1001 - Document - Cover link:presentationLink link:definitionLink link:calculationLink 1002 - Statement - Statements of Net Assets Available for Benefits link:presentationLink link:definitionLink link:calculationLink 1003 - Statement - Statement of Changes in Net Assets Available for Benefits link:presentationLink link:definitionLink link:calculationLink 1004 - Disclosure - Description of the Plan link:presentationLink link:definitionLink link:calculationLink 1005 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:definitionLink link:calculationLink 1006 - Disclosure - Plan Termination link:presentationLink link:definitionLink link:calculationLink 1007 - Disclosure - Related Party and Party-in-Interest Transactions link:presentationLink link:definitionLink link:calculationLink 1008 - Disclosure - Fair Value Measurements link:presentationLink link:definitionLink link:calculationLink 1009 - Disclosure - Guaranteed Annuity Contract with Voya link:presentationLink link:definitionLink link:calculationLink 1010 - Disclosure - Risk and Uncertainties link:presentationLink link:definitionLink link:calculationLink 1011 - Disclosure - Income Tax Status of the Plan link:presentationLink link:definitionLink link:calculationLink 1012 - Disclosure - Delinquent Participant Deferrals link:presentationLink link:definitionLink link:calculationLink 1013 - Disclosure - Subsequent Events link:presentationLink link:definitionLink link:calculationLink 1014 - Disclosure - Schedule H, Line 4a - Schedule of Delinquent Participant Contributions link:presentationLink link:definitionLink link:calculationLink 1015 - Disclosure - Schedule H, Line 4i - Schedule of Assets (Held at End of Year) link:presentationLink link:definitionLink link:calculationLink 1016 - Disclosure - Summary of Significant Accounting Policies (Policies) link:presentationLink link:definitionLink link:calculationLink 1017 - Disclosure - Description of the Plan (Tables) link:presentationLink link:definitionLink link:calculationLink 1018 - Disclosure - Fair Value Measurements (Table) link:presentationLink link:definitionLink link:calculationLink 1019 - Disclosure - Description of the Plan - Schedule of Vested and Nonforfeitable Right in the Bank's Profit Sharing Contributions (Details) link:presentationLink link:definitionLink link:calculationLink 1020 - Disclosure - Description of the Plan - Schedule of Vesting in the Bank's Safe Harbor and Any Qualified Elective Matching Contributions (Details) link:presentationLink link:definitionLink link:calculationLink 1021 - Disclosure - Description of the Plan - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1022 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1023 - Disclosure - Plan Termination - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 1024 - Disclosure - Related Party and Party-in-Interest Transactions - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1025 - Disclosure - Fair Value Measurements - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1026 - Disclosure - Fair Value Measurements - Schedule Of Plan's Investments At Fair Value (Details) link:presentationLink link:definitionLink link:calculationLink 1027 - Disclosure - Guaranteed Annuity Contract with Voya - Additional Inormation (Details) link:presentationLink link:definitionLink link:calculationLink 1028 - Disclosure - Risk and Uncertainties - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1029 - Disclosure - Income Tax Status of the Plan - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1030 - Disclosure - Delinquent Participant Deferrals - Additional Information (Details) link:presentationLink link:definitionLink link:calculationLink 1031 - Disclosure - Schedule H, Line 4a - Schedule of Delinquent Participant Contributions (Details) link:presentationLink link:definitionLink link:calculationLink 1032 - Disclosure - Schedule H, Line 4i- Schedule of Assets (Held at End of Year) (Detail) link:presentationLink link:definitionLink link:calculationLink 1033 - Disclosure - Schedule H, Line 4i- Schedule of Assets (Held at End of Year) (Detail) Alternate link:presentationLink link:definitionLink link:calculationLink Cover [Abstract] Document Information [Table] Legal Entity [Axis] Entity [Domain] EBP 001 [Member] Document Information [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Asset [Abstract] EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Investments, at fair value EBP, Investment, excluding plan interest in master trust, fair value EBP, Investment, Excluding Plan Interest in Master Trust, Contract Value Investments, at contract value EBP, Investment, Excluding Plan Interest in Master Trust, Fair and Contract Value Total investments EBP, Note Receivable from Participant Notes receivable from participants EBP, Net Asset Available for Benefit Net assets available for benefits Beginning of year End of year EBP, Statement of Change in Net Asset Available for Benefit [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Change in Net Asset Available for Benefit, Increase [Abstract] Additions to Net Assets Attributed to EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment Income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Total investment income EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment Interest and dividends EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Participant contributions EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash Employer contributions EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Other (including rollovers) EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Change in Net Asset Available for Benefit, Increase Total additions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Deductions from Net Assets Attributed to EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Benefits paid to participants Employee Benefit Plan Change In Net Asset Available For Benefit Decrease For Deemed distributions of participant loans Deemed distributions of participant loans Employee benefit plan change in net asset available for benefit decrease for deemed distributions of participant loans. EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease Total deductions EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Net increase in net assets available for benefits EBP, Description of Plan and Accounting Change [Abstract] EBP, Description of Plan [Table] EBP, Description of Plan [Line Items] EBP, Description of Plan [Text Block] Description of the Plan EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Line Items] EBP, Summary of Accounting Policy [Text Block] Summary of Significant Accounting Policies EBP, Plan Termination [Text Block] Plan Termination EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Text Block] Related Party and Party-in-Interest Transactions EBP, Investment, Fair Value and NAV [Abstract] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Text Block] Fair Value Measurements EBP, Fully Benefit-Responsive Investment Contract [Abstract] EBP, Fully Benefit-Responsive Investment Contract [Table] EBP, Fully Benefit-Responsive Investment Contract [Line Items] EBP, Fully Benefit-Responsive Investment Contract [Text Block] Guaranteed Annuity Contract with Voya EBP, Risk and Uncertainty [Abstract] EBP, Risk and Uncertainty [Table] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Text Block] Risk and Uncertainties EBP, Tax Status [Abstract] EBP, Tax Status [Table] EBP, Tax Status [Line Items] EBP, Tax Status [Text Block] Income Tax Status of the Plan EBP, Schedule of Delinquent Participant Contribution [Abstract] EBP, Schedule of Delinquent Participant Contribution [Table] EBP, Schedule of Delinquent Participant Contribution [Line Items] Employee Benefit Plan Schedule Of Delinquent Participant Contribution [Text Block] Delinquent Participant Deferrals Employee Benefit Plan Schedule Of Delinquent Participant Contribution. EBP, Subsequent Event [Abstract] EBP, Subsequent Event [Table] EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Text Block] Subsequent Events Schedule H, Line 4(a) Schedule of Delinquent Participant Contributions [Text Block] Schedule H, Line 4(a) - Schedule of Delinquent Participant Contributions Employee benefit plan delinquent participant contribution. EBP, Schedule of Asset Held for Investment [Abstract] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Text Block] Schedule H, Line 4i- Schedule of Assets (Held at End of Year) EBP, Basis of Accounting [Policy Text Block] Basis of Accounting EBP, Use of Estimate [Policy Text Block] Use of Estimates EBP, Investment [Policy Text Block] Investment Valuation and Income Recognition Employee Benefit Plan Investment Fees [Policy Text Block] Investment Fees Employee benefit plan investment fees. EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable from Participants EBP, Contribution [Policy Text Block] Contributions EBP, Payment to Participant [Policy Text Block] Benefit Payments EBP, Expense [Policy Text Block] Administrative Expenses Employee Benefit Plan, Participant Account, vested and nonforfeitable right in the Bank's profit sharing contributions [Table Text Block] Schedule of Vested and Nonforfeitable Right in the Bank's Profit Sharing Contributions Employee benefit plan, participant account, vested and nonforfeitable right in the bank's profit sharing contributions. Employee Benefit Plan, Participant Account, Vesting in the Banks safe harbor and any qualified elective matching contributions [Table Text Block] Schedule of Vesting in the Bank's Safe Harbor and Any Qualified Elective Matching Contributions Employee benefit plan, participant account, vesting in the bank's safe harbor and any qualified elective matching contributions. EBP, Investment, Fair Value and NAV [Table Text Block] EBP, Investment, fair value and NAV Employee Benefit Plan Participant Account Vested And Nonforfeitable Right As A Percentage Of Banks Profit Sharing Contributions EBP, participant account, vested and nonforfeitable right (as a percentage of bank's profit sharing contributions) Employee benefit plan, participant account, vested and nonforfeitable right (as a percentage of banks profit sharing contributions). Service Years [Axis] Service Years [Domain] Until 1 year [Member] Less than 1 year [Member] 1 year [Member] 1 year [Member] 2 years [Member] 2 years [Member] 3 Years [Member] 3 years [Member] 4 years [Member] 4 years [Member] 5 years or more [Member] 5 years or more [Member] Until 2 years [Member] Less than 2 years [Member] 2 years or more [Member] Two or More Years [Member] Employee Benefit Plan, Participant Account, Vesting Percentage (As A Percentage Of Banks Safe Harbor And Any Qualified Elective Matching Contributions) EBP, participant account, vesting percentage (as a percentage of bank's safe harbor and any qualified elective matching contributions) Employee benefit plan, participant account, vesting percentage (as a percentage of bank's safe harbor and any qualified elective matching contributions). Statistical Measurement [Axis] Statistical Measurement [Domain] Minimum [Member] Maximum [Member] Matching Percentage [Axis] Matching Percentage [Domain] Until 2 percent [Member] 2 - 4 percent [Member] Loan Type [Axis] Loan Type [Domain] Principal Residential Loan [Member] Investment Type [Axis] Investments [Domain] Notes Receivables from participant [Member] Employee Benefit Plan, Participant Eligibility, Participant Age, threshold EBP, participant eligibility, participant age, threshold Employee benefit plan, participant eligibility, participant age, threshold. Employee Benefit Plan, Participant Eligibility, Days of Service, threshold EBP, participant eligibility, days of service, threshold Employee benefit plan, participant eligibility, days of service, threshold. Employee Benefit Plan, Participant Eligibility, Hours of Service, threshold EBP, participant eligibility, hours of service, threshold Employee benefit plan, participant eligibility, hours of service, threshold. Employee benefit plan, employer contribution, eligibility, years of service, threshold EBP, employer contribution, eligibility, years of service, threshold Employee benefit plan, employer contribution, eligibility, years of service, threshold. Employee Benefit Plan Participant Contribution Pretax Minimum Annual Compensation To Total Compensation Percentage EBP, participant contribution, pretax minimum annual compensation to total compensation percentage Employee benefit plan participant contribution pretax minimum annual compensation to total compensation percentage. EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage EBP, participant contribution, pretax, maximum annual compensation to total compensation, percentage EBP, Participant Contribution, Automatic, Deferral Rate EBP, participant contribution, automatic, deferral rate Employee Benefit Plan, Catchup Contributions, Participant Age, threshold EBP, catch-up contributions, participant age, threshold Employee benefit plan, catchup contributions, participant age, threshold. EBP, Employer Contribution, Matching Percentage EBP, employer contribution, matching percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, employer contribution, participant compensation matched, percentage Employee Benefit Plan, Death or Disability, Participant Account, Vesting Percentage EBP, death or disability, participant account, vesting percentage Employee benefit plan, death or disability, participant account, vesting percentage. EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, note receivable from participant, account, minimum borrowing, amount Employee Benefit Plan Note Receivable From Participant Account Maximum Borrowing Amount Description EBP, note receivable from participant account, maximum borrowing amount, description Employee benefit plan note receivable from participant account maximum borrowing amount description. EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, asset held for investment, participant loan, interest rate Employee Benefit Plan Participant Loan Period EBP, participant loan period Employee benefit plan participant loan period. EBP, Forfeited Nonvested Account EBP, forfeited nonvested account EBP, Modified Cash Basis [true false] EBP, modified cash basis [true false] Employee Benefit Plan, Plan Termination, Participant Account, Vesting Percentage Plan Termination Employee benefit plan, plan termination, participant account, vesting percentage. EBP, Investment, Number of Shares EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Domain] EBP, Trustee [Member] Common Stock [Member] State Street ShortTerm Investment Fund [Member] STIF [Member] EBP, Asset EBP, Asset EBP, Employer, Common Stock [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value Measured at Net Asset Value Per Share [Member] EBP, Investment, Interest Rate EBP, Investment, interest rate EBP, Fully Benefit-Responsive Investment Contract, Limitation on Transacting at Contract Value, Not Probable [true false] EBP, Fully benefit-responsive investment contract, limitation on transacting at contract value, not probable [true false] EBP, Fully Benefit-Responsive Investment Contract, Termination, Description EBP, Fully benefit-responsive investment contract, termination, description EBP, Traditional Guaranteed Investment Contract [Member] EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Net Assets, Amount EBP, Risk and uncertainty, concentration of investment at fair value to net assets, amount EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Net Assets, Percentage EBP, Risk and uncertainty, concentration of investment at fair value to net assets, percentage Ebp Risk And Uncertainty Concentration Of Investment At Fair Value To Net Assets Number Of Funds EBP, Risk and uncertainty concentration of investment at fair value to net assets number of funds Ebp risk and uncertainty concentration of investment at fair value to net assets number of funds. EBP, Tax Determination Letter, Date EBP, Tax Determination Letter, Date EBP, Schedule Of Delinquent Participant Contribution, Participant Contribution Transferred Late To Plan EBP, Schedule Of Delinquent Participant Contribution, Participant Contribution Transferred Late To Plan EBP, Schedule Of Delinquent Participant Contribution, Participant Contribution Transferred Late To Plan. EBP, Schedule Of Delinquent Participant Contribution, Loan Repayments Transferred Late To Plan EBP, Schedule Of Delinquent Participant Contribution, Loan Repayments Transferred Late To Plan EBP, Schedule Of Delinquent Participant Contribution, Loan Repayments Transferred Late To Plan. Entity Tax Identification Number EBP, Plan Number EBP, Schedule of Delinquent Participant Contribution, Late Repayment Included [true false] EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan EBP, Schedule of Delinquent Participant Contribution, Not Corrected EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP EBP, Schedule of Delinquent Participant Contribution, Pending Correction in VFCP EBP, Schedule of Delinquent Participant Contribution, Corrected Investment, Identifier [Axis]