BRANDYWINE OPERATING PARTNERSHIP, L.P. General Partner Capital
Beginning balance (in shares) at Dec. 31, 2019							176,480,095
Beginning Balance at Dec. 31, 2019				$ 1,672,915	$ (2,715)	$ 1,091	$ 1,674,539
Net income	$ 8,087		$ 65	8,087		12	$ 8,075
Other comprehensive income (loss)	(7,869)	$ (7,825)	(44)	(7,869)	(7,869)
Deferred compensation obligation (in shares)							(12,376)
Deferred compensation obligation	(193)			(193)			$ (193)
Repurchase and retirement of LP units (in shares)							(5,644,200)
Repurchase and retirement of LP units				(53,858)			$ (53,858)
Share-based compensation activity (in shares)							142,468
Share-based compensation activity	2,031			2,031			$ 2,031
Adjustment of redeemable partnership units to liquidation value at period end				5,220			5,220
Distributions declared to general partnership unitholders				(32,500)			$ (32,500)
Ending balance (in shares) at Mar. 31, 2020							170,965,987
Ending Balance at Mar. 31, 2020				1,593,833	(10,584)	1,103	$ 1,603,314
Beginning balance (in shares) at Dec. 31, 2020							170,572,964
Beginning Balance at Dec. 31, 2020				1,793,082	(7,935)	72	$ 1,800,945
Net income	6,964		43	6,964		(1)	$ 6,965
Other comprehensive income (loss)	1,098	$ 1,092	$ 6	1,098	1,098
Deferred compensation obligation (in shares)							(18,058)
Deferred compensation obligation	(198)			(198)			$ (198)
Share-based compensation activity (in shares)							108,345
Share-based compensation activity	$ 2,502			2,502			$ 2,502
Adjustment of redeemable partnership units to liquidation value at period end				(1,294)			(1,294)
Distributions declared to general partnership unitholders				(32,573)			$ (32,573)
Ending balance (in shares) at Mar. 31, 2021							170,663,251
Ending Balance at Mar. 31, 2021				$ 1,769,581	$ (6,837)	$ 71	$ 1,776,347