Debt Instrument, Alternate Basis Spread on Variable Rate

No definition available.

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Namespace Prefix:	bxp_
Data Type:	dtr-types:percentItemType
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Period Type:	instant

- Definition

Line of Credit, Additional Borrowing Capacity

+ References

No definition available.

+ Details

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

- Definition

Line of credit facility, maximum borrowing percentage for loan advances

+ References

No definition available.

+ Details

Name:	bxp_LineOfCreditFacilityMaximumPercentForLoanAdvances
Namespace Prefix:	bxp_
Data Type:	dtr-types:percentItemType
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

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: 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(16))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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

- Definition

Date the credit facility terminates, in YYYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of interest rate for borrowing under credit facility. Includes, but is not limited to, terms and method for determining interest rate.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MaximumMember
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Balance Type:
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- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=bxp_A2017CreditFacilityDelayedDrawFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Unsecured Credit Facility (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Jun. 15, 2021	Dec. 31, 2021
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date		Jun. 15, 2026
Line of Credit, Additional Borrowing Capacity		$ 500,000
Line of Credit Facility, Interest Rate Description		At BPLP’s option, loans under the 2021 Credit Facility will bear interest at a rate per annum equal to (1) (a) in the case of loans denominated in Dollars, LIBOR, (b) in the case of loans denominated in Euro, EURIBOR, (c) in the case of loans denominated in Canadian Dollars, CDOR, and (d) in the case of loans denominated in Sterling, SONIA, in each case, plus a margin ranging from 70.0 to 140.0 basis points based on BPLP’s credit rating or (2) an alternate base rate equal to the greatest of (a) the Federal Funds rate plus 0.5%, (b) the Administrative Agent’s prime rate, (c) LIBOR for a one-month period plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 40 basis points based on BPLP’s credit rating. The 2021 Credit Facility includes provisions which allow LIBOR Daily Floating Rate to be switched to SOFR.
Line of credit facility, maximum percent for loan advances		65.00%
Line of Credit Facility, Commitment Fee Percentage	0.15%
Debt Instrument, Basis Spread on Variable Rate	0.775%
Debt Instrument, Alternate Basis Spread on Variable Rate	0.00%
Long-term Line of Credit	$ 0		$ 145,000
Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.30%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		1.40%
Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.10%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.70%
2017 Credit Facility, Delayed Draw Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 500,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,500,000
Long-term Line of Credit	$ 0		$ 145,000