Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue
Total revenue	$ 580,417	$ 544,345	$ 520,493
Operating expenses:
Property operating expenses	154,361	154,848	150,911
Real estate taxes	62,237	51,341	45,204
Third party management expenses	9,248	11,910	9,960
Depreciation and amortization	210,005	176,000	180,323
General and administrative expenses	32,156	27,802	28,538
Provision for impairment	0	71,707	3,057
Total operating expenses	468,007	493,608	417,993
Gain on sale of real estate
Net gain on disposition of real estate	356	2,932	32,017
Net gain on sale of undepreciated real estate	2,020	3,040	953
Total gain on sale of real estate	2,376	5,972	32,970
Operating income	114,786	56,709	135,470
Other income (expense):
Interest income	2,318	4,703	1,113
Interest expense	(81,512)	(78,199)	(81,886)
Interest expense - amortization of deferred financing costs	(2,768)	(2,498)	(2,435)
Equity in loss of Real Estate Ventures	(9,922)	(15,231)	(8,306)
Net gain on real estate venture transactions	11,639	142,233	80,526
Gain on promoted interest in unconsolidated real estate venture	0	28,283	0
Loss on early extinguishment of debt	0	(105)	(3,933)
Net income before income taxes	34,541	135,895	120,549
Income tax (provision) benefit	(12)	(423)	628
Net income	34,529	135,472	121,177
Net income attributable to noncontrolling interests	(262)	(954)	(1,004)
Net income attributable to Brandywine Realty Trust	34,267	134,518	120,173
Distribution to preferred shareholders	0	0	(2,032)
Preferred share redemption charge	0	0	(3,181)
Nonforfeitable dividends allocated to unvested restricted shareholders	(396)	(369)	(327)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	$ 33,871	$ 134,149	$ 114,633
Basic income per Common Share (in dollars per share)	$ 0.19	$ 0.75	$ 0.65
Diluted income per Common Share (in dollars per share)	$ 0.19	$ 0.75	$ 0.65
Basic weighted average shares outstanding (in shares)	176,132,941	178,519,748	175,484,350
Diluted weighted average shares outstanding (in shares)	176,686,813	179,641,492	176,808,166
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	$ 580,417	$ 544,345	$ 520,493
Operating expenses:
Property operating expenses	154,361	154,848	150,911
Real estate taxes	62,237	51,341	45,204
Third party management expenses	9,248	11,910	9,960
Depreciation and amortization	210,005	176,000	180,323
General and administrative expenses	32,156	27,802	28,538
Provision for impairment	0	71,707	3,057
Total operating expenses	468,007	493,608	417,993
Gain on sale of real estate
Net gain on disposition of real estate	356	2,932	32,017
Net gain on sale of undepreciated real estate	2,020	3,040	953
Total gain on sale of real estate	2,376	5,972	32,970
Operating income	114,786	56,709	135,470
Other income (expense):
Interest income	2,318	4,703	1,113
Interest expense	(81,512)	(78,199)	(81,886)
Interest expense - amortization of deferred financing costs	(2,768)	(2,498)	(2,435)
Equity in loss of Real Estate Ventures	(9,922)	(15,231)	(8,306)
Net gain on real estate venture transactions	11,639	142,233	80,526
Gain on promoted interest in unconsolidated real estate venture	0	28,283	0
Loss on early extinguishment of debt	0	(105)	(3,933)
Net income before income taxes	34,541	135,895	120,549
Income tax (provision) benefit	(12)	(423)	628
Net income	34,529	135,472	121,177
Net income attributable to noncontrolling interests - consolidated real estate ventures	(69)	(55)	(29)
Distribution to preferred shareholders	0	0	(2,032)
Preferred share redemption charge	0	0	(3,181)
Nonforfeitable dividends allocated to unvested restricted shareholders	(396)	(369)	(327)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	34,064	135,048	115,608
Net income attributable to Brandywine Operating Partnership	34,460	135,417	121,148
Distribution to preferred unitholders	0	0	(2,032)
Preferred unit redemption charge	0	0	(3,181)
Nonforfeitable dividends allocated to unvested restricted unitholders	$ (396)	$ (369)	$ (327)
Basic income per Common Share (in dollars per share)	$ 0.19	$ 0.75	$ 0.65
Diluted income per Common Share (in dollars per share)	$ 0.19	$ 0.75	$ 0.65
Basic weighted average shares outstanding (in shares)	177,114,932	179,959,370	176,964,149
Diluted weighted average shares outstanding (in shares)	177,668,804	181,081,114	178,287,965
Rents
Revenue
Rents	$ 554,665	$ 515,044	$ 487,323
Total revenue	554,665
Rents | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Rents	554,665	515,044	487,323
Third party management fees, labor reimbursement and leasing
Revenue
Service and other revenue	19,626	22,557	28,345
Third party management fees, labor reimbursement and leasing | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Service and other revenue	19,626	22,557	28,345
Other
Revenue
Service and other revenue	6,126	6,744	4,825
Other | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Service and other revenue	$ 6,126	$ 6,744	$ 4,825