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(Common Units) (Narrative) (Details) $ / shares in Units, $ in Thousands |  |  | 6 Months Ended |
--- | --- | --- | --- | ---
Feb. 05, 2021 USD ($) shares | Feb. 02, 2021 USD ($) | Jun. 30, 2021 USD ($) yr $ / shares shares | Dec. 31, 2020 USD ($)
Boston Properties Limited Partnership |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount | $ |  |  | $ 2,008,478 | $ 1,643,024
Unvested MYLTIP Units [Member] |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
unvested MYLTIP distributions as compared to total distributions (percentage) |  |  | 10.00% |
MYLTIP 2018 |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Final awards percentage of target | 29.20% |  |  |
Value of MYLTIP Awards | $ | $ 4,600 |  |  |
Forfeitures, in units | 285,925 |  |  |
MYLTIP | Boston Properties Limited Partnership |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Vesting Period |  |  | 3 years |
MYLTIP 2019 [Member] | Boston Properties Limited Partnership |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Noncontrolling Interest, Outstanding |  |  | 219,916 |
MYLTIP 2020 [Member] | Boston Properties Limited Partnership |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Noncontrolling Interest, Outstanding |  |  | 203,278 |
MYLTIP 2021 |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Value of MYLTIP Awards | $ |  | $ 15,300 |  |
Vesting Period |  | 3 years |  |
MYLTIP 2021 | Boston Properties Limited Partnership |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
Noncontrolling Interest, Outstanding |  |  | 352,021 |
OP Units [Member] |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
OP Units for redemption (in shares) |  |  | 177,434 |
Restriction on redemption of OP Unit to Common Stock (in years) | yr |  |  | 1 |
Redemption of OP Unit equivalent to Common Stock (in shares) |  |  | 1 |
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount | $ |  |  | $ 2,000,000 |
Closing price of common stock (in dollars per share) | $ / shares |  |  | $ 114.59 |
Vested 2012 OPP units and MYLTIPS |  |  |  |
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items] |  |  |  |
OP Units for redemption (in shares) |  |  | 122,443 |

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