XML 151 R84.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - MAP Venture (Details) $ in Thousands |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jan. 01, 2019 USD ($) | Aug. 01, 2018 USD ($) | Dec. 31, 2019 USD ($) property | Dec. 31, 2018 USD ($) | Feb. 04, 2016 ft²
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Real estate ventures aggregate indebtedness to third parties |  |  | $ 596,007 | $ 370,319 |
MAP Venture |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Ground lease annual payments |  |  | $ 11,900 |  |
Ground lease annual rent expense increase percentage through November 2025 |  |  | 2.50% |  |
Ground lease annual rent expense increase after November 2025 |  |  | 2.50% |  |
Cumulative effect on retained earnings | $ 9,200 |  | $ 4,600 |  |
Real estate ventures aggregate indebtedness to third parties |  | $ 180,800 | $ 185,000 | $ 185,000 |
Variable Interest Entity, Not Primary Beneficiary | MAP Venture |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Number of office properties owned | property |  |  | 58 |  |
Rentable square feet | ft² |  |  |  |  | 3,924,783
Secured Debt | MAP Venture |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Debt instrument, face amount |  | $ 185,000 |  |  |
Variable interest rate |  | 2.45% |  |  |
Maximum | Secured Debt | MAP Venture |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Effective interest rate |  | 6.00% |  |  |

X
- 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

X
- Definition Ground lease annual payments. + References No definition available. + Details
Name: | bdn_GroundLeaseAnnualPayments
Namespace Prefix: | bdn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Ground lease annual rent expense increase percentage for first ten years. + References No definition available. + Details
Name: | bdn_GroundLeaseAnnualRentExpenseIncreasePercentageForFirstTenYears
Namespace Prefix: | bdn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ground lease annual rent expense increase percentage, thereafter. + References No definition available. + Details
Name: | bdn_GroundLeaseAnnualRentExpenseIncreasePercentageThereafter
Namespace Prefix: | bdn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of office properties owned. + References No definition available. + Details
Name: | bdn_NumberOfOfficePropertiesOwned
Namespace Prefix: | bdn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of the cumulative effect on retained earnings net of related income tax effect. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794 + Details
Name: | us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Net rentable area for properties owned. + References No definition available. + Details
Name: | us-gaap_NetRentableArea
Namespace Prefix: | us-gaap_
Data Type: | num:areaItemType
Balance Type: | na
Period Type: | instant

X
- 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_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bdn_MAPVentureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |