v3.26.3
PARTNERS' EQUITY OF THE PARENT COMPANY - Schedule of Number of Units and Net Income Used to Calculate Basic and Diluted Earnings Per Common Partnership Unit (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Jun. 30, 2026
Mar. 31, 2026
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Sep. 30, 2026
Sep. 30, 2025
Numerator                
Net loss $ (22,142) $ (31,535) $ (48,804) $ (25,998) $ (88,936) $ (27,056) $ (102,481) $ (141,990)
Nonforfeitable dividends allocated to unvested restricted unitholders (228)     (313)     (794) (1,064)
Nonforfeitable dividends allocated to unvested restricted unitholders (228)     (313)     (794) (1,064)
Net loss attributable to Common Shareholders of Brandywine Realty Trust (22,262)     (26,232)     (102,829) (142,627)
Net loss attributable to common unitholders, diluted $ (22,262)     $ (26,232)     $ (102,829) $ (142,627)
Denominator                
Total weighted-average units outstanding, basic (in shares) 172,010,229     173,699,312     173,377,458 173,385,330
Total weighted-average units outstanding, diluted (in shares) 172,010,229     173,699,312     173,377,458 173,385,330
Loss per Common Partnership Unit:                
Net loss attributable to common shareholders, basic (in dollars per share) $ (0.13)     $ (0.15)     $ (0.59) $ (0.82)
Net loss attributable to common shareholders, diluted (in dollars per share) $ (0.13)     $ (0.15)     $ (0.59) $ (0.82)
Brandywine Operating Partnership, L.P.                
Numerator                
Net loss $ (22,142) $ (31,535) $ (48,804) $ (25,998) $ (88,936) $ (27,056) $ (102,481) $ (141,990)
Net loss attributable to noncontrolling interests 35     1     132 1
Nonforfeitable dividends allocated to unvested restricted unitholders (228)     (313)     (794) (1,064)
Nonforfeitable dividends allocated to unvested restricted unitholders (228)     (313)     (794) (1,064)
Net loss attributable to Common Shareholders of Brandywine Realty Trust (22,335)     (26,310)     (103,143) (143,053)
Net loss attributable to common unitholders, diluted $ (22,335)     $ (26,310)     $ (103,143) $ (143,053)
Denominator                
Total weighted-average units outstanding, basic (in shares) 172,525,823     174,214,907     173,893,052 173,900,925
Total weighted-average units outstanding, diluted (in shares) 172,525,823     174,214,907     173,893,052 173,900,925
Loss per Common Partnership Unit:                
Net loss attributable to common shareholders, basic (in dollars per share) $ (0.13)     $ (0.15)     $ (0.59) $ (0.82)
Net loss attributable to common shareholders, diluted (in dollars per share) $ (0.13)     $ (0.15)     $ (0.59) $ (0.82)