Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Real estate investments:
Operating properties	$ 4,631,910	$ 4,726,169
Accumulated depreciation	(998,409)	(954,665)
Operating real estate investments, net	3,633,501	3,771,504
Construction-in-progress	52,702	48,950
Land inventory	94,097	102,439
Total real estate investments, net	3,780,300	3,922,893
Cash and cash equivalents	185,517	1,549
Accounts receivable, net	13,718	13,232
Accrued rent receivable, net	128,232	122,066
Assets held for sale, net	2,371	0
Investment in real estate ventures, at equity	194,572	193,555
Deferred costs, net	126,260	122,243
Intangible assets, net	54,457	70,620
Notes receivable	7,026	7,226
Other assets	65,689	53,325
Total assets	4,558,142	4,506,709
LIABILITIES AND BENEFICIARIES’ EQUITY
Mortgage notes payable	434,895	442,974
Unsecured credit facility	0	69,000
Unsecured term loans	450,000	450,000
Unsecured senior notes, net of discounts	1,492,296	1,503,356
Accounts payable and accrued expenses	89,087	71,579
Distributions payable	25,579	23,652
Deferred income, gains and rent	69,637	82,947
Acquired lease intangibles, net	28,500	33,859
Other liabilities	46,990	55,826
Total liabilities	2,636,984	2,733,193
Commitments and contingencies (Note 17)
Equity:
6.90% Series E Preferred 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; 156,703,790 and 143,538,733 issued and outstanding in 2013 and 2012, respectively	1,565	1,434
Additional paid-in capital	2,970,576	2,780,194
Deferred compensation payable in common shares	5,431	5,352
Common shares in grantor trust, 313,023 in 2013 and 290,745 in 2012	(5,431)	(5,352)
Cumulative earnings	501,735	479,734
Accumulated other comprehensive loss	(5,825)	(15,918)
Cumulative distributions	1,567,202	1,493,206
Total equity, excluding non-controlling interest	1,900,889	1,752,278
Non-controlling interests	20,269	21,238
Total equity	1,921,158	1,773,516
Total liabilities and equity	4,558,142	4,506,709
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Real estate investments:
Operating properties	4,631,910	4,726,169
Accumulated depreciation	(998,409)	(954,665)
Operating real estate investments, net	3,633,501	3,771,504
Construction-in-progress	52,702	48,950
Land inventory	94,097	102,439
Total real estate investments, net	3,780,300	3,922,893
Cash and cash equivalents	185,517	1,549
Accounts receivable, net	13,718	13,232
Accrued rent receivable, net	128,232	122,066
Assets held for sale, net	2,371	0
Investment in real estate ventures, at equity	194,572	193,555
Deferred costs, net	126,260	122,243
Intangible assets, net	54,457	70,620
Notes receivable	7,026	7,226
Other assets	65,689	53,325
Total assets	4,558,142	4,506,709
LIABILITIES AND BENEFICIARIES’ EQUITY
Mortgage notes payable	434,895	442,974
Unsecured credit facility	0	69,000
Unsecured term loans	450,000	450,000
Unsecured senior notes, net of discounts	1,492,296	1,503,356
Accounts payable and accrued expenses	89,087	71,579
Distributions payable	25,579	23,652
Deferred income, gains and rent	69,637	82,947
Acquired lease intangibles, net	28,500	33,859
Other liabilities	46,990	55,826
Total liabilities	2,636,984	2,733,193
Commitments and contingencies (Note 17)
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	26,290	26,777
Equity:
6.90% Series E Preferred Units; issued and outstanding- 4,000,000 in 2013 and 2012	96,850	96,850
General Partnership Capital, 156,703,790 and 143,538,733 units issued and outstanding in 2013 and 2012, respectively	1,804,378	1,666,341
Accumulated other comprehensive loss	(6,360)	(16,452)
Total equity, excluding non-controlling interest	1,894,868	1,746,739
Total liabilities and equity	4,558,142	4,506,709
Series E Preferred Stock [Member]
Equity:
Total equity	$ 40	$ 40