XML 104 R81.htm IDEA: XBRL DOCUMENT v3.8.0.1

Investment in Unconsolidated Real Estate Ventures - Summary of Transaction (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Oct. 18, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 17, 2017
Schedule Of Equity Method Investments [Line Items]
Debt principal		$ (768,912)	$ (768,912)	$ (997,466)
Debt prepayment penalties			(3,933)	(66,590)	$ 0
Proceeds from real estate venture sales			145,416	21,022	6,100
Company's share of gain			$ 80,526	$ 20,000	$ 7,229
Austin Joint Venture [Member]
Schedule Of Equity Method Investments [Line Items]
Gross sales price	$ 333,250
Debt principal	(150,968)					$ (151,000)
Debt prepayment penalties	(2,120)
Closing costs and net prorations	(7,420)
Proceeds from real estate venture sales	$ 172,742
Ownership percentage	50.00%
Cash to the Company	$ 86,371
Austin Venture basis of sold properties	(92,559)
Austin Venture gain on sale	80,183
Company's share of gain	40,092	$ 52,200
Deferred gain on sale	12,072
Gain on real estate venture transactions	$ 52,164

X

- Definition

Basis of Joint Venture of sold properties.

+ References

No definition available.

+ Details

Name:	bdn_BasisOfJointVentureOfSoldProperties
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Closing costs and net prorations.

+ References

No definition available.

+ Details

Name:	bdn_ClosingCostsAndNetProrations
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

Net gain loss on real estate venture transactions including deferred gain on partial sale of venture transactions.

+ References

No definition available.

+ Details

Name:	bdn_NetGainLossOnRealEstateVentureTransactionsIncludingDeferedGainOnPartialSaleOfVentureTransactions
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Net gain (loss) on real estate venture transactions including real estate venture formation.

+ References

No definition available.

+ Details

Name:	bdn_NetGainLossOnRealEstateVentureTransactionsIncludingRealEstateVentureFormation
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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

X

- Definition

This element represents disclosure of the amount of gain which has been deferred as the result of the sale of a business or operating assets to a highly leveraged entity which deferred gain has been reflected in the accompanying statement of financial position as reduction from the related asset.

+ References

No definition available.

+ Details

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

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment.

+ References

No definition available.

+ Details

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

X

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

+ Details

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

X

- Definition

The cash inflow from the sale of an investment interest in a joint venture that the reporting entity has not previously accounted for using consolidation or the equity method of accounting.

+ 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=98514028&loc=d3e3179-108585

+ Details

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

X

- Definition

The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ 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=98514028&loc=d3e3179-108585

+ Details

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

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