3.25.1 html 471 613 1 false 90 0 false 10 false false R1.htm 0000001 - Document - Cover Sheet http://soundcb.com/role/Cover Cover Cover 1 false false R2.htm 0000002 - Document - Audit Information Sheet http://soundcb.com/role/AuditInformation Audit Information Cover 2 false false R3.htm 9952151 - Statement - Consolidated Balance Sheets Sheet http://soundcb.com/role/ConsolidatedBalanceSheets Consolidated Balance Sheets Statements 3 false false R4.htm 9952152 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://soundcb.com/role/ConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 4 false false R5.htm 9952153 - Statement - Consolidated Statements of Income Sheet http://soundcb.com/role/ConsolidatedStatementsofIncome Consolidated Statements of Income Statements 5 false false R6.htm 9952154 - Statement - Consolidated Statements of Comprehensive Income Sheet http://soundcb.com/role/ConsolidatedStatementsofComprehensiveIncome Consolidated Statements of Comprehensive Income Statements 6 false false R7.htm 9952155 - Statement - Consolidated Statements of Stockholders' Equity Sheet http://soundcb.com/role/ConsolidatedStatementsofStockholdersEquity Consolidated Statements of Stockholders' Equity Statements 7 false false R8.htm 9952156 - Statement - Consolidated Statements of Stockholders' Equity (Parenthetical) Sheet http://soundcb.com/role/ConsolidatedStatementsofStockholdersEquityParenthetical Consolidated Statements of Stockholders' Equity (Parenthetical) Statements 8 false false R9.htm 9952157 - Statement - Consolidated Statements of Cash Flows Sheet http://soundcb.com/role/ConsolidatedStatementsofCashFlows Consolidated Statements of Cash Flows Statements 9 false false R10.htm 9952158 - Disclosure - Organization and Significant Accounting Policies Sheet http://soundcb.com/role/OrganizationandSignificantAccountingPolicies Organization and Significant Accounting Policies Notes 10 false false R11.htm 9952159 - Disclosure - Accounting Pronouncements Recently Issued or Adopted Sheet http://soundcb.com/role/AccountingPronouncementsRecentlyIssuedorAdopted Accounting Pronouncements Recently Issued or Adopted Notes 11 false false R12.htm 9952160 - Disclosure - Restricted Cash Sheet http://soundcb.com/role/RestrictedCash Restricted Cash Notes 12 false false R13.htm 9952161 - Disclosure - Investments Sheet http://soundcb.com/role/Investments Investments Notes 13 false false R14.htm 9952162 - Disclosure - Loans Sheet http://soundcb.com/role/Loans Loans Notes 14 false false R15.htm 9952163 - Disclosure - Mortgage Servicing Rights Sheet http://soundcb.com/role/MortgageServicingRights Mortgage Servicing Rights Notes 15 false false R16.htm 9952164 - Disclosure - Premises and Equipment Sheet http://soundcb.com/role/PremisesandEquipment Premises and Equipment Notes 16 false false R17.htm 9952165 - Disclosure - Other Real Estate Owned and Repossessed Assets Sheet http://soundcb.com/role/OtherRealEstateOwnedandRepossessedAssets Other Real Estate Owned and Repossessed Assets Notes 17 false false R18.htm 9952166 - Disclosure - Deposits Sheet http://soundcb.com/role/Deposits Deposits Notes 18 false false R19.htm 9952167 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotes Borrowings, FHLB Stock and Subordinated Notes Notes 19 false false R20.htm 9952168 - Disclosure - Fair Value Measurements Sheet http://soundcb.com/role/FairValueMeasurements Fair Value Measurements Notes 20 false false R21.htm 9952169 - Disclosure - Leases Sheet http://soundcb.com/role/Leases Leases Notes 21 false false R22.htm 9952170 - Disclosure - Earnings Per Share Sheet http://soundcb.com/role/EarningsPerShare Earnings Per Share Notes 22 false false R23.htm 9952171 - Disclosure - Employee Benefits Sheet http://soundcb.com/role/EmployeeBenefits Employee Benefits Notes 23 false false R24.htm 9952172 - Disclosure - Income Taxes Sheet http://soundcb.com/role/IncomeTaxes Income Taxes Notes 24 false false R25.htm 9952173 - Disclosure - Capital Sheet http://soundcb.com/role/Capital Capital Notes 25 false false R26.htm 9952174 - Disclosure - Concentrations of Credit Risk Sheet http://soundcb.com/role/ConcentrationsofCreditRisk Concentrations of Credit Risk Notes 26 false false R27.htm 9952175 - Disclosure - Commitments and Contingencies Sheet http://soundcb.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 27 false false R28.htm 9952176 - Disclosure - Parent Company Financial Information Sheet http://soundcb.com/role/ParentCompanyFinancialInformation Parent Company Financial Information Notes 28 false false R29.htm 9952177 - Disclosure - Revenue from Contracts with Customers Sheet http://soundcb.com/role/RevenuefromContractswithCustomers Revenue from Contracts with Customers Notes 29 false false R30.htm 9952178 - Disclosure - Business Segments Sheet http://soundcb.com/role/BusinessSegments Business Segments Notes 30 false false R31.htm 9952179 - Disclosure - Subsequent Events Sheet http://soundcb.com/role/SubsequentEvents Subsequent Events Notes 31 false false R32.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 32 false false R33.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 33 false false R34.htm 995447 - Disclosure - Insider Trading Policies and Procedures Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc Insider Trading Policies and Procedures Notes 34 false false R35.htm 995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure Sheet http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure Cybersecurity Risk Management and Strategy Disclosure Notes 35 false false R36.htm 9955511 - Disclosure - Organization and Significant Accounting Policies (Policies) Sheet http://soundcb.com/role/OrganizationandSignificantAccountingPoliciesPolicies Organization and Significant Accounting Policies (Policies) Policies http://soundcb.com/role/OrganizationandSignificantAccountingPolicies 36 false false R37.htm 9955512 - Disclosure - Accounting Pronouncements Recently Issued or Adopted (Tables) Sheet http://soundcb.com/role/AccountingPronouncementsRecentlyIssuedorAdoptedTables Accounting Pronouncements Recently Issued or Adopted (Tables) Tables http://soundcb.com/role/AccountingPronouncementsRecentlyIssuedorAdopted 37 false false R38.htm 9955513 - Disclosure - Investments (Tables) Sheet http://soundcb.com/role/InvestmentsTables Investments (Tables) Tables http://soundcb.com/role/Investments 38 false false R39.htm 9955514 - Disclosure - Loans (Tables) Sheet http://soundcb.com/role/LoansTables Loans (Tables) Tables http://soundcb.com/role/Loans 39 false false R40.htm 9955515 - Disclosure - Mortgage Servicing Rights (Tables) Sheet http://soundcb.com/role/MortgageServicingRightsTables Mortgage Servicing Rights (Tables) Tables http://soundcb.com/role/MortgageServicingRights 40 false false R41.htm 9955516 - Disclosure - Premises and Equipment (Tables) Sheet http://soundcb.com/role/PremisesandEquipmentTables Premises and Equipment (Tables) Tables http://soundcb.com/role/PremisesandEquipment 41 false false R42.htm 9955517 - Disclosure - Other Real Estate Owned and Repossessed Assets (Tables) Sheet http://soundcb.com/role/OtherRealEstateOwnedandRepossessedAssetsTables Other Real Estate Owned and Repossessed Assets (Tables) Tables http://soundcb.com/role/OtherRealEstateOwnedandRepossessedAssets 42 false false R43.htm 9955518 - Disclosure - Deposits (Tables) Sheet http://soundcb.com/role/DepositsTables Deposits (Tables) Tables http://soundcb.com/role/Deposits 43 false false R44.htm 9955519 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes (Tables) Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotesTables Borrowings, FHLB Stock and Subordinated Notes (Tables) Tables http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotes 44 false false R45.htm 9955520 - Disclosure - Fair Value Measurements (Tables) Sheet http://soundcb.com/role/FairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://soundcb.com/role/FairValueMeasurements 45 false false R46.htm 9955521 - Disclosure - Leases (Tables) Sheet http://soundcb.com/role/LeasesTables Leases (Tables) Tables http://soundcb.com/role/Leases 46 false false R47.htm 9955522 - Disclosure - Earnings Per Share (Tables) Sheet http://soundcb.com/role/EarningsPerShareTables Earnings Per Share (Tables) Tables http://soundcb.com/role/EarningsPerShare 47 false false R48.htm 9955523 - Disclosure - Employee Benefits (Tables) Sheet http://soundcb.com/role/EmployeeBenefitsTables Employee Benefits (Tables) Tables http://soundcb.com/role/EmployeeBenefits 48 false false R49.htm 9955524 - Disclosure - Income Taxes (Tables) Sheet http://soundcb.com/role/IncomeTaxesTables Income Taxes (Tables) Tables http://soundcb.com/role/IncomeTaxes 49 false false R50.htm 9955525 - Disclosure - Commitments and Contingencies (Tables) Sheet http://soundcb.com/role/CommitmentsandContingenciesTables Commitments and Contingencies (Tables) Tables http://soundcb.com/role/CommitmentsandContingencies 50 false false R51.htm 9955526 - Disclosure - Parent Company Financial Information (Tables) Sheet http://soundcb.com/role/ParentCompanyFinancialInformationTables Parent Company Financial Information (Tables) Tables http://soundcb.com/role/ParentCompanyFinancialInformation 51 false false R52.htm 9955527 - Disclosure - Revenue from Contracts with Customers (Tables) Sheet http://soundcb.com/role/RevenuefromContractswithCustomersTables Revenue from Contracts with Customers (Tables) Tables http://soundcb.com/role/RevenuefromContractswithCustomers 52 false false R53.htm 9955528 - Disclosure - Organization and Significant Accounting Policies (Details) Sheet http://soundcb.com/role/OrganizationandSignificantAccountingPoliciesDetails Organization and Significant Accounting Policies (Details) Details http://soundcb.com/role/OrganizationandSignificantAccountingPoliciesPolicies 53 false false R54.htm 9955529 - Disclosure - Accounting Pronouncements Recently Issued or Adopted (Details) Sheet http://soundcb.com/role/AccountingPronouncementsRecentlyIssuedorAdoptedDetails Accounting Pronouncements Recently Issued or Adopted (Details) Details http://soundcb.com/role/AccountingPronouncementsRecentlyIssuedorAdoptedTables 54 false false R55.htm 9955530 - Disclosure - Investments - Schedule of Amortized Cost and Fair Value of AFS Securities (Details) Sheet http://soundcb.com/role/InvestmentsScheduleofAmortizedCostandFairValueofAFSSecuritiesDetails Investments - Schedule of Amortized Cost and Fair Value of AFS Securities (Details) Details 55 false false R56.htm 9955531 - Disclosure - Investments - Schedule of Amortized Cost and Fair Value of HTM Securities (Details) Sheet http://soundcb.com/role/InvestmentsScheduleofAmortizedCostandFairValueofHTMSecuritiesDetails Investments - Schedule of Amortized Cost and Fair Value of HTM Securities (Details) Details 56 false false R57.htm 9955532 - Disclosure - Investments - Schedule of Amortized Cost and Fair Value of AFS and HTM by Contractual Maturity (Details) Sheet http://soundcb.com/role/InvestmentsScheduleofAmortizedCostandFairValueofAFSandHTMbyContractualMaturityDetails Investments - Schedule of Amortized Cost and Fair Value of AFS and HTM by Contractual Maturity (Details) Details 57 false false R58.htm 9955533 - Disclosure - Investments - Narrative (Details) Sheet http://soundcb.com/role/InvestmentsNarrativeDetails Investments - Narrative (Details) Details 58 false false R59.htm 9955534 - Disclosure - Investments - Schedule of Aggregate Fair Value and Gross Unrealized Loss by Length of Time (Details) Sheet http://soundcb.com/role/InvestmentsScheduleofAggregateFairValueandGrossUnrealizedLossbyLengthofTimeDetails Investments - Schedule of Aggregate Fair Value and Gross Unrealized Loss by Length of Time (Details) Details 59 false false R60.htm 9955535 - Disclosure - Loans - Schedule of Composition of Loan Portfolio, Excluding Loans Held-for-sale (Details) Sheet http://soundcb.com/role/LoansScheduleofCompositionofLoanPortfolioExcludingLoansHeldforsaleDetails Loans - Schedule of Composition of Loan Portfolio, Excluding Loans Held-for-sale (Details) Details 60 false false R61.htm 9955536 - Disclosure - Loans - Narrative (Details) Sheet http://soundcb.com/role/LoansNarrativeDetails Loans - Narrative (Details) Details 61 false false R62.htm 9955537 - Disclosure - Loans - Schedule of Activity in Allowance for Credit Losses (Details) Sheet http://soundcb.com/role/LoansScheduleofActivityinAllowanceforCreditLossesDetails Loans - Schedule of Activity in Allowance for Credit Losses (Details) Details 62 false false R63.htm 9955538 - Disclosure - Loans - Schedule of Activity in Allowance for Loan Losses (Details) Sheet http://soundcb.com/role/LoansScheduleofActivityinAllowanceforLoanLossesDetails Loans - Schedule of Activity in Allowance for Loan Losses (Details) Details 63 false false R64.htm 9955539 - Disclosure - Loans - Term Loans Amortized Cost Basis by Origination Year (Details) Sheet http://soundcb.com/role/LoansTermLoansAmortizedCostBasisbyOriginationYearDetails Loans - Term Loans Amortized Cost Basis by Origination Year (Details) Details 64 false false R65.htm 9955540 - Disclosure - Loans - Schedule of Credit Quality Indicators (Details) Sheet http://soundcb.com/role/LoansScheduleofCreditQualityIndicatorsDetails Loans - Schedule of Credit Quality Indicators (Details) Details 65 false false R66.htm 9955541 - Disclosure - Loans - Schedule of Investment in Nonaccrual Loans (Details) Sheet http://soundcb.com/role/LoansScheduleofInvestmentinNonaccrualLoansDetails Loans - Schedule of Investment in Nonaccrual Loans (Details) Details 66 false false R67.htm 9955542 - Disclosure - Loans - Schedule of Recorded Investment Aging In Past Due Loans (Details) Sheet http://soundcb.com/role/LoansScheduleofRecordedInvestmentAgingInPastDueLoansDetails Loans - Schedule of Recorded Investment Aging In Past Due Loans (Details) Details 67 false false R68.htm 9955543 - Disclosure - Loans - Schedule of Collateral Dependent Loans (Details) Sheet http://soundcb.com/role/LoansScheduleofCollateralDependentLoansDetails Loans - Schedule of Collateral Dependent Loans (Details) Details 68 false false R69.htm 9955544 - Disclosure - Loans - Schedule of Related Party Loans (Details) Sheet http://soundcb.com/role/LoansScheduleofRelatedPartyLoansDetails Loans - Schedule of Related Party Loans (Details) Details 69 false false R70.htm 9955545 - Disclosure - Mortgage Servicing Rights - Narrative (Details) Sheet http://soundcb.com/role/MortgageServicingRightsNarrativeDetails Mortgage Servicing Rights - Narrative (Details) Details 70 false false R71.htm 9955546 - Disclosure - Mortgage Servicing Rights - Schedule of Change in the Balance of Mortgage Servicing Assets (Details) Sheet http://soundcb.com/role/MortgageServicingRightsScheduleofChangeintheBalanceofMortgageServicingAssetsDetails Mortgage Servicing Rights - Schedule of Change in the Balance of Mortgage Servicing Assets (Details) Details 71 false false R72.htm 9955547 - Disclosure - Mortgage Servicing Rights - Mortgage Service Rights Assumptions (Details) Sheet http://soundcb.com/role/MortgageServicingRightsMortgageServiceRightsAssumptionsDetails Mortgage Servicing Rights - Mortgage Service Rights Assumptions (Details) Details 72 false false R73.htm 9955548 - Disclosure - Premises and Equipment (Details) Sheet http://soundcb.com/role/PremisesandEquipmentDetails Premises and Equipment (Details) Details http://soundcb.com/role/PremisesandEquipmentTables 73 false false R74.htm 9955549 - Disclosure - Other Real Estate Owned and Repossessed Assets (Details) Sheet http://soundcb.com/role/OtherRealEstateOwnedandRepossessedAssetsDetails Other Real Estate Owned and Repossessed Assets (Details) Details http://soundcb.com/role/OtherRealEstateOwnedandRepossessedAssetsTables 74 false false R75.htm 9955550 - Disclosure - Deposits - Corresponding Weighted-average Cost of Funds and Maturities of Time Deposits (Details) Sheet http://soundcb.com/role/DepositsCorrespondingWeightedaverageCostofFundsandMaturitiesofTimeDepositsDetails Deposits - Corresponding Weighted-average Cost of Funds and Maturities of Time Deposits (Details) Details 75 false false R76.htm 9955551 - Disclosure - Deposits - Narrative (Details) Sheet http://soundcb.com/role/DepositsNarrativeDetails Deposits - Narrative (Details) Details 76 false false R77.htm 9955552 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes - Schedule of Outstanding Balances and related Information for FHLB Borrowings (Details) Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotesScheduleofOutstandingBalancesandrelatedInformationforFHLBBorrowingsDetails Borrowings, FHLB Stock and Subordinated Notes - Schedule of Outstanding Balances and related Information for FHLB Borrowings (Details) Details 77 false false R78.htm 9955553 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes - Schedule of Federal Home Loan Bank, Advances (Details) Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotesScheduleofFederalHomeLoanBankAdvancesDetails Borrowings, FHLB Stock and Subordinated Notes - Schedule of Federal Home Loan Bank, Advances (Details) Details 78 false false R79.htm 9955554 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes - Maturity of FHLB Advances (Details) Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotesMaturityofFHLBAdvancesDetails Borrowings, FHLB Stock and Subordinated Notes - Maturity of FHLB Advances (Details) Details 79 false false R80.htm 9955555 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes - Schedule of Borrowing Capacity from the FHLB (Details) Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotesScheduleofBorrowingCapacityfromtheFHLBDetails Borrowings, FHLB Stock and Subordinated Notes - Schedule of Borrowing Capacity from the FHLB (Details) Details 80 false false R81.htm 9955556 - Disclosure - Borrowings, FHLB Stock and Subordinated Notes - Narrative (Details) Notes http://soundcb.com/role/BorrowingsFHLBStockandSubordinatedNotesNarrativeDetails Borrowings, FHLB Stock and Subordinated Notes - Narrative (Details) Details 81 false false R82.htm 9955557 - Disclosure - Fair Value Measurements -Schedule of Fair Value Hierarchy for Financial Instruments (Details) Sheet http://soundcb.com/role/FairValueMeasurementsScheduleofFairValueHierarchyforFinancialInstrumentsDetails Fair Value Measurements -Schedule of Fair Value Hierarchy for Financial Instruments (Details) Details 82 false false R83.htm 9955558 - Disclosure - Fair Value Measurements - Schedule of Fair Value of Assets Measured on Recurring and Nonrecurring Basis (Details) Sheet http://soundcb.com/role/FairValueMeasurementsScheduleofFairValueofAssetsMeasuredonRecurringandNonrecurringBasisDetails Fair Value Measurements - Schedule of Fair Value of Assets Measured on Recurring and Nonrecurring Basis (Details) Details 83 false false R84.htm 9955559 - Disclosure - Fair Value Measurements -Schedule of Quantitative Information (Details) Sheet http://soundcb.com/role/FairValueMeasurementsScheduleofQuantitativeInformationDetails Fair Value Measurements -Schedule of Quantitative Information (Details) Details 84 false false R85.htm 9955560 - Disclosure - Leases - Narrative (Details) Sheet http://soundcb.com/role/LeasesNarrativeDetails Leases - Narrative (Details) Details 85 false false R86.htm 9955561 - Disclosure - Leases - Schedule of Balance Sheet Information Related to Leases (Details) Sheet http://soundcb.com/role/LeasesScheduleofBalanceSheetInformationRelatedtoLeasesDetails Leases - Schedule of Balance Sheet Information Related to Leases (Details) Details 86 false false R87.htm 9955562 - Disclosure - Leases - Schedule of Components of the Leases and Lease Term and Discount Rate by Lease Type (Details) Sheet http://soundcb.com/role/LeasesScheduleofComponentsoftheLeasesandLeaseTermandDiscountRatebyLeaseTypeDetails Leases - Schedule of Components of the Leases and Lease Term and Discount Rate by Lease Type (Details) Details 87 false false R88.htm 9955563 - Disclosure - Leases - Schedule of Lease Liability Maturities (Details) Sheet http://soundcb.com/role/LeasesScheduleofLeaseLiabilityMaturitiesDetails Leases - Schedule of Lease Liability Maturities (Details) Details 88 false false R89.htm 9955564 - Disclosure - Earnings Per Share (Details) Sheet http://soundcb.com/role/EarningsPerShareDetails Earnings Per Share (Details) Details http://soundcb.com/role/EarningsPerShareTables 89 false false R90.htm 9955565 - Disclosure - Employee Benefits - 401(K) Plan and Deferred Compensation Plan Narrative (Details) Sheet http://soundcb.com/role/EmployeeBenefits401KPlanandDeferredCompensationPlanNarrativeDetails Employee Benefits - 401(K) Plan and Deferred Compensation Plan Narrative (Details) Details 90 false false R91.htm 9955566 - Disclosure - Employee Benefits - Supplemental Executive Retirement Plans Narrative (Details) Sheet http://soundcb.com/role/EmployeeBenefitsSupplementalExecutiveRetirementPlansNarrativeDetails Employee Benefits - Supplemental Executive Retirement Plans Narrative (Details) Details 91 false false R92.htm 9955567 - Disclosure - Employee Benefits - Stock Options and Restricted Stock Narrative (Details) Sheet http://soundcb.com/role/EmployeeBenefitsStockOptionsandRestrictedStockNarrativeDetails Employee Benefits - Stock Options and Restricted Stock Narrative (Details) Details 92 false false R93.htm 9955568 - Disclosure - Employee Benefits - Stock Option Awards Narrative (Details) Sheet http://soundcb.com/role/EmployeeBenefitsStockOptionAwardsNarrativeDetails Employee Benefits - Stock Option Awards Narrative (Details) Details 93 false false R94.htm 9955569 - Disclosure - Employee Benefits - Schedule of Stock Option Plan Award Activity (Details) Sheet http://soundcb.com/role/EmployeeBenefitsScheduleofStockOptionPlanAwardActivityDetails Employee Benefits - Schedule of Stock Option Plan Award Activity (Details) Details 94 false false R95.htm 9955570 - Disclosure - Employee Benefits - Restricted Stock Awards Narrative (Details) Sheet http://soundcb.com/role/EmployeeBenefitsRestrictedStockAwardsNarrativeDetails Employee Benefits - Restricted Stock Awards Narrative (Details) Details 95 false false R96.htm 9955571 - Disclosure - Employee Benefits - Schedule of Nonvested Restricted Stock Awards (Details) Sheet http://soundcb.com/role/EmployeeBenefitsScheduleofNonvestedRestrictedStockAwardsDetails Employee Benefits - Schedule of Nonvested Restricted Stock Awards (Details) Details 96 false false R97.htm 9955572 - Disclosure - Employee Benefits - Employee Stock Ownership Plan Narrative (Details) Sheet http://soundcb.com/role/EmployeeBenefitsEmployeeStockOwnershipPlanNarrativeDetails Employee Benefits - Employee Stock Ownership Plan Narrative (Details) Details 97 false false R98.htm 9955573 - Disclosure - Income Taxes - Provision for Income Taxes (Details) Sheet http://soundcb.com/role/IncomeTaxesProvisionforIncomeTaxesDetails Income Taxes - Provision for Income Taxes (Details) Details 98 false false R99.htm 9955574 - Disclosure - Income Taxes - Reconciliation of Provision for Income Taxes (Details) Sheet http://soundcb.com/role/IncomeTaxesReconciliationofProvisionforIncomeTaxesDetails Income Taxes - Reconciliation of Provision for Income Taxes (Details) Details 99 false false R100.htm 9955575 - Disclosure - Income Taxes - Components of Deferred Tax Assets (Details) Sheet http://soundcb.com/role/IncomeTaxesComponentsofDeferredTaxAssetsDetails Income Taxes - Components of Deferred Tax Assets (Details) Details 100 false false R101.htm 9955576 - Disclosure - Capital (Details) Sheet http://soundcb.com/role/CapitalDetails Capital (Details) Details http://soundcb.com/role/Capital 101 false false R102.htm 9955577 - Disclosure - Concentrations of Credit Risk (Details) Sheet http://soundcb.com/role/ConcentrationsofCreditRiskDetails Concentrations of Credit Risk (Details) Details http://soundcb.com/role/ConcentrationsofCreditRisk 102 false false R103.htm 9955578 - Disclosure - Commitments and Contingencies - Schedule of Financial Instruments containing Commitments representing Credit Risk (Details) Sheet http://soundcb.com/role/CommitmentsandContingenciesScheduleofFinancialInstrumentscontainingCommitmentsrepresentingCreditRiskDetails Commitments and Contingencies - Schedule of Financial Instruments containing Commitments representing Credit Risk (Details) Details 103 false false R104.htm 9955579 - Disclosure - Commitments and Contingencies - Narrative (Details) Sheet http://soundcb.com/role/CommitmentsandContingenciesNarrativeDetails Commitments and Contingencies - Narrative (Details) Details 104 false false R105.htm 9955580 - Disclosure - Parent Company Financial Information - Balance Sheets (Details) Sheet http://soundcb.com/role/ParentCompanyFinancialInformationBalanceSheetsDetails Parent Company Financial Information - Balance Sheets (Details) Details 105 false false R106.htm 9955581 - Disclosure - Parent Company Financial Information - Statements of Income (Details) Sheet http://soundcb.com/role/ParentCompanyFinancialInformationStatementsofIncomeDetails Parent Company Financial Information - Statements of Income (Details) Details 106 false false R107.htm 9955582 - Disclosure - Parent Company Financial Information - Statements of Cash Flows (Details) Sheet http://soundcb.com/role/ParentCompanyFinancialInformationStatementsofCashFlowsDetails Parent Company Financial Information - Statements of Cash Flows (Details) Details 107 false false R108.htm 9955583 - Disclosure - Revenue from Contracts with Customers (Details) Sheet http://soundcb.com/role/RevenuefromContractswithCustomersDetails Revenue from Contracts with Customers (Details) Details http://soundcb.com/role/RevenuefromContractswithCustomersTables 108 false false R109.htm 9955584 - Disclosure - Business Segments (Details) Sheet http://soundcb.com/role/BusinessSegmentsDetails Business Segments (Details) Details http://soundcb.com/role/BusinessSegments 109 false false R110.htm 9955585 - Disclosure - Subsequent Events (Details) Sheet http://soundcb.com/role/SubsequentEventsDetails Subsequent Events (Details) Details http://soundcb.com/role/SubsequentEvents 110 false false All Reports Book All Reports sfbc-20241231.htm sfbc-20241231.xsd sfbc-20241231_cal.xml sfbc-20241231_def.xml sfbc-20241231_lab.xml sfbc-20241231_pre.xml http://fasb.org/srt/2024 http://fasb.org/us-gaap/2024 http://xbrl.sec.gov/cyd/2024 http://xbrl.sec.gov/dei/2024 http://xbrl.sec.gov/ecd/2024 true true