Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Preferred Stock, Value, Issued	$ 40	$ 40
Brandywine Realty Trust's equity:
Preferred shares, shares authorized	20,000,000	20,000,000
Preferred shares, dividend rate (as a percent)	6.90%
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred shares, shares issued	4,000,000	4,000,000
Preferred shares, shares outstanding	4,000,000	4,000,000
Common shares in grantor trust	$ 0.01	$ 0.01
Common shares of Brandywine Realty Trust's beneficial interest, shares authorized	200,000,000	200,000,000
Common shares of Brandywine Realty Trust's beneficial interest, shares issued	156,703,790	143,538,733
Common shares of Brandywine Realty Trust's beneficial interest, shares outstanding	156,703,790	143,538,733
Common shares in grantor trust	313,023	290,745
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Preferred Stock, Value, Issued	$ 96,850	$ 96,850
Brandywine Realty Trust's equity:
Preferred shares, dividend rate (as a percent)	6.90%
Preferred shares, shares issued	4,000,000	4,000,000
Preferred shares, shares outstanding	4,000,000	4,000,000
Redeemable Limited Partnership, units issued	1,763,739	1,845,737
Redeemable Limited Partnership, units outstanding	1,763,739	1,845,737
General Partners' Capital account, units issued	156,703,790	143,538,733
General Partners' Capital account, units outstanding	156,703,790	143,538,733