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, 2018							176,873,324
Beginning Balance at Dec. 31, 2018				$ 1,798,508	$ 4,725	$ 2,192	$ 1,791,591
Net income	$ 4,583		$ 60	4,583		34	$ 4,549
Other comprehensive income (loss)	(2,483)	$ (2,469)	(14)	(2,483)	(2,483)
Share Issuance from/(to) Deferred Compensation Plan (in shares)							458
Share Issuance from/(to) Deferred Compensation Plan	0			0
Partners' Capital Account, Units, Sold in Public Offering							(1,337,169)
Partners Capital Account Repurchased And Retired				(17,281)			$ (17,281)
Issuance of partnership interest in consolidated real estate ventures	22		22	22		22
Share-based compensation activity (in shares)							465,883
Share-based compensation activity	3,677			3,677			$ 3,677
Adjustment of redeemable partnership units to liquidation value at period end				(3,088)			(3,088)
Distributions declared to general partnership unitholders				33,560			$ 33,560
Ending balance (in shares) at Mar. 31, 2019							176,001,580
Ending Balance at Mar. 31, 2019				1,745,042	2,242	2,248	$ 1,740,552
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)
Share Issuance from/(to) Deferred Compensation Plan (in shares)							12,376
Share Issuance from/(to) Deferred Compensation Plan	(193)			(193)			$ (193)
Partners' Capital Account, Units, Sold in Public Offering							(5,644,200)
Partners Capital Account Repurchased And Retired							$ (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