Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1,	$ (15,918)
Change during year	12,789	(7,338)	(4,499)
Settlement of interest rate swaps	0	(2,985)	0
Reclassification of realized (gains)/losses on derivative financial instruments to operations, net	286	297	153
Balance at December 31,	(2,995)	(15,918)
Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1,	(15,918)	(6,079)	(1,945)
Change during year	12,789	(7,338)	(4,499)
Non-controlling interest- consolidated real estate venture partner's share of unrealized (gains)/losses on derivative financial instruments	(152)	187	212
Settlement of interest rate swaps		(2,985)
Reclassification of realized (gains)/losses on derivative financial instruments to operations, net	286	297	153
Balance at December 31,	(2,995)	(15,918)	(6,079)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1,	(16,452)
Change during year	12,789	(7,338)	(4,499)
Settlement of interest rate swaps	0	(2,985)	0
Reclassification of realized (gains)/losses on derivative financial instruments to operations, net	286	297	153
Balance at December 31,	(3,377)	(16,452)
BRANDYWINE OPERATING PARTNERSHIP, L.P. | Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Accumulated other comprehensive income (loss) [Line Items]
Balance at January 1,	(16,452)	(6,426)	(2,080)
Change during year	12,789	(7,338)	(4,499)
Settlement of interest rate swaps		(2,985)
Reclassification of realized (gains)/losses on derivative financial instruments to operations, net	286	297	153
Balance at December 31,	$ (3,377)	$ (16,452)	$ (6,426)