Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Real estate investments:
Operating properties	$ 4,669,289	$ 4,726,169
Accumulated depreciation	(983,808)	(954,665)
Operating real estate investments, net	3,685,481	3,771,504
Construction-in-progress	74,174	48,950
Land inventory	93,351	102,439
Total real estate investments, net	3,853,006	3,922,893
Cash and cash equivalents	263,207	1,549
Accounts receivable, net	17,389	13,232
Accrued rent receivable, net	126,295	122,066
Investment in real estate ventures, at equity	180,512	193,555
Deferred costs, net	122,954	122,243
Intangible assets, net	132,329	70,620
Notes receivable	7,026	7,226
Other Assets	62,377	53,325
Total assets	4,765,095	4,506,709
LIABILITIES AND BENEFICIARIES' EQUITY
Mortgage notes payable	670,151	442,974
Unsecured credit facility	0	69,000
Unsecured term loans	450,000	450,000
Unsecured senior notes, net of discounts	1,475,230	1,503,356
Accounts payable and accrued expenses	83,693	71,579
Distributions payable	25,584	23,652
Deferred income, gains and rent	71,635	82,947
Acquired lease intangibles, net	34,444	33,859
Other liabilities	32,923	55,826
Total liabilities	2,843,660	2,733,193
Commitments and contingencies (Note 20)
Brandywine Realty Trust's equity:
6.90% Series E Preferred Shares/Units; issued and outstanding- 4,000,000 in 2013 and 2012	40	40
Common Shares of Brandywine Realty Trust’s beneficial interest, $0.01 par value; shares authorized 200,000,000; 156,731,993 and 143,538,733 issued and outstanding in 2013 and 2012, respectively	1,566	1,434
Additional paid-in capital	2,971,596	2,780,194
Deferred compensation payable in common shares	5,407	5,352
Common shares in grantor trust, 312,280 in 2013 and 290,745 in 2012	(5,407)	(5,352)
Cumulative earnings	522,528	479,734
Accumulated other comprehensive loss	(2,995)	(15,918)
Cumulative distributions	(1,592,515)	(1,493,206)
Total equity, excluding non-controlling interests	1,900,220	1,752,278
Non-controlling interests	21,215	21,238
Total equity	1,921,435	1,773,516
Total liabilities and equity	4,765,095	4,506,709
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Real estate investments:
Operating properties	4,669,289	4,726,169
Accumulated depreciation	(983,808)	(954,665)
Operating real estate investments, net	3,685,481	3,771,504
Construction-in-progress	74,174	48,950
Land inventory	93,351	102,439
Total real estate investments, net	3,853,006	3,922,893
Cash and cash equivalents	263,207	1,549
Accounts receivable, net	17,389	13,232
Accrued rent receivable, net	126,295	122,066
Investment in real estate ventures, at equity	180,512	193,555
Deferred costs, net	122,954	122,243
Intangible assets, net	132,329	70,620
Notes receivable	7,026	7,226
Other Assets	62,377	53,325
Total assets	4,765,095	4,506,709
LIABILITIES AND BENEFICIARIES' EQUITY
Mortgage notes payable	670,151	442,974
Unsecured credit facility	0	69,000
Unsecured term loans	450,000	450,000
Unsecured senior notes, net of discounts	1,475,230	1,503,356
Accounts payable and accrued expenses	83,693	71,579
Distributions payable	25,584	23,652
Deferred income, gains and rent	71,635	82,947
Acquired lease intangibles, net	34,444	33,859
Other liabilities	32,923	55,826
Total liabilities	2,843,660	2,733,193
Commitments and contingencies (Note 20)
Redeemable limited partnership units at redemption value;
Redeemable limited partnership units at redemption value; 1,763,739 and 1,845,737 issued and outstanding in 2013 and 2012, respectively	26,486	26,777
Brandywine Realty Trust's equity:
6.90% Series E Preferred Shares/Units; issued and outstanding- 4,000,000 in 2013 and 2012	96,850	96,850
General Partnership Capital, 156,731,993 and 143,538,733 units issued and outstanding in 2013 and 2012, respectively	1,800,530	1,666,341
Accumulated other comprehensive loss	(3,377)	(16,452)
Total equity, excluding non-controlling interests	1,894,003	1,746,739
Non-controlling interests	946	0
Total equity	1,894,949	1,746,739
Total liabilities and equity	4,765,095	4,506,709
7.375% Series D Preferred Shares | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Brandywine Realty Trust's equity:
Total equity	0	0
6.90% Series E Preferred Stock [Member]
Brandywine Realty Trust's equity:
Total equity	40	40
6.90% Series E Preferred Stock [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Brandywine Realty Trust's equity:
Total equity	0	0
Series E-linked Preferred Stock [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Brandywine Realty Trust's equity:
6.90% Series E Preferred Shares/Units; issued and outstanding- 4,000,000 in 2013 and 2012		96,850
Total equity	96,850	96,850
Noncontrolling Interest [Member]
Brandywine Realty Trust's equity:
Total equity	21,215	21,238
Noncontrolling Interest [Member] | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Brandywine Realty Trust's equity:
Total equity	$ 946	$ 0