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Unsecured Senior Notes Unsecured Senior Notes (Narrative) (Details) - USD ($) $ in Thousands			9 Months Ended
	Aug. 17, 2016	Jan. 20, 2016	Sep. 30, 2016		Sep. 30, 2015
Debt Instrument [Line Items]
Proceeds from Issuance of Unsecured Debt			$ 1,989,790		$ 0
Boston Properties Limited Partnership
Debt Instrument [Line Items]
Proceeds from Issuance of Unsecured Debt			$ 1,989,790		$ 0
Boston Properties Limited Partnership | 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%
Principal Amount			$ 7,300,000
Unsecured Senior Notes 3.766% | Boston Properties Limited Partnership | Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount		$ 1,000,000	$ 1,000,000
Coupon/Stated Rate		3.65%	3.65%
Senior Notes Pricing		99.708%
Effective Rate		3.766%	3.766%	[1]
Proceeds from Issuance of Unsecured Debt		$ 988,900
Unsecured Senior Notes 3.495% | Boston Properties Limited Partnership | Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	$ 1,000,000		$ 1,000,000
Coupon/Stated Rate	2.75%		2.75%
Senior Notes Pricing	99.271%
Effective Rate	3.495%		3.495%	[1]
Proceeds from Issuance of Unsecured Debt	$ 984,700
[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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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
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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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-Topic 210
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The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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