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Schedule of Unsecured Senior Notes (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Sep. 29, 2021 | Mar. 16, 2021 | Feb. 14, 2021 | Dec. 31, 2020
--- | --- | --- | --- | --- | ---
Debt Instrument [Line Items] |  |  |  |  |  |  |
Senior Notes |  | $ 10,479,651 |  |  |  |  | $ 9,639,287
Boston Properties Limited Partnership |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Senior Notes |  | 10,479,651 |  |  |  |  | $ 9,639,287
Boston Properties Limited Partnership | Senior Notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt |  | 10,550,000 |  |  |  |  |
Debt Instrument, Unamortized Discount |  | 17,581 |  |  |  |  |
Debt Issuance Costs, Net |  | 52,768 |  |  |  |  |
Senior Notes |  | $ 10,479,651 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.954% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | [1] | 3.85% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [1],[2] | 3.954% |  |  |  |  |
Debt | [1] | $ 1,000,000 |  |  |  |  |
Long-term Debt, Maturity Date | [1],[3] | Feb. 01, 2023 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.279% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.125% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.279% |  |  |  |  |
Debt |  | $ 500,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Sep. 01, 2023 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.916% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.80% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.916% |  |  |  |  |
Debt |  | $ 700,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Feb. 01, 2024 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.350% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.20% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.35% |  |  |  |  |
Debt |  | $ 850,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Jan. 15, 2025 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.766% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.65% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.766% |  |  |  |  |
Debt |  | $ 1,000,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Feb. 01, 2026 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.495% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 2.75% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.495% |  |  |  |  |
Debt |  | $ 1,000,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Oct. 01, 2026 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 4.628% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 4.50% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 4.628% |  |  |  |  |
Debt |  | $ 1,000,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Dec. 01, 2028 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.505% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.40% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.505% |  |  |  |  |
Debt |  | $ 850,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Jun. 21, 2029 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 2.984% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 2.90% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 2.984% |  |  |  |  |
Debt |  | $ 700,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Mar. 15, 2030 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 3.343 % unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.25% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | [2] | 3.343% |  |  |  |  |
Debt |  | $ 1,250,000 |  |  |  |  |
Long-term Debt, Maturity Date | [3] | Jan. 30, 2031 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 2.671% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 2.55% |  |  | 2.55% |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 2.671% | [2] |  | 2.671% |  |
Debt |  | $ 850,000 |  |  | $ 850,000 |  |
Long-term Debt, Maturity Date | [3] | Apr. 01, 2032 |  |  |  |  |
Boston Properties Limited Partnership | Senior Notes | 4.289% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  | 4.125% |
Debt |  |  |  |  |  | $ 850,000 |
Boston Properties Limited Partnership | Senior Notes | 2.524% unsecured senior notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 2.45% |  | 2.45% |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 2.524% | [2] | 2.524% |  |  |
Debt |  | $ 850,000 |  | $ 850,000 |  |  |
Long-term Debt, Maturity Date | [3] | Oct. 01, 2033 |  |  |  |  |
[1] | See Note 15.
[2] | Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.
[3] | No principal amounts are due prior to maturity.(3)See Note 15.

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