Stock Option and Incentive Plan (Narrative) (Details) - MYLTIP 2021 $ in Millions	Feb. 02, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period	3 years
Distributions percent before measurement date	10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	Earned awards (if any) will vest 100% on February 1, 2024, but may not be converted, redeemed, sold or otherwise transferred for one additional year thereafter. Vesting will be accelerated in the event of a change in control, termination of employment by Boston Properties, Inc. without cause, or termination of employment by the award recipient for good reason, death, disability or retirement. If there is a change of control prior to February 1, 2024, earned awards will be calculated based on TSR performance up to the date of the change of control.
Value of MYLTIP Awards | $	$ 15.3
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	The 2021 MYLTIP awards consist of two, equally-weighted (50% each) components that utilize Boston Properties, Inc.’s TSR over a three-year measurement period as the performance metric. The first component of the 2021 MYLTIP, which represents one-half (50%) of the target grant-date value, retains the basic general structure of the 2020 MYLTIP awards with certain changes, including a change to the custom index against which Boston Properties, Inc.’s TSR is compared. The number of LTIP Units that can be earned under this component ranges from zero to 200% of the target number of LTIP Units, based on Boston Properties, Inc.’s annualized relative TSR performance compared to a custom index. Under this component, 100% of the target number of LTIP Units will be earned if Boston Properties, Inc.’s TSR equals the custom index TSR; for relative TSR performance between -1,000 basis points and +1,000 basis points, the number of LTIP Units earned will be determined using linear interpolation.The second component represents the remaining one-half (50%) of the target grant-date value of the 2021 MYLTIP. The number of LTIP Units that can be earned under this component ranges from zero to 200% of the target number of LTIP Units, based on Boston Properties, Inc.’s cumulative absolute TSR during the performance period. Under this component, 100% of the target number of LTIP Units will be earned if Boston Properties, Inc.’s achieves an absolute TSR equal to +1,000 basis points; if Boston Properties, Inc.’s absolute TSR is greater than -4,000 basis points but less than +6,000 basis points, then the number of LTIP Units earned will be determined using linear interpolation.
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	0
Maximum [Member] | Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	352,021
Target
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	176,009