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Unsecured Senior Notes Unsecured Senior Notes (Narrative) (Details) - USD ($) $ in Thousands |  |  | 12 Months Ended
--- | --- | --- | ---
Aug. 17, 2016 | Jan. 20, 2016 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Debt Instrument [Line Items] |  |  |  |  |  |
Maximum Secured Debt Leverage Ratio |  |  | 55.00% |  |  |
Proceeds from unsecured senior notes |  |  | $ 1,989,790 |  | $ 0 | $ 0
Senior Notes [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Maximum Leverage Ratio |  |  | 60.00% |  |  |
Maximum Secured Debt Leverage Ratio |  |  | 50.00% |  |  |
Minimum Interest Coverage Ratio |  |  | 1.50 |  |  |
Minimum Unencumbered Asset Value Percentage Of Unsecured Debt |  |  | 150.00% |  |  |
Boston Properties Limited Partnership |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Proceeds from unsecured senior notes |  |  | $ 1,989,790 |  | $ 0 | $ 0
Boston Properties Limited Partnership | Senior Notes [Member] |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Long-term Debt, Gross |  |  | $ 7,300,000 |  |  |
Boston Properties Limited Partnership | Senior Notes [Member] | Unsecured Senior Note 3.766% |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Coupon/Stated Rate |  | 3.65% | 3.65% |  |  |
Senior Notes Pricing |  | 99.708% |  |  |  |
Effective Rate |  | 3.766% | 3.766% | [1] |  |
Proceeds from unsecured senior notes |  | $ 988,900 |  |  |  |
Long-term Debt, Gross |  | $ 1,000,000 | $ 1,000,000 |  |  |
Boston Properties Limited Partnership | Senior Notes [Member] | Unsecured Senior Note 3.495% |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Coupon/Stated Rate | 2.75% |  | 2.75% |  |  |
Senior Notes Pricing | 99.271% |  |  |  |  |
Effective Rate | 3.495% |  | 3.495% | [1] |  |
Proceeds from unsecured senior notes | $ 984,700 |  |  |  |  |
Long-term Debt, Gross | $ 1,000,000 |  | $ 1,000,000 |  |  |
[1] | Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.

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- Definition Maximum Secured Debt Leverage Ratio + References No definition available. + Details
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- Definition Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 + Details
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