XML 84 R61.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Summary of Significant Accounting Policies - Deferred Costs (Textual) (Details) | 12 Months Ended
--- | ---
Dec. 31, 2016
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract] |
Remaining Lease Period - Minimum | 1 year
Remaining Lease Period - Maximum | 16 years

X
- Definition Remaining Lease Period - Maximum + References No definition available. + Details
Name: | bdn_RemainingLeasePeriodMaximum
Namespace Prefix: | bdn_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Remaining Lease Period - Minimum + References No definition available. + Details
Name: | bdn_RemainingLeasePeriodMinimum
Namespace Prefix: | bdn_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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