Consolidated Balance Sheets (USD $) In Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Real estate investments:
Rental properties	$ 4,885,041	$ 4,834,111
Accumulated depreciation	(835,713)	(776,078)
Operating real estate investments, net	4,049,328	4,058,033
Construction-in-progress	33,314	33,322
Land inventory	120,245	110,055
Total real estate investments, net	4,202,887	4,201,410
Cash and cash equivalents	733	16,565
Accounts receivable, net	14,129	16,009
Accrued rent receivable, net	103,221	95,541
Investment in real estate ventures, at equity	82,927	84,372
Deferred costs, net	113,498	106,117
Intangible assets, net	78,401	97,462
Notes receivable	19,285	18,205
Other assets	53,414	54,697
Total assets	4,668,495	4,690,378
LIABILITIES AND BENEFICIARIES' EQUITY
Mortgage notes payable	588,823	711,789
Unsecured credit facility	42,000	183,000
Unsecured term loan	183,000	183,000
Unsecured senior notes, net of discounts	1,652,198	1,352,657
Accounts payable and accrued expenses	63,263	72,235
Distributions payable	22,854	22,623
Deferred income, gains and rent	112,814	121,552
Acquired below market leases, net	25,556	29,233
Other liabilities	41,943	36,515
Total liabilities	2,732,451	2,712,604
Commitments and contingencies (Note 17)
Brandywine Realty Trust's equity:
Common Shares of Brandywine Realty Trust's beneficial interest, $0.01 par value; shares authorized 200,000,000; 135,536,709 and 134,601,796 issued in 2011 and 2010, respectively and 135,536,709 and 134,485,117 outstanding in 2011 and 2010, respectively	1,353	1,343
Additional paid-in capital	2,684,730	2,671,217
Deferred compensation payable in common stock	5,737	5,774
Common shares in treasury, at cost, 116,679 in 2010	0	(3,074)
Common shares in grantor trust, 295,852 in 2011 and 291,281 in 2010	(5,737)	(5,774)
Cumulative earnings	475,327	483,439
Accumulated other comprehensive loss	(2,474)	(1,945)
Cumulative distributions	(1,346,353)	(1,301,521)
Total Brandywine Realty Trust's equity	1,812,626	1,849,502
Non-controlling interests	123,418	128,272
Total equity	1,936,044	1,977,774
Total liabilities and equity	4,668,495	4,690,378
BRANDYWINE OPERATING PARTNERSHIP, L.P. | 7.50% Series D Preferred Shares
Brandywine Realty Trust's equity:
Preferred Shares	47,912	47,912
7.50% Series C Preferred Shares
Brandywine Realty Trust's equity:
Preferred Shares	20	20
7.375% Series D Preferred Shares
Brandywine Realty Trust's equity:
Preferred Shares	23	23
BRANDYWINE OPERATING PARTNERSHIP, L.P. | 7.375% Series E Preferred Shares
Brandywine Realty Trust's equity:
Preferred Shares	55,538	55,538
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Real estate investments:
Rental properties	4,885,041	4,834,111
Accumulated depreciation	(835,713)	(776,078)
Operating real estate investments, net	4,049,328	4,058,033
Construction-in-progress	33,314	33,322
Land inventory	120,245	110,055
Total real estate investments, net	4,202,887	4,201,410
Cash and cash equivalents	733	16,565
Accounts receivable, net	14,129	16,009
Accrued rent receivable, net	103,221	95,541
Investment in real estate ventures, at equity	82,927	84,372
Deferred costs, net	113,498	106,117
Intangible assets, net	78,401	97,462
Notes receivable	19,285	18,205
Other assets	53,414	54,697
Total assets	4,668,495	4,690,378
LIABILITIES AND BENEFICIARIES' EQUITY
Mortgage notes payable	588,823	711,789
Unsecured credit facility	42,000	183,000
Unsecured term loan	183,000	183,000
Unsecured senior notes, net of discounts	1,652,198	1,352,657
Accounts payable and accrued expenses	63,263	72,235
Distributions payable	22,854	22,623
Deferred income, gains and rent	112,814	121,552
Acquired below market leases, net	25,556	29,233
Other liabilities	41,943	36,515
Total liabilities	2,732,451	2,712,604
Commitments and contingencies (Note 17)
Redeemable limited partnership units
Redeemable limited partnership units at redemption value; 9,809,759 and 9,902,752 issued and outstanding in 2011 and 2010, respectively	128,616	132,855
Brandywine Realty Trust's equity:
General Partnership Capital, 135,536,709 and 134,601,796 units issued in 2011 and 2010, respectively and 135,536,709 and 134,485,117 units outstanding in 2011 and 2010, respectively	1,706,599	1,743,549
Accumulated other comprehensive loss	(2,621)	(2,080)
Total Brandywine Realty Trust's equity	1,807,428	1,844,919
Total liabilities and equity	$ 4,668,495	$ 4,690,378