Area of land acquired.

No definition available.

Name:	bdn_AreaOfLandAcquired
Namespace Prefix:	bdn_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Area of land under agreement to sell.

+ References

No definition available.

+ Details

Name:	bdn_AreaOfLandUnderAgreementToSell
Namespace Prefix:	bdn_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow from the acquisition of real estate intended to generate income for the owner; excludes land acquired for use by the owner.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireLand
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from earnings received from real estate partnerships.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bdn_OneThousandChesterbrookRealEstateVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bdn_GarzaLandAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Textual) (Details) - Subsequent Event [Member] $ in Millions	Jul. 14, 2016 USD ($)	Jul. 01, 2016 USD ($) a
Subsequent Event [Line Items]
Area of land under agreement to sell \| a		9.5
1000 Chesterbrook [Member]
Subsequent Event [Line Items]
Distribution received from real estate venture \| $	$ 5.1
Garza Land Acquisition [Member]
Subsequent Event [Line Items]
Acreage of land \| a		34.6
Gross purchase value of assets \| $		$ 20.6