XML 146 R124.htm IDEA: XBRL DOCUMENT v3.10.0.1

Operating Leases - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018
Leases Operating [Abstract]
Lessor, operating lease, description	The Company leases properties to tenants under operating leases with various expiration dates extending to 2082.
Operating lease extending expiration date	2082

X

- Definition

Lessor operating lease maximum extending expiration date.

+ References

No definition available.

+ Details

Name:	bdn_LessorOperatingLeaseMaximumExtendingExpirationDate
Namespace Prefix:	bdn_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_LeasesOperatingAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Description of terms and conditions of option to extend lessor's operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseOptionToExtend
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration