XML 105 R82.htm IDEA: XBRL DOCUMENT
v3.8.0.1

(Common Units) (Narrative) (Details) $ / shares in Units, $ in Millions |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Feb. 03, 2017 USD ($) shares | Feb. 04, 2016 USD ($) shares | Feb. 06, 2015 USD ($) shares | Dec. 31, 2017 USD ($) yr shares | Dec. 31, 2016 shares | Dec. 29, 2017 $ / shares | May 02, 2016 shares
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
Conversion of LTIP Units to OP Units (in units) |  |  |  |  |  |  | 625,043
MYLTIP 2014 |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
Final awards percentage of target | 27.70% |  |  |  |  |  |
Value of MYLTIP Awards | $ | $ 3.5 |  |  |  |  |  |
MYLTIP Units forfeited | 447,386 |  |  |  |  |  |
2012 OPP and 2013 MYLTIP [Member] |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
Conversion of LTIP Units to OP Units (in units) |  |  |  |  |  |  | 32,349
OP Units [Member] |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
OP Units for redemption (in shares) |  |  |  | 495,637 | 190,857 |  |
Redemption of OP units issued on conversion of LTIP Units (in shares) |  |  |  | 36,486 | 103,847 |  |
MYLTIP Units distribution as percentage of OP Unit distribution prior to measurement date |  |  |  | 10.00% |  |  |
Restriction on redemption of OP Unit to Common Stock (in years) | yr |  |  |  | 1 |  |  |
Redemption of OP Unit equivalence to Common Stock (in shares) |  |  |  | 1 |  |  |
Common units of operating partnership if converted value | $ |  |  |  | $ 2,300.0 |  |  |
Closing price of common stock (in dollars per share) | $ / shares |  |  |  |  |  | $ 130.03 |
MYLTIP 2013 |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
Final awards percentage of target |  | 109.50% |  |  |  |  |
Value of MYLTIP Awards | $ |  | $ 13.5 |  |  |  |  |
MYLTIP Units forfeited |  | 205,762 |  |  |  |  |
OPP Units 2012 [Member] |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
Outperformance awards earned | $ |  |  | $ 32.1 |  |  |  |
Potential maximum amount of Outperformance Awards earned (percent) |  |  | 80.00% |  |  |  |
Potential Awards Earned | $ |  |  | $ 40.0 |  |  |  |
2012 OPP Units forfeited |  |  | 174,549 |  |  |  |
Boston Properties Limited Partnership | MYLTIP 2014 |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
2014 MYLTIP |  |  |  | 25,107 |  |  |
Boston Properties Limited Partnership | MYLTIP 2016 [Member] |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
2016 MYLTIP |  |  |  | 473,360 |  |  |
Boston Properties Limited Partnership | MYLTIP 2017 [Member] |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
2017 MYLTIP |  |  |  | 400,000 |  |  |
Boston Properties Limited Partnership | MYLTIP 2015 [Member] |  |  |  |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |  |  |  |
2015 MYLTIP |  |  |  | 366,618 |  |  |

X
- Definition Common Stock Marketable Quoted Value Per Share + References No definition available. + Details
Name: | bxp_ClosingPriceOfCommonStockPerShare
Namespace Prefix: | bxp_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Common Units Of Operating Partnership If Converted Value + References No definition available. + Details
Name: | bxp_CommonUnitsOfOperatingPartnershipIfConvertedValue
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Conversion of LTIP Units to OP Units (in units) + References No definition available. + Details
Name: | bxp_ConversionofLTIPUnitstoOPUnitsinunits
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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 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 One OP Unit is equivalent to one common stock (share). + References No definition available. + Details
Name: | bxp_OpUnitEquivalenceToCommonStock
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition OP Units redeemed for stock from LTIP Units + References No definition available. + Details
Name: | bxp_OpUnitsRedeemedForStockFromLtipUnits
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Prior to the measurement date on February 5, 2011, 2008 OPP Units will be entitled to receive per unit distributions equal to one-tenth (10%) of the regular quarterly distributions payable on an OP Unit, but will not be entitled to receive any special distributions. + References No definition available. + Details
Name: | bxp_OutperformanceAwardsLongTermIncentivePlanUnitsDistributionAsPercentageOfOpUnitDistributionPriorToMeasurementDate
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Outperformance awards earned + References No definition available. + Details
Name: | bxp_Outperformanceawardsearned
Namespace Prefix: | bxp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 Potential maximum amount of Outperformance Awards earned (percent) + References No definition available. + Details
Name: | bxp_PotentialmaximumamountofOutperformanceAwardsearnedpercent
Namespace Prefix: | bxp_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Redemption Of OP Units Issued On Conversion Of LTIP Units + References No definition available. + Details
Name: | bxp_RedemptionOfOpUnitsIssuedOnConversionOfLtipUnits
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Restriction on redemption of OP unit to Common Stock + References No definition available. + Details
Name: | bxp_RestrictionOnRedemption
Namespace Prefix: | bxp_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition 2012 OPP Unit forfeited + References No definition available. + Details
Name: | bxp_TwoThousandTwelveOPPUnitsForfeited
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition 2015 MYLTIPS + References No definition available. + Details
Name: | bxp_TwothousandfifteenMYLTIPS
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition 2014 MYLTIP + References No definition available. + Details
Name: | bxp_TwothousandfourteenMYLTIP
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition two thousand seventeen MYLTIP + References No definition available. + Details
Name: | bxp_TwothousandseventeenMYLTIP
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition 2016 MYLTIP + References No definition available. + Details
Name: | bxp_TwothousandsixteenMYLTIP
Namespace Prefix: | bxp_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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 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_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=bxp_MYLTIPTwothousandfourteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=bxp_TwothousandtwelveOPPandtwothousandthirteenMYLTIPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=bxp_OpUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | bxp_StockOptionAndIncentivePlanAndStockRepurchasePlanAxis=bxp_OppUnitsTwoThousandAndTwelveMember
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_StatementEquityComponentsAxis=bxp_MYLTIPTwothousandsixteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=bxp_TwothousandseventeenMYLTIPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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