Debt Instrument, Extension Term

No definition available.

Name:	bdn_DebtInstrumentExtensionTerm
Namespace Prefix:	bdn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Number Of Operating Properties Securing The Debt

+ References

No definition available.

+ Details

Name:	bdn_DebtInstrumentNumberOfOperatingPropertiesSecuringTheDebt
Namespace Prefix:	bdn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Wholly Owned Subsidiaries Participating In A Loan Agreement

+ References

No definition available.

+ Details

Name:	bdn_NumberOfWhollyOwnedSubsidiariesParticipatingInALoanAgreement
Namespace Prefix:	bdn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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-Publisher FASB
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-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate amount of interest expense on all borrowings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.7,8)
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=bdn_A600MillionUnsecuredCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=bdn_SecuredOvernightFinancingRateSOFROvernightIndexSwapRateBeforeAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=bdn_DailySOFRAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bdn_A700MillionTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bdn_SecuredFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

DEBT OBLIGATIONS - Narrative (Details)				3 Months Ended
DEBT OBLIGATIONS - Narrative (Details)	Mar. 01, 2023	Jan. 19, 2023 USD ($) property subsidiary	Jun. 30, 2022	Mar. 31, 2023 USD ($)
$600 million Unsecured Credit Facility \| Unsecured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity (up to)				$ 600,000,000
Weighted-average interest rate				3.58%
Interest expense				$ 300,000
Debt instrument, face amount				$ 600,000,000
$600 million Unsecured Credit Facility \| Unsecured Debt \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate, Before Adjustment
Debt Instrument [Line Items]
Spread on variable rate				1.05%
$600 million Unsecured Credit Facility \| Unsecured Debt \| Daily SOFR Adjustment
Debt Instrument [Line Items]
Spread on variable rate			0.10%	0.10%
$70.0 million Term Loan \| Unsecured Debt
Debt Instrument [Line Items]
Debt instrument, face amount				$ 70,000,000
Debt instrument, term	1 year
Extension term	12 months
$70.0 million Term Loan \| Unsecured Debt \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate, Before Adjustment
Debt Instrument [Line Items]
Spread on variable rate				1.75%
$70.0 million Term Loan \| Unsecured Debt \| Daily SOFR Adjustment
Debt Instrument [Line Items]
Spread on variable rate			0.10%
Secured fixed rate debt \| Secured Facility
Debt Instrument [Line Items]
Number of wholly owned subsidiaries participating in a loan agreement \| subsidiary		7
Number of operating properties \| property		7
Debt instrument, face amount		$ 245,000,000
Debt instrument, interest rate, stated percentage		5.88%