Extension Option (in months)

No definition available.

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- Definition

Line of Credit, Additional Borrowing Capacity

+ References

No definition available.

+ Details

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Namespace Prefix:	bxp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of Additional Term Loans

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Number of extensions

+ References

No definition available.

+ Details

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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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- 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.

+ References

No definition available.

+ Details

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- 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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

+ Details

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

- Definition

Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Details

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- Details

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- Details

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Unsecured Term Loan (Details) $ in Thousands	Mar. 31, 2023 USD ($)	Jan. 04, 2023 USD ($) mo Rate	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Unsecured term loan \| $	$ 1,194,916		$ 730,000
2022 Unsecured Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt \| $		$ 730,000
Payment for Debt Extinguishment or Debt Prepayment Cost \| $		0
2023 Unsecured Term Loan
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity \| $		$ 1,200,000
Unsecured term loan \| $	$ 1,200,000
Debt Instrument, Basis Spread on Variable Rate \| Rate		1.00%
Line of Credit, Additional Borrowing Capacity \| $		$ 300,000
Number of extensions		1
Extension Option (in months) \| mo		12
Proceeds from Unsecured Lines of Credit \| $		$ 1,200,000
2023 Unsecured Term Loan \| Minimum [Member]
Debt Instrument [Line Items]
Number of Additional Term Loans		1
2023 Unsecured Term Loan \| Fed Funds Effective Rate Overnight Index Swap Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.50%
2023 Unsecured Term Loan \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		1.00%
2023 Unsecured Term Loan \| Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.00%
2023 Unsecured Term Loan \| Base Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.60%
2023 Unsecured Term Loan \| Base Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.00%
2023 Unsecured Term Loan \| Adjusted Term Secured Overnight Financing Rate (Adjusted Term SOFR)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.85%	0.85%
2023 Unsecured Term Loan \| Adjusted Term Secured Overnight Financing Rate (Adjusted Term SOFR) \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		1.60%
2023 Unsecured Term Loan \| Adjusted Term Secured Overnight Financing Rate (Adjusted Term SOFR) \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.75%