Entity Tax Identification Number Entity Tax Identification Number Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] Forfeited nonvested account, decrease from administrative expense EBP, Forfeited Nonvested Account, Decrease from Administrative Expense Participant plan account investment in Company stock fund, after transfers, maximum, percentage EBP, Participant Plan Account Investment in Company Stock Fund, after Transfers, Maximum, Percentage EBP, Participant Plan Account Investment in Company Stock Fund, after Transfers, Maximum, Percentage 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] Maximum contribution of eligible compensation in an after-tax basis, percentage EBP, Participant Contribution, After Tax, Maximum Annual Compensation to Total Compensation, Percentage EBP, Participant Contribution, After Tax, Maximum Annual Compensation to Total Compensation, Percentage EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] Maximum contribution of eligible compensation on a pretax basis, Percentage EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Maximum borrowing, amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Fair Value Measurements EBP, Investment, Fair Value and NAV [Text Block] Minimum borrowing, amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Investments, at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Amounts eligible to remain in the Plan EBP, Amounts Eligible to Remain in the Plan EBP, Amounts Eligible to Remain in the Plan Participant-directed brokerage account, to participant's total Plan account balance, maximum percentage EBP, Participant-Directed Brokerage Account to Participant's Total Plan Account Balance, Maximum, Percentage EBP, Participant-Directed Brokerage Account to Participant's Total Plan Account Balance, Maximum, Percentage Money market fund Money Market Funds [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Minimum annual compensation-to-total- compensation percentage to allow catch-up contributions for participants who attain age 50 during the Plan Year EBP, Participant Contribution, Pretax, Minimum Annual Compensation Contribution Percentage Threshold to Allow Catch-up Contribution for Contributors Who Meet Age Requirement EBP, Participant Contribution, Pretax, Minimum Annual Compensation Contribution Percentage Threshold to Allow Catch-up Contribution for Contributors Who Meet Age Requirement EBP, Investment, Fair Value and NAV [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Additions to (Deductions from) net assets attributed to: EBP, Change in Net Asset Available for Benefit, Increase [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Distributions EBP, Payment to Participant [Policy Text Block] EBP, Trustee [Member] EBP, Trustee [Member] Unfunded commitments EBP, Fair Value, Investment, NAV, Unfunded Commitment Stable Value Fund Stable Value Fund [Member] Stable Value Fund Amendment Flag Amendment Flag Basis of Accounting EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] Investment (in shares) EBP, Investment, Number of Shares EBP, Description of Plan and Accounting Change [Abstract] EBP, Investment, Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] Participant-directed brokerage account investments EBP, Participant-Directed [Member] Uncertain tax positions EBP, Uncertain Tax Positions EBP, Uncertain Tax Positions Sales Representatives Sales Representatives [Member] Sales Representatives Investments [Domain] Investments [Domain] Use of Estimates EBP, Use of Estimate [Policy Text Block] EBP, Related Party and Party-in-Interest [Domain] EBP, Related Party and Party-in-Interest [Domain] Schedule H, Line 4(i) - Schedule of Assets (Held at End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Risks and Uncertainties EBP, Risk and Uncertainty [Text Block] Revenue credit account EBP, Revenue Credit Account EBP, Revenue Credit Account Employer, net of forfeitures EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Axis] Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Interest on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Plan participants EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Amounts eligible for rollover into individual retirement account EBP, Amounts Eligible for Rollover Into Individual Retirement Account EBP, Amounts Eligible for Rollover Into Individual Retirement Account 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, Plan Number EBP, Plan Number EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] Description of the Plan 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 001 EBP 001 [Member] EBP 001 EBP, Schedule of Asset Held for Investment [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Note receivable from participant, allowance for credit loss EBP, Note Receivable from Participant, Allowance for Credit Loss Revenue-sharing credits generated EBP, Revenue-Sharing Credits Generated EBP, Revenue-Sharing Credits Generated Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment, Identifier [Axis] Investment, Identifier [Axis] Document Information [Line Items] Document Information [Line Items] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Table] EBP, Risk and Uncertainty [Table] Other, net EBP, Other, Net EBP, Other, Net Participant eligible compensation contribution matched by the Company, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Number of target date funds EBP, Number of Target Date Funds EBP, Number of Target Date Funds Employer contribution vesting service period EBP, Employer Contribution Vesting Service Period EBP, Employer Contribution Vesting Service Period Involuntary cash-out limit EBP, Involuntary Cash-out Limit EBP, Involuntary Cash-out Limit EBP, Tax Status [Table] EBP, Tax Status [Table] Net increase in net assets available for benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Related Party and Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Text Block] General loan, borrowing term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Dividend income on investment EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Benefits paid to participants EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Total Investments, at fair value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value 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] EBP, Tax Status [Abstract] KB Home Stock Fund EBP, Employer, Common Stock Fund [Member] Investments At Fair Value Investments At Fair Value [Member] Investments At Fair Value Notes receivable from participants EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Investment Valuation and Income Recognition EBP, Investment [Policy Text Block] Fair Value, Inputs, Level 1, Level 2, and Level 3 Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type Administrative expenses EBP, Other, Administrative Expense EBP, Other, Administrative Expense Entity Central Index Key Entity Central Index Key Notes receivable from participants, interest rate EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] EBP, Risk and Uncertainty [Abstract] EBP, Subsequent Event [Table] EBP, Subsequent Event [Table] Employee Category [Domain] Employee Category [Domain] Employee Category Forfeited nonvested account, decrease from employer contribution EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Employee Category [Axis] Employee Category [Axis] Employee Category Notes receivable from participants EBP, Note Receivable from Participant Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name EBP, Subsequent Event [Abstract] Subsequent Events EBP, Subsequent Event [Text Block] Sales representative, maximum annual compensation, amount EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount Tax Status of the Plan EBP, Tax Status [Text Block] Maximum borrowing, to total account, percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Participant-Directed and Nonparticipant-Directed Status [Domain] EBP, Participant-Directed and Nonparticipant-Directed Status [Domain] EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Line Items] EBP, Participant-Directed and Nonparticipant-Directed Status [Axis] EBP, Participant-Directed and Nonparticipant-Directed Status [Axis] Document Information [Table] Document Information [Table] Revenue-sharing credits distributed to participant accounts EBP, Revenue-Sharing Credits Distributed to Participant Accounts EBP, Revenue-Sharing Credits Distributed to Participant Accounts Notes Receivable from Participants EBP, Note Receivable from Participant [Policy Text Block] Total investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Primary residence, borrowing term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] Participant contribution to Company stock fund, maximum, percentage EBP, Participant Contribution to Company Stock Fund, Maximum, Percent EBP, Participant Contribution to Company Stock Fund, Maximum, Percent Vesting percentage EBP, Employer Contribution Vesting Percentage EBP, Employer Contribution Vesting Percentage Net assets available for benefits Beginning of year End of year EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Forfeited nonvested account EBP, Forfeited Nonvested Account Matching percentage EBP, Employer Contribution, Matching Percentage NAV Fair Value Measured at Net Asset Value Per Share [Member] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]