Debt Instrument, Amortization Period

No definition available.

Name:	bfs_DebtInstrumentAmortizationPeriod
Namespace Prefix:	bfs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of accumulated amortization of debt issuance costs.

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+ Details

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

- 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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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

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ 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

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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

+ References

No definition available.

+ Details

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

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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-SubTopic 10
-Section 50
-Paragraph 4
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+ Details

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

- 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.

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+ Details

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

- 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

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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+ Details

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

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

No definition available.

+ Details

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

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

No definition available.

+ Details

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

- Definition

Amount, before accumulated depreciation, of real estate investment by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate. Excludes real estate not held as investment or interest.

+ References

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

- Definition

The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

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Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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- Details

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- Details

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- Details

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Notes Payable, Bank Credit Facility, Interest and Amortization of Deferred Debt Costs - Narrative (Details) - USD ($)				6 Months Ended
	Jun. 30, 2022	Jun. 07, 2022	Mar. 11, 2022	Jun. 30, 2022	Jun. 30, 2021	Feb. 23, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Revolving credit facility payable, net	$ 177,554,000			$ 177,554,000			$ 103,167,000
Repayments of secured debt				53,531,000	$ 26,097,000
Principal amount	1,165,265,000			1,165,265,000
Principal amount	1,175,497,000			1,175,497,000			1,200,000,000
Debt outstanding with fixed-rate	895,500,000			895,500,000			949,000,000
Debt outstanding with variable-rate	280,000,000			280,000,000			206,000,000
Carrying value of properties collateralizing mortgage notes	1,100,000,000			1,100,000,000			1,100,000,000
Unamortized deferred debt costs	10,232,000			10,232,000			11,200,000
Debt issuance costs amortization	7,900,000			7,900,000			$ 7,700,000
Broadlands Village Mortgage
Debt Instrument [Line Items]
Guarantor obligations, maximum exposure	3,700,000			3,700,000
Principal amount	29,300,000			29,300,000
Avenel Business Park
Debt Instrument [Line Items]
Guarantor obligations, maximum exposure	6,300,000			6,300,000
The Waycroft Mortgage
Debt Instrument [Line Items]
Guarantor obligations, maximum exposure	$ 23,600,000			23,600,000
Revolving Credit Facility \| LIBOR
Debt Instrument [Line Items]
Interest rate spread on LIBOR	1.35%
Term Facility \| LIBOR
Debt Instrument [Line Items]
Interest rate spread on LIBOR	1.30%
Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity	$ 200,400,000			200,400,000
Revolving credit facility payable, net	280,000,000			280,000,000
Letter of Credit
Debt Instrument [Line Items]
Revolving credit facility payable, net	185,000			185,000
Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	525,000,000			525,000,000
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	425,000,000			425,000,000
Line of Credit \| Term Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	100,000,000			100,000,000
Line of Credit \| Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Revolving credit facility payable, net	180,000,000			$ 180,000,000
Secured Debt \| Construction-to-Permanent Loan
Debt Instrument [Line Items]
Debt instrument, face amount						$ 133,000,000
Debt instrument, interest rate, stated percentage						3.90%
Amortization period				25 years
Mortgages \| Lansdowne Town Center Mortgage
Debt Instrument [Line Items]
Repayments of secured debt			$ 28,300,000
Mortgages \| Orchard Park Mortgage
Debt Instrument [Line Items]
Repayments of secured debt		$ 8,600,000
Mortgages \| Avenel Business Park
Debt Instrument [Line Items]
Principal amount	23,500,000			$ 23,500,000
Mortgages \| The Waycroft Mortgage
Debt Instrument [Line Items]
Principal amount	154,400,000			154,400,000
Mortgages \| Ashbrook Marketplace Mortgage
Debt Instrument [Line Items]
Principal amount	21,100,000			21,100,000
Mortgages \| Kentlands Place Mortgage
Debt Instrument [Line Items]
Principal amount	$ 28,600,000			$ 28,600,000