Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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Nominal or face amount used to calculate payments on the derivative asset.

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Fixed interest rate related to the interest rate derivative.

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Nominal or face amount used to calculate payments on the derivative liability.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Derivative Instruments and Hedging Activities Derivative Instrument and Hedging Activities Notional Table (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair Value	$ (6,313)	$ (32,351)	$ (6,133)	$ (90,997)
Boston Properties Limited Partnership \| Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount						$ 550,000
767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount					$ 350,000
Derivative Asset, Notional Amount					100,000
Notional Amount		$ 450,000		$ 450,000	450,000
Fair Value					(8,264)
Liability [Member] \| 767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Fair Value					$ (8,773)
Liability [Member] \| Minimum [Member] \| 767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate					2.418%
Liability [Member] \| Maximum [Member] \| 767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate					2.95%
Assets [Member] \| 767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Fair Value					$ 509
Assets [Member] \| Minimum [Member] \| 767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate					2.336%
Assets [Member] \| Maximum [Member] \| 767 Fifth Partners LLC [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate					2.388%