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 Plan link:presentationLink link:calculationLink link:definitionLink 75040 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:calculationLink link:definitionLink 75050 - Disclosure - Fair Value Measurements link:presentationLink link:calculationLink link:definitionLink 75060 - Disclosure - Risks and Uncertainties link:presentationLink link:calculationLink link:definitionLink 75070 - Disclosure - Tax Status link:presentationLink link:calculationLink link:definitionLink 75080 - Disclosure - Party-in-Interest Transactions link:presentationLink link:calculationLink link:definitionLink 75090 - Disclosure - Subsequent Events link:presentationLink link:calculationLink link:definitionLink 75100 - Disclosure - Schedule H, Line 4i - Schedule of Assets (Held at End of Year) - SCHEDULE OF ASSETS (HELD AT END OF YEAR) link:presentationLink link:calculationLink link:definitionLink 75110 - Disclosure - Summary of Significant Accounting Policies (Policies) link:presentationLink link:calculationLink link:definitionLink 75120 - Disclosure - Fair Value Measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 75130 - Disclosure - Description of Plan - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75140 - Disclosure - Fair Value Measurements - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75150 - Disclosure - Fair Value Measurements - Schedule of Plan's Assets at Fair Value by Level Within Fair Value Hierarchy (Details) link:presentationLink link:calculationLink link:definitionLink 75160 - Disclosure - Risks and Uncertainties - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75170 - Disclosure - Tax Status - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75180 - Disclosure - Subsequent Events - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 75190 - Schedule - Schedule H, Line 4i - Schedule of Assets (Held at End of Year) - Schedule of Assets (Held at End of Year) (Details) link:presentationLink link:calculationLink link:definitionLink 75190 - Schedule - Schedule H, Line 4i - Schedule of Assets (Held at End of Year) - Schedule of Assets (Held at End of Year) (Details) [Default] link:presentationLink link:calculationLink link:definitionLink Maximum percentage of amount participants may borrow EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Forfeited balances, reduce employer matching contributions EBP, Forfeited Nonvested Account, Decrease from Employer Contribution EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative expenses EBP, Net Asset Available for Benefit NET ASSETS AVAILABLE FOR BENEFITS, BEGINNING OF YEAR NET ASSETS AVAILABLE FOR BENEFITS, END OF YEAR NET ASSETS AVAILABLE FOR BENEFITS Minimum [Member] Minimum EBP, Employer Contribution, Matching Percentage Matching percentage EBP, Schedule of Asset Held for Investment [Table] EBP, Tax Status [Line Items] EBP, Payment to Participant [Policy Text Block] Payment of Benefits EBP, Expense [Policy Text Block] Administrative Expenses EBP, Description of Plan and Accounting Change [Abstract] Subsequent Event Type [Domain] Document Period End Date Document Information [Table] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Current Value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] Investments [Domain] EBP, Statement of Net Asset Available for Benefit [Abstract] Employee Benefit Plan Participant Contribution Years of Service for Vesting Employee benefit plan participant contribution years of service for vesting. Employee benefit plan years of service vested Employee Benefit Plan Interest or Penalties Related to Uncertain Tax Positions Employee benefit plan interest or penalties related to uncertain tax positions. Interest or penalties related to uncertain tax positions EBP, Note Receivable from Participant Notes receivable from participants EBP, Tax Status [Text Block] Tax Status EBP, Liability TOTAL LIABILITIES Profit contribution minimum service hours Employee Benefit Plan Requisite Service Period Number of Hours Employee benefit plan requisite service period number of hours. EBP, Use of Estimate [Policy Text Block] Use of Estimates Employee Benefit Plan Tranche Two [Member] Employee Benefit Plan Tranche Two. Six Years of Service 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's matching Vesting schedule, description Employee Benefit Plan, Vesting in Employer Contributions Schedule Description Employee benefit plan, vesting in employer contributions schedule description. Employee Benefit Plan Maximum Number of Outstanding Loans Employee benefit plan maximum number of outstanding loans. Maximum number of outstanding loans EBP, Accounting Policy [Table] EBP, Investment [Policy Text Block] Investment Valuation and Income Recognition Common Collective Trust [Member] Collective Investment Trusts EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants Statistical Measurement [Axis] EBP, Fair Value, Investment, NAV, Redemption, Description Redemption description Money Market Funds [Member] Money Market Account EBP, Employer Contribution, Participant Compensation Matched, Percentage Maximum compensation percentage EBP, Basis of Accounting [Policy Text Block] Basis of Accounting Employee Benefit Plan Minimum In-service Distributions for Participants Permitted Employee benefit plan minimum in-service distributions for participants permitted. Minimum in-service distributions for participants permitted Employee Benefit Plan Uncertain Tax Positions Employee benefit plan uncertain tax positions. Uncertain tax positions Fair Value, Inputs, Level 3 [Member] Level 3 EBP, Investment, Fair Value and NAV [Table Text Block] Schedule of Plan's Assets at Fair Value by Level Within Fair Value Hierarchy EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Participant Loans, Current Value EBP, Change in Net Asset Available for Benefit, Increase TOTAL ADDITIONS Fair Value Hierarchy and NAV [Axis] EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] DEDUCTIONS FROM NET ASSETS ATTRIBUTED TO: EBP 001 [Member] EBP 001. EBP 001 EBP, Description of Plan [Line Items] EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Total Investments, Percentage Investment at fair value to total investments, Percentage EBP, Other Receivable Other receivable EBP, Risk and Uncertainty [Abstract] EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions Two Years of Service Employee Benefit Plan Tranche One [Member] Employee Benefit Plan Tranche One. Document Fiscal Period Focus EBP, Participant Contribution, Automatic, Deferral Rate Participant direct contributions EBP, Schedule of Asset Held for Investment [Abstract] EBP, Change in Net Asset Available for Benefit, Decrease TOTAL DEDUCTIONS EBP, Liability [Abstract] LIABILITIES EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Maximum amount participants may borrow Fair Value, Inputs, Level 1 [Member] Level 1 Investment Type [Axis] EBP, Investment, Current Value, Type [Extensible Enumeration] EBP, Asset Held for Investment, Participant Loan, Maturity Date EBP, Risk and Uncertainty [Text Block] Risks and Uncertainties Statistical Measurement [Domain] Entity Central Index Key EBP, Asset Held for Investment, Participant Loan, Interest Rate Interest rate range Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Contractual obligations to further investment Employee Benefit Plan Investment Contractual Obligations To Further Investment Employee benefit plan investment contractual obligations to further investment. Level 2 Fair Value, Inputs, Level 2 [Member] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Accounting Policy [Line Items] EBP, Investment, Fair Value and NAV [Abstract] Fair Value Hierarchy and NAV [Domain] Interest and dividends 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 Employee benefit plan normal retirement age Employee benefit plan normal retirement age. EBP, Related Party and Party-in-Interest Transactions [Text Block] Party-in-Interest Transactions EBP, Change in Net Asset Available for Benefit, Increase (Decrease) NET INCREASE IN NET ASSETS AVAILABLE FOR BENEFITS EBP, Asset [Abstract] ASSETS EBP, Fair Value, Investment, NAV, Redemption, Notice Period Notice period Stable Value Fund II [Member] Stable Value Fund II. Stable Value Fund II Document Type EBP, Description of Plan [Table] Subsequent Event [Member] Subsequent Event Defined contribution plan, minimum age eligibility Employee Benefit Plan Defined Contribution Plan Minimum Age Eligibility Employee benefit plan defined contribution plan minimum age eligibility. Employee Benefit Plan Vesting [Domain] Employee Benefit Plan Vesting Domain. EBP, Contribution [Policy Text Block] Contributions EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Participants' elective deferrals Employee Benefit Plan Asset Held For Investment Participant Loan Cost Employee benefit plan asset held for investment participant loan cost. Participant Loans, Cost EBP, Statement of Change in Net Asset Available for Benefit [Abstract] 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 Net appreciation in fair value of investments Entity Registrant Name EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Description of Plan [Text Block] Description of Plan EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Table] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] EBP, Plan Name Plan name EBP, Risk and Uncertainty [Line Items] Employee Benefit Plan, Defined Contribution Plan, Minimum Service Period for Eligibility Employee benefit plan, defined contribution plan, minimum service period for eligibility. Defined contribution plan, minimum service period for eligibility Determination letter, date EBP, Tax Determination Letter, Date EBP, Plan Number Plan number Total Investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Total Investment income EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Ending Balance EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Beginning Balance EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value, Total Investments, at fair value TOTAL INVESTMENTS, at Fair Value EBP, Tax Status [Abstract] Mutual Funds Mutual Fund [Member] Cash EBP, Noninterest-Bearing Cash Subsequent Event Type [Axis] EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Benefits paid to participants or beneficiaries EBP, Statement of Net Asset Available for Benefit [Line Items] Employee benefit plan age elect to defer additional amounts as catch-up contributions Employee benefit plan age elect to defer additional amounts as catch-up contributions. Participant age elect to defer additional amounts as catch-up contributions Employee Benefit Plan Vesting [Axis] Employee Benefit Plan Vesting Axis. EBP, Forfeited Nonvested Account Forfeitures account balance Entity Tax Identification Number Entity tax identification number EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Minimum amount participants may borrow EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable from Participants Entity [Domain] EBP, Schedule of Asset Held for Investment [Text Block] Schedule H, Line 4i - Schedule of Assets (Held at End of Year) EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment [Abstract] Investment income: The Fidelity Institutional AM Total International Equity Fund [Member] The Fidelity Institutional AM Total International Equity Fund. The Fidelity Institutional AM Total International Equity Fund EBP, Related Party and Party-in-Interest Transactions [Line Items] Maximum [Member] Maximum EBP, Investment, Fair Value [Abstract] Investments, at fair value: EBP, Investment, Fair Value and NAV [Text Block] Fair Value Measurements TOTAL ASSETS EBP, Asset Document Fiscal Year Focus Contribution limit EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage EBP, Employer, Common Stock Fund [Member] Prosperity Bancshares, Inc. Common Stock Employee Benefit Plan, Notes Receivable from Participants Loan Terms Employee benefit plan, notes receivable from participants loan terms. Loan terms EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions: EBP, Fair Value, Investment, NAV, Unfunded Commitment Unfunded commitments Amendment Flag Employee Benefit Plan Acquired Employees Participating In Their Previous Employer's Qualified Transferred Into The Plan Employee benefit plan acquired employees participating in their previous employer's qualified transferred into the plan. Acquired employees participation transferred into the plan EBP, Tax Determination Letter, Obtained [true false] Determination letter, obtained EBP, Subsequent Event [Text Block] Subsequent Events EBP, Tax Status [Table] Investment, Identifier [Axis] EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Participants' rollovers EBP, Statement of Change in Net Asset Available for Benefit [Line Items] Legal Entity [Axis] EBP, Other Liability Other liabilities EBP, Asset Held for Investment, Party-in-Interest [true false] Cover [Abstract] EBP, Asset Held for Investment Total Current Value Employee Benefit Plan Profit Sharing Contributions Employee benefit plan profit sharing contributions. Profit sharing contributions Employee Benefit Plan Investment Redemption Restrictions Employee benefit plan investment redemption restrictions. Redemption restrictions EBP, Investment, Fair Value and NAV [Table] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Risk and Uncertainty [Table] EBP, Investment, Fair Value and NAV [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Subsequent Event [Abstract] Employee Benefit Plan Participant Contribution Vested Percentage Employee benefit plan participant contribution vested percentage. Employee benefit plan vested percentage Employee Benefit Plan Investment directed withdrawals exceeding of assets invested Employee Benefit Plan Investment directed withdrawals exceeding of assets invested. Directed withdrawals exceeding of assets invested Document Information [Line Items] Flexpath Index Aggressive 2045 M. Fidelity government money market k6. Fidelity Emerging Markets K. Flexpath Index Aggressive 2055 M. Small Cap Value II I1. American Funds New Perspective R6. Flexpath Index Conservative 2045 M. C&S Us Realty RS. Fidelity Government Money Market K6 [Member] Large Cap Value Fund Cl I1 [Member] Flexpath Index Aggressive 2045 M [Member] Flexpath Index Moderate Retirement M [Member] FIAM Total International Equity Fund. Flexpath Index Conservative 2065 M [Member] Blackrock EAFE Index Fund Cl 1. Vanguard Intermed.Term Bond Index. C&S Us Realty RS [Member] Stable Value Fund I1. Flexpath Index Aggressive Retirement M [Member] Flexpath Index Conservative Retirement M [Member] Flexpath Index Moderate 2055 M [Member] American Funds American Balanced R6 [Member] Flexpath Index Moderate 2035 M. American Funds American Balanced R6. Flexpath Index Moderate 2065 M [Member] Flexpath Index Aggressive 2055 M [Member] Flexpath Index Moderate 2035 M [Member] PGIM Tot Ret Bond LP. Large Cap Value Fund Cl I1. Vanguard 500 Index Admiral. Collective Investment Trust. Flexpath Index Aggressive 2065 M. Small Cap Growth Fund II Cl I1. Calvert Equity Fund Class R6. Money market account. Fidelity Emerging Markets K [Member] Flexpath Index Conservative 2035 M. Flexpath Index Aggressive 2035 M. Flexpath Index Aggressive 2035 M [Member] Vanguard Intermed.Term Bond Index [Member] Blackrock EAFE Index Fund Cl 1 [Member] PGIM Tot Ret Bond LP [Member] Fidelity Small Cap Index Fd Instl Premium Cl. Flexpath Index Moderate 2045 M [Member] Blackrock Equity Index Cl 1 [Member] Prosperity Bancshares, Inc Common Stock [Member] FIAM Total International Equity Fund [Member] Prosperity Bank Money Market Account [Member] Vanguard 500 Index Admiral [Member] Flexpath Index Aggressive 2065 M [Member] Blackrock Equity Index Cl 1. Collective Investment Trust [Member] Flexpath Index Moderate 2065 M. American Funds New Perspective R6 [Member] Flexpath Index Conservative 2055 M [Member] Flexpath Index Conservative 2065 M. Vanguard Small Cap Index Fd Admiral. Large Cap Growth III Fund I1. Flexpath Index Moderate 2055 M. Small Cap Growth Fund II Cl I1 [Member] Stable Value Fund I1 [Member] Flexpath Index Moderate Retirement M. Flexpath Index Conservative 2055 M. Money Market Account [Member] Flexpath Index Aggressive Retirement M. Flexpath Index Conservative 2045 M [Member] Vanguard Mid Cap Index Fd Admiral. Vanguard Small Cap Index Fd Admiral [Member] Small Cap Value II I1 [Member] Fidelity Mid Cap Index Fd [Member] Flexpath Index Conservative Retirement M. Prosperity Bancshares, Inc. common stock. Fidelity Mid Cap Index Fd. Flexpath Index Conservative 2035 M [Member] Flexpath Index Moderate 2045 M. Prosperity bank money market account. Large Cap Growth III Fund I1 [Member] Calvert Equity Fund Class R6 [Member] Fidelity Small Cap Index Fd Instl Premium Cl [Member] Vanguard Mid Cap Index Fd Admiral [Member]