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Other real estate owned Other real estate owned Real Estate Acquired Through Foreclosure Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Impaired Financing Receivable, Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Additional Information [Abstract] Additional Information [Abstract] Additional Information [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Document Fiscal Year Focus Document Fiscal Year Focus Derivative Liability, Fair Value, Gross Asset Derivative Liability, Fair Value, Gross Asset Financial instrument of credit risk Notional Amount Of Commitments And Letters Of Credit Notional amount of outstanding commitments and letters of credit. Risk Participation Agreements Sold [Domain] Risk Participation Agreements Sold [Domain] Risk Participation Agreements Sold [Domain] Beginning Balance Ending Balance Financing Receivable, Allowance for Credit Loss Increase (Decrease) in Other Operating Assets and Liabilities, Net Increase (Decrease) in Other Operating Assets and Liabilities, Net Loans Held for sale, Amount Financing Receivable, Held-for-Sale Impaired loans considered to be credit risk of non-collection Impaired Loans Fair Value Non Collection Impaired loans fair value non collection. Debt Instrument [Axis] Debt Instrument [Axis] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Net Interest Income Interest Income (Expense), Net Interest on deposits Interest Expense, Deposits Goodwill Disclosure [Abstract] Goodwill Disclosure [Abstract] Goodwill Disclosure [Abstract] Securities available for sale, at fair value Available-for-sale Securities Available-for-sale Securities Financing Receivable Recorded Investment Equal To Or Greater Than Thirty Days Past Due Financing Receivable Recorded Investment Equal To Or Greater Than Thirty Days Past Due Financing receivables that are equal to or greater than 30 days past due. 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Originated Loans [Member] Originated Loans [Member] Originated Loans [Member] Loans: Loans and Leases Receivable, Net Amount [Abstract] Criticized [Member] Criticized [Member] Document Period End Date Document Period End Date Other than temporary impairment charges recognized Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net Entity Registrant Name Entity Registrant Name Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Related allowance Impaired Financing Receivable, Related Allowance Income Statement [Abstract] Income Statement [Abstract] Accumulated Other Comprehensive Income (Loss), net [Member] Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Risk participation Agreements [Line Items] Risk participation Agreements [Line Items] [Line Items] for Risk participation Agreements [Table] Amortized Cost and Estimated Fair Value of Debt Securities Available for Sale Investments Classified by Contractual Maturity Date [Table Text Block] Operating Leases, Rent Expense Operating Leases, Rent Expense Net occupancy expense Occupancy, Net Unrealized holding (losses) gains on derivatives arising during the period Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Financing Receivable, Troubled Debt Restructuring Financing Receivable, Troubled Debt Restructuring COVID-19 Related Expenses COVID-19 Related Expenses COVID-19 Related Expenses Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Commercial letters of credit [Member] Commercial Letters Of Credit [Member] Commercial letters of credit. Derivative Instruments Designated As Hedging Instruments Interest Income Derivative Instruments Designated As Hedging Instruments Interest Income Derivative Instruments Designated As Hedging Instruments Interest Income Credit Value Adjustment Recorded Related to Notional Amount Of Derivatives Outstanding Credit Value Adjustment Recorded Related To Notional Amount Of Derivatives Outstanding Table [Text Block] Notional amounts and credit value adjustment recorded related to the notional amount of derivatives outstanding. Discounted Cash Flow [Member] Discounted Cash Flow [Member] Discounted cash flow. Fair value of loans transferred from held to maturity to held for sale Transfer of Portfolio Loans and Leases to Held-for-sale Deposits (all domestic): Deposits, Domestic [Abstract] Residential Mortgage Backed Securities [Member] Residential Mortgage Backed Securities [Member] Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share US Government-sponsored Enterprises Debt Securities [Member] Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member] US Government-sponsored Enterprises Debt Securities [Member] Interest Rate Cap [Member] Interest Rate Cap [Member] Proceeds from sale of other assets Proceeds from Sale of Other Productive Assets Restatement [Domain] Scenario [Domain] Entity Tax Identification Number Entity Tax Identification Number Card-related interchange income Fees and Commissions on Debit Cards Fees and Commissions on Debit Cards Subordinated Debentures, Additional Information [Abstract] Subordinated Debentures, Additional Information [Abstract] Subordinated Debentures, Additional Information [Abstract] Loan To Different Project [Domain] Loan To Different Project [Domain] Loan To Different Project [Domain] Income Before Income Taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Fair Value Measurements Of Financial Instruments [Table] Fair Value Measurements Of Financial Instruments [Table] Fair Value Measurements Of Financial Instruments [Table] Amounts reclassified from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Hedging Designation [Axis] Hedging Designation [Axis] Entity Information [Line Items] Entity Information [Line Items] US Government Agencies Residential Mortgage-backed Securities [Member] US Government Agencies Residential Mortgage-backed Securities [Member] US Government Agency Debt Securities - Residential [Domain] US Government Agency Debt Securities - Residential [Domain] Litigation and operational losses Operational Loss Operational Loss Net loans Loans and Leases Receivable, Net Amount Gross losses Available-for-sale Securities, Gross Realized Losses Gas per MCF [Member] Gas per MMBTU [Member] Gas per MMBTU [Member] Loans and Leases Receivable, Number of Contracts Loans and Leases Receivable, Number of Contracts Loans and Leases Receivable, Number of Contracts Commercial, financial, agricultural and other [Member] Commercial Loan [Member] Net decrease in other short-term borrowings Proceeds from (Repayments of) Short-term Debt Subsequent Event Consolidation Related Expenses Estimated Subsequent Event Consolidation Related Expenses Estimated Subsequent Event Consolidation Related Expenses Total Pre-Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Premodification Legal Entity [Axis] Legal Entity [Axis] (Decrease) increase in interest payable Increase (Decrease) in Interest Payable, Net Designated as Hedging Instrument [Member] Designated as Hedging Instrument [Member] Measurement Input Type [Axis] Measurement Input Type [Axis] Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Unused Commitments [Domain] Unused Commitments [Domain] [Domain] for Unused Commitments [Axis] Collection and repossession expense Collection And Repossession Expenses Expenses incurred to collect delinquent or problem loan and lease payments or repossess assets (vehicles and real estate) used as collateral for these loans. May include the cost of attorneys, collection agencies, foreclosures and sheriffs sales. Number of Contracts Financing Receivable, Modifications, Number of Contracts Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Entity [Domain] Entity [Domain] Less: reclassification adjustment for gains on securities included in net income Reclassification adjustment for gains on securities included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Debt and Equity Securities, FV-NI [Line Items] Debt and Equity Securities, FV-NI [Line Items] Investment Securities [Abstract] Investment Securities [Abstract] Investment Securities [Abstract] Total long-term debt Long-term Debt Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Lessee, Operating Leases [Text Block] Lessee, Operating Leases [Text Block] Total unrealized gain on derivatives Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax Contractual Payment Modification [Member] Contractual Payment Modification [Member] Contractual Payment Modification [Member] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Gross Gains Gross Gains This item represents the gross gain on maturities of available for sale securities. Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments Due, Next Twelve Months Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights Risk participation Agreements [Table] Risk participation Agreements [Table] Risk participation Agreements [Table] Debt Securities [Member] Debt Securities [Member] Net amortization of premiums and discounts on securities Accretion (Amortization) of Discounts and Premiums, Investments Other real estate owned Other Real Estate Owned Assets Fair Value Other real estate owned assets fair value. Balance, beginning of period Balance, end of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value City Area Code City Area Code Deferred Revenue, by Arrangement, Disclosure [Table Text Block] Deferred Revenue, by Arrangement, Disclosure [Table Text Block] Reclassification adjustment for gains on securities included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Limited Partnership Investment [Member] Limited Partnership Investment [Member] Limited Partnership Investment [Member] Equity Components [Axis] Equity Components [Axis] Available-for-sale Securities, Gross Realized Gains Available-for-sale Securities, Gross Realized Gains Restricted Stock [Member] Restricted Stock [Member] Total past due and nonaccrual Financing Receivable, Past Due Total noninterest income Noninterest Income Noninterest Income Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Increases Decreases in Troubled Debt Restructurings [Axis] Increases Decreases in Troubled Debt Restructurings [Axis] Increases Decreases in Troubled Debt Restructurings [Axis] Minimum [Member] Minimum [Member] Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Ending balance: collectively evaluated for impaired Financing Receivable, Collectively Evaluated for Impairment Schedule of Supplemental Cash Flow Disclosures Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Average treasury shares (in shares) Weighted Average Number of Shares, Treasury Stock Cash paid during the period for: Cash Paid For Interest And Income Taxes [Abstract] Cash paid for interest and income taxes during the period. FDIC insurance Federal Deposit Insurance Corporation Premium Expense Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Debt Securities, Held-to-maturity, Restricted Debt Securities, Held-to-maturity, Restricted Fair Values of Assets and Liabilities Fair Value Disclosures [Text Block] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Recoveries Financing Receivable, Allowance for Credit Loss, Recovery Increases Decreases in Troubled Debt Restructurings [Domain] Increases Decreases in Troubled Debt Restructurings [Domain] [Domain] for Increases Decreases in Troubled Debt Restructurings [Axis] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Proceeds from maturities and redemptions of available-for-sale securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Securities held to maturity, fair value Debt Securities, Held-to-maturity, Fair Value Interest Rate Swap [Member] Interest Rate Swap [Member] Net gains on securities and other assets Gain Loss On Securities And Other Assets Gain (loss) on securities and other assets. Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Unpaid principal balance Impaired Financing Receivable, Unpaid Principal Balance Due after 1 but within 5 years Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Depreciation and amortization Depreciation, Amortization and Accretion, Net Derivative [Table] Derivative [Table] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Lease, Weighted Average Discount Rate, Percent Operating Lease, Weighted Average Discount Rate, Percent Accounts Receivable, Allowance for Credit Loss [Roll Forward] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Out-Of-Scope of Topic 606 [Member] Out-Of-Scope of Topic 606 [Member] Out-Of-Scope of Topic 606 [Member] Stock Issued During Period, Value, Treasury Stock Reissued Stock Issued During Period, Value, Treasury Stock Reissued Pass [Member] Pass [Member] Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Investment Securities [Line Items] Investment Securities [Line Items] Investment Securities [Line Items] Total noninterest expense Noninterest Expense Scope of Topic 606 [Axis] Scope of Topic 606 [Axis] Scope of Topic 606 [Axis] Weighted Average Number of Shares Issued, Basic Weighted Average Number of Shares Issued, Basic Forward Contracts [Member] Forward Contracts [Member] Recorded investment Impaired Financing Receivable, Recorded Investment Analysis of Amortized Cost and Estimated Fair Value of Securities Available for Sale Available-for-sale Securities [Table Text Block] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Impaired loans Fair Value Measurement Of Assets On Nonrecurring Basis Net Losses On Impaired Loans Net losses on impaired loans still held at the end of the period. Equity Securities [Member] Equity Securities [Member] Weighted Average Number Of Additional Shares Deferred Compensation Plan Weighted Average Number Of Additional Shares Deferred Compensation Plan Weighted Average Number Of Additional Shares Deferred Compensation Plan Loans Transferred to Other Real Estate Owned and Repossessions Loans Transferred to Other Real Estate Owned and Repossessions Loans Transferred to Other Real Estate Owned and Repossessions Impairment charges on goodwill Goodwill, Impairment Loss Data processing expense Information Technology and Data Processing Risk Participation Agreements Purchased [Domain] Risk Participation Agreements Purchased [Domain] Risk Participation Agreements Purchased [Domain] Unfunded commitments related to nonperforming loans Unfunded Commitments Related To Nonperforming Loans Unfunded commitments related to nonperforming loans. Adjustments for New Accounting Pronouncements [Axis] Accounting Standards Update [Axis] Troubled Debt Restructuring Subsequent Default [Table Text Block] Troubled Debt Restructuring Subsequent Default [Table Text Block] [Table Text Block] for Troubled Debt Restructuring Subsequent Default [Table] Gain on sale of other loans and assets Gain on sale of loans and other assets. Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Other Income, Assets and Liabilities Continue to be held Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Other Income, Assets and Liabilities Continue to be held Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Other Income, Assets and Liabilities Continue to be held Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-02 [Member] Financial Asset, 30 to 59 Days Past Due [Member] Financial Asset, 30 to 59 Days Past Due [Member] Restructuring Type [Axis] Restructuring Type [Axis] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Goodwill Goodwill Fair Value Inputs, Assets, Quantitative Information Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Due within one year, Estimated Fair Value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Total other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Proceeds from the redemption of FHLB stock Proceeds from Sale of Federal Home Loan Bank Stock Gain Losses Maturities And Impairment Gain Losses Maturities And Impairment Gain losses maturities and impairment. Unfunded commitment liability Reserve For Off Balance Sheet Activities Reserve for credit risk of off-balance sheet activities Impaired Financing Receivable, Interest Income, Accrual Method Impaired Financing Receivable, Interest Income, Accrual Method Gross (decrease) increase in market value adjustment to derivatives Gross Increase in Market Value Adjustment to Derivatives Gross Increase in Market Value Adjustment to Derivatives Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Fair Value Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Fair Value Increase in income taxes payable Increase (Decrease) in Income Taxes Payable Total unrealized gains on securities OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, before Tax Cash Dividends Declared per Common Share (in dollars per share) Common Stock, Dividends, Per Share, Declared Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Due after five but within ten years, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Short [Member] Short [Member] Schedule of Assets Measured on Non-Recurring Basis Fair Value Measurements, Nonrecurring [Table Text Block] Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Fair Value by Asset Class [Domain] Asset Class [Domain] Interest Income Interest and Dividend Income, Operating [Abstract] Assets Total Assets Assets, Fair Value Disclosure Scope of Topic 606 [Domain] Scope of Topic 606 [Domain] [Domain] for Scope of Topic 606 [Axis] Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-maturity [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Total other comprehensive income, before tax expense Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Non-cash investing and financing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Entity Central Index Key Entity Central Index Key Notional Amount Of Financial Standby Letters Of Credit Notional Amount Of Financial Standby Letters Of Credit Notional Amount Of Financial Standby Letters Of Credit Entity Emerging Growth Company Entity Emerging Growth Company Performance standby letters of credit [Member] Performance Guarantee [Member] Derivative Contract [Domain] Derivative Contract [Domain] Average Shares Outstanding Assuming Dilution (in shares) Weighted average common shares and common stock equivalents used to calculate diluted earnings per share (in shares) Weighted Average Number of Shares Outstanding, Diluted Letter of Credit [Member] Letter of Credit [Member] Basic Earnings per Share (in dollars per share) Earnings Per Share, Basic Loan To Different Project [Axis] Loan To Different Project [Axis] Loan To Different Project [Axis] Subordinated debentures Subordinated debt Subordinated Debt Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax Net decrease in federal funds purchased Increase (Decrease) in Federal Funds Purchased Operating Lease, Weighted Average Remaining Lease Term Operating Lease, Weighted Average Remaining Lease Term Default Status Of TDRs After Number Of Days Past Due Default Status Of TDRs After Number Of Days Past Due Default Status Of TDRs After Number Of Days Past Due Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Post- Modification Outstanding Recorded Investment Financing Receivable, Troubled Debt Restructuring, Postmodification Substandard [Member] Substandard [Member] Accumulated Net Unrealized Investment Gain (Loss) [Member] AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Credit Default Swap [Member] Credit Default Swap [Member] Loans with modifications to rate and payment due to reamortization Loans With Modifications To Rate And Payment Due To Reamortization Loans with modifications to rate and payment due to reamortization. Charge-offs [Axis] Charge-offs [Axis] Charge-offs [Axis] Unrecognized Tax Benefits Unrecognized Tax Benefits Proceeds from sale and maturity of held-to-maturity securities Proceeds from Sale and Maturity of Held-to-maturity Securities Common stock, $1 par value per share, 200,000,000 shares authorized; 113,914,902 shares issued at June 30, 2020 and December 31, 2019, and 98,132,697 and 98,311,840 shares outstanding at June 30, 2020 and December 31, 2019, respectively Common Stock, Value, Issued Percent of Unrealized Losses Percent of Unrealized Losses Percent of Unrealized Losses Income tax expense related to items of other comprehensive income Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Reserve Study [Member] Reserve Study [Member] Reserve Study [Member] Unsettled Bank Owned Life Insurance Proceeds Unsettled Bank Owned Life Insurance Proceeds Unsettled Bank Owned Life Insurance Proceeds Insurance and retail brokerage commissions Insurance Commissions and Fees Commercial Real Estate [Member] Commercial Real Estate [Member] Outstanding Balances of Loan Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Position [Axis] Position [Axis] Other professional fees and services Professional Fees With No Related Allowance [Member] With No Related Allowance [Member] With no related allowance. Receivable Type [Domain] Receivable [Domain] Repayments of Long-term Capital Lease Obligations Repayments of Long-term Capital Lease Obligations Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Part of Loan Relationship [Domain] Part of Loan Relationship [Domain] [Domain] for Part of Loan Relationship [Axis] First Commonwealth Capital Trust II [Member] First Commonwealth Capital Trust II [Member] First Commonwealth Capital Trust II [Member] Transfer of Loans Held-for-sale to Portfolio Loans Transfer of Loans Held-for-sale to Portfolio Loans Short-term borrowings Short-term Debt Special Mention [Member] Special Mention [Member] Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Cash and cash equivalents at January 1 Cash and cash equivalents at June 30 Cash and Cash Equivalents, at Carrying Value Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Common stock, shares issued (in shares) Common Stock, Shares, Issued Brokerage Commissions Revenue Brokerage Commissions Revenue Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Service charges on deposit accounts Fees and Commissions on Depositor Accounts Fees and Commissions on Depositor Accounts Operating Lease, Liability Operating Lease, Liability Impaired loans Impaired Loans Fair Value Impaired loans fair value. Debt Instrument [Line Items] Debt Instrument [Line Items] Derivative, Net Hedge Ineffectiveness Gain (Loss) Derivative, Net Hedge Ineffectiveness Gain (Loss) Cash and due from banks Cash and Due from Banks Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total shareholders’ equity Beginning balance Ending balance Stockholders' Equity Attributable to Parent In-Scope and Out-of-Scope Revenue [Abstract] In-Scope and Out-of-Scope Revenue [Abstract] In-Scope and Out-of-Scope Revenue [Abstract] Total liabilities and shareholders’ equity Liabilities and Equity Loss Contingencies [Line Items] Loss Contingencies [Line Items] Repayments of other long-term debt Repayments of Other Long-term Debt Accumulated other comprehensive income, net Accumulated Other Comprehensive Income (Loss), Beginning Balance Accumulated Other Comprehensive Income (Loss), Ending Balance Accumulated Other Comprehensive Income (Loss), Net of Tax Income Tax Disclosure Income Tax Disclosure [Text Block] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Debt Securities, Held-to-maturity [Table Text Block] Debt Securities, Held-to-maturity [Table Text Block] Schedule of Changes in Fair Value of Derivative Assets and Liabilities Schedule of Interest Rate Derivatives [Table Text Block] Operating Lease, Cost Operating Lease, Cost Other Investments and Securities, at Cost Other Investments and Securities, at Cost Bank owned life insurance Bank Owned Life Insurance Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Other Assets [Member] Other Assets [Member] Financial Instrument [Axis] Financial Instrument [Axis] Type of Adoption [Domain] Accounting Standards Update [Domain] Sales Transactions: Debt Securities, Realized Gain (Loss) [Abstract] Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Four Years Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost Due after 10 years Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Equity Component [Domain] Equity Component [Domain] Section 4013 Deferrals [Axis] Section 4013 Deferrals [Axis] Section 4013 Deferrals Total unrealized (losses) gains on securities OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax Dividends paid Payments of Dividends Liabilities Liabilities [Abstract] Entity Address, Address Line One Entity Address, Address Line One Trust income Fees and Commissions on Trust and Fiduciary Accounts Fees and Commissions on Trust and Fiduciary Accounts Premises and equipment, net Property, Plant and Equipment, Net Derivative Instruments Designated As Hedging Instruments Interest Expense Derivative Instruments Designated As Hedging Instruments Interest Expense Derivative Instruments Designated As Hedging Instruments Interest Expense Interest Rate Contract [Member] Interest Rate Contract [Member] Net Income Net Income Net Income (Loss) Attributable to Parent Entity Address, State or Province Entity Address, State or Province Financial instrument of credit risk Fair Value, Concentration of Risk, Commitments Supplemental Comprehensive Income Disclosures [Abstract] Supplemental Comprehensive Income Disclosures [Abstract] Supplemental Comprehensive Income Disclosures [Abstract] Weighted Average Number of Shares, Deferred Compensation Plans Weighted Average Number of Shares, Deferred Compensation Plans Weighted Average Number of Shares, Deferred Compensation Plans Increases Decreases in Nonperforming Loans [Axis] Increases Decreases in Nonperforming Loans [Axis] Increases Decreases in Nonperforming Loans [Axis] Other comprehensive income (loss) Total other comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax Swap fee income Derivative Fee Income Derivative Fee Income Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total Schedule of Trading Securities and Other Trading Assets [Table] Debt Securities, Trading, and Equity Securities, FV-NI [Table] Leases [Abstract] Leases [Abstract] Reclassification adjustment for gains on securities included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Due after ten years, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Intangible amortization Taxes, Miscellaneous Other Noninterest Expense Other Noninterest Expense Due after one but within five years, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Commercial Real Estate With No Related Allowance [Member] Commercial Real Estate With No Related Allowance [Member] Commercial real estate with no related allowance. Goodwill Goodwill Disclosure [Text Block] Per Share Data: Earnings Per Share [Abstract] Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Net Interest Income after Provision for Credit Losses Interest Income (Expense), after Provision for Loan Loss Net Investment Income [Line Items] Net Investment Income [Line Items] Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Loans held for sale Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Risk Participation Agreements [Domain] Risk Participation Agreements [Domain] [Domain] for Risk Participation Agreements [Axis] Non Accrual Status Of Loans After Number Of Days Past Due Non Accrual Status Of Loans After Number Of Days Past Due Non Accrual Status Of Loans After Number Of Days Past Due Extended Maturity [Member] Extended Maturity [Member] Debt Securities, Held-to-maturity Debt Securities, Held-to-maturity Accumulated Defined Benefit Plans Adjustment [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Shareholders’ Equity Stockholders' Equity Attributable to Parent [Abstract] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Entity Interactive Data Current Entity Interactive Data Current Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Investment Securities in Unrealized Loss Position, Qualitative Disclosure, Number of Positions, Total Investment Securities in Unrealized Loss Position, Qualitative Disclosure, Number of Positions, Total Investment Securities in Unrealized Loss Position, Qualitative Disclosure, Number of Positions, Total Charge-offs [Domain] Charge-offs [Domain] [Domain] for Charge-offs [Axis] Ending balance: collectively evaluated for impaired Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Revenue Recognition and Deferred Revenue [Abstract] Revenue Recognition and Deferred Revenue [Abstract] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Purchases of available-for-sale securities Payments to Acquire Available-for-sale Securities Nonaccrual Loans Paid Off [Axis] Nonaccrual Loans Paid Off [Axis] Nonaccrual Loans Paid Off [Axis] Supplemental Cash Flow Information [Abstract] Supplemental Cash Flow Information [Abstract] Due within one year, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Loss Contingency, Estimate of Possible Loss Loss Contingency, Estimate of Possible Loss Financing Receivable, Troubled Debt Restructuring, Commitment to Lend Financing Receivable, Troubled Debt Restructuring, Commitment to Lend Financial standby letters of credit [Member] Financial Standby Letter of Credit [Member] Common Stock [Member] Common Stock [Member] Oil per BBL/d [Member] Oil per BBL/d [Member] Oil per BBL/d [Member] Restricted Stock Units [Member] Restricted Stock Units [Member] Restricted Stock Units [Member] Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Restricted stock APIC, Share-based Payment Arrangement, Recognition and Exercise Subordinated Debentures Outstanding [Abstract] Subordinated Debentures Outstanding [Abstract] Subordinated Debentures Outstanding [Abstract] Loans Still in Deferral Period [Member] Loans Still in Deferral Period [Member] Loans Still in Deferral Period Increase in interest receivable Increase (Decrease) in Accrued Interest Receivable, Net Other comprehensive income, before tax expense: Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract] Nonperforming Loans [Axis] Nonperforming Loans [Axis] Nonperforming Loans [Axis] Loans and Leases Receivable, Gross Loans and Leases Receivable, Gross Other Comprehensive Income (Loss), Tax Other Comprehensive Income (Loss), Tax Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Income from increase in cash surrender value of bank owned life insurance Increase In Cash Surrender Value of BOLI Increase In Cash Surrender Value of BOLI Average unearned nonvested shares Weighted Average Number of Shares, Restricted Stock Financing Receivable, Troubled Debt Restructuring, Subsequent Default Financing Receivable, Troubled Debt Restructuring, Subsequent Default Revision of Prior Period [Domain] Revision of Prior Period [Domain] Furniture and equipment expense Equipment Expense Fair Value Inputs Monetary Fair Value Weighted Average Inputs Price Fair Value Weighted Average Inputs Price Subordinated Debentures [Abstract] Subordinated Debentures [Abstract] Subordinated Debentures [Abstract] Amortized Cost Available-for-sale Securities, Amortized Cost Basis Unrealized holding gains on securities arising during the period Unrealized holding gains on securities arising during the period OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Total gains or losses included in other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Nonaccrual Commercial Loans [Member] Nonaccrual Commercial Loans [Member] Nonaccrual Commercial Loans [Member] Doubtful [Member] Doubtful [Member] Gross Losses Gross Losses Gross Losses This item represents the gross loss on maturities of available for sale securities. Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Non Accrual Loans [Member] Non Accrual Loans [Member] Non Accrual Loans [Member] Stock Issued During Period, Value, Treasury Stock Reissued Stock Issued Average Shares Outstanding (in shares) Weighted average common shares and common stock equivalents used to calculate basic earnings per share (in shares) Weighted Average Number of Shares Outstanding, Basic Subsequent Events [Abstract] Capital Lease Obligations Capital Lease Obligations Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Treasury stock, shares (in shares) Treasury Stock, Shares Loans To Individuals With No Related Allowance [Member] Loans To Individuals With No Related Allowance [Member] Loans to individuals with no related allowance. Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Loss Contingencies [Table] Loss Contingencies [Table] Carrying Amount [Member] Reported Value Measurement [Member] Interest Interest Paid, Excluding Capitalized Interest, Operating Activities Debt Securities, Available-for-sale, Restricted Debt Securities, Available-for-sale, Restricted Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Subordinated Debt Par Amount Subordinated Debt Par Amount Subordinated Debt Par Amount Additional paid-in capital Additional Paid in Capital Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Three Years Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One In-Scope of Topic 606 [Member] In-Scope of Topic 606 [Member] In-Scope of Topic 606 [Member] Income tax provision Income Tax Expense (Benefit) Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due in Five Years Residential real estate [Member] Residential Real Estate [Member] Investment Income [Table] Investment Income [Table] Income Taxes Paid, Net Income Taxes Paid, Net Real Estate Construction With Related Allowance [Member] Real Estate Construction With Related Allowance [Member] Real estate construction with related allowance. Loss on sale or write-down of assets Gain (Loss) on Sale of Assets and Asset Impairment Charges Total Liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Diluted Earnings per Share (in dollars per share) Earnings Per Share, Diluted Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Two Years Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Troubled Debt Restructuring [Policy Text Block] Financing Receivable Troubled Debt Restructuring Specific Reserve Financing Receivable Troubled Debt Restructuring Specific Reserve Loans to individuals [Member] Consumer Loan [Member] Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Total Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Derivative [Line Items] Derivative [Line Items] Derivative [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Other Liabilities Other Liabilities, Fair Value Disclosure Payments for Purchase of Other Assets Payments for Purchase of Other Assets Deferred tax (benefit) expense Deferred Income Tax Expense (Benefit) Credit Default Swap, Selling Protection [Member] Credit Default Swap, Selling Protection [Member] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Management Fees, Incentive Revenue (Deprecated 2018-01-31) Incentive Revenue Incentive Revenue Maximum [Member] Maximum [Member] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Loans Held for Sale Loans Held-for-sale, Fair Value Disclosure Dividends, declared (USD per share) Dividends, Common Stock, Cash Document Information [Table] Document Information [Table] Retained Earnings [Member] Retained Earnings [Member] Foreign Exchange [Member] Foreign Exchange [Member] Measurement Basis [Axis] Measurement Basis [Axis] Charge-offs 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