Interest on deposits Total Interest Expense, Deposits Balance sheet assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Due after 5 years through 10 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Supplemental information: Supplemental Cash Flow Information [Abstract] Actuarial (gain) loss Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Earnings Per Share Earnings Per Share, Policy [Policy Text Block] State Current State and Local Tax Expense (Benefit) Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period C&I C&I [Member] C&I [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Leasehold Improvements Leasehold Improvements [Member] Net income Net income Net Income (Loss) Attributable to Parent Consolidated Entities [Axis] Consolidated Entities [Axis] Operating lease, right-of-use asset Operating Lease, Right-of-Use Asset Pension Plans Pension and Other Postretirement Plans, Policy [Policy Text Block] Noninterest-bearing Noninterest-bearing Deposit Liabilities Interest cost Interest cost on projected benefit obligations Defined Benefit Plan, Interest Cost Condensed Financial Information of Parent Company Condensed Financial Information of Parent Company Only Disclosure [Text Block] Accumulated Amortization Total intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Statistical Measurement [Domain] Statistical Measurement [Domain] Other Other Intangible Assets [Member] Four years Time Deposits, Weighted Average Interest Rate, Maturities Year Four Cash dividends Dividends, Common Stock, Cash Schedule of Debtor Troubled Debt Restructuring, Current Period Schedule of Debtor Troubled Debt Restructuring, Current Period [Table Text Block] Security Exchange Name Security Exchange Name $250 or more Interest Expense Time Deposits 250000 or More Interest expense incurred on time deposits, including certificates of deposits, of $250,000 or more in domestic offices. Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Real Estate, Faith-Based, Mortgage Real Estate Faith-based Mortgage [Member] Real Estate Faith-based Mortgage [Member] Issuance of common shares pursuant to stock-based compensation plan, net (in shares) Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture Additional paid-in capital Additional Paid in Capital, Common Stock Operating lease, weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Net increase in noninterest-bearing demand deposits Net Increase (Decrease) In Noninterest-Bearing Demand Deposits Net change during the reporting period in noninterest-bearing demand deposits. Lease liability Deferred Tax Asset, Lease Liability Deferred Tax Asset, Lease Liability Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Segments [Axis] Segments [Axis] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Tier I Capital (to risk-weighted assets), Capital Requirements, Ratio Tier I capital (to risk-weighted assets), capital requirements ratio The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. Common Equity Tier I Capital (to risk-weighted assets), Requirement to be Well-Capitalized, Ratio Common Equity Tier I Capital (to risk-weighted assets), requirement to be well capitalized ratio The Common Equity Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Retirement Benefits [Abstract] Retirement Benefits [Abstract] Net (decrease) increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Entity File Number Entity File Number Stock-based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Increase (decrease) in current income tax liability Increase (Decrease) in Income Taxes Payable Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Schedule of Investment Securities Debt Securities, Available-for-sale [Table Text Block] Amortization of intangible assets Amortization of Intangible Assets Nonperforming Loans Subject To Special Monitoring Nonperforming Loans Subject To Special Monitoring [Member] Nonperforming Loans Subject To Special Monitoring [Member] Changes in unrecognized tax benefits as a result of tax positions taken during a prior year Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Opportunistic Opportunistic [Member] Opportunistic [Member] Net deferred tax assets Deferred Tax Assets, Net PPP Paycheck protection program ("PPP") [Member] Paycheck protection program ("PPP") [Member] Weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Subsequent Events [Abstract] Subsequent Events [Abstract] Buildings Building [Member] Provision for (release of) credit losses (Release of) provision for credit losses Provision for (release of) credit losses Financing Receivable, Credit Loss, Expense (Reversal) Total deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Fair value of shares vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Granted in period, weighted average fair value (in dollars per share) Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Actual return Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Proceeds from maturities of securities available-for-sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Total Time Deposits, Weighted Average Interest Rate, Aggregate Aggregate percentage of weighted average interest rate for time deposits held by the entity with maturities from one to five years. Aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding Award Type [Domain] Award Type [Domain] 90 Days and Over Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Cass Commercial Bank Cass Commercial Bank [Member] Cass Commercial Bank [Member] Local Phone Number Local Phone Number Credit Facility [Domain] Credit Facility [Domain] Assets Assets: Assets [Abstract] Net actuarial loss in accumulated other comprehensive loss Defined Benefit Plan, Amortization of Gain (Loss) Land Land [Member] Condensed Income Statement [Table] Condensed Income Statement [Table] Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] State and political subdivisions US States and Political Subdivisions Debt Securities [Member] Reduction of tax benefits over the next twelve months Decrease in Unrecognized Tax Benefits is Reasonably Possible Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Acquired Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] FinancingReceivableRecordedInvestmentClassOfFinancin Class of Financing Receivable [Domain] Preferred stock, par value $.50 per share; 2,000,000 shares authorized and no shares issued Preferred Stock, Value, Issued Premises and Equipment Property, Plant and Equipment, Policy [Policy Text Block] U.S. Passive U.S. Passive [Member] United States Passive [Member]. Interest on federal funds sold and other short-term investments Interest on federal funds sold and other short-term investments Interest income on federal funds sold and other short-term investments. Weighted average discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Trade Name Trade Names [Member] Retained Earnings Retained Earnings [Member] Purchase of common shares (in shares) Stock Issued During Period, Shares, Purchase of Assets Total deposits Deposits Promotional expense Marketing and Advertising Expense Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Interest Expense: Interest Expense [Abstract] Right of use asset Deferred Tax Liabilities, Leasing Arrangements Unfunded Loan Commitment Unfunded Loan Commitment [Member] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Performance-based stock vested Performance Based Stock Performance-based stock. Interest-Bearing Deposits Deposit Liabilities Disclosures [Text Block] Emerging Markets Emerging Markets [Member] Emerging Markets [Member]. Supplemental executive retirement plan accrual Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits Less allowance for credit losses Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Net amortization and deferral Defined Benefit Plan, Amortization of Prior Service Cost (Credit) (Increase) decrease in accounts receivable Increase (Decrease) in Accounts Receivable Performing Loans Subject To Special Monitoring Performing Loans Subject To Special Monitoring [Member] Performing Loans Subject To Special Monitoring [Member] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised Income from subsidiaries – management fees Investment Income, Nonoperating Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Percentage of shares vested Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Amortization of restricted stock bonus Amortization of restricted stock bonus Amount of amortization of the restricted stock bonus. Plan assets, target allocation percentage % of Total Portfolio Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Accounts and drafts payable Accounts Payable, Fair Value Disclosure (Reductions) increases resulting from: (Reductions) increases resulting from: (Reductions) increases resulting from: Reserve for unfunded commitments Reserve for unfunded commitments Reserve for unfunded commitments. Short-term borrowings Repayments of Short-term Debt Basic Earnings Per Share (in dollars per share) Earnings Per Share, Basic 30-59 Days Financial Asset, 30 to 59 Days Past Due [Member] Condensed Balance Sheet Condensed Balance Sheet [Table Text Block] 2-3 years Lessee, Operating Lease, Liability, to be Paid, Year Three Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] Loans, net Loans, net Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Tax-exempt income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Beginning balance (in shares) Ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Common Equity Tier I Capital (to risk-weighted assets), Capital Requirements, Ratio Common Equity Tier I Capital (to risk-weighted assets), capital requirements ratio The minimum Common Equity Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. Due after 1 year through 5 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Other operating Total other operating expense Other Noninterest Expense Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Number of troubled debt restructured loans subsequently defaulted Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Diluted: Earnings Per Share, Diluted [Abstract] Schedule of Plan's Pension Costs Schedule of Plan's Pension Costs [Table Text Block] Tabular disclosure of net periodic pension costs. Adjustment Impact of ASU 2016-13 Adoption Cumulative Effect, Period of Adoption, Adjustment [Member] Operating lease, payments Operating Lease, Payments Total deferred tax liabilities Deferred Tax Liabilities, Net Number of shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Property, Plant and Equipment, Other Types Property, Plant and Equipment, Other Types [Member] Net (decrease) increase in short-term borrowings Proceeds from (Repayments of) Short-term Debt Information Services Information Services [Member] Information Services [Member] Premises and equipment Deferred Tax Liabilities, Property, Plant and Equipment Three years Time Deposit Maturities, Year Three Information services payment and processing revenue Information Services Payment And Processing [Member] Information Services Payment And Processing Allowance for unfunded commitments Impaired Financing Receivable, Related Allowance Funded status: Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] Entity Voluntary Filers Entity Voluntary Filers Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Core Fixed Income Fixed Income Funds [Member] Loans Excluding Unfunded Commitments Loans Excluding Unfunded Commitments [Member] Loans Excluding Unfunded Commitments Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Total Assets, Fair Value Disclosure Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Cash Flows From Investing Activities: Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Other operating activities, net Other, net Other Operating Activities, Cash Flow Statement Net interest income after (release of) provision for credit losses Net interest income after (release of) provision for credit losses Interest Income (Expense), after Provision for Loan Loss Other liabilities Other Liabilities Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] State taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Entity Small Business Entity Small Business Cash Cash and Cash Equivalents [Member] Real Estate, Faith-based, Construction Real Estate Faith-based Construction [Member] Real Estate Faith-based Construction [Member] Tax-equivalized pre-tax income Income (Loss) from Continuing Operations Including Tax Equivalent Adjustment, Before Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations Including Tax Equivalent Adjustment, Before Income Taxes, Noncontrolling Interest Total Capital (to risk weighted assets), Requirement to be Well-Capitalized, Ratio Total capital (to risk-weighted assets), requirement to be well capitalized ratio The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action. Changes in unrecognized tax benefits as a result of tax position taken during the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Balance sheet liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Participating Mortgage Loans [Table] Participating Mortgage Loans [Table] Total liabilities and shareholders’ equity Liabilities and Equity Tier I Capital (to risk-weighted assets), Requirement to be Well-Capitalized, Amount Banking Regulation, Tier One Risk-Based Capital, Well Capitalized, Minimum Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Total Time Deposits Other Income and Expenses [Abstract] Other Income and Expenses [Abstract] 4-5 years Lessee, Operating Lease, Liability, to be Paid, Year Five Scenario [Axis] Scenario [Axis] Plan amendments Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment Tier I Capital (to average assets), Capital Requirements, Ratio Tier I capital (to average assets), capital requirements ratio The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations. Uninsured scheduled maturities, year one Time Deposit Liability Uninsured, Maturity, Within Year One Time Deposit Liability Uninsured, Maturity, Within Year One Benefits paid Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Weighted- Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Net increase (decrease) in interest-bearing demand and savings deposits Net Increase (Decrease) In Interest-Bearing Demand And Savings Deposits Net change during the reporting period in interest-bearing demand and savings deposits. Tax effect Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Liabilities and Shareholders’ Equity Liabilities and Equity [Abstract] Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Bank service fees Bank Service Fees [Member] Bank Service Fees Common Stock and Earnings per Share Earnings Per Share [Text Block] Purchase of common shares Treasury Stock, Value, Acquired, Cost Method Entity Interactive Data Current Entity Interactive Data Current Decreases in unrecognized tax benefits as a result of settlements with taxing authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Two Exercise of SARs Stock Issued During Period, Value, Stock Options Exercised Standby letters of credit Standby Letters of Credit [Member] Minimum Minimum [Member] Plan assets, measurement input Defined Benefit Plan, Plan Assets, Measurement Input Defined Benefit Plan, Plan Assets, Measurement Input Available-for-sale securities, gross realized gains Debt Securities, Available-for-sale, Realized Gain 1-2 years Lessee, Operating Lease, Liability, to be Paid, Year Two Long-term line of credit Long-term Line of Credit Total Financial and Nonfinancial Liabilities, Fair Value Disclosure Unamortized intangible assets: Unamortized intangible assets: Unamortized Intangible Asset Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Balance at January 1 Balance at December 31 Unrecognized Tax Benefits Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Other Operating Expense Other Operating Income and Expense [Text Block] Entity Address, State or Province Entity Address, State or Province Due after 10 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] AFS, 12 months or more, Estimated Fair Value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Savings deposits Deposits, Savings Deposits U.S. Large Cap Passive U.S. Large Cap Passive [Member] United States Large Cap Passive [Member]. Finance receivable, related parties Loans and Leases Receivable, Related Parties Unused Available Lines of Credit Debt Disclosure [Text Block] Shares outstanding at January 1 Shares outstanding at December 31 Shares, Outstanding Deposits Deposits, by Type [Abstract] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Stock-based Compensation Share-based Payment Arrangement [Text Block] Cash dividends paid Payments of Ordinary Dividends, Common Stock Equity Securities Equity Securities [Member] Common Equity Tier I Capital (to risk-weighted assets), Requirement to be Well-Capitalized, Amount Common Equity Tier I Capital (to risk-weighted assets), requirement to be well capitalized amount The amount of Common Equity Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action. Accounting Policies [Abstract] Accounting Policies [Abstract] 2025 Defined Benefit Plan, Expected Future Benefit Payment, Year Four Summary of ACL by Category Summary of Allowance For Credit Loss by Category [Table Text Block] Summary of ACL by Category. Shares issued (in shares) Stock Issued During Period, Shares, New Issues Number of reportable segments Number of Reportable Segments Number of loans individually evaluated for impairment Number Of Loans Individually Evaluated for Impairment Number Of Loans Individually Evaluated for Impairment Schedule of Assumed Long-term Rate of Return on Assets Schedule of Assumed Long-term Rate of Return on Assets [Table Text Block] Tabular disclosure for assumed long term rate of return on assets. Operating lease, liability Total lease liability Operating Lease, Liability Federal Current Federal Tax Expense (Benefit) Schedule of Performance Shares Activity Share-based Payment Arrangement, Performance Shares, Outstanding Activity [Table Text Block] Document Transition Report Document Transition Report Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Common stock, par value $.50 per share; 40,000,000 shares authorized; 15,505,772 shares issued at December 31, 2021 and 2020; 13,734,295 and 14,392,669 shares outstanding at December 31, 2021 and 2020, respectively. Common Stock, Value, Issued Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Unrecognized compensation expense, period for recognition Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Beginning balance (in dollars per share) Ending balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Postage and supplies Supplies and Postage Expense Performance-based Restricted Stock Performance Shares [Member] Current Financial Asset, Not Past Due [Member] Leases Lessee, Operating Leases [Text Block] Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Entity Emerging Growth Company Entity Emerging Growth Company $100 to less than $250 Time Deposits, More than $100,000 Less than $250,000 The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more and total to less than $250,000. Accrued pension liability Defined Benefit Plan, Funded (Unfunded) Status of Plan Restricted Stock Restricted Stock [Member] Six Corresponding Banks Six Corresponding Banks [Member] Six Corresponding Banks ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Receivables [Abstract] Receivables [Abstract] Other Commitments [Table] Other Commitments [Table] Investment Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Legal Entity [Axis] Legal Entity [Axis] Auditor Name Auditor Name Cover [Abstract] Adjusted Balance As Reported Under ASU 2016-13 Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Allowance for credit losses Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Financing Receivable, Allowance for Credit Loss Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Treasury stock (in shares) Treasury Stock, Shares Schedule of Unrealized Loss on Investments Schedule of Unrealized Loss on Investments [Table Text Block] Net interest income Intersegment income (expense) Interest Income (Expense), Net Discount on cash flows Lessee, Operating Lease, Liability, Undiscounted Excess Amount Pre-Modification Outstanding Balance Financing Receivable, Troubled Debt Restructuring, Premodification Rate of increase in compensation levels Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Two Corresponding Banks Two Corresponding Banks [Member] Two Corresponding Banks Schedule of Other Operating Cost and Expense, by Component Schedule of Other Operating Cost and Expense, by Component [Table Text Block] Condensed Cash Flow Statement Condensed Cash Flow Statement [Table Text Block] Post-Modification Outstanding Balance Financing Receivable, Troubled Debt Restructuring, Postmodification Tax effect OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax CRE CRE [Member] CRE [Member] Comprehensive Income: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Financial Instrument [Axis] Financial Instrument [Axis] Entity [Domain] Entity [Domain] Securities available-for-sale, at fair value Fair Value Total Debt Securities, Available-for-Sale, Excluding Accrued Interest Fee revenues Fee revenues, in-scope of FASB ASC 606 Revenue from Contract with Customer, Excluding Assessed Tax Stock compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Five years Time Deposits, Weighted Average Interest Rate, Maturities Year Five Amortization expense, next rolling twelve months Finite-Lived Intangible Assets, Amortization Expense, Next Rolling Twelve Months Outside service fees Outside service fees Outside service fees. Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Loans Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Other income (out-of-scope of ASC 606) Revenue Not from Contract with Customer Small Cap U.S. Equities Small Cap U.S. Equities [Member] Equity Securities Small Cap [Member] Consolidation Items [Domain] Consolidation Items [Domain] Carrying Amount Reported Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Measurement Input Type [Domain] Measurement Input Type [Domain] Cass Information Systems, Inc. Cass Information Systems Inc. [Member] Cass Information Systems Inc. [Member] Plan assets: Plan assets: Plan assets: AFS, Less than 12 months, Estimated Fair Value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Common Stock Common Stock [Member] Net increase in loans Payments for (Proceeds from) Loans and Leases Other intangible assets, net Other Intangible Assets, Net Industry Segment Information Segment Reporting Disclosure [Text Block] Professional fees Professional Fees Over 5 years Lessee, Operating Lease, Liability, to be Paid, Due after Year Four Lessee, Operating Lease, Liability, to be Paid, Due after Year Four 401(k) employer contribution amount Defined Contribution Plan, Employer Discretionary Contribution Amount Loans Financing Receivable [Policy Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] Due after 1 year through 5 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Gains on sales of securities Debt Securities, Available-for-sale, Realized Gain (Loss) Document Fiscal Year Focus Document Fiscal Year Focus Shares forfeited Shares Issued, Shares, Share-based Payment Arrangement, Forfeited Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Faith-based CRE Faith-based CRE [Member] Faith-based CRE [Member] Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year Cash and Cash Equivalents, at Carrying Value Participating Mortgage Loans [Line Items] Participating Mortgage Loans [Line Items] Additional Paid-in Capital Additional Paid-in Capital [Member] SERP Supplemental Executive Retirement Plan [Member] Supplemental Executive Retirement Plan [Member]. Depreciation Depreciation Time deposits: Time Deposits [Abstract] 2026-2030 Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Cash dividends (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Treasury Stock Treasury Stock [Policy Text Block] Disclosure of accounting policy for an entity's treasury stock, including the average cost per share, carrying basis for each class of treasury stock, description of share repurchase program authorized by an entity's board of directors, the number of shares repurchased, the cost of the shares repurchased, the remaining maximum dollar value of shares available for repurchase under the program, the treatment of the purchase price in excess of the current market value, number of shares held for each class of treasury stock, and other information necessary to a fair presentation. Treasury Stock Treasury Stock [Member] Real estate investment trusts Defined Benefit Plan, Real Estate [Member] Employee restricted stock units vested Stock Issued During Period, Shares, Conversion of Units Purchases of securities available-for-sale Net (increase) decrease in securities Payments to Acquire Debt Securities, Available-for-sale Number of troubled debt restructured loans Number of Loans Financing Receivable, Modifications, Number of Contracts Non-marketable Equity Investments Equity Method Investments [Policy Text Block] Capital Requirements and Regulatory Restrictions Regulatory Capital Requirements under Banking Regulations [Text Block] Schedule of Prospective Adoption of New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Table Text Block] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Share-based compensation adjustment Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount Gains on sales of securities Gain on sales of investment securities Debt and Equity Securities, Gain (Loss) Increase (Decrease) in Other Operating Liabilities Increase (Decrease) in Other Operating Liabilities Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Non-option equity instruments, granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Percentage of target opportunity for awards to vest Percentage of target opportunity for awards to vest Percentage of target opportunity for awards to vest. Purchases of premises and equipment, net Payments to Acquire Property, Plant, and Equipment ASC 715 pension funding liability Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions Available-for-sale securities, percentage of total securities Available-for-sale, Securities in Unrealized Loss Positions, Percentage Of Total Securities The percentage of the number of investment positions in the available-for-sale investments determined to be temporarily impaired. Employer contribution Defined Benefit Plan, Plan Assets, Contributions by Employer Accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Maximum Maximum [Member] Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Tax effect Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Total liabilities Total liabilities Liabilities Deferred tax assets: Deferred Tax Assets, Net [Abstract] Award Type [Axis] Award Type [Axis] Tier I Capital (to risk-weighted assets), Actual, Ratio Tier I capital (to risk-weighted assets), actual ratio Ratio of Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework. Cash Flows From Financing Activities: Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Lessee, Operating Lease, Liability, Maturity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Consolidation Items [Axis] Consolidation Items [Axis] Measurement Input Type [Axis] Measurement Input Type [Axis] Total shareholders’ equity Beginning balance Ending balance Total shareholders’ equity Stockholders' Equity Attributable to Parent Time Deposits, Fiscal Year Maturity [Abstract] Time Deposits, Fiscal Year Maturity [Abstract] Common stock, shares issued (in shares) Common Stock, Shares, Issued Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued City Area Code City Area Code Three years Time Deposits, Weighted Average Interest Rate, Maturities Year Three Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Total Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax Other Other Loan [Member] Other Loan FASB ASC 715 pension adjustment Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Lease payments due Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Entity Address, City or Town Entity Address, City or Town Common Equity Tier I Capital (to risk-weighted assets), Actual, Ratio Common Equity Tier I Capital (to risk-weighted assets), actual ratio Common Equity Tier 1 capital divided by risk weighted assets as defined by regulations. Interest-Bearing Deposits [Abstract] Interest-Bearing Deposits [Abstract] Interest-Bearing Deposits [Abstract] Tier I Capital (to risk-weighted assets), Requirement to be Well-Capitalized, Ratio Tier I capital (to risk-weighted assets), requirement to be well capitalized ratio The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Available-for-sale securities, gross realized losses Debt Securities, Available-for-sale, Realized Loss Premium related to purchase of state and political subdivisions Premium related to purchase of state and political subdivisions The premium related to the purchase of state and political subdivisions. Purchase of common shares for treasury Payments for Repurchase of Common Stock Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures In Period, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures In Period, Weighted Average Exercise Price Premises, useful life Property, Plant and Equipment, Useful Life Schedule of Expected Benefit Payments [Table Text Block] Schedule of Expected Benefit Payments [Table Text Block] Shareholders’ Equity: Shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Schedule of Unrecognized Tax Benefits Roll Forward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Net decrease in time deposits Increase (Decrease) in Time Deposits Risk and Uncertainties Concentration Risk, Credit Risk, Policy [Policy Text Block] International (Developed) International (Developed) [Member] Foreign Equity Securities Developed [Member] Tier I Capital (to average assets), Requirement to be Well-Capitalized, Ratio Tier I capital (to average assets), requirement to be well capitalized ratio The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action. Amortization [Abstract] Amortization [Abstract] Total interest expense Interest expense Interest Expense Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Expected long-term rate of return on assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Total interest income Interest and Dividend Income, Operating Data processing services Information Technology and Data Processing Net periodic pension cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Schedule of Maturities of Time Deposits Schedule of Maturities of Time Deposits [Table Text Block] Schedule of maturities of time deposits. 60-89 Days Financial Asset, 60 to 89 Days Past Due [Member] Short-term borrowings Proceeds from Short-term Debt 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year One Total loans Total Loans Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss, Current Retained earnings Retained Earnings (Accumulated Deficit) Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Recoveries Financing Receivable, Allowance for Credit Loss, Recovery Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Taxable Interest Income, Securities, Operating, Taxable Entity Filer Category Entity Filer Category Savings deposits Interest Expense, Savings Deposits Percent of Total Weighted Average Rate of Time Deposits [Abstract] Income Statement [Abstract] Income Statement [Abstract] Fair Value Estimate of Fair Value Measurement [Member] One-Year Nominal Return One-Year Nominal Return The expected percentage of one-year nominal return on assets. Entity Registrant Name Entity Registrant Name Non- accrual Financing Receivable, Nonaccrual Short-term investments Short-term Investments Banking Services Banking Services [Member] Banking Services [Member] Employee restricted stock grants Stock Issued During Period, Shares, Restricted Stock Award, Gross Amortization expense, rolling year four Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Four Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Summary of Loan Categories Summary of Loan Categories [Table Text Block] Tabular disclosure for loan categories. Income tax expense Total income tax expense Income Tax Expense (Benefit) 2024 Defined Benefit Plan, Expected Future Benefit Payment, Year Three Amendment Flag Amendment Flag Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Equity Components [Axis] Equity Components [Axis] Entity Tax Identification Number Entity Tax Identification Number Tier I Capital (to risk-weighted assets), Actual, Amount Common Equity Tier I Capital (to risk-weighted assets), actual amount Common Equity Tier 1 Risk Based Capital as defined in the regulations. Deposits Deposits, Fair Value Disclosure Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Accrued interest receivable Accrued Interest Receivable, Fair Value Disclosure Accrued Interest Receivable, Fair Value Disclosure Total undiscounted cash flows Lessee, Operating Lease, Liability, to be Paid Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Forfeitures (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Stock-Based Compensation Share-based Payment Arrangement [Policy Text Block] Interest and fees on loans Interest and Fee Income, Loans and Leases Pension Deferred Tax Liabilities Pension Costs Deferred tax liabilities, pension costs. Federal Deferred Federal Income Tax Expense (Benefit) Fair Value Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Schedule of Stock Appreciation Right Activity Share-based Payment Arrangement, Stock Appreciation Right, Activity [Table Text Block] First Seven Years Of Service SERP, Year One Through Seven [Member] SERP, Year One Through Seven Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Equipment Equipment Expense Product and Service [Axis] Product and Service [Axis] Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Interest and dividends on securities: Interest and Dividend Income, Securities, by Taxable Status [Abstract] Preferred stock, par or stated value per share (in dollars per share) Preferred Stock, Par or Stated Value Per Share Entity Public Float Entity Public Float Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Expenses: Expenses: Expenses: Equity Component [Domain] Equity Component [Domain] Beginning balance (in shares) Ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number U.S. Small/Mid Cap Growth U.S. Small/Mid Cap Growth [Member] United States Small And Mid Cap Growth [Member]. Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Short-term lease, cost Short-term Lease, Cost Directors’ stock grants Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Pension Plan, Year One Through Seven Pension Plan, Year One Through Seven [Member] Pension Plan, Year One Through Seven Less than 1 year Lessee, Operating Lease, Liability, to be Paid, Year One Shares repurchased Stock Repurchased During Period, Shares Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] (Decrease) increase in pension liability Increase (Decrease) in Obligation, Pension Benefits Intangible assets Deferred Tax Liabilities, Other Finite-Lived Assets Statement [Line Items] Statement [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Payments in advance of funding Payments in advance of funding The normal cycle for payment of Transportation invoices to a carrier, on behalf of the company's customer, is: the customer provides the funds to the company prior to the payment of the invoice by the company to the carrier. Payments in excess of funding are generated when, according to a service agreement with a few selected carriers, the company pays the carrier prior to receipt of the funds from the customer. The company receives a fee from the carrier for making this accelerated payment. Other income Other Income Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures Non-U. S. Core Non-U.S. Core [Member] Non United States Core [Member]. Corporate, Eliminations and Other Corporate, Reconciling Items, And Eliminations [Member] Corporate, Reconciling Items, And Eliminations Issuance of common shares pursuant to stock-based compensation plan, net Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Retirement Plan Type [Domain] Retirement Plan Type [Domain] Liabilities: Liabilities [Abstract] Accounts and drafts payable Accounts and drafts payable Accounts and drafts payable, Carrying Amount Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business and includes carrying value of amounts due on drafts payable on the balance sheet date. 3-4 years Lessee, Operating Lease, Liability, to be Paid, Year Four Debt Disclosure [Abstract] Debt Disclosure [Abstract] Funding Sources Average Funding Sources Average Funding Sources Income before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Schedule of Interest on Deposits Schedule of Interest on Deposits [Table Text Block] Tabular disclosure of interest expense on deposit accounts. Operating Expense: Noninterest Expense [Abstract] Schedule of Intangible Assets and Goodwill Schedule of Intangible Assets and Goodwill [Table Text Block] Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Deferred tax asset Deferred Tax Assets, Valuation Allowance Auditor Location Auditor Location Tier I Capital (to risk-weighted assets), Capital Requirements, Amount Banking Regulation, Tier One Risk-Based Capital, Capital Adequacy, Minimum AFS, Total Estimated Fair Value Debt Securities, Available-for-sale, Unrealized Loss Position Segment Reporting [Abstract] Segment Reporting [Abstract] Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Finite-lived, intangible assets, useful life Finite-Lived Intangible Asset, Useful Life Schedule of Interest Bearing Deposits Schedule of Interest Bearing Deposits [Table Text Block] Tabular disclosure of interest bearing deposits. Internally developed software Internally Developed Software [Member] Internally Developed Software [Member] Interest on short-term borrowings Interest Expense, Short-term Borrowings Employee Benefit Plans Retirement Benefits [Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Total Capital (to risk-weighted assets), Capital Requirements, Amount Banking Regulation, Total Risk-Based Capital, Capital Adequacy, Minimum Exempt from federal income taxes Interest Income, Securities, Operating, Tax Exempt Unrecognized tax benefit, interest on income taxes accrued Unrecognized Tax Benefits, Interest on Income Taxes Accrued Less than $100 Interest Expense, Time Deposits, Less than $100,000 Document Annual Report Document Annual Report Other comprehensive income Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Estimated Forecast [Member] Employee SARs exercised Employee SARs exercised Number of share options and stock appreciation rights exercised during the current period. Total Capital (to risk-weighted assets), Capital Requirements, Ratio Total capital (to risk-weighted assets), capital requirements ratio The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. Title of 12(b) Security Title of 12(b) Security Total assets Total Assets Assets Common stock, shares authorized (in shares) Common Stock, Shares Authorized Annual Standard Deviation Annual Standard Deviation The expected percentage of annual standard deviation on assets. Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Document Type Document Type Parent Company Parent Company [Member] Other Revenue Not from Contract with Customer, Other Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Product and Service [Domain] Product and Service [Domain] Amortization expense, rolling year two Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Two Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Prior service cost Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax Five years Time Deposit Maturities, Year Five Common Equity Tier I Capital (to risk-weighted assets), Capital Requirements, Amount Common Equity Tier I Capital (to risk-weighted assets), capital requirements amount The minimum amount of Common Equity Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action. Unappropriated retained earnings Retained Earnings, Unappropriated Reclassification adjustments for gains included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Schedule of Line of Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Mortgage-backed securities issued or guaranteed by U.S. government agencies or sponsored enterprises Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Interest income Interest and Dividend Income, Including Tax Equivalent Adjustment, Operating Interest and Dividend Income, Including Tax Equivalent Adjustment, Operating Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Domain] Interest Income (Expense), after Provision for Loan Loss [Abstract] Interest Income (Expense), after Provision for Loan Loss [Abstract] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Credit Exposure Of Loan Portfolio [Axis] Credit Exposure Of Loan Portfolio [Axis] Credit exposure Of Loan Portfolio [Domain] Schedule of Debt Schedule of Debt [Table Text Block] Total fee revenue and other income Fee income from customers Noninterest Income Beginning balance (in dollars per share) Ending balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Weighted Average Exercise Price Furniture, fixtures and equipment Furniture and Fixtures [Member] Corporate bonds Corporate Bond Securities [Member] Basic: Earnings Per Share, Basic [Abstract] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract] Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted Earnings Per Share (in dollars per share) Earnings Per Share, Diluted Segments [Domain] Segments [Domain] Interest-bearing demand deposits Demand Deposit Accounts Effect of dilutive restricted stock, performance based restricted stock (“PBRS”), and SARs (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Service cost Service cost – benefits earned during the year Defined Benefit Plan, Service Cost Net actuarial loss Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Percentage holding required to account investments under non-marketable equity investments Percentage holding required to account investments under non-marketable equity investments The percentage holding required to account investments under non-marketable equity investments. Loans Subject To Normal Monitoring Loans Subject To Normal Monitoring [Member] Loans Subject To Normal Monitoring [Member] Cash paid for income taxes Income Taxes Paid, Net Investments in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Leasehold improvements Leaseholds and Leasehold Improvements [Member] Accounting Standards Update [Extensible Enumeration] Accounting Standards Update [Extensible Enumeration] Subsequent Events Subsequent Events [Text Block] Invoice payment fees Information Services Payment And Processing Revenue, Invoice Payment Fees [Member] Information Services Payment And Processing Revenue, Invoice Payment Fees Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Other intangible assets, net Intangible Assets, Net (Excluding Goodwill) Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Common shares in treasury, at cost (1,771,477 and 1,113,103 shares at December 31, 2021 and 2020, respectively) Treasury Stock, Value Average remaining contractual terms Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Equity in undistributed income of subsidiaries Equity in undistributed income of subsidiaries Income (Loss) from Equity Method Investments Large Cap U.S. Equities Large Cap U.S. Equities [Member] Equity Securities Large Cap [Member] Schedule of Restricted Stock Activity Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Disclosures about Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Cash and due from banks Cash and Due from Banks Federal Home Loan Bank Federal Home Loan Bank [Member] Federal Home Loan Bank [Member] Tier I Capital (to average assets), Capital Requirements, Amount Banking Regulation, Tier One Leverage Capital, Capital Adequacy, Minimum Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Summary of Operations Summary of Operations [Policy Text Block] Summary of Operations. Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Investments in bank-owned life insurance Bank Owned Life Insurance Other assets Other Assets Marketable Securities [Table] Marketable Securities [Table] Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Financial Instruments [Domain] Financial Instruments [Domain] Due after 5 years through 10 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Measurement Input, Long Term Rate Of Return Measurement Input, Long Term Rate Of Return [Member] Measurement Input, Long Term Rate Of Return Non-U.S. Equity Securities Non-U.S. Equity Securities [Member] Foreign Equity Securities [Member]. Fee Revenue and Other Income: Revenues [Abstract] Deferred tax liabilities: Deferred Tax Liabilities, Net [Abstract] Profit sharing expense Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Interest Income: Interest and Dividend Income, Operating [Abstract] Purchased software Software Computer Software, Intangible Asset [Member] Document Period End Date Document Period End Date Commercial letters of credit Commercial letters of credit [Member] Commercial letters of credit member. Entity Central Index Key Entity Central Index Key Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Commercial and industrial Commercial and Industrial [Member] Commercial And Industrial Loan Information services revenue Information services payment and processing revenue Revenue earned from providing services relating to transportation invoice rating, payment, audit, accounting and transportation information to many of the nation's largest companies. Consolidated Entities [Domain] Consolidated Entities [Domain] Time deposits: Interest Expense, Time Deposits [Abstract] Invoice processing fees Information Services Payment And Processing Revenue, Invoice Processing Fees [Member] Information Services Payment And Processing Revenue, Invoice Processing Fees State Deferred State and Local Income Tax Expense (Benefit) Total Capital (to risk-weighted assets), Actual, Amount Banking Regulation, Total Capital, Actual Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Four years Time Deposit Maturities, Year Four Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Due in 1 year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Financing receivable, allowance for credit loss, individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Premises and equipment, net Total Property, Plant and Equipment, Net Premises and Equipment Property, Plant and Equipment Disclosure [Text Block] Weighted average interest rate Weighted average interest rate The weighted average interest rate of interest bearing deposits. Condensed Financial Information Disclosure [Abstract] Condensed Financial Information Disclosure [Abstract] Balance, January 1 Balance, December 31 Defined Benefit Plan, Benefit Obligation International (Emerging) International (Emerging) [Member] Foreign Equity Securities Emerging [Member ] Lender Name [Axis] Lender Name [Axis] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Trading Symbol Trading Symbol Earnings Per Share [Abstract] Earnings Per Share [Abstract] Premises and equipment, gross Property, Plant and Equipment, Gross Financing receivable, individually evaluated for impairment, value Financing Receivable, Individually Evaluated for Impairment Other Deferred Tax Liabilities, Other Net change in other assets Increase (Decrease) in Other Operating Assets AFS, Total Unrealized Losses Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Total net revenue Revenues Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Tier I Capital (to average assets), Requirement to be Well-Capitalized, Amount Banking Regulation, Tier One Leverage Capital, Well Capitalized, Minimum Purchase of bank-owned life insurance Payment to Acquire Life Insurance Policy, Investing Activities Condensed Income Statement Condensed Income Statement [Table Text Block] Tier I Capital (to average assets), Actual, Amount Banking Regulation, Tier One Leverage Capital, Actual Line of Credit Facility [Table] Line of Credit Facility [Table] Proceeds from sales of securities available-for-sale Proceeds from Sale of Debt Securities, Available-for-sale Other Commitments [Line Items] Other Commitments [Line Items] Interest-bearing demand deposits Interest Expense, Demand Deposit Accounts Less than $100 Time Deposits, Less than $100,000 Interest-bearing Total Interest-bearing Deposit Liabilities Summary of the Fair Value Measurements by Type of Asset Summary of the Fair Value Measurements by Type of Asset [Table Text Block] Tabular disclosure for fair value of plan assets by type of asset. Goodwill, gross carrying amount Goodwill, Gross Revenue, Performance Obligation [Abstract] Revenue, Performance Obligation [Abstract] Issuance of common stock: Shares Granted or Issued, Share-based Payment Arrangement [Abstract] Available-for-sale securities, number of positions Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions Patent Patents [Member] Real Estate, Commercial, Mortgage Real Estate Commercial Mortgage [Member] Real Estate Commercial Mortgage Net increase (decrease) in accounts and drafts payable Increase (Decrease) In Accounts and Drafts Payable Net change during the reporting period in the carrying amount of accounts and drafts payable. Total intangible assets, net Intangible Assets, Net (Including Goodwill) Entity Current Reporting Status Entity Current Reporting Status Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Fair value, January 1 Fair value, December 31 Total plan assets Defined Benefit Plan, Plan Assets, Amount Effective tax rate Effective Income Tax Rate Reconciliation, Percent Schedule of Credit Exposure of the Loan Portfolio Schedule of Credit Exposure of the Loan Portfolio [Table Text Block] Tabular disclosure for credit exposure of loan portfolio by internally assigned credit grade. Two years Time Deposit Maturities, Year Two Personnel Salaries and employee benefits Labor and Related Expense Net amortization of premium/discount on investment securities Accretion (Amortization) of Discounts and Premiums, Investments Audit Information [Abstract] Audit Information [Abstract] Noncontributory Profit Sharing Program Noncontributory Profit Sharing Program [Member] Noncontributory Profit Sharing Program [Member] Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents U.S. Core U.S. Core Opportunistic [Member] United States Core Opportunistic [Member]. Common stock, par or stated value (in dollars per share) Common Stock, Par or Stated Value Per Share Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Amortization expense, rolling year three Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Three Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Other financing activities, net Proceeds from (Payments for) Other Financing Activities Gross Carrying Amount Finite-Lived Intangible Assets, Gross One year Time Deposit Maturities, Year One Leases [Abstract] Leases [Abstract] Total Capital (to risk weighted assets), Requirement to be Well-Capitalized, Amount Banking Regulation, Total Risk-Based Capital, Well Capitalized, Minimum Income Taxes Income Tax, Policy [Policy Text Block] Shares exercised, intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Exercised Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Exercised Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Restricted securities Debt Securities, Available-for-sale, Restricted Net unrealized (loss) gain on securities available-for-sale OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Total operating expense Noninterest Expense Entity Address, Postal Zip Code Entity Address, Postal Zip Code Weighted average common shares outstanding assuming dilution (in shares) Weighted Average Number of Shares Outstanding, Diluted Income Taxes Income Tax Disclosure [Text Block] Exercised (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercises in Period, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercises in Period, Weighted Average Exercise Price $100 to less than $250 Interest Expense Time Deposits 100000 or More and Less Than 250000 Interest expense incurred on time deposits, including certificates of deposits, $100,000 or more and less than $250,000 in domestic offices. Credit Exposure Of Loan Portfolio [Domain] Credit Exposure Of Loan Portfolio Domain [Domain] Credit Exposure Of Loan Portfolio Domain Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Cash and cash equivalents Cash, Cash Equivalents, and Short-term Investments Income before undistributed income of subsidiaries Income before undistributed income of subsidiaries. Income before undistributed income of subsidiaries. Reductions to unrecognized tax benefits as a result of a lapse of the applicable statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Information Services Revenue Information Services Revenue [Policy Text Block] The accounting policy for information services revenue. Measurement Basis [Axis] Measurement Basis [Axis] Construction Construction [Member] Faith-Based Real Estate Faith-Based Real Estate [Member] Faith Based Real Estate One [Member] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Auditor Firm ID Auditor Firm ID Commitments to extend credit Commitments to Extend Credit [Member] Loans, net Loans Receivable, Fair Value Disclosure Occupancy Occupancy, Net Credit Facility [Axis] Credit Facility [Axis] Finite Lived Intangible Assets Major Class Name Domain Finite-Lived Intangible Assets, Major Class Name [Domain] Entity Address, Address Line One Entity Address, Address Line One Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Entity Address, Address Line Two Entity Address, Address Line Two Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Projected benefit obligation: Benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Marketable Securities [Line Items] Marketable Securities [Line Items] Allowance for Credit Losses Financing Receivable, Allowance for Credit Losses, Policy for Uncollectible Amounts [Policy Text Block] Amortization expense, rolling year five Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Five Cash Flows From Operating Activities: Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Entity Shell Company Entity Shell Company Summary of Projected Benefit Obligation Summary of Projected Benefit Obligation [Table Text Block] Tabular disclosure for projected benefit obligation, assets, funded status and amounts recognized. Real Estate, Commercial, Construction Real Estate Commercial Construction [Member] Real Estate Commercial Construction Loan Asset acquisition of Gateway Giving, LLC Asset acquisition of Gateway Giving, LLC Payments to Acquire Businesses, Gross Telecommunications Communication Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Current Fiscal Year End Date Current Fiscal Year End Date Schedule of Pretax Amounts in Accumulated Other Comprehensive Loss Schedule of Pretax Amounts in Accumulated Other Comprehensive Loss [Table Text Block] Tabular disclosure for pre-tax amounts in accumulated other comprehensive loss. Weighted average discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Statement [Table] Statement [Table] Customer lists Customer Lists [Member] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Asset backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises Asset-backed Securities [Member] Impact of New and Not Yet Adopted Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Other Deferred Tax Assets, Other Available-for-sale securities, number of positions, greater than one year Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions 2026 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Schedule of Assumptions used to Determine Net Pension Cost Schedule of Assumptions used to Determine Net Pension Cost [Table Text Block] Tabular disclosure for Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost. One year Time Deposits, Weighted Average Interest Rate, Maturities Year One Unrecognized compensation expense Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Statistical Measurement [Axis] Statistical Measurement [Axis] Expected income tax expense Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Goodwill Goodwill Tax equivalent adjustment Income Tax Effects Allocated Directly to Equity, Prior Period Adjustment Pension Plan, Service After Year Seven Pension Plan, Service After Year Seven [Member] Pension Plan, Service After Year Seven Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Due after 10 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Common Equity Tier I Capital (to risk-weighted assets), Actual, Amount Banking Regulation, Tier One Risk-Based Capital, Actual $250 or more (1) Time Deposits, More than $250,000 The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $250,000 or more. Unrealized gain on investment securities available-for-sale Deferred Tax Liabilities, Unrealized Gains on Trading Securities AFS, Less than 12 months, Unrealized Losses Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Tier I Capital (to average assets), Actual, Ratio Tier I capital (to average assets), actual ratio Tier 1 Leverage Capital divided by average assets as defined in the regulations. Federal tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Amount Schedule of Assumptions used to Determine Projected Benefit Obligation Schedule of Assumptions used to Determine Projected Benefit Obligation [Table Text Block] Tabular disclosure for assumptions used calculating benefit obligation. Scenario [Domain] Scenario [Domain] Uninsured scheduled maturities, year one through three Time Deposit Liability Uninsured, Maturity, Year One Through Three Time Deposit Liability Uninsured, Maturity, Year One Through Three Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Loans Allowance for loan/credit losses on loans Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Net increase (decrease) in accounts and drafts payable Increase (Decrease) in Accounts Payable and Other Operating Liabilities Pension Plan The Plan Pension Plan [Member] Accrued interest payable Accrued Liabilities, Fair Value Disclosure (Increase) decrease in payments in advance of funding Net (increase) decrease in payments in advance of funding (Increase) Decrease In Payments In Excess Of Funding Net change during the reporting period in the carrying amount of payments in excess of funding. Due in 1 year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Operating lease, cost Operating Lease, Cost After Year Seven SERP, Service After Year Seven [Member] SERP, Service After Year Seven Investment in Debt Securities Investment in Debt Securities [Policy Text Block] Disclosure of accounting policy for investments in debt securities. Schedule of Common Stock Outstanding Roll Forward Schedule of Common Stock Outstanding Roll Forward [Table Text Block] Two years Time Deposits, Weighted Average Interest Rate, Maturities Year Two Other Other Expenses AFS, 12 months or more, Unrealized Losses Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Capital (to risk-weighted assets), Actual, Ratio Total capital (to risk-weighted assets), actual ratio Total Capital divided by risk weighted assets as defined in the regulations. Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Foreclosed Assets Financing Receivable, Held-for-investment, Foreclosed Asset [Policy Text Block] Deferred income tax (benefit) expense Deferred Income Tax Expense (Benefit) Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Individually Evaluated Loans Impairment of Loans [Policy Text Block] Disclosure of accounting policy for impairment of loans. Accounting Standards Update 2016-13 [Member]