Debt Disclosure [Abstract] Notes Payable, Revolving Credit Facility, Interest and Amortization of Deferred Debt Costs Debt Disclosure [Text Block] Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series D Cumulative Redeemable Preferred Stock Series D Cumulative Redeemable Preferred Stock [Member] Series D Cumulative Redeemable Preferred Stock [Member] Series C Cumulative Preferred Stock Series C Cumulative Preferred Stock [Member] Series C Cumulative Preferred Stock [Member] Statement [Line Items] Statement [Line Items] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization of deferred leasing costs Depreciation, Depletion and Amortization Amortization of deferred debt costs Amortization of Debt Issuance Costs and Discounts Compensation costs of stock grants and options Share-based Compensation Credit losses on operating lease receivables Provision for Loan, Lease, and Other Losses Increase in accounts receivable and accrued income Increase (Decrease) in Accounts and Notes Receivable Additions to deferred leasing costs Increase (Decrease) in Deferred Leasing Fees Decrease in prepaid expenses Increase (Decrease) in Prepaid Expense Increase in other assets Increase (Decrease) in Other Operating Assets Increase in accounts payable, accrued expenses and other liabilities Increase Decrease In Accounts Payable Accrued Expenses And Other Liabilities The net change during the reporting period in the aggregate amount of accounts payable accrued expenses and other liabilities incurred but not paid. Decrease in deferred income Increase (Decrease) in Deferred Income Taxes Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Acquisitions of real estate investments Payments to Acquire Other Real Estate Additions to real estate investments Payments to Acquire Real Estate Additions to development and redevelopment projects Payments to Develop Real Estate Assets Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from notes payable Proceeds from Issuance of Secured Debt Repayments on notes payable Repayments of Secured Debt Proceeds from term loan facility Proceeds from Issuance of Medium-term Notes Proceeds from revolving credit facility Proceeds from Lines of Credit Repayments on revolving credit facility Repayments of Lines of Credit Proceeds from construction loan Proceeds from Construction Loans Payable Additions to deferred debt costs Payments of Debt Issuance Costs Proceeds from the issuance of: Proceeds from Issuance or Sale of Equity [Abstract] Common stock Proceeds from Issuance of Common Stock Partnership units Proceeds from Issuance of Common Limited Partners Units Series D preferred stock Proceeds from Issuance of Preferred Stock and Preference Stock Series C preferred stock redemption payment Payments for Repurchase of Redeemable Preferred Stock Preferred stock redemption costs Payment For Preferred Stock Redemption Costs Payment For Preferred Stock Redemption Costs Distributions to: Payments of Dividends [Abstract] Preferred stockholders Payments of Ordinary Dividends, Preferred Stock and Preference Stock Common stockholders Payments of Ordinary Dividends, Common Stock Noncontrolling interests Payments of Ordinary Dividends, Noncontrolling Interest Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents, beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents, end of period Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Increase in accrued real estate investments and development costs Noncash or Part Noncash Increase (Decrease) In Accrued Real Estate Investments And Development Costs Noncash or Part Noncash Increase (Decrease) in Real Estate Investments and Development Costs Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock Option Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Formation and Structure Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Noncontrolling Interest [Abstract] Noncontrolling Interests - Holders of Convertible Limited Partnership Units in the Operating Partnership Noncontrolling Interest Disclosure [Text Block] Accounting Policies [Abstract] Schedule of Construction in Progress Schedule of Construction in Progress [Table Text Block] Schedule of Construction in Progress [Table Text Block] Basic and Diluted Shares Outstanding Schedule of Weighted Average Number of Shares [Table Text Block] Related Party Transactions [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Ashbrook Marketplace Ashbrook Marketplace [Member] Ashbrook Marketplace [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] BF Saul Real Estate Investment Trust BF Saul Real Estate Investment Trust [Member] BF Saul Real Estate Investment Trust [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Company contribution to a multi employer 401K plan at discretionary amount of employee's cash compensation, maximum percentage Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Company contribution to a multi employer 401K plan at discretionary amount of employee's cash compensation, amount Defined Contribution Plan, Employer Discretionary Contribution Amount Deferred compensation, employee contribution, percentage Deferred Compensation Arrangement With Individual Contributions By Plan Participants Percentage Of Salary Maximum Deferred Compensation Arrangement with Individual, Contributions by Plan Participants, Percentage of Salary, Maximum Deferred compensation, company contribution, amount Deferred Compensation Arrangement with Individual, Contributions by Employer Deferred compensation, company contribution, percentage Deferred Compensation Arrangement with Individual, Employer Contribution, Percentage Deferred Compensation Deferred Compensation Arrangement with Individual, Employer Contribution, Percentage Deferred Compensation Deferred compensation, cumulative unfunded liability Deferred Compensation Arrangement with Individual, Recorded Liability Ancillary costs and expenses Ancillary Costs And Expenses Ancillary Costs and Expenses Liability due to The Saul Organization for the Company's share of these ancillary costs and expenses Due to Related Parties Area of real estate acquired (in acres) Related Party Transaction, Area of Real Estate Acquired Related Party Transaction, Area of Real Estate Acquired Limited partnership units issued for purchase (in shares) Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued Percentage of annual increase in base rent Operating Leases Annual Increase In Rent Expense Operating Leases Annual Increase in Rent Expense Rent expense Operating Lease, Cost Insurance commissions and fees expense Operating Insurance and Claims Costs, Production Fair Value Disclosures [Abstract] Fair Value of Financial Instruments [Table] Fair Value Of Financial Instruments [Table] Fair Value of Financial Instruments [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swap Interest Rate Swap [Member] Fair Value of Financial Instruments [Line Items] Fair Value Of Financial Instruments [Line Items] Fair Value of Financial Instruments [Line Items] Notes payable, fixed interest rate Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate Notes payable, aggregate fair value Notes Payable, Fair Value Disclosure Notes payable, principal balance Notes Payable Fair value of derivative liability Derivative Liability Scheduled Maturities of Debt, Including Scheduled Principal Amortization Schedule of Maturities of Long-term Debt [Table Text Block] Interest Expense and Amortization of Deferred Debt Costs Schedule Of Interest Costs Incurred Table [Table Text Block] Schedule of Interest Costs Incurred Properties Acquired, in Development and Disposed Schedule of Real Estate Properties [Table Text Block] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Trading Symbol Trading Symbol Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Segment Reporting [Abstract] Business Segments Segment Reporting Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Other comprehensive income Other Comprehensive Income (Loss), Net of Tax [Abstract] Change in unrealized loss on cash flow hedge Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Change in unrealized loss on cash flow hedge Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Total comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Total comprehensive income attributable to Saul Centers, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Extinguishment of issuance costs upon redemption of preferred shares Preferred Stock Redemption Premium Preferred stock dividends Preferred Stock Dividends, Income Statement Impact Total comprehensive income available to common stockholders Total Comprehensive Income Loss Available To Common Stockholders Total Comprehensive Income (Loss) Available To Common Stockholders Real Estate [Abstract] Real Estate [Table] Real Estate [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] In-place Leases Leases, Acquired-in-Place [Member] Above Market Rent Above Market Leases [Member] Below Market Rent Below Market Leases [Member] Below Market Leases [Member] Real Estate Property Ownership [Axis] Real Estate Property Ownership [Axis] Real Estate Properties [Domain] Real Estate Properties [Domain] 7316 Wisconsin Avenue 7316 Wisconsin Avenue [Member] 7316 Wisconsin Avenue [Member] 2018 Acquisitions 2018 Acquisitions [Member] 2018 Acquisitions [Member] Real Estate [Line Items] Real Estate [Line Items] Land Land and Land Improvements Buildings Buildings and Improvements, Gross Intangible assets Real Estate Investments, Other Total Purchase Price Real Estate Investment Property, at Cost Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Options Equity Option [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Weighted average common stock outstanding-Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Effect of dilutive options (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average common stock outstanding-Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Non-dilutive options (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Organization, Consolidation and Presentation of Financial Statements Disclosure [Table] Organization Consolidation And Presentation Of Financial Statements Disclosure [Table] Organization, Consolidation and Presentation of Financial Statements Disclosure [Table] Shopping Centers Shopping Centers [Member] Shopping Centers [Member] Mixed-Use Properties Mixed Use Properties [Member] Mixed-Use Properties [Member] Non-operating Development Properties Nonoperating Development Properties [Member] Nonoperating Development Properties [Member] Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] Distribution of REIT taxable income (excluding net capital gains) to its stockholders (percent) Minimum Percentage Of Taxable Income Distribution To Shareholders Minimum Percentage of Taxable Income Distribution to Shareholders Number of partnerships Number of Partnerships Number of Partnerships Number of real estate properties Number of Real Estate Properties Interest incurred Interest Expense, Debt Amortization of deferred debt costs Capitalized interest Interest Costs Capitalized Adjustment Interest expense Interest Expense Less: Interest income Interest Income, Operating Interest expense, net Noncash Interest Expense Accretion And Amortization Of Deferred Finance Fees Noncash Interest Expense Accretion And Amortization Of Deferred Finance Fees Significant Accounting Policies [Table] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Corporate Headquarters Corporate Headquarters [Member] Corporate Headquarters [Member] Common Stock Common Stock [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Revenues Sales Revenue, Services, Net [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Giant Food Giant Food [Member] Giant Food [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Held-for-sale Property Held-for-sale [Member] Property Held-for-sale [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Building Building [Member] Building Improvements Building Improvements [Member] Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Number of tenants Number Of Tenants Number of Tenants Number of shopping centers Number of Stores Percentage of total revenue Percentage Of Total Revenue Percentage of Total Revenue Number of shopping centers Number Of Shopping Centers Number Of Shopping Centers Percentage of ownership in operating partnership Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Accounts receivable, net representing rental income accrued Accrued Fees and Other Revenue Receivable Allowance for doubtful accounts receivables representing rental income accrued Allowance for Doubtful Accounts, Premiums and Other Receivables Period expected for the sale of property to occur Assets Held-for-sale, Period of Sale Assets Held-for-sale, Period of Sale Deferred debt costs Debt Issuance Costs, Net Accumulated amortization, deferred debt costs Accumulated Amortization, Debt Issuance Costs Deferred leasing costs, net Deferred Costs, Leasing, Net Accumulated amortization deferred leasing cost Deferred Costs, Leasing, Accumulated Amortization Amortization expense deferred leasing cost Amortization of Deferred Leasing Fees Interest capitalized Commercial development projects, availability for occupancy, maximum period after major construction activity Commercial Development Projects, Availability for Occupancy after Construction, Maximum Period Commercial Development Projects, Availability for Occupancy after Construction, Maximum Period Estimated useful life (in years) Property, Plant and Equipment, Useful Life Depreciation expense Depreciation, Depletion and Amortization, Nonproduction Repairs and maintenance expense Cost of Property Repairs and Maintenance Shares credited to directors' deferred fee accounts (in shares) Deferred Compensation Arrangement with Individual, Shares Issued Shares due to exercise of employee stock options and issuance of directors' deferred stock (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Operating lease term of contract Lessor, Operating Lease, Term of Contract Number of options to extend lease Lessee, Operating Lease, Option To Extend, Number Of Options Lessee, Operating Lease, Option To Extend, Number Of Options Lease renewal term Lessee, Operating Lease, Renewal Term Right-of-use asset Operating Lease, Right-of-Use Asset Operating lease liability Operating Lease, Liability Statement of Financial Position [Abstract] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Cumulative redeemable preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Cumulative redeemable preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Common stock, par value (in usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecast Scenario, Forecast [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] New Facility New Facility [Member] New Facility [Member] Park Van Ness Loan Park Van Ness Loan [Member] Park Van Ness Loan [Member] Broadlands Village Mortgage Broadlands Village Mortgage [Member] Broadlands Village Mortgage [Member] Olde Forte Village Olde Forte Village [Member] Olde Forte Village [Member] Kentlands Square II Bank Loan Kentlands Square II Bank Loan [Member] Kentlands Square II Bank Loan [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Unsecured Revolving Credit Facility Unsecured Revolving Credit Facility [Member] Unsecured Revolving Credit Facility [Member] Term Loan Term Facility [Member] Term Facility [Member] Revolving Line Revolving Credit Facility [Member] Letter of Credit Letter of Credit [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Line of Credit Line of Credit [Member] 4.65% due January 2034 Four Point Six Five Maturing January Twenty Thirty Four [Member] Four Point Six Five Maturing January Twenty Thirty Four [Member] Fixed Rate Mortgage Notes Payable Fixed Rate Mortgage Notes Payable [Member] Fixed Rate Mortgage Notes Payable Debt Instrument [Line Items] Debt Instrument [Line Items] Principal amount Long-term Debt, Gross Debt outstanding with fixed-rate Long-term Debt, Percentage Bearing Fixed Interest, Amount Debt outstanding with variable-rate Long-term Debt, Percentage Bearing Variable Interest, Amount Outstanding line of credit Long-term Line of Credit Carrying value of properties collateralizing mortgage notes SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Interest rate spread on LIBOR (percentage) Debt Instrument, Basis Spread on Variable Rate Line of credit facility, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Debt instrument, term Debt Instrument, Term Construction-to-permanent loan Debt Instrument, Face Amount Interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Periodic payment Debt Instrument, Periodic Payment Amortization period Debt Instrument, Amortization Period Debt Instrument, Amortization Period Final payment amount Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid Principal amount Long-term Debt Guarantor obligations, maximum exposure Guarantor Obligations, Maximum Exposure, Undiscounted Notes payable Secured Debt Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Class of Stock [Line Items] Class of Stock [Line Items] Income attributable to noncontrolling interests Income (Loss) Attributable to Noncontrolling Interest, before Tax Depositary shares outstanding (in shares) Preferred Stock, Depositary Shares Outstanding Preferred Stock, Depositary Shares Outstanding Depository shares to cumulative redeemable preferred stock ratio Depository Shares To Redeemable Preferred Stock Ratio Depository Shares to Redeemable Preferred Stock Ratio Cumulative redeemable preferred stock liquidation preference (in usd per share) Preferred Stock, Liquidation Preference Per Share Annual dividend on depositary shares (in usd per share) Depository Shares Dividends Per Share Depository Shares Dividends per Share Percentage of redeemable preferred stock Preferred Stock Redemption Percentage Of Originally Issued Shares Preferred Stock Redemption, Percentage of Originally Issued Shares Real Estate Transactions Real Estate Disclosure [Text Block] Related Party Transactions Related Party Transactions Disclosure [Text Block] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Business Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Noncontrolling Interest [Table] Noncontrolling Interest [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Noncontrolling Interest Noncontrolling Interest [Member] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Percentage of ownership interest of noncontrolling interest Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Limited partnership units (in shares) Limited Partners' Capital Account, Units Outstanding Limited partnership units, conversion ratio Limited Partners Capital Account Convertible Units Conversion Ratio Limited Partners' Capital Account, Convertible Units, Conversion Ratio Outstanding stock percent that should be acquired for rights to be exercised Minimum Outstanding Stock Percentage That Should Be Acquired For Rights Issued To Become Exercisable Minimum Outstanding Stock Percentage That Should be Acquired for Rights Issued to Become Exercisable Limited partnership units convertible into shares of common stock, eligible for conversion (in shares) Limited Partners Capital Account Convertible Units Eligible For Conversion Limited Partners' Capital Account, Convertible Units, Eligible for Conversion Fully converted partnership units and diluted weighted average shares outstanding (in shares) Partners Capital Account Units Converted And Weighted Average Shares Outstanding Diluted Partners' Capital Account, Units, Converted and Weighted Average Shares Outstanding, Diluted Income Statement [Abstract] Revenue Revenues [Abstract] Rental Revenue Operating Lease, Lease Income Other Other Operating Income Total revenue Revenues Expenses Costs and Expenses [Abstract] Property operating expenses Direct Costs of Leased and Rented Property or Equipment Real estate taxes Real Estate Tax Expense Interest expense, net and amortization of deferred debt costs Depreciation and amortization of deferred leasing costs General and administrative General and Administrative Expense Total expenses Operating Expenses Net Income Noncontrolling interests Income attributable to noncontrolling interests Net income attributable to Saul Centers, Inc. Net Income (Loss) Attributable to Parent Preferred stock dividends Net income available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Per share net income available to common stockholders Earnings Per Share [Abstract] Basic and diluted (in usd per share) Earnings Per Share, Basic and Diluted Dividends declared per common share outstanding (in usd per share) Common Stock, Dividends, Per Share, Declared Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Glebe Road Glebe Road [Member] Glebe Road [Member] Other Other Property [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Construction in progress Development in Process Equity Stockholders' Equity Note Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Dividends [Axis] Dividends [Axis] Dividends [Domain] Dividends [Domain] Dividend Distributions Payable Dividend Declared [Member] Issuance of Series D Cumulative preferred stock (in shares) Stock Issued During Period, Shares, New Issues Partial redemption of Series C Cumulative preferred stock (in shares) Stock Redeemed or Called During Period, Shares Shares pursuant to dividend reinvestment plan (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan Issuance of partnership units pursuant to dividend reinvestment plan (in shares) Partnership Units Issued During Period Partnership Units Issued During Period Distributions payable on preferred stock, per share (in usd per share) Preferred Stock, Dividends Per Share, Declared Distributions payable common stock, per share (in usd per share) Distributions partnership units, per unit (in usd per share) Distributions Per Limited Partnership Unit Outstanding, Basic Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Expired/Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Outstanding at end of period (in shares) Exercisable at end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted Average Exercise Price per share Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at beginning of period (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in usd per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised (in usd per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Expired/Forfeited (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Outstanding at end of period (in usd per share) Exercisable at end of period (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Roll Forward] Outstanding at beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Intrinsic Value Exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Expired/Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Intrinsic Value Outstanding at end of period Exercisable at end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Nature of Operations Nature Of Operations Policy [Policy Text Block] Nature of Operations Principles of Consolidation Consolidation, Policy [Policy Text Block] Consolidation, Variable Interest Entity Consolidation, Variable Interest Entity, Policy [Policy Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Accounts Receivable, Accrued Income and Allowance for Doubtful Accounts Receivables, Policy [Policy Text Block] Assets Held for Sale Assets Held For Sale [Policy Text Block] Assets Held for Sale, Policy Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Construction In Progress Construction In Progress [Policy Text Block] Construction In Progress Deferred Debt Costs Debt, Policy [Policy Text Block] Deferred Income Deferred Revenue [Policy Text Block] Deferred Revenue, Policy Deferred Leasing Costs Deferred Charges, Policy [Policy Text Block] Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Legal Contingencies Commitments and Contingencies, Policy [Policy Text Block] Postemployment Benefits Postemployment Benefit Plans, Policy [Policy Text Block] Predevelopment Expenses Pre Development Expense Policy [Policy Text Block] Pre-Development Expense Real Estate Investment Properties Real Estate, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Leases [Policy Text Block] Stock-based Employee Compensation, Stock Plan and Deferred Compensation Plan for Directors Compensation Related Costs, Policy [Policy Text Block] Noncontrolling Interests Noncontrolling Interests [Policy Text Block] Noncontrolling Interests, Policy Per Share Data Earnings Per Share, Policy [Policy Text Block] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Reclassifications Reclassification, Policy [Policy Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Stock Options Issued Share-based Compensation, Stock Options, Activity [Table Text Block] Summary of Option Activity Schedule of Stock Options Roll Forward [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Number of reportable business segments Number of Reportable Segments Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Real Estate Real Estate [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Corporate and Other Corporate, Non-Segment [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Real estate rental operations: Real Estate Rental Operations [Abstract] Real Estate Rental Operations [Abstract] Revenue Expenses Cost of Goods and Services Sold Income from real estate Gross Profit Interest expense and amortization of deferred debt costs Depreciation and amortization of deferred leasing costs Depreciation, Depletion and Amortization, Including Discontinued Operations Depreciation, Depletion and Amortization, Including Discontinued Operations General and administrative Capital investment Payments to Acquire Productive Assets Total assets Assets Series C Cumulative Redeemable Preferred Stock Assets Assets [Abstract] Real estate investments Real Estate Investments, Net [Abstract] Land Land Buildings and equipment Investment Building and Building Improvements Construction in progress Accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Real estate investments, net Real Estate Investment Property, Net Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable and accrued income, net Accounts and Notes Receivable, Net Deferred leasing costs, net Prepaid expenses, net Prepaid Expense Other assets Other Assets Total assets Liabilities Liabilities [Abstract] Revolving credit facility payable Term loan facility payable Loans Payable Construction loan payable Construction Loan Dividends and distributions payable Dividends Payable Accounts payable, accrued expenses and other liabilities Accounts Payable Accrued Expenses And Other Liabilities Accounts payable, accrued expenses and other liabilities Deferred income Deferred Revenue, Leases, Net Total liabilities Liabilities Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Preferred stock, 1,000,000 shares authorized: Series C Cumulative Redeemable, 42,000 shares issued and outstanding, Series D Cumulative Redeemable, 30,000 shares issued and outstanding respectively Preferred Stock, Value, Issued Common stock, $0.01 par value, 40,000,000 shares authorized, 22,860,039 and 22,739,207 shares issued and outstanding, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Distributions in excess of accumulated earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Saul Centers, Inc. equity Stockholders' Equity Attributable to Parent Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Balloon Payments Longterm Debt Maturities Balloon Payments [Abstract] Long-term Debt, Maturities, Balloon Payments [Abstract] April 1 through December 31, 2019 Long-term Debt, Maturities, Balloon Payments Remainder Of Fiscal Year Long-term Debt, Maturities, Balloon Payments, Remainder of Fiscal Year 2020 Long-term Debt, Maturities, Balloon Payments In Year Two Long-term Debt, Maturities, Balloon Payments in Year Two 2021 Long-term Debt, Maturities, Balloon Payments In Year Three Long-term Debt, Maturities, Balloon Payments in Year Three 2022 Long-term Debt, Maturities, Balloon Payments in Year Four Long-term Debt Maturities Balloon Payments in Year Four 2023 Long-term Debt, Maturities, Balloon Payments In Year Five Long-term Debt, Maturities, Balloon Payments in Year Five 2024 Long-term Debt, Maturities, Balloon Payments In Year Six Long-term Debt Maturities Balloon Payments In Year Six Thereafter Long-term Debt, Maturities, Balloon Payments After Year Six Long-term Debt Maturities Balloon Payments After Year Six Principal amount Scheduled Principal Amortization Long-term Debt, Fiscal Year Maturity [Abstract] April 1 through December 31, 2019 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt, Maturities, Repayments of Principal in Year Four 2023 Long-term Debt, Maturities, Repayments of Principal in Year Five 2024 Long-term Debt, Maturities, Repayments of Principle in Year Six Long-term Debt, Maturities, Repayments of Principle in Year Six Thereafter Long-term Debt, Maturities, Repayments of Principle After Year Six Long-term Debt, Maturities, Repayments of Principle After Year Six Principal amount Debt Instrument, Periodic Payment Terms, Principal Payments Due Debt Instrument, Periodic Payment Terms, Principal Payments Due Total Long Term Debt Maturities Repayments Of Principal And Balloon Payments [Abstract] Long-Term Debt, Maturities, Repayments of Principal and Balloon Payments [Abstract] April 1 through December 31, 2019 Long-term Debt, Maturities Repayments Of Principal And Balloon Payments Remainder Of Fiscal Year Long-term Debt, Maturities, Repayments of Principal and Balloon Payments, Remainder of Fiscal Year 2020 Long-term Debt, Maturities, Repayments Of Principal And Balloon Payments In Year Two Long-term Debt, Maturities, Repayments of Principal and Balloon Payments in Year Two 2021 Long-term Debt, Maturities, Repayments Of Principal And Balloon Payments In Year Three Long-term Debt, Maturities, Repayments of Principal and Balloon Payments in Year Three 2022 Long-term Debt, Maturities, Repayments Of Principal And Balloon Payments In Year Four Long-term Debt, Maturities, Repayments of Principal and Balloon Payments in Year Four 2023 Long-term Debt, Maturities, Repayments Of Principal And Balloon Payments In Year Five Long-term Debt, Maturities, Repayments of Principal and Balloon Payments in Year Five 2024 Long-term Debt, Maturities, Repayments Of Principal And Balloon Payments In Year Six Long-term Debt Maturities Repayments Of Principal And Balloon Payments In Year Six Thereafter Long-term Debt, Maturities, Repayments Of Principal And Balloon Payments After Year Six Long-term Debt Maturities Repayments Of Principal And Balloon Payments After Year Six Principal amount Unamortized deferred debt costs Net Total Saul Centers, Inc. Parent [Member] Preferred Stock Preferred Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Distributions in Excess of Accumulated Earnings Retained Earnings [Member] Accumulated Other Comprehensive (Loss) AOCI Attributable to Parent [Member] Dividend Paid Dividend Paid [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance Issuance of 30,000 shares of Series D Cumulative preferred stock Stock Issued During Period, Value, New Issues Redemption of 30,000 shares of Series C Cumulative preferred stock Stock Redeemed or Called During Period, Value Issuance of common stock: Common Stock Transactions [Abstract] Common Stock Transactions [Abstract] Issuance of shares pursuant to dividend reinvestment plan Stock Issued During Period, Value, Dividend Reinvestment Plan Issuance of shares due to exercise of employee stock options, director share grant and issuance of directors’ deferred shares Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Issuance of 38,037 partnership units pursuant to dividend reinvestment plan Limited Partner's Units Issued During Period, Value, Dividend Reinvestment Plan Limited Partner's Units Issued During Period, Value, Dividend Reinvestment Plan Issuance of 13,742 partnership units pursuant to dividend reinvestment plan Partnership Units Issued During Period, Value Partnership Units Issued During Period, Value Net income Preferred stock distributions: Dividends, Preferred Stock [Abstract] Preferred stock distributions Dividends, Preferred Stock, Cash Common stock distributions payable Dividends, Common Stock Ending Balance Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Period [Axis] Period [Axis] Period [Axis] Period [Domain] Period [Domain] Period [Domain] 2016 2016 [Member] 2016 [Member] 2017 2017 [Member] 2017 [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Option expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Option vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Closing share price (in usd per share) Share Price Granted (in shares) Weighted average remaining contractual life of the Company's outstanding options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted average remaining contractual life of the Company's exercisable options Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Options [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Options [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award Options [Table] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Directors Director [Member] Officers Officer [Member] 4/24/2009 Period Six [Member] Period 6 [Member] 5/7/2010 Period Seven [Member] Period 7 [Member] 5/13/2011 Period Eight [Member] Period 8 [Member] 5/4/2012 Period Nine [Member] Period 9 [Member] 5/10/2013 Period Ten [Member] Period 10 [Member] 5/9/2014 Period Eleven [Member] Period Eleven [Member] 5/8/2015 May 8, 2015 [Member] May 8, 2015 [Member] 5/6/2016 May 6, 2016 [Member] May 6, 2016 [Member] 5/5/2017 May 5, 2017 [Member] May 5, 2017 [Member] 5/11/2018 May 11, 2018 [Member] May 11, 2018 [Member] Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] Total grant (in shares) Share Based Compensation Arrangement By Share Based Payment Award Options Total Grants In Period Gross Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Total Grants in Period, Gross Vested (in shares) Share Based Compensation Arrangement By Share Based Payment Award Options Vested In Period Share Based Compensation Arrangement by Share Based Payment Award, Options, Vested in Period Exercised (in shares) Share Based Compensation Arrangement By Share Based Payment Award Options Total Exercises In Period Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Total Exercises In Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Exercisable at end of period (in shares) Remaining unexercised (in shares) Share Based Compensation Arrangement By Share Based Payment Award Options Remaining Unexercised Number Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Remaining Unexercised, Number Exercise price (in usd per share) Volatility (percentage) Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Volatility Share Based Compensation Arrangement by Share Based Payment Award, Fair Value Assumptions, Volatility Expected life (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Assumed yield (percentage) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Risk-free rate (percentage) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Total value at grant date Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Fair Value Share based Compensation Arrangement by Share based Payment Award, Options, Grants in Period, Fair Value Estimated forfeitures Share Based Compensation Arrangement By Share Based Payment Award Options Forfeited In Period Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeited in Period, Fair Value Expensed in previous years Allocated Share Based Compensation Expense In Previous Years Allocated Share-Based Compensation Expense in Previous Years Expensed in 2019 Allocated Share-based Compensation Expense Future expense Employee And Non Employee Service Share-Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options Employee and Non Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options Weighted average term of remaining future expense (in years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Parcel Adjacent To 7316 Wisconsin Avenue Parcel Adjacent To 7316 Wisconsin Avenue [Member] Parcel Adjacent To 7316 Wisconsin Avenue [Member] Additions to real estate investments, noncash Noncash or Part Noncash Acquisition, Value of Assets Acquired Acquisition costs Real Estate Inventory, Acquisition Costs Real Estate Inventory, Acquisition Costs Payments to acquire real estate Property acquisition costs Real Estate Inventory, Capitalized Interest Costs Real estate investments