Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Real estate investments:
Operating properties	$ 4,701,289	$ 4,669,289
Accumulated depreciation	(1,019,306)	(983,808)
Operating real estate investments, net	3,681,983	3,685,481
Construction-in-progress	90,140	74,174
Land inventory	96,427	93,351
Total real estate investments, net	3,868,550	3,853,006
Cash and cash equivalents	236,291	263,207
Accounts receivable, net	23,123	17,389
Accrued rent receivable, net	128,331	126,295
Investment in real estate ventures, at equity	180,237	180,512
Deferred costs, net	123,216	122,954
Intangible assets, net	125,162	132,329
Other assets	75,138	69,403
Total assets	4,760,048	4,765,095
LIABILITIES AND BENEFICIARIES’ EQUITY
Mortgage notes payable	666,305	670,151
Unsecured term loans	450,000	450,000
Unsecured senior notes, net of discounts	1,475,501	1,475,230
Accounts payable and accrued expenses	106,963	83,693
Distributions payable	25,604	25,584
Deferred income, gains and rent	72,937	71,635
Acquired lease intangibles, net	32,229	34,444
Other liabilities	35,357	32,923
Total liabilities	2,864,896	2,843,660
Commitments and contingencies (Note 16)
Equity:
6.90% Series E Preferred Shares/Units, $0.01 par value; issued and outstanding- 4,000,000 in 2014 and 2013	40	40
Common Shares of Brandywine Realty Trust’s beneficial interest, $0.01 par value; shares authorized 200,000,000; 156,916,901 and 156,731,993 issued and outstanding in 2014 and 2013, respectively	1,567	1,566
Additional paid-in capital	2,974,094	2,971,596
Deferred compensation payable in common shares	6,267	5,407
Common shares in grantor trust, 384,571 in 2014 and 312,279 in 2013	(6,267)	(5,407)
Cumulative earnings	520,322	522,528
Accumulated other comprehensive loss	(3,905)	(2,995)
Cumulative distributions	1,617,878	1,592,515
Total equity, excluding non-controlling interest	1,874,240	1,900,220
Non-controlling interests	20,912	21,215
Total beneficiaries' equity	1,895,152	1,921,435
Total liabilities and beneficiaries' equity	4,760,048	4,765,095
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Real estate investments:
Operating properties	4,701,289	4,669,289
Accumulated depreciation	(1,019,306)	(983,808)
Operating real estate investments, net	3,681,983	3,685,481
Construction-in-progress	90,140	74,174
Land inventory	96,427	93,351
Total real estate investments, net	3,868,550	3,853,006
Cash and cash equivalents	236,291	263,207
Accounts receivable, net	23,123	17,389
Accrued rent receivable, net	128,331	126,295
Investment in real estate ventures, at equity	180,237	180,512
Deferred costs, net	123,216	122,954
Intangible assets, net	125,162	132,329
Other assets	75,138	69,403
Total assets	4,760,048	4,765,095
LIABILITIES AND BENEFICIARIES’ EQUITY
Mortgage notes payable	666,305	670,151
Unsecured term loans	450,000	450,000
Unsecured senior notes, net of discounts	1,475,501	1,475,230
Accounts payable and accrued expenses	106,963	83,693
Distributions payable	25,604	25,584
Deferred income, gains and rent	72,937	71,635
Acquired lease intangibles, net	32,229	34,444
Other liabilities	35,357	32,923
Total liabilities	2,864,896	2,843,660
Commitments and contingencies (Note 16)
Redeemable limited partnership units at redemption value;
Redeemable limited partnership units at redemption value; 1,763,739 issued and outstanding in 2014 and 2013, respectively	26,691	26,486
Equity:
6.90% Series E Preferred Shares/Units, $0.01 par value; issued and outstanding- 4,000,000 in 2014 and 2013	96,850	96,850
General Partnership Capital, 156,916,901 and 156,731,993 units issued and outstanding in 2014 and 2013, respectively	1,774,950	1,800,530
Accumulated other comprehensive loss	(4,297)	(3,377)
Total equity, excluding non-controlling interest	1,867,503	1,894,003
Non-controlling interests	958	946
Total beneficiaries' equity	1,868,461	1,894,949
Total liabilities and beneficiaries' equity	4,760,048	4,765,095
Series E Preferred Stock [Member]
Equity:
Total beneficiaries' equity	$ 40	$ 40