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Derivative Instruments and Hedging Activities (Details) $ in Thousands |  | 3 Months Ended |
--- | --- | --- | ---
Jan. 06, 2016 USD ($) swaps | Mar. 31, 2016 USD ($) yr swaps | Dec. 31, 2015 USD ($)
Interest Rate Swap [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Derivative, Net Liability Position, Aggregate Fair Value |  | $ 69,300 |
Assets Needed for Immediate Settlement, Aggregate Fair Value |  | 69,300 |
Amount of loss related to the effective portion recognized in other comprehensive loss |  | 68,900 |
Notional Amount |  | 1,000,000 | $ 950,000
Estimated current balance held in Accumulated Other Comprehensive Loss to be reclassified into earnings within the next twelve months |  | $ (2,100) |
Boston Properties Limited Partnership | Interest Rate Swap [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Number of interest rate swap agreements entered into (swap contracts) | swaps |  | 17 |
Term of anticipated mortgage loan (in years) | yr |  | 10 |
Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years) | yr |  | 10 |
Average Fixed Interest Rate |  | 2.423% |
Notional Amount |  | $ 550,000 | 550,000
767 Fifth Partners LLC [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Ownership Percentage by the Company |  | 60.00% |
767 Fifth Partners LLC [Member] | Interest Rate Swap [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Number of interest rate swap agreements entered into (swap contracts) | swaps | 2 | 16 |
Term of anticipated mortgage loan (in years) | yr |  | 10 |
Maximum period of hedging exposure to the variability in future cash flows for forecasted transactions (in years) | yr |  | 10 |
Average Fixed Interest Rate |  | 2.619% |
Notional Amount | $ 50,000 | $ 450,000 | $ 400,000

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition The aggregate fair value of assets needed to immediately settle the derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624258-113959 + Details
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- Definition The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624258-113959 + Details
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