Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1		$ (5,192)
Change during year		2,371	$ (1,010)	$ (1,190)
Settlement of interest rate swaps		0	0	(828)
Reclassification of realized losses on derivative financial instruments to operations, net	[1]	1,104	420	388
Balance at December 31,		(1,745)	(5,192)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1		(5,597)
Change during year		2,371	(1,010)	(1,190)
Settlement of interest rate swaps		0	0	(828)
Reclassification of realized losses on derivative financial instruments to operations, net	[2]	1,104	420	388
Balance at December 31,		(2,122)	(5,597)
Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1		(5,192)	(4,607)	(2,995)
Change during year		2,371	(1,010)	(1,190)
Allocation of unrealized (gains)/losses on derivative financial instruments to non-controlling interests		(28)	5	18
Settlement of interest rate swaps				(828)
Reclassification of realized losses on derivative financial instruments to operations, net		1,104	420	388
Balance at December 31,		(1,745)	(5,192)	(4,607)
Accumulated Other Comprehensive Income (Loss) [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1		(5,597)	(5,007)	(3,377)
Change during year		2,371	(1,010)	(1,190)
Settlement of interest rate swaps				(828)
Reclassification of realized losses on derivative financial instruments to operations, net		1,104	420	388
Balance at December 31,		$ (2,122)	$ (5,597)	$ (5,007)

[1] Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

[2] Amounts reclassified from comprehensive income to interest expense within the Consolidated Statement of Operations.