75000 - Document - Document and Entity Information link:presentationLink link:calculationLink link:definitionLink 75010 - Statement - Statements of Net Assets Available for Benefits link:presentationLink link:calculationLink link:definitionLink 75020 - Statement - Statement of Changes in Net Assets Available for Benefits link:presentationLink link:calculationLink link:definitionLink 75030 - Disclosure - Description of the Plan link:presentationLink link:calculationLink link:definitionLink 75040 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 75050 - Disclosure - Investments link:presentationLink link:calculationLink link:definitionLink 75060 - Disclosure - Net Assets of Nonparticipant-directed Investments link:presentationLink link:calculationLink link:definitionLink 75070 - Disclosure - Contributions link:presentationLink link:calculationLink link:definitionLink 75080 - Disclosure - Parties-in-interest Transactions link:presentationLink link:calculationLink link:definitionLink 75090 - Disclosure - Fair Value of Plan Assets link:presentationLink link:calculationLink link:definitionLink 75100 - Disclosure - Risks and Uncertainties link:presentationLink link:calculationLink link:definitionLink 75110 - Disclosure - Schedule of Assets (Held at End of Year) link:presentationLink link:calculationLink link:definitionLink 75120 - Disclosure - Schedule of Reportable Transactions link:presentationLink link:calculationLink link:definitionLink 75130 - Disclosure - Summary of Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 75140 - Disclosure - Investments (Tables) link:presentationLink link:calculationLink link:definitionLink 75150 - Disclosure - Net Assets of Nonparticipant-directed Investments (Tables) link:presentationLink link:calculationLink link:definitionLink 75160 - Disclosure - Contributions (Tables) link:presentationLink link:calculationLink link:definitionLink 75170 - Disclosure - Parties-in-interest Transactions (Tables) link:presentationLink link:calculationLink link:definitionLink 75180 - Disclosure - Fair Value of Plan Assets (Tables) link:presentationLink link:calculationLink link:definitionLink 75190 - Disclosure - Schedule of Assets (Held at End of Year) (Tables) link:presentationLink link:calculationLink link:definitionLink 75200 - Disclosure - Schedule of Reportable Transactions (Tables) link:presentationLink link:calculationLink link:definitionLink 75210 - Disclosure - Description of the Plan - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75220 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75230 - Disclosure - Investments - Summary of Plan's Investment in Company's Common Stock (Details) link:presentationLink link:calculationLink link:definitionLink 75240 - Disclosure - Investments - Summary of Participant-Directed and Nonparticipant-Directed Investments in Company Common Stock (Details) link:presentationLink link:calculationLink link:definitionLink 75250 - Disclosure - Net Assets of Nonparticipant-directed Investments - Summary of Net Assets (Details) link:presentationLink link:calculationLink link:definitionLink 75260 - Disclosure - Net Assets of Nonparticipant-directed Investments - Schedule of Net Assets and Significant Components of Changes in Net Assets Relating to Nonparticipant Directed Investments (Details) link:presentationLink link:calculationLink link:definitionLink 75270 - Disclosure - Contributions - Summary of Contributions to the Plan (Details) link:presentationLink link:calculationLink link:definitionLink 75280 - Disclosure - Parties-in-interest Transactions - Summary of Parties-in-Interest Balances (Details) link:presentationLink link:calculationLink link:definitionLink 75290 - Disclosure - Parties-in-interest Transactions - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75300 - Disclosure - Fair Value of Plan Assets - Summary of Fair Value Measurements of Assets Recognized (Details) link:presentationLink link:calculationLink link:definitionLink 75310 - Disclosure - Fair Value of Plan Assets - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75320 - Disclosure - Fair Value of Plan Assets - Summary of Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements Recognized (Details) link:presentationLink link:calculationLink link:definitionLink 75330 - Disclosure - Schedule of Assets (Held at End of Year) (Details) link:presentationLink link:calculationLink link:definitionLink 75330 - Disclosure - Schedule of Assets (Held at End of Year) (Details) [Default] link:presentationLink link:calculationLink link:definitionLink 75340 - Disclosure - Schedule of Reportable Transactions (Details) link:presentationLink link:calculationLink link:definitionLink 75340 - Disclosure - Schedule of Reportable Transactions (Details) [Default] link:presentationLink link:calculationLink link:definitionLink Additions EBP, Change in Net Asset Available for Benefit, Increase [Abstract] EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Total benefits paid Benefits paid to participants or their beneficiaries EBP, Receivable [Abstract] Receivables Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] EBP, Related Party and Party-in-Interest Transactions [Line Items] Document Fiscal Period Focus GreatBanc Trust Company GreatBanc Trust Company [Member] GreatBanc Trust Company. EBP, Fully Benefit-Responsive Investment Contract [Table] EBP, Nonparticipant-Directed [Member] Nonparticipant-Directed Nonparticipant Directed EBP, Description of Plan [Text Block] Description of the Plan EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants Investment, Identifier [Axis] EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative expense Administrative fees EBP, Description of Plan [Line Items] Employee Benefit Plan, Change In Net Asset Available For Benefit, Increase From Change In Value Of Common Stock Employee benefit plan, change in net asset available for benefit, increase from change in value of common stock. Change in value of BancPlus Corporation common stock EBP, Employer Contribution, Matching Percentage Matching contributions EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Investment, Fair Value and NAV [Abstract] Summary of Parties-in-Interest Balances EBP, Related Party and Party-in-Interest Transactions [Table Text Block] EBP, Accounting Policy [Line Items] EBP Change in Net Asset Available for Benefit Increase (Decrease) Net Of Transfer Ebp change in net asset available for benefit increase (decrease) net of transfer. Change in net assets EBP, Unobservable Input Valuation Rate EBP, Unobservable Input Valuation Rate. Unobservable input valuation rate Employee Benefit Plan Commissions Paid by Plan Sponsor Employee benefit plan commissions paid by plan sponsor. Commissions paid by plan sponsor Terminated Participants Accounts Balance Terminated participants accounts balance. Terminated participants accounts balance EBP, Investment, Fair Value and NAV Balances of Recurring Fair Value Measurements Recognized [Table Text Block] EBP, Investment, fair value and NAV balances of recurring fair value measurements recognized. Summary of Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements Recognized EBP, Schedule of Asset Held for Investment [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Contribution [Table] EBP, Schedule of Reportable Transaction [Abstract] EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount EBP, note receivable from participant, account, maximum borrowing, amount Employee Benefit Plan Schedule of Reportable Transactions [Text Block] Employee benefit plan schedule of reportable transactions. Schedule of Reportable Transactions Common Collective Trusts Common Collective Trust [Member] Amendment Flag EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash, Total Employer Employer contributions Deductions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Deductions from Net Assets EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, note receivable from participant, account, minimum borrowing, amount EBP, Payment to Participant [Policy Text Block] Payment of Benefits Employee Benefit Plan Change In Net Asset Available For Benefit Transfers Employee benefit plan change in net asset available for benefit transfers. Transfers to Participant-directed Investments Company Common Stock Common Stock [Member] Employee Benefit Plan Lease Rental Employee benefit plan lease rental. Lease Rental Participant contributions receivable EBP, Participant Contribution, Receivable EBP, Schedule of Asset Held for Investment [Line Items] Fair Value Hierarchy and NAV [Axis] EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Investment Income (Loss), before Investment Expense [Abstract] Investment Income EBP, Investment, Current Value, Type [Extensible Enumeration] Investment Type [Axis] Document Type EBP, Participant-Directed [Member] Participant-Directed Participant Directed Entity Central Index Key EBP, Forfeited Nonvested Account, Reallocated to Participant EBP, forfeited nonvested account, reallocated to participant EBP, Investment Sold, Excluding Plan Interest in Master Trust, Current Value Sales, Current Value of Asset on Transaction Date EBP, Accounting Policy [Table] EBP, Basis of Accounting [Policy Text Block] Basis of Accounting EBP, Schedule of Reportable Transaction [Line Items] EBP, Schedule of Reportable Transaction [Table] EBP, Reportable Transaction, Change in Net Asset Available for Benefit, Decrease from Expense Incurred Expenses Incurred with Transaction EBP, Description of Plan [Table] Annual Safe Harbor Matching Contributions of First Three Percentage of the Participant's Contributions Annual safe harbor matching contributions of first three percentage of the participant's contributions. Annual safe harbor matching contributions of first three percentage of the participant's contributions EBP, Participant-Directed and Nonparticipant-Directed Status [Axis] EBP, Employer, Common Stock [Member] Company Common Stock BancPlus Corporation Common Stock EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment, Total Interest and dividend income Employee Benefit Plans Vesting Percentage Participants Terminating Due to Normal Retirement, Death, or Disability Employee benefit plans vesting percentage participants terminating due to normal retirement, death, or disability. Employee benefit plans vesting percentage participants terminating due to normal retirement, death, or disability EBP, Investment, Excluding Plan Interest in Master Trust, Cost Cost Employee Benefit Plan, Change In Net Asset Available For Benefit, Decrease From Loans Deemed Distributed Employee benefit plan, change in net asset available for benefit, decrease from loans deemed distributed. Loans deemed distributed EBP, Investment, Fair Value [Abstract] Investments, at Fair Value EBP, Investment, Number of Shares Number of shares Annual Safe Harbor Matching Contributions of Next Two Percentage of the Participant's Contributions Annual safe harbor matching contributions of next two percentage of the participant's contributions. Annual safe harbor matching contributions of next two percentage of the participant's contributions Minimum [Member] Minimum EBP, Related Party and Party-in-Interest Transactions [Text Block] Parties-in-interest Transactions EBP, Change in Net Asset Available for Benefit, Increase Total additions Total additions Fair Value, Inputs, Level 3 [Member] Significant Unobservable Inputs (Level 3) EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Nonparticipant-Directed Investment [Table Text Block] Schedule of Net Assets and Significant Components of Changes in Net Assets Relating to Nonparticipant Directed Investments Benefits Paid Directly to Participants Employee Benefit Plan, Change in Net Asset Available for Benefit, Decrease, Benefits Paid Directly to Participants [Abstract] Employee benefit plan, change in net asset available for benefit, decrease, benefits paid directly to participants. Selling Price EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price Summary of Contributions to the Plan EBP, Contribution [Table Text Block] Distributions EBP, Investment, Level 3 Reconciliation, Distributions EBP, investment, level 3 reconciliation, distributions. Document Information [Line Items] EBP, Nonparticipant-Directed Investment [Line Items] EBP, Statement of Net Asset Available for Benefit [Abstract] Participant salary deferrals EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Employee Benefit Plan Number Of Fair Value Appraisal Approaches Employee benefit plan number of fair value appraisal approaches. Number of fair value appraisal approaches EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions Additions to Net Assets EBP, Tax Determination Letter, Date Determination letter, date EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Current Value Purchases, Current Value of Asset on Transaction Date EBP, Fully Benefit-Responsive Investment Contract [Text Block] Investments EBP, Nonparticipant-Directed Investment [Abstract] EBP, Related Party and Party-in-Interest Transactions [Abstract] Employee Benefit Plan, Dividends [Policy Text Block] Employee benefit plan, dividends. Dividends BankPlus Wealth Mgmt Conservative [Member] BankPlus Wealth Mgmt Conservative member. BankPlus Wealth Mgmt Conservative Fair Value Measurements Total investments Balance, December 31 Balance, January 1 EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Total Parties-in-interest balances Appraised value EBP, Use of Estimate [Policy Text Block] Use of Estimates BankPlus Wealth Mgmt Cons Growth [Member] BankPlus Wealth Mgmt Cons Growth member. BankPlus Wealth Mgmt Cons Growth Employee Benefit Plan Change in Net Asset Available for Benefit Decrease For Trustee Fees Employee benefit plan change in net asset available for benefit decrease for trustee fees. Trustee fees Mutual Fund [Member] Mutual Funds Money Market Mutual Fund Entity [Domain] EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost Purchases, Cost of Asset Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Fair Value of Plan Assets EBP, Investment, Fair Value and NAV [Text Block] BankPlus Wealth Management [Member] BankPlus Wealth Management. BankPlus Wealth Management EBP, Description of Plan and Accounting Change [Abstract] EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Notes receivable from participants, payable semimonthly, Current Value EBP, Statement of Change in Net Asset Available for Benefit [Line Items] Employee Benefit Plan, Investment Valuation And Income Recognition [Policy Text Block] Employee benefit plan, investment valuation and income recognition. Investment Valuation and Income Recognition Statistical Measurement [Domain] Notes receivable from participants EBP, Note Receivable from Participant Document Period End Date EBP, Risk and Uncertainty [Table] Fair Value Hierarchy and NAV [Domain] EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Purchase Price Purchase Price EBP, Contribution [Abstract] 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, Tax Determination Letter, Obtained [true false] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Investment Interest income Employee Benefit Plans Vesting Percentage Greater Than Two Years and Fully Vested Upon Completing Six Years of Service Employee benefit plans vesting percentage greater than two years and fully vested upon completing six years of service. Employee benefit plans vesting percentage greater than two years and fully vested upon completing six years of service EBP, Participant-Directed and Nonparticipant-Directed Status [Domain] Cover [Abstract] Investments [Domain] EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment Income EBP, Risk and Uncertainty [Abstract] EBP, Net Asset Available for Benefit Net Assets Available for Benefits, Beginning of Year Net Assets Available for Benefits, End of Year Net assets Net Assets Available for Benefits EBP, Investment, Fair Value and NAV [Table Text Block] Summary of Fair Value Measurements of Assets Recognized EBP, Contribution [Line Items] EBP, Schedule of Asset Held for Investment [Abstract] Employee Benefit Plan Participant Contributions Description Employee benefit plan participant contributions description. Employee benefit plan participant contributions description EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Current Value EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable from Participants EBP, Schedule of Asset Held for Investment [Table Text Block] Schedule of Assets (Held at End of Year) EBP, Fully Benefit-Responsive Investment Contract [Table Text Block] Summary of Participant-Directed and Nonparticipant-Directed Investments in Company's Common Stock Employee Benefit Plan, Administrative Expenses [Policy Text Block] Employee benefit plan, administrative expenses. Administrative Expenses EBP, Fully Benefit-Responsive Investment Contract [Abstract] EBP, Statement of Net Asset Available for Benefit [Table] Document Fiscal Year Focus Change in fair value of Company common stock EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment, Total EBP, Statement of Change in Net Asset Available for Benefit [Table] Employee Benefit Plan Investment Level 3 Reconciliation Shares acquired by Plan Sponsor Employee benefit plan investment level 3 reconciliation shares acquired by plan sponsor. Shares acquired by Plan Sponsor Shares acquired by Plan Sponsor Purchases EBP, Investment, Level 3 Reconciliation, Increase from Purchase Total assets EBP, Asset Participant salary deferrals Employee Benefit Plan Change In Net Asset Available For Benefit Increase For Participant Salary Deferrals Employee benefit plan change in net asset available for benefit increase for participant salary deferrals. Other assets EBP, Other Asset EPIC Retirement Plan Services [Member] EPIC Retirement Plan Services member. EPIC Retirement Plan Services Money Market Funds [Member] Money Market Mutual Fund EBP, Fully Benefit-Responsive Investment Contract [Line Items] EBP, Plan Number Plan number EBP, Investment, Fair Value and NAV [Line Items] Document Information [Table] Legal Entity [Axis] EBP, Plan Name Plan name EBP, Risk and Uncertainty [Line Items] BankPlus Wealth Mgmt Aggressive [Member] BankPlus Wealth Mgmt Aggressive member. BankPlus Wealth Mgmt Aggressive EBP, Asset [Abstract] Assets Total investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Employee Benefit Plans Vesting Percentage Participants Completed Six Years of Service Employee benefit plans vesting percentage participants completed six years of service. Employee benefit plans vesting percentage participants completed six years of service Employee benefit plan years of service in fully vesting of employee contribution Employee Benefit Plan Years of Service in Fully Vesting of Employee Contribution Employee benefit plan years of service in fully vesting of employee contribution. Plan Tax Status Employee Benefit Plan, Plan Tax Status [Policy Text Block] Employee benefit plan, plan tax status. BankPlus Wealth Mgmt Growth BankPlus Wealth Mgmt Growth [Member] BankPlus Wealth Mgmt Growth member. Net appreciation in fair value of mutual funds Employee Benefit Plan, Change In Net Asset Available For Benefit, Increase From Net Appreciation In Fair Value Of Mutual Funds Employee benefit plan, change in net asset available for benefit, increase from net appreciation in fair value of mutual funds. EBP, Investment, Fair Value and NAV [Table] Participant rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Money Market Mutual Fund Money Market Mutual Fund [Member] Money Market Mutual Fund. EBP, Contribution [Text Block] Contributions EBP, Investment, Level 3 Reconciliation [Roll Forward] Maximum [Member] Maximum Statistical Measurement [Axis] EBP, Statement of Change in Net Asset Available for Benefit [Abstract] EBP 001 EBP 001 [Member] EBP 001. BankPlus Wealth Mgmt Mod Growth [Member] BankPlus Wealth Mgmt Mod Growth, member. BankPlus Wealth Mgmt Mod Growth EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Dividends on Company common stock Sales, Cost of Asset EBP, Investment Sold, Excluding Plan Interest in Master Trust, Cost Entity Registrant Name EBP, Receivable Total receivables EBP, Asset Held for Investment, Participant Loan, Interest Rate Interest rates EBP, Nonparticipant-Directed Investment [Table] Schedule of Reportable Transactions EBP, Schedule of Reportable Transaction [Table Text Block] EBP, Nonparticipant-Directed Investment [Text Block] Net Assets of Nonparticipant-directed Investments EBP, Related Party and Party-in-Interest [Domain] EBP, Related Party and Party-in-Interest [Axis] EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Realized Gain (Loss) on Investment Net Gain or (Loss) Risks and Uncertainties EBP, Risk and Uncertainty [Text Block] EBP, Change in Net Asset Available for Benefit, Decrease Total deductions Stock Employee Benefit Plan, Change In Net Asset Available For Benefit, Decrease From Stock Employee benefit plan, change in net asset available for benefit, decrease from stock. EBP, Investment, Level 3 Reconciliation, Increase (Decrease) from Unrealized Gain (Loss) Unrealized gain Fair Value, Inputs, Level 1 [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution Total participant contributions Schedule of Assets (Held at End of Year) Employee Benefit Plan Schedule of Assets Held For Investments [Text Block] Employee benefit plan schedule of assets held for investments. Employee Benefit Plan, Change In Net Asset Available For Benefit, Increase From Dividends On Common Stock Employee benefit plan, change in net asset available for benefit, increase from dividends on common stock. Dividends on BancPlus Corporation common stock Entity Tax Identification Number EIN Maturity date EBP, Asset Held for Investment, Participant Loan, Maturity Date EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Additions less deductions Change in net assets Additions less deductions Employee Benefit Plan, Change In Net Asset Available For Benefit, Decrease From Cash Employee benefit plan, change in net asset available for benefit, decrease from cash. Cash Terminated Participants Accounts Vested Balance Terminated participants accounts vested balance. Terminated participants accounts vested balance Employee Benefit Plan Years of Service in Vesting of Employee Contribution Employee benefit plan years of service in vesting of employee contribution. Employee benefit plan years of service in vesting of employee contribution EBP, Asset Held for Investment, Party-in-Interest [true false] BlackRock [Member] JP Morgan. William Blair. Reliance Trust. Fidelity. American Funds [Member] Vanguard [Member] Invesco. Invesco [Member] American Funds. Goldman Sachs. PIMCO. PIMCO [Member] Fidelity [Member] Loomis Sayles. Goldman Sachs [Member] Neuberger Berman. Vanguard. Neuberger Berman [Member] William Blair [Member] JP Morgan [Member] BlackRock. BancPlus Corporation common stock [Member] Reliance Trust [Member] Loomis Sayles [Member] BancPlus Corporation common stock.