REAL ESTATE INVESTMENTS - Schedule of Gross Carrying Value of Operating Properties (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Long Lived Assets Held-for-sale [Line Items]
Total	$ 3,696,066	$ 3,617,240
Continuing Operations
Long Lived Assets Held-for-sale [Line Items]
Land	414,179	403,998
Building and improvements	2,783,304	2,760,357
Tenant improvements	$ 498,583	$ 452,885

Real Estate Investment Property Held For Use And Sale

No definition available.

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Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(13))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Carrying amount as of the balance sheet date of improvements having a life longer than one year that were made for the benefit of one or more tenants.

+ References

+ Details

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Balance Type:	debit
Period Type:	instant

- Details

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