XML 76 R50.htm IDEA: XBRL DOCUMENT
v3.20.4

Real Estate (Narrative) (Details) $ in Thousands |  |  |  |  |  | 1 Months Ended | 2 Months Ended | 6 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 16, 2020 USD ($) | Nov. 03, 2020 ft² | Jun. 25, 2020 USD ($) ft² | Feb. 20, 2020 USD ($) ft² Buildings | Jan. 28, 2020 USD ($) ft² Buildings | Jan. 27, 2020 USD ($) | Feb. 19, 2020 USD ($) | Jun. 24, 2020 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Aug. 15, 2020 ft² apartments | Jul. 31, 2020 USD ($) | Jun. 26, 2020 USD ($) ft² | Jun. 01, 2020 ft² | Mar. 26, 2020 ft²
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate |  |  |  |  |  |  |  |  | $ 519,303 |  | $ 90,824 | $ 455,409 |  |  |  |  |
Gains on sales of real estate |  |  |  |  |  |  |  |  | 618,982 |  | 709 | 182,356 |  |  |  |  |
Payments to Acquire Equity Method Investments |  |  |  |  |  |  |  |  | 172,436 |  | 87,392 | 345,717 |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  | $ 2,765,686 |  | 2,960,562 | 2,717,076 |  |  |  |  |
Capital Gallery [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  | 455,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contractual Sales Price |  |  | $ 253,700 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate |  |  | 246,600 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate |  |  | $ 203,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Operating Income (Loss) |  |  |  |  |  |  |  | $ 6,300 |  |  | 15,000 | 14,500 |  |  |  |  |
Crane Meadow |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contractual Sales Price | $ 14,300 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate | 14,200 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate | $ 5,200 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
New Dominion Technology Park [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  | 493,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Contractual Sales Price |  |  |  | $ 256,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate |  |  |  | 254,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate |  |  |  | $ 192,300 |  |  |  |  |  |  |  |  |  |  |  |  |
Operating Income (Loss) |  |  |  |  |  |  | $ 1,600 |  |  |  | 6,800 | 8,200 |  |  |  |  |
Number of buildings | Buildings |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |
Gateway Center [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate |  |  |  |  | $ 217,700 |  |  |  |  |  |  |  |  |  |  |  |
Operating Income (Loss) |  |  |  |  |  | $ 200 |  |  |  |  | 10,400 | 8,600 |  |  |  |  |
425 Fourth Street [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate purchase price |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 140,100 |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 850,000 |  |
17Fifty Presidents Street |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 276,000
Leased percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100.00%
20 Citypoint |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 211,000 |
Leased percentage |  |  |  |  |  |  |  |  | 100.00% |  |  |  |  |  |  |  |
Capital Gallery [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  | 631,000 |  |  |  |  |  |  |  |  |  |  |  | 176,000 |  |
759 Harrison Street [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate purchase price |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 4,500 |  |  |
200 West Street |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leased percentage |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lessor, Operating Lease, Lease Not yet Commenced, Description |  | 10-year |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lessor Operating Lease Lease Not Yet Commenced Leased SF | ft² |  | 138,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Residential Building | The Skylyne |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  |  |  |  |  |  |  |  |  | 331,000 |  |  |  |
Number of Units in Real Estate Property | apartments |  |  |  |  |  |  |  |  |  |  |  |  | 402 |  |  |  |
Gateway Commons Complex [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area (in sf) | ft² |  |  |  |  | 768,000 |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Equity Method Investments |  |  |  |  | $ 350,000 |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  | 50.00% |  |  |  | 50.00% | [1] |  |  |  |  |  |  |
Number of buildings | Buildings |  |  |  |  | 3 |  |  |  |  |  |  |  |  |  |  |  |
Gateway Commons Complex prior to deferred contribution [Member] [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  | 55.00% |  |  |  |  |  |  |  |  |  |  |  |
Gateway Commons Complex Future Development[Member] [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  | 49.00% |  |  |  |  |  |  |  |  |  |  |  |
Joint Venture Partner [Member] | Gateway Commons Complex [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Equity Method Investments |  |  |  |  | $ 280,800 |  |  |  |  |  |  |  |  |  |  |  |
Future payment to acquire interest in equity method investment |  |  |  |  | $ 69,200 |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  | 50.00% |  |  |  |  |  |  |  |  |  |  |  |
Number of buildings | Buildings |  |  |  |  | 3 |  |  |  |  |  |  |  |  |  |  |  |
Joint Venture Partner [Member] | Gateway Commons Complex Future Development[Member] [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  | 51.00% |  |  |  |  |  |  |  |  |  |  |  |
Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from sales of real estate |  |  |  |  |  |  |  |  | $ 519,303 |  | 90,824 | 455,409 |  |  |  |  |
Gains on sales of real estate |  |  |  |  |  |  |  |  | 631,945 |  | 858 | 190,716 |  |  |  |  |
Payments to Acquire Equity Method Investments |  |  |  |  |  |  |  |  | 172,436 |  | 87,392 | 345,717 |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  | $ 2,765,686 |  | $ 2,960,562 | $ 2,717,076 |  |  |  |  |
Boston Properties Limited Partnership | Capital Gallery [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate |  |  | $ 207,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Boston Properties Limited Partnership | New Dominion Technology Park [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate |  |  |  | $ 197,100 |  |  |  |  |  |  |  |  |  |  |  |  |
Boston Properties Limited Partnership | Gateway Center [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gains on sales of real estate |  |  |  |  | $ 222,400 |  |  |  |  |  |  |  |  |  |  |  |
[1] | As a result of the partner’s deferred contribution, the Company owns an approximately 55% interest in the joint venture at December 31, 2020. Future development projects will be owned 49% by the Company and 51% by its partner.

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 Future payment to acquire interest in equity method investment + References No definition available. + Details
Name: | bxp_Futurepaymenttoacquireinterestinequitymethodinvestment
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Leased percentage + References No definition available. + Details
Name: | bxp_Leasedpercentage
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Lessor Operating Lease Lease Not Yet Commenced Leased SF + References No definition available. + Details
Name: | bxp_LessorOperatingLeaseLeaseNotYetCommencedLeasedSF
Namespace Prefix: | bxp_
Data Type: | num:areaItemType
Balance Type: | na
Period Type: | instant

X
- Definition number of buildings + References No definition available. + Details
Name: | bxp_Numberofbuildings
Namespace Prefix: | bxp_
Data Type: | xbrli:integerItemType
Balance Type: | na
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 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230 + Details
Name: | us-gaap_GainLossOnDispositionOfAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Description of lessor's operating lease that has not yet commenced. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 30 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919359-209981 + Details
Name: | us-gaap_LessorOperatingLeaseLeaseNotYetCommencedDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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 The number of units in a real estate property owned as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash outflow associated with the purchase of or advances to an 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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=121586364&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_RealEstatePropertiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -URI http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

X
- Details
Name: | dei_LegalEntityAxis=bxp_JointVenturePartnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=bxp_BostonPropertiesLimitedPartnershipMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |