Capital Commitment Targets, Construction Loan Amount

No definition available.

Name:	bdn_CapitalCommitmentTargetsConstructionLoanAmount
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual Obligation, Amount of Funded Commitment

+ References

No definition available.

+ Details

Name:	bdn_ContractualObligationAmountOfFundedCommitment
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Equity method investment summarized financial information debt.

+ References

No definition available.

+ Details

Name:	bdn_EquityMethodInvestmentSummarizedFinancialInformationDebt
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated potential additional contribution obligation.

+ References

No definition available.

+ Details

Name:	bdn_EstimatedPotentialAdditionalContributionObligation
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Limited Payment Guarantee, Percent of Principle Balance

+ References

No definition available.

+ Details

Name:	bdn_LimitedPaymentGuaranteePercentOfPrincipleBalance
Namespace Prefix:	bdn_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Real Estate Investment, Loan To Value Ratio

+ References

No definition available.

+ Details

Name:	bdn_RealEstateInvestmentLoanToValueRatio
Namespace Prefix:	bdn_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Settlement Liabilities

+ References

No definition available.

+ Details

Name:	bdn_SettlementLiabilities
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unusual Or Infrequent Item, Or Both, Restoration Liability

+ References

No definition available.

+ Details

Name:	bdn_UnusualOrInfrequentItemOrBothRestorationLiability
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This element represents the carrying value of a short-term real estate loan to finance building costs. The funds are disbursed as needed or in accordance with a prearranged plan; generally, a portion of the funds is disbursed at inception and the remainder as construction progresses. The money is repaid on completion of the project, usually from the proceeds of a mortgage loan. The rate is normally higher than the prime rate, and there is usually an origination fee. The effective yield on these loans tends to be high, and the lender has a security interest in the real property. Note that there are separate concepts for the current and noncurrent portions of long-term construction loans.

+ References

+ Details

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

- Definition

Amount of contractual obligation, including, but not limited to, long-term debt, lease obligation, purchase obligation, and other commitments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

+ Details

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

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482900/835-30-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

+ 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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

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

- Definition

Net rentable area for properties owned.

+ References

No definition available.

+ Details

Name:	us-gaap_NetRentableArea
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 840
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481501/840-20-50-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-1

+ Details

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

- Definition

The book value of investments in real estate joint ventures including direct and indirect investments.

+ 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/1943274/2147478777/944-210-S99-1

Reference 2: 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)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_RealEstateInvestmentsJointVentures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3

+ Details

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

- Definition

Amount of insurance proceeds for an event or transaction that is unusual in nature or infrequent in occurrence, or both.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483613/220-20-50-1

+ Details

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

- Details

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

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=us-gaap_NaturalDisastersAndOtherCasualtyEventsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_OtherCommitmentsAxis=bdn_PreferredEquityInvestmentObligationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=bdn_A3151MarketStreetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=us-gaap_ScenarioPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=bdn_A3025JFKBoulevardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bdn_A3025JFKBoulevardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bdn_OneUptownVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=bdn_CarryGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_PaymentGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bdn_UnconsolidatedRealEstateVenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bdn_MAPVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_OtherCommitmentsAxis=bdn_AdditionalFundingForTenantAndCapitalImprovementOfPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bdn_TwoLoganSquareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES (Details)		12 Months Ended
COMMITMENTS AND CONTINGENCIES (Details)	Oct. 21, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jun. 28, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jul. 14, 2022 USD ($)	Jul. 23, 2021 USD ($)	Feb. 02, 2021 USD ($)	Sep. 30, 2004 ft²
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness			$ 757,021,000			$ 1,412,758,000
Investment in real estate ventures, at equity			570,455,000			552,494,000
Drexel Square
Property Subject to or Available for Operating Lease [Line Items]
Other commitments			5,200,000
Estimated potential additional contribution obligation			2,000,000.0
Natural Disasters and Other Casualty Events
Property Subject to or Available for Operating Lease [Line Items]
Restoration liability		$ 800,000
Insurance proceeds		$ 2,800,000
Preferred Equity Investment Obligation
Property Subject to or Available for Operating Lease [Line Items]
Other commitments			15,000,000
Contractual obligation, amount of funded commitment			2,700,000
3151 Market Street
Property Subject to or Available for Operating Lease [Line Items]
Investment in real estate ventures, at equity			316,900,000				$ 317,000,000
3151 Market Street \| Scenario, Plan
Property Subject to or Available for Operating Lease [Line Items]
Debt instrument, face amount			$ 174,300,000
Real estate investment, loan to value ratio			55.00%
Affiliated Entity \| 3025 JFK Boulevard
Property Subject to or Available for Operating Lease [Line Items]
Construction loan amount								$ 186,700,000
3025 JFK Boulevard
Property Subject to or Available for Operating Lease [Line Items]
Limited payment guarantee, percent of principle balance (up to)								25.00%
Investment in real estate ventures, at equity									$ 34,800,000
One Uptown Venture \| Carry Guarantee
Property Subject to or Available for Operating Lease [Line Items]
Limited payment guarantee, percent of principle balance (up to)								30.00%
Construction loan amount								$ 121,700,000
One Uptown Venture \| Payment Guarantee
Property Subject to or Available for Operating Lease [Line Items]
Limited payment guarantee, percent of principle balance (up to)								15.00%
Construction loan amount								$ 85,000,000
Unconsolidated Real Estate Ventures
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness			$ 757,000,000
MAP Venture
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness			$ 0			$ 179,842,000
Investment in real estate ventures, at equity				$ 0	$ 0
MAP Venture \| Fixed rate debt
Property Subject to or Available for Operating Lease [Line Items]
Debt instrument, interest rate, stated percentage			8.00%		8.00%
MAP Venture \| Additional Funding For Tenant And Capital Improvement Of Properties
Property Subject to or Available for Operating Lease [Line Items]
Other commitment			$ 12,000,000		$ 12,000,000
Two Logan Square
Property Subject to or Available for Operating Lease [Line Items]
Rentable area (in square feet) \| ft²										708,844
Settlement liabilities			$ 600,000
Two Logan Square \| Fixed rate debt
Property Subject to or Available for Operating Lease [Line Items]
Repayments of long-term debt	$ 79,800,000