Consolidated Statements of Cash Flows (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Supplemental disclosure:
Capitalized interest	$ 1,997,000	$ 10,385,000	$ 8,893,000
Deferred gain debt			12,900,000
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Supplemental disclosure:
Capitalized interest	1,997,000	10,385,000	8,893,000
Deferred gain debt			$ 12,900,000