CONSOLIDATED STATEMENTS OF PARTNERS’ EQUITY - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest - Consolidated Real Estate Ventures	BRANDYWINE OPERATING PARTNERSHIP, L.P.	BRANDYWINE OPERATING PARTNERSHIP, L.P. Cumulative Effect, Period of Adoption, Adjustment	BRANDYWINE OPERATING PARTNERSHIP, L.P. Accumulated Other Comprehensive Income (Loss)	BRANDYWINE OPERATING PARTNERSHIP, L.P. Noncontrolling Interest - Consolidated Real Estate Ventures	BRANDYWINE OPERATING PARTNERSHIP, L.P. General Partner Capital	BRANDYWINE OPERATING PARTNERSHIP, L.P. General Partner Capital Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2018								176,873,324
Partners' Equity, beginning balance at Dec. 31, 2018				$ 1,798,508	$ (5,336)	$ 4,725	$ 2,192	$ 1,791,591	$ (5,336)
Net income	$ 34,529		$ 262	34,529			69	$ 34,460
Other comprehensive loss	(7,440)	$ (7,399)	(41)	(7,440)		(7,440)
Deferred compensation obligation (in shares)								97,485
Deferred compensation obligation	0
Conversion of LP Units to common shares (in shares)								1,245
Conversion of LP Units to common shares				16				$ 16
Repurchase and retirement of LP units (in shares)								(1,337,169)
Repurchase and retirement of LP units				(17,297)				$ (17,297)
Issuance of partnership interest in consolidated real estate venture	27		27	27			27
Share-based compensation activity (in shares)								845,210
Share-based compensation activity	10,027			10,027				$ 10,027
Purchase of partnership interest in consolidated real estate venture	(2,180)		(1,197)				(1,197)	(983)
Adjustment of redeemable partnership units to liquidation value at period end				(3,615)				(3,615)
Distributions declared to general partnership unitholders				(134,324)				$ (134,324)
Ending balance (in shares) at Dec. 31, 2019								176,480,095
Partners' Equity, ending balance at Dec. 31, 2019				1,672,915		(2,715)	1,091	$ 1,674,539
Net income	307,326		1,799	307,326			20	$ 307,306
Other comprehensive loss	(5,220)	(5,191)	(29)	(5,220)		(5,220)
Deferred compensation obligation (in shares)								32,256
Deferred compensation obligation	(206)			(206)				$ (206)
Repurchase and retirement of LP units (in shares)								(6,248,483)
Repurchase and retirement of LP units				(59,999)				$ (59,999)
Distributions from consolidated real estate venture	(22)		(22)	(22)			(22)
Share-based compensation activity (in shares)								309,096
Share-based compensation activity	6,236			6,236				$ 6,236
Sale of partnership interest to consolidated real estate venture	(1,017)		(1,017)
Adjustment of redeemable partnership units to liquidation value at period end				3,074				3,074
Distributions declared to general partnership unitholders				(130,005)				$ (130,005)
Ending balance (in shares) at Dec. 31, 2020								170,572,964
Partners' Equity, ending balance at Dec. 31, 2020				1,793,082		(7,935)	72	$ 1,800,945
Net income	12,366		77	12,366			(3)	$ 12,369
Other comprehensive loss	5,569	$ 5,541	28	5,569		5,569
Deferred compensation obligation (in shares)								(18,058)
Deferred compensation obligation	(198)			(198)				$ (198)
Units issued to acquire noncontrolling interest (in units)								226,695
Partners' Capital Account, Acquisitions				3,052				$ 3,052
Repurchase and retirement of LP units				(2,334)				$ (2,334)
Issuance of partnership interest in consolidated real estate venture	2,765		$ 2,765	2,765			2,765
Share-based compensation activity (in shares)								344,656
Share-based compensation activity	$ 6,354			6,354				$ 6,354
Adjustment of redeemable partnership units to liquidation value at period end				(232)				(232)
Distributions declared to general partnership unitholders				(130,345)				$ (130,345)
Ending balance (in shares) at Dec. 31, 2021								171,126,257
Partners' Equity, ending balance at Dec. 31, 2021				$ 1,690,079		$ (2,366)	$ 2,834	$ 1,689,611