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Unsecured Senior Notes (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended
		Jan. 15, 2025	Mar. 31, 2025	Mar. 31, 2024	Aug. 26, 2024
Debt Instrument [Line Items]
Repayments of Unsecured Debt			$ 850,000	$ 700,000
Boston Properties Limited Partnership
Debt Instrument [Line Items]
Repayments of Unsecured Debt			850,000	$ 700,000
Senior Notes | Boston Properties Limited Partnership
Debt Instrument [Line Items]
Debt			9,850,000
3.350% unsecured senior notes | Senior Notes | Boston Properties Limited Partnership
Debt Instrument [Line Items]
Debt		$ 850,000
Debt Instrument, Interest Rate, Stated Percentage		3.20%
Repayments of Unsecured Debt		$ 863,600
Debt Instrument, Increase, Accrued Interest		$ 13,600
5.842% unsecured senior notes | Senior Notes | Boston Properties Limited Partnership
Debt Instrument [Line Items]
Debt			$ 850,000
Debt Instrument, Interest Rate, Stated Percentage			5.75%		5.75%
Debt Instrument, Interest Rate, Effective Percentage	[1]		5.842%
[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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