2.4.0.6 Html 342 531 1 true 88 0 false 4 false false R1.htm 0001 - Document - Document and Entity Information Sheet http://sgfc.com/role/DocumentAndEntityInformation Document and Entity Information true false R2.htm 0002 - Statement - Consolidated Balance Sheets Sheet http://sgfc.com/role/BalanceSheets Consolidated Balance Sheets false false R3.htm 0003 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://sgfc.com/role/BalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) false false R4.htm 0004 - Statement - Consolidated Statements of Income Sheet http://sgfc.com/role/StatementsOfIncome Consolidated Statements of Income false false R5.htm 0005 - Statement - Consolidated Statements of Comprehensive Income Sheet http://sgfc.com/role/StatementsOfComprehensiveIncome Consolidated Statements of Comprehensive Income false false R6.htm 0006 - Statement - Consolidated Statements of Changes in Stockholders' Equity (Unaudited) Sheet http://sgfc.com/role/StatementsOfChangesInStockholdersEquity Consolidated Statements of Changes in Stockholders' Equity (Unaudited) false false R7.htm 0007 - Statement - Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) Sheet http://sgfc.com/role/StatementsOfChangesInStockholdersEquityParenthetical Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) false false R8.htm 0008 - Statement - Consolidated Statements of Cash Flows Sheet http://sgfc.com/role/StatementsOfCashFlows Consolidated Statements of Cash Flows false false R9.htm 0009 - Disclosure - Summary of Significant Accounting Policies Sheet http://sgfc.com/role/SummaryOfSignificantAccountingPolicies Summary of Significant Accounting Policies false false R10.htm 0010 - Disclosure - Investment Securities Sheet http://sgfc.com/role/InvestmentSecurities Investment Securities false false R11.htm 0011 - Disclosure - Loans and Allowance for Loan Losses Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses Loans and Allowance for Loan Losses false false R12.htm 0012 - Disclosure - Premises and Equipment Sheet http://sgfc.com/role/PremisesAndEquipment Premises and Equipment false false R13.htm 0013 - Disclosure - Intangible Assets Sheet http://sgfc.com/role/IntangibleAssets Intangible Assets false false R14.htm 0014 - Disclosure - Deposits Sheet http://sgfc.com/role/Deposits Deposits false false R15.htm 0015 - Disclosure - Short-Term Borrowed Funds Sheet http://sgfc.com/role/Short-TermBorrowedFunds Short-Term Borrowed Funds false false R16.htm 0016 - Disclosure - Long-Term Debt Sheet http://sgfc.com/role/Long-TermDebt Long-Term Debt false false R17.htm 0017 - Disclosure - Employee Benefits and Retirement Plans Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans Employee Benefits and Retirement Plans false false R18.htm 0018 - Disclosure - Income Taxes Sheet http://sgfc.com/role/IncomeTaxes Income Taxes false false R19.htm 0019 - Disclosure - Related Party Transactions Sheet http://sgfc.com/role/RelatedPartyTransactions Related Party Transactions false false R20.htm 0020 - Disclosure - Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk Sheet http://sgfc.com/role/CommitmentsContingentLiabilitiesAndFinancialInstrumentsWithOff-BalanceSheetRisk Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk false false R21.htm 0021 - Disclosure - Fair Value Measurements and Disclosures Sheet http://sgfc.com/role/FairValueMeasurementsAndDisclosures Fair Value Measurements and Disclosures false false R22.htm 0022 - Disclosure - Supplemental Financial Data Sheet http://sgfc.com/role/SupplementalFinancialData Supplemental Financial Data false false R23.htm 0023 - Disclosure - Stockholders' Equity / Regulatory Matters Sheet http://sgfc.com/role/StockholdersEquityRegulatoryMatters Stockholders' Equity / Regulatory Matters false false R24.htm 0024 - Disclosure - Parent Company Financial Data Sheet http://sgfc.com/role/ParentCompanyFinancialData Parent Company Financial Data false false R25.htm 0025 - Disclosure - Earnings Per Share Sheet http://sgfc.com/role/EarningsPerShare Earnings Per Share false false R26.htm 0026 - Disclosure - Quarterly Data Sheet http://sgfc.com/role/QuarterlyData Quarterly Data false false R27.htm 0027 - Disclosure - Segment Reporting Sheet http://sgfc.com/role/SegmentReporting Segment Reporting false false R28.htm 0028 - Disclosure - Subsequent Events Sheet http://sgfc.com/role/SubsequentEvents Subsequent Events false false R29.htm 0029 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://sgfc.com/role/SummaryOfSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) false false R30.htm 0030 - Disclosure - Summary of Significant Accounting Policies (Tables) Sheet http://sgfc.com/role/SummaryOfSignificantAccountingPoliciesTables Summary of Significant Accounting Policies (Tables) false false R31.htm 0031 - Disclosure - Investment Securities (Tables) Sheet http://sgfc.com/role/InvestmentSecuritiesTables Investment Securities (Tables) false false R32.htm 0032 - Disclosure - Loans and Allowance for Loan Losses (Tables) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLossesTables Loans and Allowance for Loan Losses (Tables) false false R33.htm 0033 - Disclosure - Premises and Equipment (Tables) Sheet http://sgfc.com/role/PremisesAndEquipmentTables Premises and Equipment (Tables) false false R34.htm 0034 - Disclosure - Intangible Assets (Tables) Sheet http://sgfc.com/role/IntangibleAssetsTables Intangible Assets (Tables) false false R35.htm 0035 - Disclosure - Deposits (Tables) Sheet http://sgfc.com/role/DepositsTables Deposits (Tables) false false R36.htm 0036 - Disclosure - Short-Term Borrowed Funds (Tables) Sheet http://sgfc.com/role/Short-TermBorrowedFundsTables Short-Term Borrowed Funds (Tables) false false R37.htm 0037 - Disclosure - Long-Term Debt (Tables) Sheet http://sgfc.com/role/Long-TermDebtTables Long-Term Debt (Tables) false false R38.htm 0038 - Disclosure - Employee Benefits and Retirement Plans (Tables) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlansTables Employee Benefits and Retirement Plans (Tables) false false R39.htm 0039 - Disclosure - Income Taxes (Tables) Sheet http://sgfc.com/role/IncomeTaxesTables Income Taxes (Tables) false false R40.htm 0040 - Disclosure - Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk (Tables) Sheet http://sgfc.com/role/CommitmentsContingentLiabilitiesAndFinancialInstrumentsWithOff-BalanceSheetRiskTables Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk (Tables) false false R41.htm 0041 - Disclosure - Fair Value Measurements and Disclosures (Tables) Sheet http://sgfc.com/role/FairValueMeasurementsAndDisclosuresTables Fair Value Measurements and Disclosures (Tables) false false R42.htm 0042 - Disclosure - Supplemental Financial Data (Tables) Sheet http://sgfc.com/role/SupplementalFinancialDataTables Supplemental Financial Data (Tables) false false R43.htm 0043 - Disclosure - Stockholders' Equity / Regulatory Matters (Tables) Sheet http://sgfc.com/role/StockholdersEquityRegulatoryMattersTables Stockholders' Equity / Regulatory Matters (Tables) false false R44.htm 0044 - Disclosure - Parent Company Financial Data (Tables) Sheet http://sgfc.com/role/ParentCompanyFinancialDataTables Parent Company Financial Data (Tables) false false R45.htm 0045 - Disclosure - Earnings Per Share (Tables) Sheet http://sgfc.com/role/EarningsPerShareTables Earnings Per Share (Tables) false false R46.htm 0046 - Disclosure - Quarterly Data (Tables) Sheet http://sgfc.com/role/QuarterlyDataTables Quarterly Data (Tables) false false R47.htm 0047 - Disclosure - Segment Reporting (Tables) Sheet http://sgfc.com/role/SegmentReportingTables Segment Reporting (Tables) false false R48.htm 0048 - Disclosure - Summary of Significant Accounting Policies (Details Narrative) Sheet http://sgfc.com/role/SummaryOfSignificantAccountingPoliciesDetailsNarrative Summary of Significant Accounting Policies (Details Narrative) false false R49.htm 0049 - Disclosure - Summary of Significant Accounting Policies - Summary of Premises and Equipment (Details) Sheet http://sgfc.com/role/SummaryOfSignificantAccountingPolicies-SummaryOfPremisesAndEquipmentDetails Summary of Significant Accounting Policies - Summary of Premises and Equipment (Details) false false R50.htm 0050 - Disclosure - Summary of Significant Accounting Policies - Summary of Accumulated Other Comprehensive Income (Loss) (Details) Sheet http://sgfc.com/role/SummaryOfSignificantAccountingPolicies-SummaryOfAccumulatedOtherComprehensiveIncomeLossDetails Summary of Significant Accounting Policies - Summary of Accumulated Other Comprehensive Income (Loss) (Details) false false R51.htm 0051 - Disclosure - Investment Securities (Details Narrative) Sheet http://sgfc.com/role/InvestmentSecuritiesDetailsNarrative Investment Securities (Details Narrative) false false R52.htm 0052 - Disclosure - Schedule of Securities Available for Sale Securities (Details) Sheet http://sgfc.com/role/ScheduleOfSecuritiesAvailableForSaleSecuritiesDetails Schedule of Securities Available for Sale Securities (Details) false false R53.htm 0053 - Disclosure - Schedule of Securities Held to Maturity (Details) Sheet http://sgfc.com/role/ScheduleOfSecuritiesHeldToMaturityDetails Schedule of Securities Held to Maturity (Details) false false R54.htm 0054 - Disclosure - Schedule of Information Pertaining to Securities Gross Unrealized Losses by Investments (Details) Sheet http://sgfc.com/role/ScheduleOfInformationPertainingToSecuritiesGrossUnrealizedLossesByInvestmentsDetails Schedule of Information Pertaining to Securities Gross Unrealized Losses by Investments (Details) false false R55.htm 0055 - Disclosure - Summary of Amortized Cost and Estimated Fair Value of Securities Sheet http://sgfc.com/role/SummaryOfAmortizedCostAndEstimatedFairValueOfSecurities Summary of Amortized Cost and Estimated Fair Value of Securities false false R56.htm 0056 - Disclosure - Loans and Allowance for Loan Losses (Details Narrative) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLossesDetailsNarrative Loans and Allowance for Loan Losses (Details Narrative) false false R57.htm 0057 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Composition of Corporation's Loan Portfolio (Details) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfCompositionOfCorporationsLoanPortfolioDetails Loans and Allowance for Loan Losses - Schedule of Composition of Corporation's Loan Portfolio (Details) false false R58.htm 0058 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Past Due Loans and Nonaccrual Loans (Details) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfPastDueLoansAndNonaccrualLoansDetails Loans and Allowance for Loan Losses - Schedule of Past Due Loans and Nonaccrual Loans (Details) false false R59.htm 0059 - Disclosure - Schedule of Impaired Loans Segregated by Class of Loans (Details) Sheet http://sgfc.com/role/ScheduleOfImpairedLoansSegregatedByClassOfLoansDetails Schedule of Impaired Loans Segregated by Class of Loans (Details) false false R60.htm 0060 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Troubled Debt Restructuring by Loan Class Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfTroubledDebtRestructuringByLoanClass Loans and Allowance for Loan Losses - Schedule of Troubled Debt Restructuring by Loan Class false false R61.htm 0061 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Troubled Debt Restructurings By Types of Concessions Made Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfTroubledDebtRestructuringsByTypesOfConcessionsMade Loans and Allowance for Loan Losses - Schedule of Troubled Debt Restructurings By Types of Concessions Made false false R62.htm 0062 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Internal Loan Grading by Class of Loans (Details) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfInternalLoanGradingByClassOfLoansDetails Loans and Allowance for Loan Losses - Schedule of Internal Loan Grading by Class of Loans (Details) false false R63.htm 0063 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Changes in Allowance for Loan Losses (Details) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfChangesInAllowanceForLoanLossesDetails Loans and Allowance for Loan Losses - Schedule of Changes in Allowance for Loan Losses (Details) false false R64.htm 0064 - Disclosure - Loans and Allowance for Loan Losses - Schedule of Allowance for Loan Losses Methodology (Details) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ScheduleOfAllowanceForLoanLossesMethodologyDetails Loans and Allowance for Loan Losses - Schedule of Allowance for Loan Losses Methodology (Details) false false R65.htm 0065 - Disclosure - Loans and Allowance for Loan Losses - Impaired Loans With Specific Reserves and Recorded Balance of Related Loans (Details) Sheet http://sgfc.com/role/LoansAndAllowanceForLoanLosses-ImpairedLoansWithSpecificReservesAndRecordedBalanceOfRelatedLoansDetails Loans and Allowance for Loan Losses - Impaired Loans With Specific Reserves and Recorded Balance of Related Loans (Details) false false R66.htm 0066 - Disclosure - Premises and Equipment (Details Narrative) Sheet http://sgfc.com/role/PremisesAndEquipmentDetailsNarrative Premises and Equipment (Details Narrative) false false R67.htm 0067 - Disclosure - Premises and Equipment - Summary of Premises and Equipment (Details) Sheet http://sgfc.com/role/PremisesAndEquipment-SummaryOfPremisesAndEquipmentDetails Premises and Equipment - Summary of Premises and Equipment (Details) false false R68.htm 0068 - Disclosure - Intangible Assets (Details Narrative) Sheet http://sgfc.com/role/IntangibleAssetsDetailsNarrative Intangible Assets (Details Narrative) false false R69.htm 0069 - Disclosure - Intangible Assets - Summary of Inatngible Assets (Details) Sheet http://sgfc.com/role/IntangibleAssets-SummaryOfInatngibleAssetsDetails Intangible Assets - Summary of Inatngible Assets (Details) false false R70.htm 0070 - Disclosure - Intangible Assets - Schedule of Expected Amortization Expense (Details) Sheet http://sgfc.com/role/IntangibleAssets-ScheduleOfExpectedAmortizationExpenseDetails Intangible Assets - Schedule of Expected Amortization Expense (Details) false false R71.htm 0071 - Disclosure - Deposits (Details Narrative) Sheet http://sgfc.com/role/DepositsDetailsNarrative Deposits (Details Narrative) false false R72.htm 0072 - Disclosure - Deposits - Schedule of Maturities of Certificates of Deposits (Details) Sheet http://sgfc.com/role/Deposits-ScheduleOfMaturitiesOfCertificatesOfDepositsDetails Deposits - Schedule of Maturities of Certificates of Deposits (Details) false false R73.htm 0073 - Disclosure - Short-Term Borrowed Funds (Details Narrative) Sheet http://sgfc.com/role/Short-TermBorrowedFundsDetailsNarrative Short-Term Borrowed Funds (Details Narrative) false false R74.htm 0074 - Disclosure - Short-Term Borrowed Funds - Summary of FHLB (Details) Sheet http://sgfc.com/role/Short-TermBorrowedFunds-SummaryOfFhlbDetails Short-Term Borrowed Funds - Summary of FHLB (Details) false false R75.htm 0075 - Disclosure - Long-Term Debt (Details Narrative) Sheet http://sgfc.com/role/Long-TermDebtDetailsNarrative Long-Term Debt (Details Narrative) false false R76.htm 0076 - Disclosure - Long-Term Debt - Schedule of Long-Term Debt (Details) Sheet http://sgfc.com/role/Long-TermDebt-ScheduleOfLong-TermDebtDetails Long-Term Debt - Schedule of Long-Term Debt (Details) false false R77.htm 0077 - Disclosure - Long-Term Debt - Summary of Maturities of Long-Term Debt (Details) Sheet http://sgfc.com/role/Long-TermDebt-SummaryOfMaturitiesOfLong-TermDebtDetails Long-Term Debt - Summary of Maturities of Long-Term Debt (Details) false false R78.htm 0078 - Disclosure - Employee Benefits and Retirement Plans (Details Narrative) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlansDetailsNarrative Employee Benefits and Retirement Plans (Details Narrative) false false R79.htm 0079 - Disclosure - Employee Benefits And Retirement Plans - Schedule of Computed Benefit Obligations and Net Assets and Related Changes (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-ScheduleOfComputedBenefitObligationsAndNetAssetsAndRelatedChangesDetails Employee Benefits And Retirement Plans - Schedule of Computed Benefit Obligations and Net Assets and Related Changes (Details) false false R80.htm 0080 - Disclosure - Employee Benefits and Retirement Plans - Amount Recognized in Consolidated Balance Sheet (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-AmountRecognizedInConsolidatedBalanceSheetDetails Employee Benefits and Retirement Plans - Amount Recognized in Consolidated Balance Sheet (Details) false false R81.htm 0081 - Disclosure - Employee Benefits and Retirement Plans - Amounts Recognized in Comprehensive Income (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-AmountsRecognizedInComprehensiveIncomeDetails Employee Benefits and Retirement Plans - Amounts Recognized in Comprehensive Income (Details) false false R82.htm 0082 - Disclosure - Employee Benefits and Retirement Plans - Assumptions Used to Determine Benefit Obligation (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-AssumptionsUsedToDetermineBenefitObligationDetails Employee Benefits and Retirement Plans - Assumptions Used to Determine Benefit Obligation (Details) false false R83.htm 0083 - Disclosure - Employee Benefits and Retirement Plans - Assumptions Used to Determine Net Periodic Pension Cost(Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-AssumptionsUsedToDetermineNetPeriodicPensionCostdetails Employee Benefits and Retirement Plans - Assumptions Used to Determine Net Periodic Pension Cost(Details) false false R84.htm 0084 - Disclosure - Employee Benefits and Retirement Plans - Pension Asset Allocation and Fair Value Measurement (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-PensionAssetAllocationAndFairValueMeasurementDetails Employee Benefits and Retirement Plans - Pension Asset Allocation and Fair Value Measurement (Details) false false R85.htm 0085 - Disclosure - Employee Benefits and Retirement Plans - Estimated Future Benefit Payments (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-EstimatedFutureBenefitPaymentsDetails Employee Benefits and Retirement Plans - Estimated Future Benefit Payments (Details) false false R86.htm 0086 - Disclosure - Employee Benefits and Retirement Plans - Summary of Stock Options (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-SummaryOfStockOptionsDetails Employee Benefits and Retirement Plans - Summary of Stock Options (Details) false false R87.htm 0087 - Disclosure - Employee Benefits and Retirement Plans - Summary of Changes in Stock Options (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-SummaryOfChangesInStockOptionsDetails Employee Benefits and Retirement Plans - Summary of Changes in Stock Options (Details) false false R88.htm 0088 - Disclosure - Employee Benefits and Retirement Plans - Summary of Stock Options Outstanding and Exercisable (Details) Sheet http://sgfc.com/role/EmployeeBenefitsAndRetirementPlans-SummaryOfStockOptionsOutstandingAndExercisableDetails Employee Benefits and Retirement Plans - Summary of Stock Options Outstanding and Exercisable (Details) false false R89.htm 0089 - Disclosure - Income Taxes - Schedule of Components of Income Tax Expense (Details) Sheet http://sgfc.com/role/IncomeTaxes-ScheduleOfComponentsOfIncomeTaxExpenseDetails Income Taxes - Schedule of Components of Income Tax Expense (Details) false false R90.htm 0090 - Disclosure - Income Taxes - Schedule of Income Taxes (Details) Sheet http://sgfc.com/role/IncomeTaxes-ScheduleOfIncomeTaxesDetails Income Taxes - Schedule of Income Taxes (Details) false false R91.htm 0091 - Disclosure - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) Sheet http://sgfc.com/role/IncomeTaxes-ScheduleOfEffectiveIncomeTaxRateReconciliationDetails Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) false false R92.htm 0092 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) Sheet http://sgfc.com/role/IncomeTaxes-ScheduleOfDeferredTaxAssetsAndLiabilitiesDetails Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) false false R93.htm 0093 - Disclosure - Related Party Transactions (Details Narrative) Sheet http://sgfc.com/role/RelatedPartyTransactionsDetailsNarrative Related Party Transactions (Details Narrative) false false R94.htm 0094 - Disclosure - Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk (Details Narrative) Sheet http://sgfc.com/role/CommitmentsContingentLiabilitiesAndFinancialInstrumentsWithOff-BalanceSheetRiskDetailsNarrative Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk (Details Narrative) false false R95.htm 0095 - Disclosure - Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk - Contractual or Notional Amounts of Financial Instruments (Details) Sheet http://sgfc.com/role/CommitmentsContingentLiabilitiesAndFinancialInstrumentsWithOff-BalanceSheetRisk-ContractualOrNotionalAmountsOfFinancialInstrumentsDetails Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk - Contractual or Notional Amounts of Financial Instruments (Details) false false R96.htm 0096 - Disclosure - Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk - Schedule of Future Cash Payments (Details) Sheet http://sgfc.com/role/CommitmentsContingentLiabilitiesAndFinancialInstrumentsWithOff-BalanceSheetRisk-ScheduleOfFutureCashPaymentsDetails Commitments, Contingent Liabilities, and Financial Instruments with Off-Balance Sheet Risk - Schedule of Future Cash Payments (Details) false false R97.htm 0097 - Disclosure - Fair Value Measurements and Disclosures - Schedule of Assets Recorded at Fair Value on a Recurring Basis (Details) Sheet http://sgfc.com/role/FairValueMeasurementsAndDisclosures-ScheduleOfAssetsRecordedAtFairValueOnRecurringBasisDetails Fair Value Measurements and Disclosures - Schedule of Assets Recorded at Fair Value on a Recurring Basis (Details) false false R98.htm 0098 - Disclosure - Fair Value Measurements and Disclosures - Schedule of Fair Value of Assets Recorded on a Nonrecurring Basis (Details) Sheet http://sgfc.com/role/FairValueMeasurementsAndDisclosures-ScheduleOfFairValueOfAssetsRecordedOnNonrecurringBasisDetails Fair Value Measurements and Disclosures - Schedule of Fair Value of Assets Recorded on a Nonrecurring Basis (Details) false false R99.htm 0099 - Disclosure - Fair Value Measurements and Disclosures - Schedule of Carrying and Estimated Fair Value of Assets and Liabilities Recorded at Fair Value (Details) Sheet http://sgfc.com/role/FairValueMeasurementsAndDisclosures-ScheduleOfCarryingAndEstimatedFairValueOfAssetsAndLiabilitiesRecordedAtFairValueDetails Fair Value Measurements and Disclosures - Schedule of Carrying and Estimated Fair Value of Assets and Liabilities Recorded at Fair Value (Details) false false R100.htm 0100 - Disclosure - Fair Value Measurements and Disclosures - Schedule of Carrying and Estimated Fair Value of Assets and Liabilities (Details) Sheet http://sgfc.com/role/FairValueMeasurementsAndDisclosures-ScheduleOfCarryingAndEstimatedFairValueOfAssetsAndLiabilitiesDetails Fair Value Measurements and Disclosures - Schedule of Carrying and Estimated Fair Value of Assets and Liabilities (Details) false false R101.htm 0101 - Disclosure - Supplemental Financial Data - Schedule of Components of Operating Expenses (Details) Sheet http://sgfc.com/role/SupplementalFinancialData-ScheduleOfComponentsOfOperatingExpensesDetails Supplemental Financial Data - Schedule of Components of Operating Expenses (Details) false false R102.htm 0102 - Disclosure - Stockholders' Equity / Regulatory Matters (Details Narrative) Sheet http://sgfc.com/role/StockholdersEquityRegulatoryMattersDetailsNarrative Stockholders' Equity / Regulatory Matters (Details Narrative) false false R103.htm 0103 - Disclosure - Stockholders' Equity / Regulatory Matters - Summary of Leverage Ratio (Details) Sheet http://sgfc.com/role/StockholdersEquityRegulatoryMatters-SummaryOfLeverageRatioDetails Stockholders' Equity / Regulatory Matters - Summary of Leverage Ratio (Details) false false R104.htm 0104 - Disclosure - Parent Company Financial Data - Schedule of Balance Sheet Information of Parent Company (Details) Sheet http://sgfc.com/role/ParentCompanyFinancialData-ScheduleOfBalanceSheetInformationOfParentCompanyDetails Parent Company Financial Data - Schedule of Balance Sheet Information of Parent Company (Details) false false R105.htm 0105 - Disclosure - Parent Company Financial Data - Schedule of Balance Sheet Information of Parent Company (Details) (Parenthetical) Sheet http://sgfc.com/role/ParentCompanyFinancialData-ScheduleOfBalanceSheetInformationOfParentCompanyDetailsParenthetical Parent Company Financial Data - Schedule of Balance Sheet Information of Parent Company (Details) (Parenthetical) false false R106.htm 0106 - Disclosure - Parent Company Financial Data - Schedule of Statements of Operations Information of Parent Company (Details) Sheet http://sgfc.com/role/ParentCompanyFinancialData-ScheduleOfStatementsOfOperationsInformationOfParentCompanyDetails Parent Company Financial Data - Schedule of Statements of Operations Information of Parent Company (Details) false false R107.htm 0107 - Disclosure - Parent Company Financial Data - Schedule of Cash Flow Information of Parent Company (Details) Sheet http://sgfc.com/role/ParentCompanyFinancialData-ScheduleOfCashFlowInformationOfParentCompanyDetails Parent Company Financial Data - Schedule of Cash Flow Information of Parent Company (Details) false false R108.htm 0108 - Disclosure - Earnings Per Share - Schedule of Earnings Per Share (Details) Sheet http://sgfc.com/role/EarningsPerShare-ScheduleOfEarningsPerShareDetails Earnings Per Share - Schedule of Earnings Per Share (Details) false false R109.htm 0109 - Disclosure - Quarterly Data - Summary of Quarterly Data (Details) Sheet http://sgfc.com/role/QuarterlyData-SummaryOfQuarterlyDataDetails Quarterly Data - Summary of Quarterly Data (Details) false false R110.htm 0110 - Disclosure - Segment Reporting (Details Narrative) Sheet http://sgfc.com/role/SegmentReportingDetailsNarrative Segment Reporting (Details Narrative) false false R111.htm 0111 - Disclosure - Segment Reporting - Schedule of Segment Reporting Information (Details) Sheet http://sgfc.com/role/SegmentReporting-ScheduleOfSegmentReportingInformationDetails Segment Reporting - Schedule of Segment Reporting Information (Details) false false All Reports Book All Reports Process Flow-Through: 0002 - Statement - Consolidated Balance Sheets Process Flow-Through: Removing column 'Dec. 31, 2010' Process Flow-Through: Removing column 'Dec. 31, 2009' Process Flow-Through: 0003 - Statement - Consolidated Balance Sheets (Parenthetical) Process Flow-Through: 0004 - Statement - Consolidated Statements of Income Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2012' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2012' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2012' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2012' Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2011' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2011' Process Flow-Through: 0005 - Statement - Consolidated Statements of Comprehensive Income Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2012' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2012' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2012' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2012' Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2011' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2011' Process Flow-Through: 0007 - Statement - Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) Process Flow-Through: 0008 - Statement - Consolidated Statements of Cash Flows sgb-20121231.xml sgb-20121231.xsd sgb-20121231_cal.xml sgb-20121231_def.xml sgb-20121231_lab.xml sgb-20121231_pre.xml true true