XML 115 R93.htm IDEA: XBRL DOCUMENT
v3.20.4

DEFERRED COSTS - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Deferred Costs (Textual) [Abstract] |  |  |
Capitalized internal direct leasing costs | $ 1.6 | $ 1.7 | $ 3.9

X
- Definition Capitalized internal direct leasing costs. + References No definition available. + Details
Name: | bdn_CapitalizedInternalDirectLeasingCosts
Namespace Prefix: | bdn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Deferred costs textual. + References No definition available. + Details
Name: | bdn_DeferredCostsTextualAbstract
Namespace Prefix: | bdn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration