Document And Entity Information Statistical Measurement [Axis] Note To Financial Statement Details Textual Document Fiscal Period Focus EBP, Basis of Accounting [Policy Text Block] Significant Accounting Policies Document Fiscal Year Focus Note B - Summary of Significant Accounting Policies Schedule H, Line 4i Note B - Summary of Significant Accounting Policies - Fair Value Measurements (Details) Amendment Flag Schedule H, Line 4i - Schedule of Assets (Held at End of Year) 2 (Details) Schedule H, Line 4i - Schedule of Assets (Held at End of Year) 2 2 (Details) us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentPartyInInterest EBP, Asset Held for Investment, Party-in-Interest [true false] Notes To Financial Statements Notes To Financial Statements [Abstract] Minimum [Member] dei_DocumentPeriodEndDate Document Period End Date Statistical Measurement [Domain] us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution Total contributions Maximum [Member] Legal Entity [Axis] EBP, Schedule of Asset Held for Investment [Table] us-gaap-ebp_EmployeeBenefitPlanParticipantLoanMaturityDate EBP, Asset Held for Investment, Participant Loan, Maturity Date Notes receivable from participants dei_EntityTaxIdentificationNumber Entity Tax Identification Number Entity [Domain] Interest income on notes receivable from participants Entity Central Index Key Net appreciation in fair value of investments dei_EntityRegistrantName Entity Registrant Name Entity Current Reporting Status EBP, Description of Plan [Text Block] EBP, Asset Held for Investment EBP, Related Party and Party-in-Interest Transactions [Table] Current Fiscal Year End Date us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterDate EBP, Tax Determination Letter, Date NOTES RECEIVABLE FROM PARTICIPANTS us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease Total additions Entity Shell Company Common Collective Trust [Member] Entity Emerging Growth Company Entity Small Business Investments [Domain] EBP, Employer, Common Stock [Member] us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant Benefits paid to participants Accounting Policies [Abstract] Participant rollovers Employer us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment Total investment income Investments, at contract value EBP, Investment, Contract Value Valuation Approach and Technique [Domain] us-gaap-ebp_EmployeeBenefitPlanTaxQualificationStatusExtensibleEnumeration EBP, Tax Qualification Status [Extensible Enumeration] Valuation, Market Approach [Member] Statement of Stockholders' Equity [Abstract] EBP, Tax Status [Text Block] us-gaap-ebp_EmployeeBenefitPlanInvestmentFairAndContractValue Total Investments us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount EBP, Forfeited Nonvested Account us-gaap-ebp_EmployeeBenefitPlanInvestmentValuationTechniqueExtensibleEnumeration EBP, Investment, Valuation Technique [Extensible Enumeration] SAGIC DIVERSIFIED BOND I Equity Components [Axis] Investments, at fair value Class of Stock [Axis] Equity Component [Domain] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 1 [Member] EBP, Subsequent Event [Table] us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease NET INCREASE IN NET ASSETS AVAILABLE FOR BENEFITS Deductions Additions us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate EBP, Asset Held for Investment, Participant Loan, Interest Rate us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccountDecreaseForEmployerContribution EBP, Forfeited Nonvested Account, Decrease from Employer Contribution EBP, Participant-Directed [Member] EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Investment income Interest and dividend income Total investments measured at fair value us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairValue EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Investment, Identifier [Axis] EBP, Accounting Policy [Table] Receivables: EBP, Description of Plan [Table] us-gaap-ebp_EmployeeBenefitPlanReceivable Total Receivables Statement [Table] EBP, Tax Status [Table] Fair Value Hierarchy and NAV [Domain] us-gaap-ebp_EmployeeBenefitPlanPlanNumber EBP, Plan Number jjsf_PolicyTable Statement of Financial Position [Abstract] us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLimitationOnTransactingAtContractValueNotProbable EBP, Fully Benefit-Responsive Investment Contract, Limitation on Transacting at Contract Value, Not Probable [true false] us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractDescription EBP, Fully Benefit-Responsive Investment Contract, Description EBP, Fully Benefit-Responsive Investment Contract [Text Block] us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration SAGIC DIVERSIFIED BOND I Fixed Annuity [Member] EBP, Participant-Directed and Nonparticipant-Directed Status [Domain] Investment Type [Axis] us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage EBP, Employer Contribution, Matching Percentage Mutual Fund [Member] us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares EBP, Investment, Number of Shares (in shares) EBP, Schedule of Asset Held for Investment [Text Block] EBP, Use of Estimate [Policy Text Block] EBP, Subsequent Event [Text Block] us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingAmount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, Expense [Policy Text Block] us-gaap-ebp_EmployeeBenefitPlanParticipantContributionPretaxMaximumAnnualCompensationToTotalCompensationPercentage EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage jjsf_EBPMinimumAgeOfParticipants EBP, Minimum Age of Participants The minimum age of participants in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). EBP 221935537 001 [Member] Relating to EBP 221935537 001. EBP, Employer, Common Stock Fund [Member] dei_DocumentType Document Type jjsf_EBPVestingPercentageInFourthYear EBP, Vesting Percentage in Fourth Year Represents the vesting percentage in the fourth year of service in an employee benefit plan (EBP). jjsf_EBPAgeToBeEligibleForInserviceWithdrawals EBP, Age to be Eligible for In-service Withdrawals Represents the age to be eligible for in-service withdrawals of an employee benefit plan (EBP). EBP, Summary of Accounting Policy [Text Block] Document Information [Line Items] jjsf_EBPVestingPercentage EBP, Vesting Percentage Represents the vesting percentage of an employee benefit plan (EBP). EBP, Investment [Policy Text Block] jjsf_EBPVestingPercentageForFirstThreeYears EBP, Vesting Percentage for First Three Years Represents the vesting percentage for the first three years of service in an employee benefit plan (EBP). jjsf_EBPInitialCatchUpContributionAmount EBP, Initial Catch Up Contribution, Amount Represents the amount of initial catch contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Document Information [Table] jjsf_EBPElgibleAgeForIncreasedCatchupContributions EBP, Elgible Age for Increased Catch-up Contributions The age of participant to make increased catch-up contributions to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). jjsf_EBPParticipantContributionPretaxMinimumAnnualCompensationToTotalCompensationPercentage EBP, Participant Contribution, Pretax, Minimum Annual Compensation to Total Compensation, Percentage Percentage of minimum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute to total pretax annual compensation. jjsf_EBPMinimumAgeForVoluntaryCatchupContributions EBP, Minimum Age for Voluntary Catch-up Contributions The minimum age of participant to make voluntary catch-up contributions to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Entity Interactive Data Current Statement [Line Items] jjsf_EBPAgeForRequiredDistributions EBP, Age for Required Distributions Represents the age that distributions become required as part of an employee benefit plan (EBP). jjsf_EBPPercentageOfPlanSponsorsStockToCauseRequiredDistributions EBP, Percentage of Plan Sponsor's Stock to Cause Required Distributions Represents the percentage of plan sponsor's stock that causes required distributions in an employee benefit plan (EBP). Fair Value Hierarchy and NAV [Axis] jjsf_EBPInvestmentContractInterestRate EBP, Investment, Contract Interest Rate Represents the interest rate of an investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), including, but not limited to, insurance contract meeting fully benefit-responsive investment criteria. EBP, Fair Value Measurement [Policy Text Block] Disclosure of accounting policy for fair value measurement of an employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). EBP, Risks and Uncertainties [Policy Text Block] Disclosure of accounting policy for risks and uncertainties in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). EBP, Payment to Participant [Policy Text Block] us-gaap-ebp_EmployeeBenefitPlanParticipantContributionPretaxMaximumAnnualCompensationAmount EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount jjsf_EBPTerminationVestingPercentage EBP, Termination Vesting Percentage Represents the vesting percentage in the event of termination of employee benefit plan (EBP). us-gaap-ebp_EmployeeBenefitPlanInvestmentSoldExcludingPlanInterestInMasterTrustSellingPrice EBP, Investment, Sold, Number of Shares Schedule of Assets [Text Block] The entire disclosure for schedule of assets. us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage EBP, Employer Contribution, Participant Compensation Matched, Percentage us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterObtained EBP, Tax Determination Letter, Obtained [true false] us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustParticipationStatusExtensibleEnumeration EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease Total deductions EBP, Related Party and Party-in-Interest Transactions [Text Block] Holding Account [Member] Relating to a Holding Account. ASSETS: EBP, Plan Termination [Text Block] us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit NET ASSETS AVAILABLE FOR BENEFITS Beginning of year End of year us-gaap-ebp_EmployeeBenefitPlanInvestmentAcquiredExcludingPlanInterestInMasterTrustCost EBP, Investment, Purchased, Number of Shares EBP, Fully Benefit-Responsive Investment Contract [Table] EBP, Investment, Fair Value and NAV [Table Text Block] us-gaap_PolicyTextBlockAbstract Accounting Policies Participants EBP, Investment, Fair Value and NAV [Table] us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Retirement Plan Tax Status [Domain] us-gaap_TableTextBlock Notes Tables Qualified Plan [Member]