XML 52 R37.htm IDEA: XBRL DOCUMENT
v3.19.2

Real Estate Narrative (Details) $ in Thousands |  |  |  |  | 1 Months Ended | 2 Months Ended | 3 Months Ended | 5 Months Ended | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 28, 2019 USD ($) ft² | Jun. 03, 2019 USD ($) | May 09, 2019 ft² | Jan. 24, 2019 USD ($) ft² a | Jan. 23, 2019 USD ($) | Jun. 02, 2019 USD ($) | Jun. 30, 2019 USD ($) | Jun. 27, 2019 USD ($) | Jun. 30, 2018 USD ($) | Jun. 02, 2019 USD ($) | Jun. 30, 2019 USD ($) | Jun. 27, 2019 USD ($) | Jun. 30, 2018 USD ($) | Dec. 31, 2018 USD ($) | Apr. 18, 2019 USD ($) ft² | Jan. 10, 2019 USD ($) ft²
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Document Period End Date |  |  |  |  |  |  |  |  |  |  | Jun. 30, 2019 |  |  |  |  |
Accelerated depreciation |  |  |  |  |  |  | $ 177,411 |  | $ 156,417 |  | $ 342,005 |  | $ 322,214 |  |  |
Right of use assets - finance leases |  |  |  |  |  |  | 187,269 |  |  |  | 187,269 |  |  | $ 0 |  |
Proceeds from sales of real estate |  |  |  |  |  |  |  |  |  |  | 60,398 |  | 141,249 |  |  |
Gains (loss) on sales of real estate |  |  |  |  |  |  | 1,686 |  | 18,292 |  | $ 781 |  | 114,689 |  |  |
Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Document Period End Date |  |  |  |  |  |  |  |  |  |  | Jun. 30, 2019 |  |  |  |  |
Accelerated depreciation |  |  |  |  |  |  | 175,199 |  | 154,474 |  | $ 337,881 |  | 318,327 |  |  |
Right of use assets - finance leases |  |  |  |  |  |  | 187,269 |  |  |  | 187,269 |  |  | 0 |  |
Proceeds from sales of real estate |  |  |  |  |  |  |  |  |  |  | 60,398 |  | 141,249 |  |  |
Gains (loss) on sales of real estate |  |  |  |  |  |  | 1,835 |  | 18,770 |  | 930 |  | 117,677 |  |  |
325 Main Street [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of Lease Signed (in years) |  |  | 15-year |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  | 115,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Accelerated depreciation |  |  |  |  |  |  | 9,900 |  |  |  |  |  |  |  |  |
325 Main Street [Member] | Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Accelerated depreciation |  |  |  |  |  |  | $ 9,500 |  |  |  |  |  |  |  |  |
Platform 16 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  | 1,100,000 |  |  |  |  |  |  |  |  |  |  |  |
Finance Lease fixed purchase price |  |  |  | $ 134,800 |  |  |  |  |  |  |  |  |  |  |  |
Right of use assets - finance leases |  |  |  | $ 122,600 |  |  |  |  |  |  |  |  |  |  |  |
Lessee, Finance Lease, Term of Contract |  |  |  | 65 years |  |  |  |  |  |  |  |  |  |  |  |
Area of Land | a |  |  |  | 5.6 |  |  |  |  |  |  |  |  |  |  |  |
Carnegie Center [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,700,000
Aggregate purchase price |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 51,500
Deferred purchase price |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 8,600
164 exington Road [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² | 64,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gross Sale Price | $ 4,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate | 3,800 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  |  |  |  |  |  |  | $ (100) | (100) |  |  | $ (100) | (100) |  |  |
Gains (loss) on sales of real estate | 2,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
164 exington Road [Member] | Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains (loss) on sales of real estate | $ 2,600 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
2600 Tower Oaks Boulevard [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  | 179,000 |  |  |  |  |  |  |  |  |  |  |  |
Gross Sale Price |  |  |  | $ 22,700 |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate |  |  |  | $ 21,400 |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  |  |  |  | $ (200) |  |  |  | (100) |  |  |  | (300) |  |  |
Gains (loss) on sales of real estate |  |  |  |  |  |  |  |  |  |  | (600) |  |  |  |  |
Impairment loss |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,100 |  |
2600 Tower Oaks Boulevard [Member] | Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment loss |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,500 |  |
One Tower Center [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 410,000 |
Gross Sale Price |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 38,000 |
Proceeds from sales of real estate |  | $ 36,600 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  |  |  |  |  | $ (100) |  |  | $ (700) | $ (900) |  |  | $ (1,300) |  |  |
Gains (loss) on sales of real estate |  | $ (800) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment loss |  |  |  |  |  |  |  |  |  |  | 24,000 |  |  |  |  |
One Tower Center [Member] | Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment loss |  |  |  |  |  |  |  |  |  |  | $ 22,300 |  |  |  |  |
Future Office Building [Member] | 325 Main Street [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  | 420,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Square Footage Of Signed Lease | ft² |  |  | 379,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Future Retail Building [Member] | 325 Main Street [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  | 41,000 |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Aggregate purchase price + References No definition available. + Details
Name: | bxp_Aggregatepurchaseprice
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Contractual Sales Price + References No definition available. + Details
Name: | bxp_ContractualSalesPrice
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred purchase price + References No definition available. + Details
Name: | bxp_Deferredpurchaseprice
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Finance Lease fixed purchase price + References No definition available. + Details
Name: | bxp_FinanceLeasefixedpurchaseprice
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Square Footage Of Signed Lease. + References No definition available. + Details
Name: | bxp_SquareFootageOfSignedLease
Namespace Prefix: | bxp_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Term of Lease Signed (in years) + References No definition available. + Details
Name: | bxp_TermofLeaseSignedinyears
Namespace Prefix: | bxp_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD. + References No definition available. + Details
Name: | dei_DocumentPeriodEndDate
Namespace Prefix: | dei_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Area of land held. + References No definition available. + Details
Name: | us-gaap_AreaOfLand
Namespace Prefix: | us-gaap_
Data Type: | num:areaItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_DepreciationAndAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of operating income (loss) attributable to disposal group, including, but not limited to, discontinued operation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760 + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of lessee's right to use underlying asset under finance lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
Name: | us-gaap_FinanceLeaseRightOfUseAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the amount of gain (loss) on sale of properties during the reporting period gross of the applicable income taxes realized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 974 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-15.(a)(1)(ii) -URI http://asc.fasb.org/extlink&oid=6875705&loc=d3e641549-123027 + Details
Name: | us-gaap_GainLossOnSaleOfPropertiesBeforeApplicableIncomeTaxes
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
Name: | us-gaap_LesseeFinanceLeaseTermOfContract1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
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 Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment
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_RealEstateLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bxp_ThreeTwoFiveMainStreetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bxp_PlatformSixteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bxp_CarnegieCenterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bxp_OneSixtyFourLexingtonRoadMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bxp_TwoSixZeroZeroTowerOaksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bxp_OneTowerCenterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=bxp_FutureOfficeBuildingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=bxp_FutureRetailBuildingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |