XML 126 R103.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Subsequent Events subsequent Events (Details) | Feb. 23, 2018 ft² | Feb. 06, 2018 USD ($) yr indices shares | Feb. 04, 2018 USD ($) shares | Feb. 02, 2018 shares | Jan. 31, 2018 ft² apartments | Jan. 24, 2018 ft² | Jan. 09, 2018 USD ($) ft² | Dec. 31, 2017 shares | Dec. 31, 2016 shares | May 17, 2016 shares
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Common stock, shares issued | shares |  |  |  |  |  |  |  | 154,404,186 | 153,869,075 | 1,507
Subsequent Event [Member] | MYLTIP 2015 [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Final awards percentage of target |  |  | 22.00% |  |  |  |  |  |  |
Value of MYLTIP Awards |  |  | $ 3,600,000 |  |  |  |  |  |  |
MYLTIP Units forfeited | shares |  |  | 337,847 |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIPS 2018 [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Target Tier |  | $ 16,200,000 |  |  |  |  |  |  |  |
Indices Used to Compare TSR | indices |  | 2 |  |  |  |  |  |  |  |
Percentage of annualized TSR for Reduction of Earned Awards |  | 0.00% |  |  |  |  |  |  |  |
Percentage to Cause Some Awards to be Earned Even if on a Relative Basis it Would Not Result in any Earned Awards |  | 12.00% |  |  |  |  |  |  |  |
Distributions percent before measurement date |  | 10.00% |  |  |  |  |  |  |  |
Value of MYLTIP Awards |  | $ 13,300,000 |  |  |  |  |  |  |  |
MYLTIP Value Amortized Into Earnings, Years | yr |  | 4 |  |  |  |  |  |  |  |
TSR measurement (in years) | yr |  | 3 |  |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIPS 2018 [Member] | Cohen & Steers Realty Majors Portfolio Index [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Weighted Percentage of Index Used to Compare to TSR |  | 50.00% |  |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIPS 2018 [Member] | NAREIT Office Index adjusted [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Weighted Percentage of Index Used to Compare to TSR |  | 50.00% |  |  |  |  |  |  |  |
Subsequent Event [Member] | Minimum [Member] | MYLTIPS 2018 [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Potential Awards Earned |  | $ 0 |  |  |  |  |  |  |  |
Subsequent Event [Member] | Maximum [Member] | MYLTIPS 2018 [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Potential Awards Earned |  | $ 32,300,000 |  |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIP vesting 2021 | MYLTIPS 2018 [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Vesting Percentage |  | 50.00% |  |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIP vesting 2022 | MYLTIPS 2018 [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Vesting Percentage |  | 50.00% |  |  |  |  |  |  |  |
Subsequent Event [Member] | Restricted Stock [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Common stock, shares issued | shares |  |  |  | 18,226 |  |  |  |  |  |
Boston Properties Limited Partnership | Subsequent Event [Member] | LTIP Units [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
LTIP units issued (in shares) | shares |  | 195,546 |  |  |  |  |  |  |  |
500 E Street | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Net Contractual Sales Price |  |  |  |  |  |  | $ 118,600,000 |  |  |
Net Rentable Area | ft² |  |  |  |  |  |  | 262,000 |  |  |
17Fifty Presidents Street [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  |  | 276,000 |  |  |  |
Signature at Reston | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  | 515,000 |  |  |  |  |
Number of apartment units | apartments |  |  |  |  | 508 |  |  |  |  |
Reston Gateway | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² | 1,000,000.0 |  |  |  |  |  |  |  |  |
Square Footage Of Signed Lease | ft² | 850,000 |  |  |  |  |  |  |  |  |

X
- Definition Distributions Percent Before Measurement Date + References No definition available. + Details
Name: | bxp_DistributionsPercentBeforeMeasurementDate
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Final awards percentage of target + References No definition available. + Details
Name: | bxp_Finalawardspercentageoftarget
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indices Used to Compare TSR + References No definition available. + Details
Name: | bxp_IndicesUsedtoCompareTSR
Namespace Prefix: | bxp_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition LTIP units issued + References No definition available. + Details
Name: | bxp_LtipUnitsIssued
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition MYLTIP Units Forfeited + References No definition available. + Details
Name: | bxp_MYLTIPUnitsForfeited
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition MYLTIP Value Amortized Into Earnings, Years + References No definition available. + Details
Name: | bxp_MyltipValueAmortizedIntoEarningsYears
Namespace Prefix: | bxp_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Number of apartment units + References No definition available. + Details
Name: | bxp_Numberofapartmentunits
Namespace Prefix: | bxp_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage to Cause Some Awards to be Earned Even if on a Relative Basis it Would Not Result in any Earned Awards + References No definition available. + Details
Name: | bxp_PercentageToCauseSomeAwardsToBeEarnedEvenIfOnRelativeBasisItWouldNotResultInAnyEarnedAwards
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of annualized TSR for Reduction of Earned Awards + References No definition available. + Details
Name: | bxp_PercentageofannualizedTSRforReductionofEarnedAwards
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Potential Awards Earned + References No definition available. + Details
Name: | bxp_PotentialAwardsEarned
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 TSR Measurement, Years. + References No definition available. + Details
Name: | bxp_TSRMeasurementYears
Namespace Prefix: | bxp_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Target Tier + References No definition available. + Details
Name: | bxp_TargetTier
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Value of MYLTIP Awards + References No definition available. + Details
Name: | bxp_ValueOfMyltipAwards
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Weighted Percentage of Index Used to Compare to TSR + References No definition available. + Details
Name: | bxp_WeightedPercentageofIndexUsedtoComparetoTSR
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
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 Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bxp_StockOptionAndIncentivePlanAndStockRepurchasePlanAxis=bxp_MYLTIPtwothousandfifteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bxp_StockOptionAndIncentivePlanAndStockRepurchasePlanAxis=bxp_MYLTIPSTwothousandeighteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bxp_PerformanceIndexAxis=bxp_CohenSteersRealtyMajorsPortfolioIndexMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bxp_PerformanceIndexAxis=bxp_NareitOfficeIndexAdjustedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bxp_VestingPeriodAxis=bxp_MYLTIPvestingtwothousandtwentyoneMemberMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bxp_VestingPeriodAxis=bxp_MYLTIPvestingtwothousandtwentytwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=bxp_LtipUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bxp_FiveZeroZeroEStreetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bxp_RestonsignaturesiteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bxp_RestonGatewayMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |