XML 58 R42.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Mortgage Notes Payable, Revolving Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Additional Information (Detail) |  |  |  |  |  |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 12, 2019 USD ($) | Jan. 10, 2019 USD ($) | Dec. 18, 2018 USD ($) | Oct. 03, 2018 USD ($) | Nov. 20, 2017 USD ($) | Aug. 14, 2017 USD ($) | Jan. 18, 2017 USD ($) | Sep. 30, 2017 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2019 USD ($) | Oct. 01, 2021 USD ($) | Oct. 01, 2020 USD ($) | Nov. 21, 2019 USD ($) | Jun. 03, 2019 USD ($) | Jan. 04, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Sep. 01, 2017 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding debt |  |  |  |  |  |  |  |  |  | $ 1,100,000,000 |  |  |  |  |  |  |  |
Fixed rate mortgages |  |  |  |  |  |  |  |  |  | 821,503,000 |  |  |  |  |  | $ 880,271,000 |  |
Variable rate debt |  |  |  |  |  |  |  |  |  | 74,691,000 |  |  |  |  |  | 74,591,000 |  |
Principal amount |  |  |  |  |  |  |  |  |  | 1,100,921,000 |  |  |  |  |  | 1,000,000,000.0 |  |
Debt outstanding with fixed-rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 910,200,000 |  |
Debt outstanding with variable-rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 122,000,000.0 |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  | 271,662,000 |  |  |  |  |  |  |  |
Unamortized deferred debt costs |  |  |  |  |  |  |  |  |  | 9,733,000 |  |  |  |  |  | 10,300,000 |  |
Accumulated amortization |  |  |  |  |  |  |  |  |  | 7,500,000 |  |  |  |  |  | 7,300,000 |  |
Capitalization of debt issuance cost |  |  |  |  |  |  |  |  |  | 1,000,000.0 |  |  |  |  |  | 3,200,000 | $ 2,600,000 |
Mortgage Notes Payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  |  | 41,000,000.0 |  |  |  |  |  | 51,000,000.0 |  |
Fixed rate mortgage notes payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed rate mortgages |  |  |  |  |  |  |  |  |  | 938,400,000 |  |  |  |  |  | 910,200,000 |  |
Fixed rate mortgage notes payable | 3.75% due December 2032 | Washington Square |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  | $ 28,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate loans payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate debt |  |  |  |  |  |  |  |  |  | 162,500,000 |  |  |  |  |  |  |  |
New Facility | Line of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  | $ 400,000,000.0 |  |  |  |  |  |  |  |
Extension in line of credit facility period |  |  |  |  |  |  |  |  |  | 1 year |  |  |  |  |  |  |  |
Available borrowing capacity |  |  |  |  |  |  |  |  |  | $ 237,300,000 |  |  |  |  |  |  |  |
Outstanding line of credit |  |  |  |  |  |  |  |  |  | 87,500,000 |  |  |  |  |  |  |  |
Letter of credit available borrowing capacity |  |  |  |  |  |  |  |  |  | 185,000 |  |  |  |  |  |  |  |
New Facility | Revolving Credit Facility | Line of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  | $ 325,000,000.0 |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  |  | 1.35% |  |  |  |  |  |  |  |
New Facility | Revolving Credit Facility | Term Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  |  | 1.30% |  |  |  |  |  |  |  |
New Facility | Term Facility | Line of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  | $ 75,000,000.0 |  |  |  |  |  |  |  |
Park Van Ness Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed rate mortgages |  |  |  |  |  |  |  |  |  | 68,100,000 |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  |  | 6,700,000 |  |  |  |  |  |  |  |
Park Van Ness Loan | 4.88% due September 2032 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  |  |  |  |  |  | $ 413,460 |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.88%
Amortization schedule |  |  |  |  |  |  |  | 25 years |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid |  |  |  |  |  |  |  | $ 39,600,000 |  |  |  |  |  |  |  |  |  |
Kentlands Square I | Revolving Credit Facility | 4.41% mortgage maturing 2033 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  | $ 6,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Kentlands Square II Bank Loan | Fixed rate mortgage notes payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  |  | 8,500,000 |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  | 34,000,000.0 |  |  |  |  |  |  |  |
Burtonsville Fixed Rate Mortgage | 3.39% due January 2032 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  |  |  |  |  | $ 40,000,000.0 |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  |  |  |  |  | $ 197,900 |  |  |  |  |  |  |  |  |  |  |
Loan term |  |  |  |  |  |  | 15 years |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  |  |  |  |  | 3.39% |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  |  |  |  |  | 25 years |  |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid |  |  |  |  |  |  | $ 20,300,000 |  |  |  |  |  |  |  |  |  |  |
Waycroft Construction Loan | 4.67% Construction To Permanent Loan Due 2035 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  |  |  |  | $ 157,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  |  |  |  | 4.67% |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  |  |  |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |
Washington Square 2017 Mortgage | 3.75% due December 2032 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  |  |  | 60,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  |  |  | $ 308,500 |  |  |  |  |  |  |  |  |  |  |  |  |
Loan term |  |  |  |  | 15 years |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  |  |  | 3.75% |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  |  |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid |  |  |  |  | $ 31,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Broadlands Village |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  |  | 3,900,000 |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  | 31,200,000 |  |  |  |  |  |  |  |
Broadlands Village | 4.41% mortgage maturing 2033 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  | 15,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  |  | 32,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  |  | $ 176,200 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan term |  |  |  | 15 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  |  | 4.41% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid |  |  |  | $ 17,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Avenel Business Park |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  |  | 6,300,000 |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  | 26,300,000 |  |  |  |  |  |  |  |
The Glen Mortgage | 4.41% mortgage maturing 2033 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  | $ 7,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
The Glen Mortgage | 4.69% fixed rate loan maturing in 2034 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  | $ 22,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  | $ 129,800 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan term |  |  | 15 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  | 4.69% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid |  |  | $ 12,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Countryside |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 12,700,000 |  |  |
Olde Forte Village | Four Point Six Five Maturing January Twenty Thirty Four [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  | $ 22,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  | $ 124,700 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan term |  | 15 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  | 4.65% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid |  | $ 12,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Briggs Chancy MarketPlace |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 12,400,000 |  |  |  |
Shops at Monocacy | 4.69% fixed rate loan maturing in 2034 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Balloon payment to be paid | $ 15,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shops at Monocacy | Four Point Six Five Maturing January Twenty Thirty Four [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount | 28,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment | $ 152,600 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan term | 15 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate | 4.14% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Thruway |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  |  |  |  |  | $ 35,600,000 |  |  |  |  |
Debt Covenant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Carrying value of properties collateralized |  |  |  |  |  |  |  |  |  | $ 1,100,000,000 |  |  |  |  |  | $ 1,100,000,000 |  |
Credit agreement leverage ratio |  |  |  |  |  |  |  |  |  | 60.00% |  |  |  |  |  |  |  |
Interest coverage ratio required minimum |  |  |  |  |  |  |  |  |  | 2.0 |  |  |  |  |  |  |  |
Required fixed charge coverage ratio |  |  |  |  |  |  |  |  |  | 1.4 |  |  |  |  |  |  |  |
Scenario, Forecast | Park Van Ness Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  |  |  | $ 0 | $ 3,300,000 |  |  |  |  |  |
Scenario, Forecast | Waycroft Construction Loan | 4.67% Construction To Permanent Loan Due 2035 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  |  |  |  |  |  |  | $ 887,900 |  |  |  |  |  |  |  |  |
Park Van Ness | Fixed rate mortgage notes payable | 4.88% due September 2032 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed rate mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 71,600,000
Minimum | New Facility | Revolving Credit Facility | Line of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  |  | 1.35% |  |  |  |  |  |  |  |
Minimum | New Facility | Revolving Credit Facility | Term Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  |  | 1.30% |  |  |  |  |  |  |  |
Maximum | New Facility | Revolving Credit Facility | Line of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  |  | 1.95% |  |  |  |  |  |  |  |
Maximum | New Facility | Revolving Credit Facility | Term Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  |  | 1.90% |  |  |  |  |  |  |  |

X
- Definition Credit Agreement Leverage Ratio + References No definition available. + Details
Name: | bfs_CreditAgreementLeverageRatio
Namespace Prefix: | bfs_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Amortization Period + References No definition available. + Details
Name: | bfs_DebtInstrumentAmortizationPeriod
Namespace Prefix: | bfs_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest Coverage Ratio Required Minimum + References No definition available. + Details
Name: | bfs_InterestCoverageRatioRequiredMinimum
Namespace Prefix: | bfs_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Letter of Credit Facilities, Maximum Borrowing Capacity + References No definition available. + Details
Name: | bfs_LetterOfCreditFacilitiesMaximumBorrowingCapacity
Namespace Prefix: | bfs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line of Credit Facility Potential Term Extension Period + References No definition available. + Details
Name: | bfs_LineOfCreditFacilityPotentialTermExtensionPeriod
Namespace Prefix: | bfs_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Long-term Debt, Repayments of Principal and Balloon Payments + References No definition available. + Details
Name: | bfs_LongtermDebtRepaymentsOfPrincipalAndBalloonPayments
Namespace Prefix: | bfs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Required Fixed Charge Coverage Ratio + References No definition available. + Details
Name: | bfs_RequiredFixedChargeCoverageRatio
Namespace Prefix: | bfs_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of accumulated amortization of debt issuance costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AccumulatedAmortizationDeferredFinanceCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- 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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: 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 http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 3: 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: 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 http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt 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(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Amount of the required periodic payments including both interest and principal payments. + 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentPeriodicPayment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 + Details
Name: | us-gaap_DeferredFinanceCostsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + 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 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 + Details
Name: | us-gaap_DeferredFinanceCostsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=118943654&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Including the current and noncurrent portions, aggregate carrying value as of the balance sheet date of loans payable (with maturities initially due after one year or beyond the operating cycle if longer). + 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(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 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)(a)(2)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 + Details
Name: | us-gaap_LoansPayable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: 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(a)(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 3: 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 http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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
Name: | us-gaap_LongtermDebtPercentageBearingFixedInterestAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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
Name: | us-gaap_LongtermDebtPercentageBearingVariableInterestAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The carrying amount, as of the date of the latest financial statement presented, of real estate owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729 + Details
Name: | us-gaap_PledgedAssetsNotSeparatelyReportedRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower. + References Reference 1: 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(a)(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 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 http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_SecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of collateralized debt obligations classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 + Details
Name: | us-gaap_SecuredDebtOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_MortgageNotesPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_FixedRateMortgageNotesPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_ThreePointSevenFiveMaturingDecemberTwentyThirtyTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bfs_WashingtonSquareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_VariableRateLoansPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_NewFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_TermFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=bfs_TermFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_ParkVanNessLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_FourPointEightEightMaturingSeptemberTwentyThirtyTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_KentlandsSquareIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_FourPointFourOneMaturingOctoberTwentyThirtyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_KentlandsSquareIIBankLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_FixedRateMortgageNotesPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_BurtonsvilleFixedRateMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_ThreePointThreeNineMaturingFebruaryTwentyThirtyTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_WaycroftConstructionLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_FourPointSixSevenPercentConstructionToPermanentLoanDueTwentyThirtyFiveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_WashingtonSquare2017MortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_BroadlandsVillageMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_AvenelBusinessParkMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_TheGlenMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_FourPointSixNinePercentFixedRateLoanMaturingInTwentyThirtyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_CountrysideMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_OldeForteVillageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=bfs_FourPointSixFiveMaturingJanuaryTwentyThirtyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_BriggsChancyMarketPlaceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_ShopsatMonocacyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_ThruwayMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=bfs_DebtCovenantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | bfs_RealEstatePropertyNameAxis=bfs_ParkVanNessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |