Legal Entity [Axis] STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS [Abstract] Investment Type [Axis] Net Assets Available for Benefits Beginning of Year End of Year STATEMENTS OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS [Abstract] Total investment income Total contributions Total Additions Total Deductions Net Increase DESCRIPTION OF PLAN [Abstract] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract] COMMON/COLLECTIVE TRUST FUNDS [Abstract] FAIR VALUE MEASUREMENTS [Abstract] Fair Value Hierarchy and NAV [Axis] TAX STATUS [Abstract] RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS [Abstract] ADMINISTRATION OF PLAN ASSETS [Abstract] RISKS AND UNCERTAINTIES [Abstract] SUBSEQUENT EVENTS [Abstract] Schedule H - Line 4(i) - Schedule of Assets (Held at End of Year) [Abstract] Document Type Document Period End Date Document Fiscal Year Focus Entity Registrant Name Entity Central Index Key Amendment Flag Assets Investments Investments Fair value of shares of Donegal Group Inc. common stock held by plan Investment Income Dividends and Interest Net Appreciation in Fair Value of Investments Net realized/unrealized appreciation (depreciation) in fair value of Donegal Group Inc. common stock Contributions Employer Participants Rollover Net Assets Available for Benefits Benefits Paid to Participants Administrative Expenses Donegal Mutual Insurance Company 401(k) Plan [Member] Common/collective Trust Funds [Member] Common/Collective Trust Funds [Member] Registered Investment Companies [Member] Employer Securities [Member] Class A and Class B Donegal Group Inc. Common Stock [Member] DESCRIPTION OF PLAN SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES COMMON/COLLECTIVE TRUST FUNDS FAIR VALUE MEASUREMENTS Fair Value Measurements for the Plan’s Investments TAX STATUS RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS ADMINISTRATION OF PLAN ASSETS PLAN TERMINATION RISKS AND UNCERTAINTIES SUBSEQUENT EVENTS Schedule H - Line 4(i) - Schedule of Assets (Held at End of Year) Identity of issue, borrower, lessor, or similar party Number of units (in Shares) Number of shares of Donegal Group Inc. common stock held by the plan (in Shares) Description of investment Participation status Current value Party-in-interest Total assets Investments at Far value [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Investment, Identifier [Axis] Registered Investment Companies [Member] EBP, Related Party and Party-in-Interest [Axis] EBP, Contribution, Participating Employer [Axis] Statistical Measurement [Axis] EBP, Participant-Directed and Nonparticipant-Directed Status [Axis] EBP, description available Minimum hours scheduled or worked per year to be eligible to participate in the Plan (in Hours) Minimum time of service to be eligible to participate in the Plan Participants minimum contribution percentage of annual compensation Participants maximum contribution percentage of annual compensation Company matching percentage Employee contribution eligible for matching by the company Employer contribution deferrals percentage Employee deferrals automatically annual percentage increase Participant retirement age Employer contribution vesting percentage Employer contribution vesting period Early retirement age Participants vested balance (in Dollars) Threshold automatic rollover age Threshold vesting percentage required for forfeitures Forfeitures used to reduce employer contributions (in Dollars) Unallocated forfeiture amount (in Dollars) Number of investments in common/collective trust funds (in Investment) Unfunded commitments relating to common/collective trust funds Changes in methodologies used or transfers between levels Tax determination letter, ruled Tax determination letter, date Tax determination letter, status Dividends received from Donegal Group Inc. Officer or employee compensation from plan Percentage of vested plan participants Name of Plan Employer Identification Number Three Digit Plan Number Basis of Accounting Use of Estimates Investment Valuation and Income Recognition Contributions Payment of Benefits Expenses Employees Regularly Scheduled [Member] Part Time and Temporary Employees [Member] Part Time and Temporary Employees Hours Per Two Years [Member] Participants Initial 3% Contributions Eligible For 100% Company Matching [Member] Participants 4% to 9% Contributions Eligible for 50% Company Matching [Member] Maximum [Member] Participants Generally Will Receive a Lump-Sum Distribution [Member] Minimum [Member] Participants May Receive a Lump-Sum Distribution or a Direct Rollover to an Individual Retirement Account [Member] Participants Assets will Generally be Held in the Plan Until the Retirement or Early Retirement Age [Member] Level 2 [Member] Level 3 [Member] Class A Donegal Group Inc. Common Stock [Member] Class B Donegal Group Inc. Common Stock [Member] Investments [Domain] Entity [Domain] EBP, Statement of Net Asset Available for Benefit [Table] STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] STATEMENTS OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS [Abstract] EBP, Description of Plan [Table] DESCRIPTION OF PLAN [Abstract] EBP, Accounting Policy [Table] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract] Common/Collective Trust Funds [Table] COMMON/COLLECTIVE TRUST FUNDS [Abstract] EBP, Investment, Fair Value and NAV [Table] FAIR VALUE MEASUREMENTS [Abstract] EBP, Tax Status [Table] TAX STATUS [Abstract] EBP, Related Party and Party-in-Interest Transactions [Table] RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS [Abstract] EBP, Administration of Plan Assets [Table] ADMINISTRATION OF PLAN ASSETS [Abstract] EBP, Plan Termination [Table] PLAN TERMINATION [Abstract] EBP, Risk and Uncertainty [Table] RISKS AND UNCERTAINTIES [Abstract] EBP, Subsequent Event [Table] SUBSEQUENT EVENTS [Abstract] EBP, Schedule of Asset Held for Investment [Table] Schedule H - Line 4(i) - Schedule of Assets (Held at End of Year) [Abstract] EBP, Accounting Policy [Line Items] Fair Value Hierarchy and NAV [Domain] EBP, Related Party and Party-in-Interest [Domain] EBP, Contribution, Participating Employer [Domain] Statistical Measurement [Domain] EBP, Participant-Directed and Nonparticipant-Directed Status [Domain] Minimum number of hours an employee is generally scheduled to work per year in order to become eligible to participate in the employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Minimum time of service required for an employee group to become eligible to participate in the plan. Amount of administration expense incurred by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). The entire disclosure for administration of plan assets of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). The entire disclosure for a regulated trust, responsible for collective investment and reinvestment of asset from employee benefit plan maintained by more than one employer or controlled group. Age at which a participant may elect early retirement under the terms of the employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Percentage of company contributions and related earnings that is nonforfeitable to a participant after completion of the specified period of credited service under the terms of the plan employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). The number of investments in common/collective trust funds held by employee stock purchase, savings, or similar plan (employee benefit plan (EBP)). Percentage of a participant’s account balance that is nonforfeitable upon termination of the employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). The automatic annual percentage increase applied to a plan participant's salary deferral rate under an employee benefit/retirement plan. 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. Age at which a participant attains normal retirement under the terms of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Maximum threshold age of participant to roll over vested balance, if no election is made, to an individual retirement account in accordance with the plan provisions under the employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee benefit plan, threshold vesting percentage required for forfeitures. Amount of benefit plan, in vested account, no longer allocated to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). The period an employee must work before becoming fully vested, 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Employees regularly scheduled to work who are subject to the annual minimum hours requirement to become eligible to participate in the plan. Part-time and temporary employees who are subject to a minimum hours worked requirement measured over two consecutive years to become eligible to participate in the plan. Part-time and temporary employees who are subject to the annual minimum hours worked requirement to become eligible to participate in the plan. Percentage of participant's compensation contribution eligible for 50% matching contribution by the company as defined by the Plan. Participants whose account assets generally are retained in the plan until the participant reaches normal retirement age or early retirement age. Participants whose benefits generally are paid in the form of a lump-sum distribution. Percentage of participant's compensation contribution eligible for 100% matching contribution by the company as defined by the Plan. Participants whose vested balance may be distributed as a lump-sum payment or, if no election is made, as a direct rollover to an individual retirement account. Represents registered investment companies. Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Disclosure of information about administration of plan assets arrangement in which employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) participates. Qualified Plan [Member] Participant-directed Investments [Member] Vanguard Institutional Target Retirement 2040 [Member] Shares of Class A Common Stock [Member] Common/Collective Trust [Member] Fidelity Advisor Equity Growth Z [Member] Fidelity 500 Index Instl Prem [Member] Registered Investment Company [Member] Galliard Stable Return C [Member] Putnam Large Cap Value Trust CL-I [Member] Vanguard Institutional Target Retirement 2055 [Member] Vanguard Federal Money Market Fund Investor [Member] Vanguard Institutional Target Retirement 2030 [Member] Fidelity US Bond Index [Member] T. Rowe Price Small Cap Stock Fund [Member] Dodge & Cox Inc X [Member] Vanguard Institutional Target Retirement 2035 [Member] Vanguard Institutional Target Retirement 2070 [Member] Columbia Trust Contrarian Core 1 [Member] Vanguard Institutional Target Retirement 2045 [Member] Vanguard Institutional Target Retirement 2065 [Member] Thornburg Strategic Inc R6 [Member] Vanguard Institutional Target Retirement 2025 [Member] T. Rowe Price Mid Cap Value Fund [Member] Baron Asset Fund R6 [Member] MFS International Diversification R6 [Member] Donegal Group Inc. [Member] T. Rowe Price Capital Appreciation Fund [Member] American Funds New Perspective Fund R6 [Member] Vanguard Institutional Target Retirement 2060 [Member] Vanguard Institutional Target Retirement 2020 [Member] Vanguard Institutional Target Retirement 2050 [Member] Vanguard Institutional Target Retirement [Member] Shares of Class B Common Stock [Member] Neuberger & Berman Genesis R6 [Member] Investments In Fair Value Hierarchy Member Common Collective Trust Funds Line Items EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Employer, Common Stock [Member] EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Participant Contribution, Automatic, Deferral Rate Fair Value, Inputs, Level 3 [Member] EBP, Tax Qualification Status [Extensible Enumeration] EBP, Employer Contribution, Matching Percentage Employee Benefit Plan Participant Retirement Age EBP, Plan Number Employee Benefit Plan Employer Contribution Vesting Percentage EBP, Investment, Fair Value and NAV [Table Text Block] EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP003 Member Employee Benefit Plan Number Of Investments In Common Collective Trust Funds EBP, Description, Available [true false] EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment EBP, Expense [Policy Text Block] EBP, Related Party and Party-in-Interest Transactions [Line Items] EBPMinimum Hours Scheduled Per Year To Be Eligible To Participate In Plan Employee Benefit Plan Administration Expenses Fair Value, Inputs, Level 1 [Member] EBP, Change in Net Asset Available for Benefit, Increase EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Participants Assets Will Generally Be Held In The Plan Until The Retirement Or Early Retirement Age Member EBP, Summary of Accounting Policy [Text Block] EBP, Tax Status [Text Block] Participants May Receive ALump Sum Distribution Or ADirect Rollover To An Individual Retirement Account Member EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Registered Investment Companies Member Employee Benefit Plan Administration Of Plan Assets Text Block EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Employees Regularly Scheduled Member Employee Benefit Plan Administration Of Plan Assets Line Items Participants Initial3 Contributions Eligible For100 Company Matching Member Employee Benefit Plan Participant Contribution Automatic Annual Deferral Rate Increase EBP, Change in Net Asset Available for Benefit, Increase from Contribution Employee Benefit Plan Vested Account Employee Benefit Plan Early Retirement Age EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value EBP, Investment, Current Value, Type [Extensible Enumeration] EBP, Asset [Abstract] EBP, Use of Estimate [Policy Text Block] EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Employee Benefit Plan Threshold Automatic Rollover Age EBP, Investment, Fair Value [Abstract] EBP, Subsequent Event [Line Items] EBP, Description of Plan [Text Block] Document Fiscal Year Focus EBP, Tax Determination Letter, Date EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment EBP, Subsequent Event [Text Block] Employee Benfit Plan Employer Contribution Vesting Period EBP, Forfeited Nonvested Account Minimum [Member] EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Plan Termination [Text Block] EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] EBP, Investment, Number of Shares EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Asset Held for Investment, Party-in-Interest [true false] EBPMinimum Time Of Service To Be Eligible To Participate In Plan EBP, Net Asset Available for Benefit [Abstract] EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash Fair Value, Inputs, Level 2 [Member] EBP, Risk and Uncertainty [Text Block] Part Time And Temporary Employees Member EBP, Change in Net Asset Available for Benefit, Decrease Employee Benefit Plan Participant Contribution Pretax Minimum Annual Compensation To Total Compensation Percentage EBP, Basis of Accounting [Policy Text Block] EBP, Investment, Fair Value and NAV [Line Items] EBP, Asset Held for Investment EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Net Asset Available for Benefit EBP, Investment [Policy Text Block] Maximum [Member] EBP, Schedule of Asset Held for Investment [Line Items] Document Type EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Investment, Level 3 Reconciliation, Increase from Transfer into Level 3 Entity Tax Identification Number EBP, Contribution [Policy Text Block] Amendment Flag EBP, Tax Status [Line Items] Document Period End Date EBP, Investment, Fair Value and NAV [Text Block] EBP, Schedule of Asset Held for Investment [Table Text Block] Participants4 To9 Contributions Eligible For50 Company Matching Member EBP, Risk and Uncertainty [Line Items] Entity Central Index Key EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Employee Benefit Plan Participant Account Vested Percentage Upon Plan Termination EBP, Fair Value, Investment, NAV, Unfunded Commitment Investment, Identifier [Axis] EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Mutual Fund [Member] Part Time And Temporary Employees Hours Per Two Years Member Employee Benefit Plan Threshold Vesting Percentage For Forfeitures EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover EBP, Plan Name EBP, Payment to Participant [Policy Text Block] Entity Registrant Name Employee Benefit Plan Common Collective Trust Funds Text Block Participants Generally Will Receive ALump Sum Distribution Member EBP, Change in Net Asset Available for Benefit, Increase (Decrease) EBP, Tax Determination Letter, Obtained [true false]