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Stock Option and Incentive Plan Stock and Units (Narrative) (Details) $ / shares in Units, $ in Thousands |  |  |  |  | 12 Months Ended
--- | --- | --- | --- | --- | ---
Feb. 04, 2022 USD ($) shares | Feb. 01, 2022 USD ($) | Feb. 05, 2021 USD ($) shares | Feb. 06, 2020 USD ($) shares | Dec. 31, 2022 USD ($) days $ / shares shares | Dec. 31, 2021 USD ($) $ / shares shares | Dec. 31, 2020 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Shares issued | shares |  |  |  |  | 156,836,767 | 156,623,749 |
Vesting Period |  |  |  |  | 4 years |  |
Stock based compensation expense |  |  |  |  | $ 50,700 | $ 49,700 | $ 43,000
Common Stock, Value, Issued |  |  |  |  | $ 1,568 | $ 1,565 |
Restricted Stock [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Shares issued | shares |  |  |  |  | 41,818 | 57,383 | 29,630
LTIP Units [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Value Of LTIP Units Issued |  |  |  |  | $ 28,900 | $ 23,800 | $ 26,300
Weighted average price (per unit) | $ / shares |  |  |  |  | $ 103.06 | $ 84.43 | $ 127.14
Expected life assumed to calculate per unit fair value per LTIP unit (in years) |  |  |  |  | 5 years 8 months 12 days | 5 years 8 months 12 days | 5 years 8 months 12 days
Risk-free rate |  |  |  |  | 1.71% | 0.65% | 1.47%
Expected price volatility |  |  |  |  | 31.00% | 30.00% | 18.00%
MYLTIP 2019 [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Final awards percentage of target | 69.00% |  |  |  |  |  |
Value of MYLTIP Awards | $ 8,600 |  |  |  |  |  |
Forfeitures, in units | shares | 144,043 |  |  |  |  |  |
MYLTIP 2018 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Final awards percentage of target |  |  | 29.20% |  |  |  |
Value of MYLTIP Awards |  |  | $ 4,600 |  |  |  |
Forfeitures, in units | shares |  |  | 285,925 |  |  |  |
MYLTIP 2017 [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Final awards percentage of target |  |  |  | 83.80% |  |  |
Value of MYLTIP Awards |  |  |  | $ 17,600 |  |  |
Forfeitures, in units | shares |  |  |  | 270,942 |  |  |
Employee Stock |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  | 9,813 | 9,846 | 7,195
Weighted Average Price of Shares Purchased | $ / shares |  |  |  |  | $ 87.30 | $ 89.73 | $ 90.53
Number of Business Days, Average Closing Price | days |  |  |  |  | 10 |  |
MYLTIP 2022 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Value of MYLTIP Awards |  | $ 17,300 |  |  |  |  |
Vesting Period |  | 3 years |  |  |  |  |
Boston Properties Limited Partnership | LTIP Units [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  | 280,616 | 281,640 | 207,181
Boston Properties Limited Partnership | MYLTIP 2022 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  | 254,061 |  |
Boston Properties Limited Partnership | MYLTIP 2021 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  |  | 352,021 |
Restricted Stock [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Employee and director payment per share (in dollars per share) | $ / shares |  |  |  |  | $ 0.01 |  |
Common Stock, Value, Issued |  |  |  |  | $ 4,700 | $ 5,800 | $ 4,000
Common Stock Weighted Average Price (in dollars per share) | $ / shares |  |  |  |  | $ 111.47 | $ 100.60 | $ 133.81
LTIP and MYLTIP Units [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Employee and director payment per share (in dollars per share) | $ / shares |  |  |  |  | $ 0.25 |  |
Ltips (including vested MYLTIPS) And Restricted Stock [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Unrecognized compensation expenses |  |  |  |  | $ 20,600 |  |
Unvested MYLTIP Units [Member] |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Unrecognized compensation expenses |  |  |  |  | $ 4,900 |  |
Weighted-average period (years) |  |  |  |  | 1 year 10 months 24 days |  |

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