XML 127 R105.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Limited Partners' NonControlling Interests in the Parent Company (Textual) (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Noncontrolling Interest [Abstract] |  |
Aggregate amount related to non-controlling interests classified within equity | $ 10.1 | $ 15.2
Settlement value of non controlling interest in operating partnership | $ 12.6 | $ 26.9

X
- Definition Minority interest in operating partnerships settlement value. + References No definition available. + Details
Name: | bdn_MinorityInterestInOperatingPartnershipsSettlementValue
Namespace Prefix: | bdn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount of the equity interests owned by noncontrolling partners in an operating partnership included in the entity's consolidated financial statements. + References No definition available. + Details
Name: | us-gaap_MinorityInterestInOperatingPartnerships
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_NoncontrollingInterestAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration