Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue
Total revenue	$ 534,852	$ 580,417	$ 544,345
Operating expenses
Property operating expenses	132,172	154,361	154,848
Real estate taxes	63,032	62,237	51,341
Third party management expenses	10,252	9,248	11,910
Depreciation and amortization	188,283	210,005	176,000
General and administrative expenses	30,288	32,156	27,802
Provision for impairment	0	0	71,707
Total operating expenses	424,027	468,007	493,608
Gain on sale of real estate
Net gain on disposition of real estate	289,461	356	2,932
Net gain on sale of undepreciated real estate	201	2,020	3,040
Total gain on sale of real estate	289,662	2,376	5,972
Operating income	400,487	114,786	56,709
Other income (expense):
Interest income	1,939	2,318	4,703
Interest expense	(73,911)	(81,512)	(78,199)
Interest expense - amortization of deferred financing costs	(2,904)	(2,768)	(2,498)
Equity in loss of Real Estate Ventures	(18,584)	(9,922)	(15,231)
Net gain on real estate venture transactions	75	11,639	142,233
Gain on promoted interest in unconsolidated real estate venture	0	0	28,283
Loss on early extinguishment of debt	0	0	(105)
Net income before income taxes	307,102	34,541	135,895
Income tax (provision) benefit	224	(12)	(423)
Net income	307,326	34,529	135,472
Net income attributable to noncontrolling interests	(1,799)	(262)	(954)
Net income attributable to Brandywine Realty Trust	305,527	34,267	134,518
Nonforfeitable dividends allocated to unvested restricted shareholders	(410)	(396)	(369)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	$ 305,117	$ 33,871	$ 134,149
Basic income per Common Share (in dollars per shares)	$ 1.77	$ 0.19	$ 0.75
Diluted income per Common Share (in dollars per share)	$ 1.77	$ 0.19	$ 0.75
Basic weighted average shares outstanding (in shares)	171,926,079	176,132,941	178,519,748
Diluted weighted average shares outstanding (in shares)	172,317,076	176,686,813	179,641,492
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	$ 534,852	$ 580,417	$ 544,345
Operating expenses
Property operating expenses	132,172	154,361	154,848
Real estate taxes	63,032	62,237	51,341
Third party management expenses	10,252	9,248	11,910
Depreciation and amortization	188,283	210,005	176,000
General and administrative expenses	30,288	32,156	27,802
Provision for impairment	0	0	71,707
Total operating expenses	424,027	468,007	493,608
Gain on sale of real estate
Net gain on disposition of real estate	289,461	356	2,932
Net gain on sale of undepreciated real estate	201	2,020	3,040
Total gain on sale of real estate	289,662	2,376	5,972
Operating income	400,487	114,786	56,709
Other income (expense):
Interest income	1,939	2,318	4,703
Interest expense	(73,911)	(81,512)	(78,199)
Interest expense - amortization of deferred financing costs	(2,904)	(2,768)	(2,498)
Equity in loss of Real Estate Ventures	(18,584)	(9,922)	(15,231)
Net gain on real estate venture transactions	75	11,639	142,233
Gain on promoted interest in unconsolidated real estate venture	0	0	28,283
Loss on early extinguishment of debt	0	0	(105)
Net income before income taxes	307,102	34,541	135,895
Income tax (provision) benefit	224	(12)	(423)
Net income	307,326	34,529	135,472
Net income attributable to noncontrolling interests - consolidated real estate ventures	(20)	(69)	(55)
Net income attributable to Brandywine Operating Partnership	307,306	34,460	135,417
Nonforfeitable dividends allocated to unvested restricted shareholders	(410)	(396)	(369)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	$ 306,896	$ 34,064	$ 135,048
Basic income per Common Share (in dollars per shares)	$ 1.77	$ 0.19	$ 0.75
Diluted income per Common Share (in dollars per share)	$ 1.77	$ 0.19	$ 0.75
Basic weighted average shares outstanding (in shares)	172,907,713	177,114,932	179,959,370
Diluted weighted average shares outstanding (in shares)	173,298,710	177,668,804	181,081,114
Rents
Revenue
Total revenue	$ 513,504	$ 554,665	$ 515,044
Rents | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	513,504	554,665	515,044
Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	18,580	19,626	22,557
Third party management fees, labor reimbursement and leasing | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	18,580	19,626	22,557
Other
Revenue
Total revenue	2,768	6,126	6,744
Other | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	$ 2,768	$ 6,126	$ 6,744