Consolidated Statements of Partners' Equity - USD ($) $ in Thousands	Total	BRANDYWINE OPERATING PARTNERSHIP, L.P.	General Partner Capital [Member] BRANDYWINE OPERATING PARTNERSHIP, L.P.	Series E-linked Preferred Stock [Member] BRANDYWINE OPERATING PARTNERSHIP, L.P.	Accumulated Other Comprehensive Loss [Member]	Accumulated Other Comprehensive Loss [Member] BRANDYWINE OPERATING PARTNERSHIP, L.P.	Noncontrolling Interest [Member]	Noncontrolling Interest [Member] BRANDYWINE OPERATING PARTNERSHIP, L.P.
Beginning Balance at Dec. 31, 2014		$ 2,134,755	$ 2,041,902	$ 96,850		$ (5,007)		$ 1,010
Beginning Balance, Shares at Dec. 31, 2014			179,293,160	4,000,000
Net income	$ 31,960	31,960	$ 31,964				$ 221	(4)
Other comprehensive loss	(3,917)	(3,917)			$ (3,883)	(3,917)	(34)
Share Issuance from/(to) Deferred Compensation Plan	(2)	(2)	$ (2)
Share Issuance from/to Deferred Compensation Plan, Shares			86,723
Issuance of partnership interest in consolidated real estate venture		1,025						1,025
Repurchase and retirement of LP Units		(60,817)	$ (60,817)
Repurchase and retirement of LP units, Shares			(4,701,302)
Bonus share issuance	125
Bonus share issuance, Shares			8,447
Equity issuance costs	(100)	(100)	$ (100)
Share-based compensation activity	4,043	4,042	$ 4,042
Share-based compensation activity, Shares			509,675
Adjustment of redeemable partnership units to liquidation value at period end		1,634	$ 1,634
Distribution to preferred shareholders	(5,175)	(5,175)	(5,175)
Distributions to general partnership unitholders		(80,620)	(80,620)
Ending Balance at Sep. 30, 2015		2,022,910	$ 1,932,953	$ 96,850		(8,924)		2,031
Ending Balance, Shares at Sep. 30, 2015			175,196,703	4,000,000
Beginning Balance at Dec. 31, 2015		1,929,977	$ 1,836,692	$ 96,850		(5,597)		2,032
Beginning Balance, Shares at Dec. 31, 2015			174,688,568	4,000,000
Net income	52,871	52,871	$ 52,859				425	12
Other comprehensive loss	(9,946)	(9,946)			$ (9,860)	(9,946)	(86)
Share Issuance from/(to) Deferred Compensation Plan	(47)	(47)	$ (47)
Share Issuance from/to Deferred Compensation Plan, Shares			(8,311)
Issuance of partnership interest in consolidated real estate venture	73	73					73	73
Conversion of LP Units to Common Shares	0	875	$ 875				$ (875)
Conversion of LP Units to Common Shares, Shares			55,303
Share-based compensation activity	4,934	4,929	$ 4,929
Share-based compensation activity, Shares			405,200
Adjustment of redeemable partnership units to liquidation value at period end		(1,935)	$ (1,935)
Redemption value of limited partnership units		(875)	(875)
Distribution to preferred shareholders	$ (5,175)	(5,175)	(5,175)
Distributions to general partnership unitholders		(82,524)	(82,524)
Ending Balance at Sep. 30, 2016		$ 1,888,223	$ 1,804,799	$ 96,850		$ (15,543)		$ 2,117
Ending Balance, Shares at Sep. 30, 2016			175,140,760	4,000,000