Rollover EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum [Member] Maximum [Member] EBP, Forfeited Nonvested Account, Decrease from Administrative Expense EBP, Forfeited Nonvested Account, Decrease from Administrative Expense Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Mutual funds Mutual Fund [Member] EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage EBP 001 [Member] EBP 001 [Member] EBP 001 EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount EBP, Investment, Fair Value and NAV [Text Block] EBP, Investment, Fair Value and NAV [Text Block] EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, Employer Contribution, Vesting percentage based on years of service [Table Text Block] EBP, Employer Contribution, Vesting percentage based on years of service [Table Text Block] EBP, Employer Contribution, Vesting percentage based on years of service EBP, Investment, Fair Value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value EBP, Participant Contribution, 0% Election Deferral Rate EBP, Participant Contribution, 0% Election Deferral Rate EBP, Participant Contribution, 0% Election Deferral Rate Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] EBP, Investment, Fair Value and NAV [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Payment to Participant [Policy Text Block] EBP, Payment to Participant [Policy Text Block] EBP, Fair Value, Investment, NAV, Unfunded Commitment EBP, Fair Value, Investment, NAV, Unfunded Commitment Amendment Flag Amendment Flag EBP, Basis of Accounting [Policy Text Block] EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] EBP, Investment, Number of Shares EBP, Investment, Number of Shares EBP, Description of Plan and Accounting Change [Abstract] EBP, Participant Super Catch-Up Contribution, Maximum Amount EBP, Participant Super Catch-Up Contribution, Maximum Amount EBP, Participant Super Catch-Up Contribution, Maximum Amount Investments [Domain] Investments [Domain] EBP, Use of Estimate [Policy Text Block] EBP, Use of Estimate [Policy Text Block] EBP, Schedule of Asset Held for Investment [Text Block] EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Employer EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash EBP, Investment, Purchased, Number of Shares EBP, Investment, Purchased, Number of Shares EBP, Employer Contribution, Vesting Percentage, Four or more years of service EBP, Employer Contribution, Vesting Percentage, Four or more years of service EBP, Employer Contribution, Vesting Percentage, Four or more years of service Minimum [Member] Minimum [Member] Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Investment Type [Axis] Investment Type [Axis] Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Participant EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover EBP, Employer Contribution, Participant Compensation Matched, Percentage, Next 2% EBP, Employer Contribution, Participant Compensation Matched, Percentage, Next 2% EBP, Employer Contribution, Participant Compensation Matched, Percentage, Next 2% Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Interest and dividends EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] EBP, Description of Plan [Text Block] EBP, Description of Plan [Text Block] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total additions EBP, Change in Net Asset Available for Benefit, Increase Investment, Identifier [Axis] Investment, Identifier [Axis] Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense EBP, Risk and Uncertainty [Policy Text Block] EBP, Risk and Uncertainty [Policy Text Block] EBP, Fair Value, Investment, NAV, Redemption, Description EBP, Fair Value, Investment, NAV, Redemption, Description EBP, Statement of Change in Net Asset Available for Benefit [Abstract] EBP, Investment, Sold, Number of Shares EBP, Investment, Sold, Number of Shares EBP, Tax Determination Letter, Obtained [true false] EBP, Tax Determination Letter, Obtained [true false] EBP, Employer Contribution, Matching Percentage, 100% EBP, Employer Contribution, Matching Percentage, 100% EBP, Employer Contribution, Matching Percentage, 100% EBP, Employer Contribution, Vesting Percentage, Less than two years of service EBP, Employer Contribution, Vesting Percentage, Less than two years of service EBP, Employer Contribution, Vesting Percentage, Less than two years of service EBP, Employer Contribution, Participant Compensation Matched, Percentage, First 2% EBP, Employer Contribution, Participant Compensation Matched, Percentage, First 2% EBP, Employer Contribution, Participant Compensation Matched, Percentage, First 2% Net increase EBP, Change in Net Asset Available for Benefit, Increase (Decrease) EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] EBP, Participant Contribution, Automatic Increase EBP, Participant Contribution, Automatic Increase EBP, Participant Contribution, Automatic Increase EBP, Investment Sold, Excluding Plan Interest in Master Trust, Cost EBP, Investment Sold, Excluding Plan Interest in Master Trust, Cost EBP, Participant Contribution, Automatic, Deferral Rate EBP, Participant Contribution, Automatic, Deferral Rate Participant distributions and withdrawals EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] Markel Group Inc. common stock EBP, Employer, Common Stock Fund [Member] Document Period End Date Document Period End Date EBP, Employer Contribution, Vesting Percentage, Three years of service EBP, Employer Contribution, Vesting Percentage, Three years of service EBP, Employer Contribution, Vesting Percentage, Three years of service EBP, Plan Name EBP, Plan Name EBP, Investment [Policy Text Block] EBP, Investment [Policy Text Block] EBP, Asset Held for Investment, Party-in-Interest [true false] EBP, Asset Held for Investment, Party-in-Interest [true false] Document Type Document Type Entity Central Index Key Entity Central Index Key EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, Asset Held for Investment, Participant Loan, Interest Rate Collective investment trusts Common Collective Trust [Member] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] EBP, Forfeited Nonvested Account, Decrease from Employer Contribution EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Notes receivable from participants EBP, Note Receivable from Participant EBP, Tax Status [Policy Text Block] EBP, Tax Status [Policy Text Block] EBP, Tax Status EBP, Summary of Accounting Policy [Text Block] EBP, Summary of Accounting Policy [Text Block] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Entity Registrant Name Entity Registrant Name EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost EBP, Investment, Excluding Plan Interest in Master Trust, Cost EBP, Investment, Excluding Plan Interest in Master Trust, Cost EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount EBP, Employer Contribution, Matching Percentage, 50% EBP, Employer Contribution, Matching Percentage, 50% EBP, Employer Contribution, Matching Percentage, 50% EBP, Employer Contribution, Vesting Percentage, Two years of service EBP, Employer Contribution, Vesting Percentage, Two years of service EBP, Employer Contribution, Vesting Percentage, Two years of service EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Employer Contribution, Vesting Percentage, Plan termination EBP, Employer Contribution, Vesting Percentage, Plan termination EBP, Employer Contribution, Vesting Percentage, Plan termination EBP, Note Receivable from Participant [Policy Text Block] EBP, Note Receivable from Participant [Policy Text Block] Total net investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment EBP, Participant Catch-Up Contribution, Maximum Amount EBP, Participant Catch-Up Contribution, Maximum Amount EBP, Participant Catch-Up Contribution, Maximum Amount EBP, Forfeited Nonvested Account, Unused at year end EBP, Forfeited Nonvested Account, Unused at year end EBP, Forfeited Nonvested Account, Unused at year end EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] Assets available for benefits EBP, Net Asset Available for Benefit, Beginning Balance EBP, Net Asset Available for Benefit, Ending Balance EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] EBP, Forfeited Nonvested Account EBP, Forfeited Nonvested Account EBP, Participant Contribution, Maximum Contribution Rate EBP, Participant Contribution, Maximum Contribution Rate EBP, Participant Contribution, Maximum Contribution Rate EBP, Employer Contribution, Matching Percentage EBP, Employer Contribution, Matching Percentage EBP, Employer Contribution EBP, Employer Contribution EBP, Employer Contribution EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] Fair Value Measured at Net Asset Value [Member] Fair Value Measured at Net Asset Value Per Share [Member] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]