Debt Instrument, Alternate Basis Spread on Variable Rate

No definition available.

Name:	bxp_DebtInstrumentAlternateBasisSpreadOnVariableRate
Namespace Prefix:	bxp_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Extension Option (in months)

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Number of extensions

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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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+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash inflow from debt classified as other.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with either short term or long term maturity that is uncollateralized (where debt is not backed by the pledge of collateral).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash outflow for the payment of debt classified as other.

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

+ References

+ Details

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Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Period Type:

- Details

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Period Type:

Unsecured Term Loans (Details) $ in Thousands			3 Months Ended
Unsecured Term Loans (Details) $ in Thousands	Mar. 31, 2025 USD ($)	Mar. 28, 2025 USD ($)	Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)	Jan. 04, 2023 USD ($)
Debt Instrument [Line Items]
Borrowings on unsecured term loans			$ 700,000	$ 0
Repayment of unsecured term loans			700,000	0
Repayments of Unsecured Debt			850,000	$ 700,000
Unsecured term loans, net	$ 796,158		$ 796,158		$ 798,813
Term Loan Facility
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.05%
2023 Unsecured Term Loan
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						$ 1,200,000
Repayments of Unsecured Debt		$ 700,000
Term Loan Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 700,000
Debt Instrument, Maturity Date		Mar. 30, 2029
Number of extensions		2
Extension Option (in months)		6
Proceeds from Unsecured Lines of Credit		$ 700,000
Debt Instrument, Alternate Basis Spread on Variable Rate	0.00%		0.00%
Debt	$ 700,000		$ 700,000