Composition of the loans Loans and Leases Receivable, Net of Deferred Income [Abstract] Statistical Measurement [Domain] Statistical Measurement [Domain] Schedule of Amortized Cost and Fair Value of Debt Securities Debt Securities, Available-for-Sale [Table Text Block] Denominator for Earnings per Share: Earnings Per Share, Diluted, Other Disclosure [Abstract] Net Unrealized Losses Debt Securities, Available-For-Sale, Accumulated Gross Unrealized Gain (Loss) [Abstract] Debt Securities, Available-For-Sale, Accumulated Gross Unrealized Gain (Loss) Short-term borrowings Short-Term Debt, Fair Value Award Timing Predetermined Award Timing Predetermined [Flag] Interest income recognized on nonaccrual Financing Receivable, Nonaccrual, Interest Income Amortization Investment Program, Proportional Amortization Method, Applied, Amortization Expense Entity File Number Entity File Number Additional Paid-in Capital Additional Paid-in Capital [Member] Interest rate swaps - commercial loans Interest 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Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Taxable Interest Income, Securities, Operating, Taxable Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts and Financing Receivables [Table] Securities held in a deferred compensation plan Debt Securities, Trading, and Equity Securities, FV-NI Asset Pledged as Collateral without Right Asset Pledged as Collateral without Right [Member] Cash dividends declared Dividends, Common Stock, Cash Total Shareholders’ Equity Balance at beginning of period Balance at end of period Equity, Attributable to Parent Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Insider Trading Policies and Procedures [Line Items] Common stock, authorized (in shares) Common Stock, Shares Authorized Hedging Designation [Domain] Hedging 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[Table] Equity Method Investment [Table] Gross amounts not offset, netting adjustment Derivative Asset, Subject to Master Netting Arrangement, Collateral, Obligation to Return Security Not Offset Accounting Policies [Abstract] Accounting Policies [Abstract] Total Debt Securities, Available-for-Sale, Unrealized Loss Position Due after ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Treasury Stock Treasury Stock, Common [Member] Current fiscal year Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Net increase (decrease) in demand, money market and savings deposits Increase (Decrease) in Demand Deposits Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Total unrealized gains (losses) on available-for-sale debt securities Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain (Loss), before Tax Income tax (expense) benefit Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Gain Adjustment, Tax Expense (Benefit) Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Gain Adjustment, Tax Expense (Benefit) Collateral Adjustments Measurement Input, Comparability Adjustment [Member] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount 90+ Days Past Due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] LIABILITIES Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Interest rate swap contracts - cash flow hedge Interest Rate Swap - Cash Flow Hedge [Member] Interest Rate Swap - Cash Flow Hedge Weighted-Average Term Extension (in months) Financing Receivable, Modified, Weighted Average Term Increase from Modification Income Before Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Investment Securities: Interest and Dividend Income, Securities, by Taxable Status [Abstract] Revolving-Term Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan Net Recoveries (Charge-offs) Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Year three Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount More than five years Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Total Interest Expense Interest Expense, Operating Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Measurement Input Type [Axis] Measurement Input Type [Axis] Name Measure Name Due in one year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Pre-Tax Amount Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Proceeds from maturities, prepayments and calls of securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Financing Receivable, Nonaccrual [Line Items] Financing Receivable, Nonaccrual [Line Items] Document Fiscal Period Focus Document Fiscal Period Focus Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Award Timing Method Award Timing Method [Text Block] Schedule of Unrealized Gains (Losses) of Debt Securities Unrealized Gain (Loss) on Investments [Table Text Block] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Award Type Award Type [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] TAX CREDIT EQUITY INVESTMENTS Investment Program, Proportional Amortization Method, Elected [Text Block] Total Assets Assets Investment, Name [Domain] Investment, Name [Domain] Other consumer Consumer, Other [Member] Trading Symbol Trading Symbol Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Tax-exempt Interest Income, Securities, Operating, Tax Exempt Financing Receivable, Allowance for Credit Loss [Roll Forward] Financing Receivable, Allowance for Credit Loss [Roll Forward] Entity Address, City or Town Entity Address, City or Town Appraisals Of Collateral Appraisals Of Collateral [Member] Appraisals Of Collateral Derivatives (Included In Other Assets) [Abstract] Derivatives (Included In Other Assets) [Abstract] Derivatives (Included In Other Assets) Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Allowance for Credit Losses Credit Loss, Financial Instrument [Policy Text Block] Borrowings, junior subordinated debt securities and other Interest Expense, Borrowings Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Emerging Growth Company Entity Emerging Growth Company Marketing Marketing Expense Dividends declared per share (in dollars per share) Cash dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Right of use assets obtained in exchange for lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Gross amounts not offset, cash collateral Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Not Offset Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Total Derivatives Gain (Loss) Derivative, Gain (Loss) on Derivative, Net Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Total Noninterest Income Noninterest Income Common stock, outstanding (in shares) Common Stock, Shares, Outstanding Schedule of Marketable Securities Marketable Securities [Table Text Block] Derivatives not Designated as Hedging Instruments Summary of Derivative Instruments [Abstract] PEO PEO [Member] NONINTEREST EXPENSE Noninterest Expense [Abstract] Tax credits and other tax benefits recognized Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization Expense Schedule of Contractual Maturities of Debt Securities Investments Classified by Contractual Maturity Date [Table Text Block] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Provision for credit losses Financing Receivable And Off Balance Sheet Liability, Credit Loss, Expense (Reversal) Financing Receivable And Off Balance Sheet Liability, Credit Loss, Expense (Reversal) Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Interest-bearing demand Interest-Bearing Domestic Deposit, Demand Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Certificates of deposit Time Deposits Retained Earnings Retained Earnings [Member] Pledged Status [Domain] Pledged Status [Domain] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Cash and due from banks at beginning of period Cash and Due From Banks at End of Period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Derivative financial assets Derivative financial assets Derivative Asset Income tax expense Income Tax Expense (Benefit) 12 Months or More Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Other assets Other Assets Fair Value, Measurements, Nonrecurring Fair Value, Nonrecurring [Member] Total Securities Available for Sale Investments, Fair Value Disclosure Other intangible assets, net Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Designated as Hedging Instruments Designated as Hedging Instrument [Member] Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Modified [Table] Other Noninterest Income, Other Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] Net Unrealized Losses, Net of Tax Included in Accumulated Other Comprehensive Loss AOCI, Debt Securities, Available-for-Sale, Adjustment, after Tax Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Total Liabilities Liabilities, Fair Value Disclosure Collateral receivable Securities Received as Collateral Revolving Financing Receivable, Excluding Accrued Interest, Revolving Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] City Area Code City Area Code Schedule of Allowance for Credit Loss Financing Receivable, Allowance for Credit Loss [Table Text Block] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net Cash Provided by Operating Activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Debt securities Fair Value Total Available-for-Sale Debt Securities, Fair Value Debt Securities, Available-for-Sale, Excluding Accrued Interest Equity Method Investments and Joint Ventures [Abstract] Proceeds from sales of securities Proceeds from Sale of Debt Securities, Available-for-Sale Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Cash Flows [Extensible Enumeration] Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Cash Flows [Extensible Enumeration] Subsequent Event Subsequent Event [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Cash Flow Hedge Cash Flow Hedging [Member] NET INTEREST INCOME Interest Income (Expense), Operating Other liabilities Other Liabilities Goodwill Goodwill Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Gross amounts recognized Derivative Liability, Subject to Master Netting Arrangement, before Offset Equity Components [Axis] Equity Components [Axis] Year four Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Standby letters of credit Standby Letters of Credit [Member] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Available-for-Sale Debt Securities With Fixed Maturities Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value Commercial real estate Commercial Real Estate [Member] Other Performance Measure, Amount Other Performance Measure, Amount Entity Address, State or Province Entity Address, State or Province Substandard Substandard [Member] Total Interest and 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Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Available-for-Sale Debt Securities With Fixed Maturities Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Amortized Cost Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Purchase accounting fair value adjustments Financing Receivable, Unamortized Purchase Premium (Discount) Repayments on long-term borrowings Repayments of Long-Term Debt Entity Interactive Data Current Entity Interactive Data Current Carrying Value Reported Value Measurement [Member] Year-to-date Gross Charge-offs Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Modified [Line Items] Equity [Abstract] Equity [Abstract] Nonaccrual Beginning of Period Nonaccrual End of Period Nonaccrual Financing Receivable, Nonaccrual Commercial and industrial Commercial And Industrial [Member] Commercial and industrial. Total Noninterest Expense Noninterest Expense Net loss on sale of securities Debt and Equity Securities, Gain (Loss) INTEREST AND DIVIDEND INCOME Interest and Fee Income, Loan and Lease, Held-in-Portfolio [Abstract] Not Designated as Hedging Instruments Not Designated as Hedging Instrument [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] U.S. Treasury securities US Treasury Securities [Member] Deposits Interest Expense, Deposits Other Commitments [Line Items] Other Commitments [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Data processing and information technology Information Technology and Data Processing Unrealized Losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract] NONINTEREST INCOME Noninterest Income [Abstract] Low Income Housing Tax Credit Low Income Housing Tax Credit [Member] Low Income Housing Tax Credit Doubtful Doubtful [Member] Amount of Gain Recognized in Other Comprehensive Income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME Comprehensive Income (Loss) Note [Text Block] Unearned income Financing Receivable, Unamortized Loan Cost (Fee) Weighted Average Weighted Average [Member] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Stock repurchased during period, value Stock Repurchased During Period, Value Entity Central Index Key Entity Central Index Key PEO Name PEO Name Noninterest-bearing demand Noninterest-Bearing Domestic Deposit, Demand Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Supplemental Disclosures Supplemental Cash Flow Elements [Abstract] Residential mortgage-backed securities of U.S. government corporations and agencies Residential Mortgage-Backed Securities [Member] Schedule of Loans Credit Quality Indicators Financing Receivable Credit Quality Indicators [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Unfunded commitments Investment Program, Proportional Amortization Method, Elected, Commitment Arrangement Duration Trading Arrangement Duration Investment Proportional Amortization Method Elected Statement Of Financial Position Extensible Enumeration Not Disclosed Flag Investment Proportional Amortization Method Elected Statement Of Financial Position Extensible Enumeration Not Disclosed Flag Investment Proportional Amortization Method Elected Statement Of Financial Position Extensible Enumeration Not Disclosed Flag Business Assets Business Assets [Member] Business Assets Schedule of Value of Derivative Assets and Derivative Liabilities Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Dividends Dividend Income, Operating Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Net Unrealized Losses, Net of Tax Included in Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Losses Adjustment Net Of Tax Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Losses Adjustment Net Of Tax Subsequent Event Type [Axis] Subsequent Event Type [Axis] ASSETS Assets [Abstract] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Other Commitments [Axis] Other Commitments [Axis] FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] SHAREHOLDERS’ EQUITY Equity, Attributable to Parent [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Entity Address, Address Line One Entity Address, Address Line One Summary of Restructured Loans for Periods Presented Financing Receivable, Modified [Table Text Block] Repurchase of S&T Stock Total cost of repurchases Treasury Stock, Value, Acquired, Cost Method Reclassified 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Value as of Grant Date Award Grant Date Fair Value Entity Registrant Name Entity Registrant Name Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Year five Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Other taxes Taxes, Other Salaries and employee benefits Labor and Related Expense Document Quarterly Report Document Quarterly Report Less Than 12 Months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Total Assets Assets measured at fair value on a nonrecurring basis Assets, Fair Value Disclosure Total Number of debt securities in unrealized loss position Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions Long-term borrowings Long-Term Debt, Fair Value Deposits: Deposits [Abstract] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Total Past Due Loans Financial Asset, Past Due [Member] Financial Instrument Performance Status [Axis] Financial Instrument Performance Status [Axis] Schedule of Loans on Nonaccrual Status and Loans Past Due 90 days Or More Financing Receivable, Nonaccrual [Table Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Number of operating segment Number of Operating Segments Mortgage servicing rights Servicing Asset at Fair Value, Amount Redemptions of Federal Home Loan Bank stock Payments for (Proceeds from) Federal Home Loan Bank Stock Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Net Unrealized Losses, Net of Tax Included in Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Gain Adjustment Net Of Tax Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Gain Adjustment Net Of Tax Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration] Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration] Restatement Determination Date: Restatement Determination Date [Axis] Non-PEO NEO Non-PEO NEO [Member] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Schedule of Interest Rate Derivatives Schedule of Interest Rate Derivatives [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Federal Home Loan Bank and other restricted stock, at cost Restricted Investments Notional Amount Derivative Liability, Notional Amount Gross Unrealized Gains Total unrealized gains (losses) on available-for-sale debt securities Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Name Trading Arrangement, Individual Name All Award Types Award Type [Domain] Amount of defaulted TDRs that defaulted Financing Receivable, Modified, Subsequent Default Equity Awards Adjustments Equity Awards Adjustments [Member] Loans held for sale Loan, Held-for-Sale, Fair Value Disclosure Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Compensation Amount Outstanding Recovery Compensation Amount Junior subordinated debt securities Junior Subordinated Notes, Noncurrent Consumer real estate Consumer Real Estate [Member] Consumer real estate. Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Measurements Estimate of Fair Value Measurement [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Accrual Performing Financial Instruments [Member] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Due after one year through five years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Name Awards Close in Time to MNPI Disclosures, Individual Name Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Schedule of Tax Effects of Components of Other Comprehensive Income (Loss) Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Service charges on deposit accounts Deposit Account [Member] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Due after five years through ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 12 Months or More Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Interest receivable Interest Receivable, Debt Securities Available For Sale Interest Receivable, Debt Securities Available For Sale Tax credit investment Investment, Proportional Amortization Method, Elected, Amount Appraisal Adjustments Measurement Input, Appraised Value [Member] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Financial Instruments [Domain] Financial Instruments [Domain] SECURITIES Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Interest Income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Long-term debt, measurement input Loans Receivable, Measurement Input Loans Receivable, Measurement Input Debit and credit card Credit and Debit Card [Member] Minimum Minimum [Member] Net Interest Income After Provision for Credit Losses Interest Income (Expense), after Provision for Loan Loss Derivative Assets (Included in Other Assets) Derivative Asset [Abstract] Income tax (expense) benefit Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Loss Adjustment, Tax Expense (Benefit) Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Loss Adjustment, Tax Expense (Benefit) Change in net unrealized gains (losses) on available-for-sale debt securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Gross amounts not offset, cash collateral Derivative Asset, Subject to Master Netting Arrangement, Collateral, Obligation to Return Cash Not Offset INTEREST EXPENSE Interest Expense, Operating and Nonoperating [Abstract] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Company Selected Measure Name Company Selected Measure Name Net available-for-sale securities losses reclassified into earnings AOCI, Accumulated Gain (Loss), Debt Securities, Available-For-Sale, Reclassified, Parent [Member] AOCI, Accumulated Gain (Loss), Debt Securities, Available-For-Sale, Reclassified, Parent Fair Value Measurement [Domain] Fair Value Measurement [Domain] Gross amounts offset Derivative Liability, Subject to Master Netting Arrangement, Asset Offset Purchases of securities Payments to Acquire Debt Securities, Available-for-Sale Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Obligations of states and political subdivisions US States and Political Subdivisions Debt Securities [Member] Year two Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] All Executive Categories All Executive Categories [Member] Collateral [Domain] Collateral Held [Domain] Common stock ($2.50 par value)
Authorized—$50,000,000 shares
Issued—41,449,444 shares at March 31, 2026 and December 31, 2025
Outstanding—36,259,649 shares at March 31, 2026 and 37402705 shares at December 31, 2025 Common Stock, Value, Issued Loans, including fees Interest and Fee Income, Loans and Leases COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Denominator for Treasury Stock Method—Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Segments Segment Reporting, Policy [Policy Text Block] Current fiscal year Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Entity Small Business Entity Small Business Long-term borrowings Other Long-Term Debt Other expense and tax credits [Extensible Enumeration] Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization, Statement of Income or Comprehensive Income [Extensible Enumeration] Derivative Liabilities (Included 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from potentially dilutive shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount All Adjustments to Compensation All Adjustments to Compensation [Member] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Amendment Flag Amendment Flag Fair Value Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Schedule of Age Analysis of Past Due Loans Segregated by Class of Loans Financing Receivable, Past Due [Table Text Block] Treasury stock — 5,189,795 shares at March 31, 2026 and 4046739 shares at December 31, 2025, at cost Treasury Stock, Common, Value Other Commitments [Table] Other Commitments [Table] Termination Date Trading Arrangement Termination Date Net Cash Provided by Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Cash and due from banks, interest-bearing amounts Interest-Bearing Deposits in Banks and Other Financial 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Period, Shares Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Net decrease (increase) in loans Payments for (Proceeds from) Loans and Leases Financial Instrument Performance Status [Domain] Financial Instrument Performance Status [Domain] Savings Deposits, Savings Deposits Gross amounts not offset, netting adjustment Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Security Not Offset Statement [Line Items] Statement [Line Items] Gross Unrealized Losses Debt Securities, Available-For-Sale, Accumulated Gross Unrealized Loss [Abstract] Debt Securities, Available-For-Sale, Accumulated Gross Unrealized Loss Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and due from banks, including interest-bearing deposits of $276,406 and $106,286 at March 31, 2026 and December 31, 2025 Cash and Cash Equivalent Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block] Unused commitments to extend credit Unused Commitments to Extend Credit Subsequent Event [Line Items] Subsequent Event [Line Items] Common Stock Common Stock [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Short-term borrowings Other Short-Term Borrowings Net increase (decrease) in cash and due from banks Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration] Investment Program, Proportional Amortization Method, Applied, Amortization 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