XML 87 R62.htm IDEA: XBRL DOCUMENT
v3.22.4

Investments in Unconsolidated Joint Ventures (Statements of Operations of the Joint Ventures) (Details) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Mar. 30, 2021
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |
Total revenue |  | $ 3,108,581 |  | $ 2,888,621 |  | $ 2,765,686 |  |
Expenses |  |  |  |  |  |  |  |
Transaction costs |  | 2,905 |  | 5,036 |  | 1,531 |  |
Depreciation and amortization |  | 749,775 |  | 717,336 |  | 683,751 |  |
Total expenses |  | 2,050,056 |  | 1,920,581 |  | 1,860,364 |  |
Other income (expense) |  |  |  |  |  |  |  |
Losses from early extinguishment of debt |  | 0 |  | (45,182) |  | 0 |  |
Interest expense |  | (437,139) |  | (423,346) |  | (431,717) |  |
Gains on sales of real estate |  | 437,019 |  | 123,660 |  | 618,982 |  |
Net income |  | 1,020,584 |  | 631,932 |  | 1,018,691 |  |
Income (Loss) from Equity Method Investments |  | (59,840) |  | (2,570) |  | (85,110) |  |
Straight Line Rent Adjustments |  | 108,000 |  | 104,300 |  | 104,900 |  |
Write-off (reinstatement) for accrued rent and accounts receivables |  | (1,500) |  | 1,300 |  | 90,300 |  |
Above and below market rent adjustments, net |  | 9,100 |  | 4,200 |  | 6,500 |  |
Unconsolidated Joint Ventures [Member] |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |
Total revenue | [1] | 512,078 |  | 383,649 |  | 319,560 |  |
Expenses |  |  |  |  |  |  |  |
Operating |  | 198,632 |  | 158,498 |  | 144,347 |  |
Transaction costs |  | 837 |  | 470 |  | 1,027 |  |
Depreciation and amortization |  | 181,041 |  | 147,121 |  | 141,853 |  |
Total expenses |  | 380,510 |  | 306,089 |  | 287,227 |  |
Other income (expense) |  |  |  |  |  |  |  |
Losses from early extinguishment of debt |  | (1,327) |  | 0 |  | 0 |  |
Interest expense |  | (154,065) |  | (108,884) |  | (98,051) |  |
Unrealized gain on derivative instruments |  | 1,681 |  | 0 |  | 0 |  |
Gains on sales of real estate |  | 0 |  | 0 |  | 11,737 | [2] |
Net income |  | (22,143) |  | (31,324) |  | (53,981) |  |
Company's share of net income |  | (2,551) |  | (10,254) |  | (16,256) |  |
Gain on Sale of Investments |  | 0 |  | 10,257 | [3] | 0 |  |
Impairment loss on investment |  | (50,705) | [4] | 0 |  | (60,524) | [4] |
Basis differential | [5] | (6,584) |  | (2,573) |  | (8,330) |  |
Income (Loss) from Equity Method Investments |  | (59,840) |  | (2,570) |  | (85,110) |  |
Straight Line Rent Adjustments |  | (62,900) |  | (17,200) |  | (10,100) |  |
Above and below market rent adjustments, net |  | 400 |  | 400 |  | $ 900 |  |
Parcels of undeveloped land |  |  |  |  |  | 2 |  |
Annapolis Junction NFM, LLC [Member] |  |  |  |  |  |  |  |
Other income (expense) |  |  |  |  |  |  |  |
Gain on Sale of Investments |  |  |  | 10,300 |  |  |  |
Ownership Percentage |  |  |  |  |  |  |  | 50.00%
Colorado Center [Member] | Unconsolidated Joint Ventures [Member] |  |  |  |  |  |  |  |
Other income (expense) |  |  |  |  |  |  |  |
Straight Line Rent Adjustments |  | 500 |  | $ 800 |  | $ 1,800 |  |
Dock 72 [Member] | Unconsolidated Joint Ventures [Member] |  |  |  |  |  |  |  |
Other income (expense) |  |  |  |  |  |  |  |
Impairment loss on investment |  | $ 50,700 |  |  |  | $ 60,500 |  |
[1] | Includes straight-line rent adjustments of approximately $62.9 million, $17.2 million and $(10.1) million for the years ended December 31, 2022, 2021 and 2020, respectively.
[2] | For the year ended December 31, 2020, represents the gain on sale of Annapolis Junction Building Eight and two land parcels. The gain on sale of real estate is included in Loss from Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations.
[3] | During the year ended December 31, 2021, the Company completed the sale of its 50% ownership interest in Annapolis Junction NFM LLC. The Company recognized a gain on sale of investment of approximately $10.3 million.
[4] | During the years ended December 31, 2022 and December 31, 2020, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture that owns Dock 72 in Brooklyn, New York totaling approximately $50.7 million and $60.5 million, respectively.
[5] | Includes straight-line rent adjustments of approximately $0.5 million, $0.8 million and $1.8 million for the years ended December 31, 2022, 2021 and 2020, respectively. Also includes net above-/below-market rent adjustments of approximately $0.4 million, $0.4 million and $0.9 million for the years ended December 31, 2022, 2021 and 2020, respectively.

X
- Definition Above And Below Market Rent Adjustments + References No definition available. + Details
Name: | bxp_AboveAndBelowMarketRentAdjustments
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Company's share of net income (loss) + References No definition available. + Details
Name: | bxp_CompanysShareOfNetIncomeLoss
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Income Statement Basis Differential + References No definition available. + Details
Name: | bxp_IncomeStatementBasisDifferential
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Parcels of undeveloped land + References No definition available. + Details
Name: | bxp_ParcelsOfUndevelopedLand
Namespace Prefix: | bxp_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total costs of sales and operating expenses for the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 + Details
Name: | us-gaap_CostsAndExpenses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_CostsAndExpensesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
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 https://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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 + Details
Name: | us-gaap_DepreciationAndAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types: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 https://asc.fasb.org/extlink&oid=126954810&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 https://asc.fasb.org/extlink&oid=126905981&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 https://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 The difference between the carrying value and the sale price of an investment. A gain would be recognized when the sale price of the investment is greater than the carrying value of the investment. This element refers to the Gain included in earnings and not to the cash proceeds of the sale. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(a)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(13)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(b)(9)(a)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(b)(7)(c)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 + Details
Name: | us-gaap_GainOnSaleOfInvestments
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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=126972273&loc=d3e12355-112629 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=126972273&loc=d3e12317-112629 Reference 3: 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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 + Details
Name: | us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 8A -URI https://asc.fasb.org/extlink&oid=124260329&loc=SL6284422-111562 + Details
Name: | us-gaap_ImpairmentOfInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of income (loss) for proportionate share of equity method investee's income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(12)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(10)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 3: 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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(13)(f)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (g) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570 + Details
Name: | us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of the cost of borrowed funds accounted for as interest expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (210.5-03(11)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.9) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. + References No definition available. + Details
Name: | us-gaap_OperatingExpenses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 + Details
Name: | us-gaap_OtherCostAndExpenseOperating
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OtherIncomeAndExpensesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. + References Reference 1: 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 https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669619-108580 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3000-108585 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 19 -URI https://asc.fasb.org/extlink&oid=126929396&loc=SL4569616-111683 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 22: 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 https://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 23: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669625-108580 Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 29: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (c)(1) -URI https://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684 Reference 31: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4J -URI https://asc.fasb.org/extlink&oid=120409616&loc=SL4591551-111686 Reference 32: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4K -URI https://asc.fasb.org/extlink&oid=120409616&loc=SL4591552-111686 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794 + Details
Name: | us-gaap_ProfitLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 https://asc.fasb.org/extlink&oid=126901519&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 https://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 https://asc.fasb.org/extlink&oid=123596393&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 https://asc.fasb.org/extlink&oid=126901519&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 https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9031-108599 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9038-108599 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599 Reference 19: 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 https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 20: 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 https://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 22: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 23: 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 https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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
- Definition Amount of the adjustment to rental revenues to measure escalating leasing revenues on a straight line basis. + References No definition available. + Details
Name: | us-gaap_StraightLineRentAdjustments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for 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 28 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 + Details
Name: | us-gaap_UnrealizedGainLossOnDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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

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

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