Statement of Stockholders' Equity [Abstract] Other comprehensive income, tax Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Dividends paid, per share (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Investments, Debt and Equity Securities [Abstract] Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-maturity [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Residential mortgage-backed securities Residential Mortgage Backed Securities [Member] Fixed rate Fixed Rate Residential Mortgage [Member] Variable rate Adjustable Rate Residential Mortgage [Member] Investment Secondary Categorization [Axis] Investment Secondary Categorization [Axis] Investments by Secondary Categorization [Domain] Investments by Secondary Categorization [Domain] Pass-through Pass Through Mortgage Backed Securities [Member] Represents information pertaining to pass-through mortgage-backed securities. Agency CMOs Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Marketable securities held to maturity Schedule of Held-to-maturity Securities [Line Items] Amortized cost Debt Securities, Held-to-maturity, Maturity, Amortized Cost, Net [Abstract] Marketable securities held-to-maturity, amortized cost Debt Securities, Held-to-maturity, Amortized Cost, before Other-than-temporary Impairment Gross unrealized holding gains Held-to-maturity Securities, Debt Maturities, Gross Unrealized Gain [Abstract] Marketable securities held-to-maturity, gross unrealized holding gains Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Gross unrealized holding losses Held-to-maturity Securities, Unrealized Losses [Abstract] Marketable securities held-to-maturity, gross unrealized holding losses Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Fair value Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract] Marketable securities held-to-maturity, fair value Debt Securities, Held-to-maturity, Fair Value Statement of Comprehensive Income [Abstract] Unrealized holding gains (losses), tax Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Reclassification adjustment for gains included in net income, tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Change in fair value of interest rate swaps. tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent Change in fair value of interest rate swaps, tax Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent Reclassification adjustments for prior period service costs and net losses included in net income, tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax Leases [Abstract] Operating lease costs (office operations) Operating Lease, Cost Variable lease costs (office operations) Variable Lease, Cost Total operating lease costs Lease, Cost Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Core Deposits Core Deposits [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Donegal Financial Services Corporation Donegal Financial Services Corporation [Member] Donegal Financial Services Corporation [Member] Acquisition Business Acquisition [Line Items] Consideration paid: Business Combination, Consideration Transferred [Abstract] Northwest Bancshares, Inc. common stock issued Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Cash paid to DFSC Payments to Acquire Businesses, Gross Total consideration paid Business Combination, Consideration Transferred Recognized amounts of identifiable assets acquired and (liabilities assumed), at fair value Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract] Cash and cash equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Investment securities available-for-sale Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities Loans Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Loans Receivable Represents the amount of loans receivable acquired at the acquisition date. Federal Home Loan Bank stock Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Federal Home Loan Bank Stock Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Federal Home Loan Bank Stock Premises and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Core deposit intangible Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Deposits Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits Liabilities Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Total identifiable net assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Goodwill Goodwill Fair Value Disclosures [Abstract] Significant unrealized appreciation or depreciation in financial instruments Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Financial Instruments Total Unrealized Gains (Losses) Period Increase (Decrease) The increase (decrease) of financial instruments measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period. Such increase (decrease) may be comprised of changes in fair value (gains or losses) unrealized. Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Interest rate lock commitments Interest Rate Lock Commitments [Member] Forward commitments Forward Contracts [Member] Interest rate swaps Interest Rate Swap [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying amount Reported Value Measurement [Member] Estimated fair value Estimate of Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Carrying amount and estimated fair value of the entity's financial instruments included in the consolidated statement of financial condition Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Securities available-for-sale Debt Securities, Available-for-sale Securities held-to-maturity Loans receivable, net Loans Receivable, Fair Value Disclosure Residential mortgage loans held-for-sale Disposal Group, Including Discontinued Operation, Assets Accrued interest receivable Interest Receivable Derivative assets Derivative Asset FHLB stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Total financial assets Assets, Fair Value Disclosure Financial liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Savings and checking deposits Savings and Demand Deposits The carrying amount of savings and demand deposits as of the balance sheet date. Time deposits Deposits, Fair Value Disclosure Borrowed funds Debt and Lease Obligation Junior subordinated debentures Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust Interest rate swaps Derivative Liability Accrued interest payable Accrued Liabilities, Fair Value Disclosure Total financial liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Leases Lessee, Operating Leases [Text Block] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Loans measured for impairment Impaired Loans [Member] Represents information pertaining to impaired loans. Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Measurements, Nonrecurring Fair Value, Nonrecurring [Member] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Estimated cost to sell Measurement Input, Cost to Sell [Member] Discount rate Measurement Input, Discount Rate [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Real estate owned Other Real Estate Owned [Member] Represents information pertaining to real estate owned, comprising of property acquired through foreclosure or voluntarily conveyed by delinquent borrowers. Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Discounted cash flow Discounted Cash Flow Valuation Technique [Member] Represents the discounted cash flow technique used to measure fair value. Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Weighted Average Weighted Average [Member] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Loans measured for impairment Real estate owned Other Real Estate Estimated cost to sell loans measured for impairment Loans Receivable, Measurement Input Loans Receivable, Measurement Input Estimated cost to sell Other Real Estate Owned, Measurement Input Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Income Taxes - Uncertain Tax Positions Income Tax Uncertainties, Policy [Policy Text Block] Recently Adopted Accounting Standards and Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common stock Common Stock [Member] Paid-in capital Additional Paid-in Capital [Member] Retained earnings Retained Earnings [Member] Accumulated other comprehensive loss AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance beginning of the period (in shares) Shares, Issued Balance beginning of the period Stockholders' Equity Attributable to Parent Reclassification due to adoption of ASU No. 2018-02 Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect Reclassification due to adoption of ASU No. 2016-02 Cumulative Effect of New Accounting Principle in Period of Adoption Comprehensive income: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Net income Net Income (Loss) Available to Common Stockholders, Basic Other comprehensive income, net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Acquisition of Union Community Bank (UCB) (in shares) Stock Issued During Period, Shares, Acquisitions Acquisition of Union Community Bank (UCB) Stock Issued During Period, Value, Acquisitions Exercise of stock options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Stock-based compensation expense (in shares) Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Stock-based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Stock-based compensation forfeited (in shares) Shares Issued, Shares, Share-based Payment Arrangement, Forfeited Stock-based compensation forfeited Shares Granted, Value, Share-based Payment Arrangement, Forfeited Dividends paid Dividends, Cash Balance end of period (in shares) Balance end of the period Schedule of intangible assets subject to amortization Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of the actual aggregate amortization expense as well as estimated aggregate amortization expense, based upon current levels of intangible assets Schedule of Amortization Expense [Table Text Block] Tabular disclosure of the amount of amortization expense and estimated amortization expense for intangible assets. Schedule of the changes in carrying amount of goodwill Schedule of Goodwill [Table Text Block] Schedule of the carrying amount and estimated fair value of the entity's financial instruments included in the consolidated statement of financial condition Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of assets and liabilities measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of fair value measurement for nonrecurring assets Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of quantitative information about assets measured at fair value on a recurring and nonrecurring basis for Level 3 fair value measurements Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Retirement Benefits [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension benefits Pension Plan [Member] Other post-retirement benefits Other Postretirement Benefits Plan [Member] Employee benefit plans Defined Benefit Plan Disclosure [Line Items] Components of net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of the net loss Defined Benefit Plan, Amortization of Gain (Loss) Net periodic cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Estimated contribution for the current year Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Equity [Abstract] Schedule of changes in accumulated other comprehensive income by component Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Unrealized gains and (losses) on securities available- for-sale AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Change in fair value of interest rate swaps Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Change in fair value of interest rate swaps Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Change in defined benefit pension plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Total Accumulated other comprehensive income (net of tax) Accumulated Other Comprehensive Income (Loss) [Line Items] Changes in accumulated other comprehensive income by component AOCI Attributable to Parent, Net of Tax [Roll Forward] Other comprehensive income before reclassification adjustments (1) OCI, before Reclassifications, Net of Tax, Attributable to Parent Amounts reclassified from accumulted other comprehensive income Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Other comprehensive income/(loss) Realized gain on securities (gain on sales of investments, net) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Reclassification adjustment for prior period service costs included in net income, net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax Reclassification adjustment for defined benefit plan loss included in net income, net of tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Reclassification adjustment for prior period service costs included in net income, tax Receivables [Abstract] Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Residential mortgage loans Residential Mortgage [Member] Home equity loans Home Equity Loan [Member] Commercial real estate loans Commercial Real Estate [Member] Commercial loans Commercial Loan [Member] Troubled debt restructurings Financing Receivable, Troubled Debt Restructuring [Line Items] Number of contracts Financing Receivable Modifications Number of Contract [Roll Forward] Beginning balance Financing Receivable Modifications, Outstanding Number Of Contracts Financing Receivable Modifications, Outstanding Number Of Contracts Number of contracts new TDRs Financing Receivable Modifications Number Of Contracts 2 Additions Number additions during the period of financing receivables that have been modified by troubled debt restructurings. Number of re-modified TDRs Financing Receivable, Modifications, Number of Contracts remodified Number of financing receivables that have been re-modified by troubled debt restructurings. Number of contracts charged off Financing Receivable Modifications Number of Contracts Charged Off The number of financing receivables that have been modified by troubled debt restructurings and were charged off during the reporting period. Number of contracts paid off Financing Receivable Modifications, Number of Contracts Paid-off The number of financing receivables that have been modified by troubled debt restructurings and were paid off during the reporting period. Ending balance Amount Financing Receivable, Modifications, Recorded Investment [Roll Forward] A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. Beginning TDR balance Financing Receivable, Troubled Debt Restructuring New TDRs Financing Receivable, Modifications, Recorded Investment Additions The amount of additions during the period in recorded investment related to financing receivables that has been modified by troubled debt restructurings. Re-modified TDRs Financing Receivable Modifications Recorded Investment Re-modifications The amount of the recorded investment related to existing financing receivables that were previously modified by troubled debt restructurings and have subsequently been re-modified during the period. Net paydowns Financing Receivable, Modifications, Recorded Investment Net Paydowns The amount of net paydowns out of recorded investment related to financing receivables that have been modified by troubled debt restructurings. Amount of contracts charged off Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down Amount of contracts paid off Financing Receivable Modifications, Amount Paid-off The amount of financing receivables that have been modified by troubled debt restructurings and were paid off during the reporting period. Ending TDR balance Accruing TDRs Financing Receivable, Modifications Recorded Investment, Accrual The accruing portion of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. Non-accrual TDRs Financing Receivable, Modifications, Recorded Investment, NonAccrual The non-accruing portion of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Debt securities Debt Securities [Member] Total mortgage-backed securities Collateralized Mortgage Backed Securities [Member] Collateralized mortgage obligations Collateralized Mortgage Obligations [Member] Interest rate swaps Measured on recurring basis Fair Value, Recurring [Member] Level 1 Level 2 Level 3 U.S. government and agencies US Government Agencies Debt Securities [Member] Government sponsored enterprises US Government-sponsored Enterprises Debt Securities [Member] States and political subdivisions US States and Political Subdivisions Debt Securities [Member] Corporate Corporate Debt Securities [Member] GNMA Government National Mortgage Association Certificates and Obligations (GNMA) [Member] FNMA Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] FHLMC Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member] Non-agency Mortgage-backed Securities, Issued by Private Enterprises [Member] Assets and liabilities measured at fair value on a recurring basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Residential mortgage-backed securities: Mortgage-backed Securities Available-for-sale, Fair Value Disclosure Total liabilities Financial Liabilities Fair Value Disclosure Investment securities and impairment of investment securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Personal Banking Personal Banking [Member] Represents information pertaining to personal banking. Commercial Banking Business Banking [Member] Represents information pertaining to business banking. Consumer finance loans Consumer Finance Loans [Member] Consumer Finance Loans Consumer loans Consumer Loan [Member] Evaluation of impaired loans by portfolio segment and by class of financing receivable Financing Receivable, Impaired [Line Items] Loans collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Loans individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Loans individually evaluated for impairment for which there is a related impairment reserve Financing Receivable Individually Evaluated for Impairment Reserved The balance of financing receivables that were individually evaluated for impairment for which there is a related impairment reserve. Related impairment reserve Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Loans individually evaluated for impairment for which there is no related reserve Financing Receivable Individually Evaluated for Impairment Not Reserved The balance of financing receivables that were individually evaluated for impairment for which there is no related impairment reserve. Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Line of Credit Line of Credit [Member] Securities Sold under Agreements to Repurchase Securities Sold under Agreements to Repurchase [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Schedule of Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Axis] Schedule of Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Axis] Financial Instruments Subject to Mandatory Redemption, Financial Instrument [Domain] Financial Instruments Subject to Mandatory Redemption, Financial Instrument [Domain] Trust preferred investments Trust Preferred Securities Subject to Mandatory Redemption [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Northwest Bancorp Capital Trust III Northwest Bancorp Capital Trust I I I [Member] Represents information pertaining to Northwest Bancorp Capital Trust III, a Delaware statutory business trust. Northwest Bancorp Statutory Trust IV Northwest Bancorp Statutory Trust I V [Member] Represents information pertaining to Northwest Bancorp Statutory Trust IV, a Connecticut statutory trust. LNB Trust II L N B Statutory Trust I I [Member] Represents information pertaining to LNB Statutory Trust II, a Connecticut statutory trust. Union National Capital Trust I Union National Capital Trust I [Member] Union National Capital Trust I [Member] Union National Capital Trust II Union National Capital Trust II [Member] Union National Capital Trust II [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Revolving line of credit Long-term Line of Credit Securities sold under agreements to repurchase Securities Sold under Agreements to Repurchase Number of statutory business trusts owned Number of Business Trusts Owned Represents the number of business trusts owned by the entity. Cumulative trust preferred securities issued (in shares) Trust Preferred Securities Issued The element represents the total number of cumulative trust preferred securities issued. Cumulative trust preferred securities issued, liquidation value per preferred security (in dollars per security) Trust Preferred Liquidation Value The element represents the per share liquidation value of the trust preferred securities. Total value of cumulative trust preferred securities issued Trust Preferred Issued Total Value The element represents the total face value of cumulative trust preferred securities issued. Spread on variable rate basis (as a percent) Debt Instrument, Basis Spread on Variable Rate Junior subordinated debentures Effective rate (as a percent) Debt Instrument, Interest Rate, Effective Percentage Number of additional business trusts owned Number of Additional Business Trusts Owned Number of Additional Business Trusts Owned Maximum period for which interest payment on the subordinated debentures can be deferred Debt Instrument, Interest Deferral Option Maximum Period Represents the maximum period for which interest payment on the subordinated debentures can be deferred. Interest deferral Debt Instrument, Interest Payment Deferred Represents the amount of interest payment deferred on the subordinated debentures of the entity. Subsequent Events [Abstract] Subsequent events Subsequent Events [Text Block] Earnings Per Share [Abstract] Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Title of Individual [Axis] Title of Individual [Domain] Title of Individual [Domain] Employees Employees [Member] Employees [Member] Director Director [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Employee Stock Option Share-based Payment Arrangement, Option [Member] Restricted Stock Restricted Stock [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] Stock Related Compensation Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of banking locations Number of Banking Locations Represents the number of banking locations in which the entity operates. Options granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Options exercise price (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Options weighted average grant date fair value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Restricted common shares granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Restricted common shares weighted average grant date fair value (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 Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Stock-based compensation expense Share-based Payment Arrangement, Expense Compensation expense yet to be recognized Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Unrecognized tax benefits liability Unrecognized Tax Benefits Operating lease ROU assets (other assets) Operating Lease, Right-of-Use Asset Operating lease liabilities (other liabilities) Operating Lease, Liability Retained earnings Retained Earnings (Accumulated Deficit) Commitments and Contingencies Disclosure [Abstract] Legal Proceedings Legal Matters and Contingencies [Text Block] Lease, Cost Lease, Cost [Table Text Block] Assets And Liabilities, Lessee Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee [Table Text Block] Lessee, Operating Lease, Liability, Maturity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Financing Receivable, Troubled Debt Restructuring [Line Items] Number of contracts Financing Receivable, Modifications, Number of Contracts Recorded investment at the time of modification Financing Receivable, Troubled Debt Restructuring, Premodification Current recorded investment Financing Receivable, Troubled Debt Restructuring, Postmodification Current allowance Financing Receivable, Modification Allowance for Credit Losses The reserve to cover probable credit losses related to financing receivables that have been modified by troubled debt restructurings during the reporting period. Number of TDR contracts with subsequent default Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Recorded investment at the time of modification Financing Receivable Modification that Subsequently Defaulted Pre-Modification Recorded Investment Pre-modification amount of outstanding recorded investment related to financing receivables (as of the balance sheet date) that have been modified by troubled debt restructurings and then subsequently defaulted during the reporting period. Current recorded investment Financing Receivable, Troubled Debt Restructuring, Subsequent Default Current allowance Increase (Decrease) in Financing Receivable Modifications Recorded Investment Reserve The increase decrease in the amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings. Subsequent default measurement period Financing Receivable, Troubled Debt Restructuring, Subsequent Default Measurement Period Financing Receivable, Troubled Debt Restructuring, Subsequent Default Measurement Period Cumulative roll forward of credit related impairment losses recognized in earnings for debt securities held and not intended to be sold: Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] Beginning balance Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held Credit losses on debt securities for which other-than-temporary impairment was not previously recognized Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment Reduction for losses realized during the quarter Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold Reduction for securities sold/called realized during the quarter Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Called This item represents reductions in the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security because of the exercise of a call option of impaired securities during the period. Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses Ending balance Lessee, Operating Lease, Liability, Payment, Due [Abstract] Lessee, Operating Lease, Liability, Payment, Due [Abstract] 2019 Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total lease payments Lessee, Operating Lease, Liability, Payments, Due Less amount of lease payments representing interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Total present value of lease payments Lease Maturities Before Topic 842 Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total lease payments Operating Leases, Future Minimum Payments Due Investment Holdings [Table] Investment Holdings [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Municipal securities Marketable securities Investment Holdings [Line Items] Less than 12 months - Fair value Held to Maturity and Available for Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value This item represents the aggregate fair value of investments in debt and equity securities categorized as held-to-maturity and available-for-sale securities that have been in a continuous unrealized loss position for less than twelve months. Less than 12 months - Unrealized loss Held to Maturity and Available for Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses 1 This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for less than twelve months. 12 months or more - Fair value Held to Maturity and Available for Sale Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value This item represents the aggregate fair value of investments in debt and equity securities categorized as held-to-maturity and available-for-sale securities that have been in a continuous unrealized loss position for twelve months or longer. 12 months or more - Unrealized loss Held to Maturity and Available for Sale Securities Continuous Unrealized Loss Position 12 Months or Longer Aggregate Losses 2 Amount of the excess of amortized cost basis over fair value of securities that have been in a loss position for twelve months or longer for securities which are categorized as held-to-maturity and available-for-sale securities. Total - Fair value Held to Maturity and Available for Sale Securities Continuous Unrealized Loss Position Fair Value This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized as held-to-maturity and available-for-sale securities. Total - Unrealized loss Held to Maturity and Available for Sale Securities Continuous Unrealized Loss Position Aggregate Losses 1 This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized as held-to-maturity and available-for-sale securities. Schedule of the portfolio of investment securities available-for-sale Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Schedule of the portfolio of investment securities held-to-maturity Debt Securities, Held-to-maturity [Table Text Block] Schedule of the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of the cumulative roll forward of credit losses recognized in earnings for debt securities held and not intended to be sold Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Total loans receivable Loans and Leases Receivable, Net of Deferred Income Allowance for loan losses Loans and Leases Receivable Allowance Excluding Unallocated The allowance for loan and lease losses represents the reserve to cover probable credit losses related to all loans and leases, as well as probable credit losses inherent in the remainder of the loan portfolio as of the balance sheet date excluding unallocated amounts. Nonaccrual loans Financing Receivable, Nonaccrual Loans past due 90 days or more and still accruing Financing Receivable, Recorded Investment, 90 Days Or More Past Maturity And Still Accruing Financing Receivable, Recorded Investment, 90 Days Or More Past Maturity And Still Accruing TDRs Allowance related to TDRs Allowance for Credit Losses, Changes in Method of Calculating Impairment Allowance for Credit Losses, Changes in Method of Calculating Impairment Additional commitments to customers with loans classified as TDRs Financing Receivable, Modifications, Recorded Investment Additional Commitment The amount of additional commitments to lend to customers who have financing receivables that have been modified by troubled debt restructurings. Nonaccrual TDRs Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of derivatives not designated as hedging instruments Derivatives Not Designated as Hedging Instruments [Table Text Block] Derivative instruments gain (loss) Derivative Instruments, Gain (Loss) [Table Text Block] Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Originated Originated Loan [Member] Represents information pertaining to originated loans. Acquired Acquired Loan [Member] Represents total acquired loans. Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Pass Pass [Member] Special mention Special Mention [Member] Substandard Substandard [Member] Doubtful Doubtful [Member] Loss Unlikely to be Collected Financing Receivable [Member] Special mention or substandard Special Mention And Substandard [Member] Represents information pertaining to special mention or substandard financing receivables. Credit quality indicators Financing Receivable, Credit Quality Indicator [Line Items] Total loans Loans receivable Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Statement of Financial Position [Abstract] Assets Assets [Abstract] Cash and cash equivalents Cash and Due from Banks Marketable securities available-for-sale (amortized cost of $801,465 and $811,015, respectively) Marketable securities held-to-maturity (fair value of $19,237 and $22,446, respectively) Debt Securities, Held-to-maturity Total cash and cash equivalents and marketable securities Cash, Cash Equivalents and Marketable Securities Cash, cash equivalents and marketable securities. Residential mortgage loans held-for-sale Loans Receivable Held-for-sale, Amount Total loans Loans Receivable, Net Of Deferred Income And Loans In Process Loans Receivable, Net Of Deferred Income And Loans In Process Allowance for loan losses Loans and Leases Receivable, Allowance Loans receivable, net Loans and Leases Receivable, Net Amount Federal Home Loan Bank stock, at cost Federal Home Loan Bank Stock Accrued interest receivable Real estate owned, net Real Estate Acquired Through Foreclosure Premises and equipment, net Property, Plant and Equipment, Net Bank-owned life insurance Bank Owned Life Insurance Other intangible assets Intangible Assets, Net (Excluding Goodwill) Other assets Other Assets Total assets Assets Liabilities and shareholders’ equity Liabilities and Equity [Abstract] Liabilities: Liabilities [Abstract] Noninterest-bearing demand deposits Noninterest-bearing Domestic Deposit, Checking Interest-bearing demand deposits Interest-bearing Domestic Deposit, Checking Money market deposit accounts Deposits, Money Market Deposits Savings deposits Deposits, Savings Deposits Time deposits Time Deposits Total deposits Deposits Borrowed funds Advances by borrowers for taxes and insurance Advance Payments by Borrowers for Taxes and Insurance Accrued interest payable Interest Payable Other liabilities Other Liabilities Total liabilities Liabilities Shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $0.01 par value: 50,000,000 authorized, no shares issued Preferred Stock, Value, Issued Common stock, $0.01 par value: 500,000,000 shares authorized, 106,658,067 and 103,354,030 shares issued and outstanding, respectively Common Stock, Value, Issued Paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity Total liabilities and shareholders’ equity Liabilities and Equity Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount Changes in accretable yield Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] Beginning balance Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Accretion Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion Net reclassification from nonaccretable yield Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference Ending balance Basis of Presentation and Informational Disclosures Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Schedule of net periodic costs for the defined benefit pension plans and the post retirement healthcare plans Schedule of Net Benefit Costs [Table Text Block] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] 90 Days or greater delinquent Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Less than 90 days delinquent Financing Receivables, Less Than 90 Days Past Due [Member] Financing Receivables, Less Than 90 Days Past Due [Member] Composition of impaired loans by portfolio segment and by class of financing receivable Nonaccrual loans Loans less than 90 days delinquent reviewed for impairment Financing Receivable Recorded Accruing Loans Reviewed for Impairment Represents the amount of accruing loans reviewed for impairment. TDRs less than 90 days delinquent not included elsewhere Financing Receivable Recorded Accruing Loans Not Reviewed for Impairment Represents the amount accruing trouble debt reconstruction reviewed for impairment. Total impaired loans Impaired Financing Receivable, Recorded Investment Average recorded investment in impaired loans Impaired Financing Receivable, Average Recorded Investment Interest income recognized on impaired loans Impaired Financing Receivable, Interest Income, Accrual Method Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Customer and Contract Customer Contracts [Member] Intangible assets subject to amortization Finite-Lived Intangible Assets [Line Items] Amortizable intangible assets: Finite-Lived Intangible Assets, Net [Abstract] Intangible asset - gross Finite-Lived Intangible Assets, Gross Acquisitions Finite-lived Intangible Assets Acquired Less: accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Intangible asset - net Finite-Lived Intangible Assets, Net Amortization expense Amortization of Intangible Assets Estimated amortization expense Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] For the year ending December 31, 2019 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year For the year ending December 31, 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Two For the year ending December 31, 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Three For the year ending December 31, 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Four For the year ending December 31, 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Five For the year ending December 31, 2024 Finite-Lived Intangible Assets, Amortization Expense, after Year Five Total loans receivable, gross Loans and Leases Receivable, Gross Deferred loan costs Loans and Leases Receivable, Deferred Income Allowance for loan losses Undisbursed loan proceeds Loans and Leases Receivable, Loans in Process Total loans receivable, net Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Debt issued by government sponsored enterprises: Corporate debt securities Marketable securities available-for-sale Debt Securities, Available-for-sale [Line Items] Amortized cost Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract] Due in less than one year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Due in one year through five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Due in five years through ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Due after ten years Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost Residential mortgage-backed securities Debt Securities, Available-for-sale, Amortized Cost Gross unrealized holding gains Available-for-sale Securities, Debt Maturities, Gross Unrealized Gain [Abstract] Due in less than one year Available-for-sale Securities, Debt Maturities, within One Year, Gross Unrealized Gain Represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature within one year of the balance sheet date. Due in one year through five years Available-for-sale Securities, Debt Maturities, after One Through Five Years, Gross Unrealized Gain Represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature after one year and through five years from the balance sheet date. Due in five years through ten years Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Gross Unrealized Gain Represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature after five years and through ten years from the balance sheet date. Due after ten years Available-for-sale Securities, Debt Maturities, after Ten Years, Gross Unrealized Gain Represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature after ten years from the balance sheet date. Residential mortgage-backed securities, gross unrealized holding gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross unrealized holding losses Available-for-sale Securities, Unrealized Losses [Abstract] Due in less than one year Available-For-Sale Securities, Debt Maturities, One Year Or Less, Gross Unrealized Loss Available-For-Sale Securities, Debt Maturities, One Year Or Less, Gross Unrealized Loss Due in one year through five years Available-for-sale Securities, Debt Maturities, after One Through Five Years, Gross Unrealized Loss Represents the gross unrealized losses for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature after one year and through five years from the balance sheet date. Due in five years through ten years Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Gross Unrealized Loss Represents the gross unrealized losses for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature after five years and through ten years from the balance sheet date. Due after ten years Available-for-sale Securities, Debt Maturities, after Ten Years, Gross Unrealized Loss Represents the gross unrealized losses for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities and which are expected to mature after ten years from the balance sheet date. Residential mortgage-backed securities, gross unrealized holding losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Fair value Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] Due in less than one year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Due in one year through five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Due in five years through ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Due after ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Guarantees [Abstract] Guarantees Guarantees [Text Block] Schedule of Guarantor Obligations [Table] Schedule of Guarantor Obligations [Table] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Letter of Credit Letter of Credit [Member] Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Maximum potential amount of future payments Guarantor Obligations, Maximum Exposure, Undiscounted Maximum exposure collateralized Guarantee Obligations Maximum Exposure Collateralized Represents the maximum potential amount of future payments which is fully collateralized. Liability recognized for the obligations Contract with Customer, Liability Schedule of Recognized Identified Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Derivative [Table] Derivative [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Derivative [Line Items] Derivative [Line Items] Asset derivatives, notional amount Derivative Asset, Notional Amount Derivative assets, fair value Liability derivatives, notional amount Derivative Liability, Notional Amount Liability derivatives, fair value Acquisition Business Combination Disclosure [Text Block] Income Statement [Abstract] Interest income: Interest and Dividend Income, Operating [Abstract] Loans receivable Interest and Fee Income, Loans and Leases Mortgage-backed securities Interest Income, Securities, Mortgage Backed Taxable investment securities Interest Income, Securities, Operating, Taxable Tax-free investment securities Interest Income, Securities, Operating, Tax Exempt Federal Home Loan Bank stock dividends Dividend Income, Operating Interest-earning deposits Interest Income, Deposits with Financial Institutions Total interest income Interest and Dividend Income, Operating Interest expense: Interest Expense [Abstract] Deposits Interest Expense, Deposits Borrowed funds Interest Expense, Borrowings Total interest expense Interest Expense Net interest income Interest Income (Expense), Net Provision for loan losses Provision for Loan and Lease Losses Net interest income after provision for loan losses Interest Income (Expense), after Provision for Loan Loss Noninterest income: Noninterest Income [Abstract] Gain on sale of loans Gain (Loss) on Sales of Loans, Net Gain on sale of investments Debt and Equity Securities, Gain (Loss) Service charges and fees Fees and Commissions, Mortgage Banking and Servicing Trust and other financial services income Fees And Commissions, Trust Services And Other Income Fees And Commissions, Trust Services And Other Income Insurance commission income Insurance Commissions and Fees Loss on real estate owned, net Gains (Losses) on Sales of Other Real Estate Income from bank-owned life insurance Bank Owned Life Insurance Income Mortgage banking income Mortgage Banking Income The noninterest income derived from mortgage banking activities (fees and commissions), including fees earned from servicing third-party assets. Other operating income Noninterest Income, Other Operating Income Total noninterest income Noninterest Income Noninterest expense: Noninterest Expense [Abstract] Compensation and employee benefits Labor and Related Expense Premises and occupancy costs Occupancy, Net Office operations General and Administrative Expense Collections expense Noninterest Expense, Collection Of Receivables Noninterest Expense, Collection Of Receivables Processing expenses Information Technology and Data Processing Marketing expenses Marketing Expense Federal deposit insurance premiums Federal Deposit Insurance Corporation Premium Expense, Net Federal Deposit Insurance Corporation Premium Expense, Net Professional services Professional Fees Amortization of intangible assets Real estate owned expense Foreclosed Real Estate Expense Restructuring/acquisition expense Restructuring And Acquisition Related Costs Restructuring And Acquisition Related Costs Other expenses Other Noninterest Expense Total noninterest expense Noninterest Expense Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Federal and state income taxes expense Income Tax Expense (Benefit) Net income Basic earnings per share (in dollars per share) Earnings Per Share, Basic Diluted earnings per share (in dollars per share) Earnings Per Share, Diluted Summary of loans receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Schedule of information related to the outstanding principal balance and related carrying value of acquired loans Schedule Of Outstanding Principal Balance and Carrying Value Of Acquired Loans [Table Text Block] Information related to the outstanding principal balance and related carrying value of acquired loans. Schedule of the changes in the accretable discount Changes In Accretable Discount [Table Text Block] Tabular disclosure of the changes in the accretable discount. Schedule of the composition of impaired loans by portfolio segment and by class of financing receivable Impaired Financing Receivables [Table Text Block] Schedule of the changes in the allowance for losses on loans receivable Financing Receivable, Allowance for Credit Loss [Table Text Block] Schedule of loan portfolio by portfolio segment and by class of financing receivable Schedule of Loans by Portfolio Segment and Class of Financing Receivable [Table Text Block] Tabular disclosure of information related to loans by portfolio segment and by class of financing receivable. Schedule of the evaluation of impaired loans by portfolio segment and by class of financing receivable Schedule of Evaluation of Impaired Financing Receivables [Table Text Block] Tabular disclosure of the evaluation of impaired financing receivables. Schedule of roll forward of troubled debt restructurings Financing Receivable, Modifications, Recorded Investment Roll Forward [Table Text Block] Tabular disclosure of the change in outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. Schedule of troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable Financing Receivable, Troubled Debt Restructuring [Table Text Block] Schedule of troubled debt restructurings (including re-modified TDRs) by type of modification by portfolio segment and by class of financing receivable Schedule of Modified Troubled Debt Restructurings by Portfolio Segment and Class of Financing Receivable [Table Text Block] Tabular disclosure of modified troubled debt restructurings by portfolio segment and by class of financing receivable. Schedule of re-modified troubled debt restructurings by portfolio segment and by class of financing receivable Schedule of remodified Troubled Debt Restructurings by Portfolio Segment and Class of Financing Receivable [Table Text Block] Tabular disclosure of re-modified troubled debt restructurings by portfolio segment and by class of financing receivable. Schedule of loan delinquencies Financing Receivable, Past Due [Table Text Block] Schedule of credit quality indicators Financing Receivable Credit Quality Indicators [Table Text Block] Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Allowance for loan losses Financing Receivable, Allowance for Credit Loss [Line Items] Changes in allowance for losses on allocated loans receivable Allowance for Loan and Lease Losses [Roll Forward] Balance at the beginning of the period Current period provision Charge-offs Allowance for Loan and Lease Losses, Write-offs Recoveries Allowance for Loan and Lease Loss, Recovery of Bad Debts Balance at the end of the period Disclosures About Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Cover page. Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Entity Shell Company Entity Shell Company Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Entity Central Index Key Entity Central Index Key Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] 30-59 Days delinquent Financial Asset, 30 to 59 Days Past Due [Member] 60-89 Days delinquent Financial Asset, 60 to 89 Days Past Due [Member] Loan payment delinquencies Financing Receivable, Past Due [Line Items] Total delinquency Financing Receivable, Past Due Current Financing Receivable, Not Past Due Total loans 90 days or greater delinquent and accruing Financing Receivable, 90 Days or More Past Due, Still Accruing Statement of Cash Flows [Abstract] Interest on deposits and borrowings, interest credited to deposit accounts Cash Paid for Interest on Deposits This element represents interest paid to depositors on deposit accounts held by the institution. Marketable securities available-for-sale, amortized cost Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Net income Other comprehensive income net of tax: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Net unrealized holding gains/(losses) on marketable securities: Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract] Unrealized holding gains/(losses) net of tax of ($525), $788, ($4,549), $2,869, respectively Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Reclassification adjustment for gains included in net income, net of tax of $0, $17, $1 and $54, respectively Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net unrealized holding gains/(losses) on marketable securities Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Change in fair value of interest rate swaps, net of tax of $0, ($51), $0 and ($204), respectively Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Change in fair value of interest rate swaps, net of tax of $0, ($51), $0 and ($204), respectively Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent Defined benefit plan: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent [Abstract] Reclassification adjustments for prior period service costs and net losses included in net income, net of tax of ($83), ($90), ($250) and ($271), respectively Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent Pension and Other Post-retirement Benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Rate Interest Rate Below Market Reduction [Member] Payment Payment Modification [Member] Reflects details pertaining to modification made on payment on loans. Maturity date Extended Maturity [Member] Other Other Modification [Member] Reflects details pertaining to the other type of modification made on loans that are not separately disclosed. Troubled debt restructurings Net income available to common shareholders Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Dilutive potential shares due to effect of stock options (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Total weighted average common shares and dilutive potential shares (in shares) Weighted Average Number of Shares Outstanding, Diluted Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Lease term of contract (up to) Lessee, Operating Lease, Term of Contract Lease renewal term Lessor, Operating Lease, Renewal Term Earnings Per Share Earnings Per Share [Text Block] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other Income Other Income [Member] Mortgage Banking Income Mortgage Banking Income [Member] Mortgage Banking Income [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Hedging derivatives: Gain (Loss) on Derivative Instruments, Net, Pretax [Abstract] Increase in interest expense Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Increase in interest expense Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Non-hedging swap derivatives: Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract] Decrease in other income Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Reconciliation of debt securities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Beginning balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total net realized investment gains/ (losses) and net change in unrealized appreciation/ (depreciation): Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Assets Total Gains (Losses) Realized and Unrealized [Abstract] Included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Transfers from Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Transfers into Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Ending balance Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedging Cash Flow Hedging [Member] Derivative notional amount Derivative, Notional Amount Total consideration Number of offices acquired Business Combination, Number Of Offices Acquired Business Combination, Number Of Offices Acquired Number of counterparty shareholders Business Combination, Number of Counterparty Shareholders Business Combination, Number of Counterparty Shareholders Cash as percent of total consideration Business Combination, Consideration Transferred, Cash, Percent Business Combination, Consideration Transferred, Cash, Percent Stock as percent of total consideration Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Percent Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Percent Stock issued for acquisition (in shares) Value of stock issued for purchase Closing price of Company's stock issued for purchase (in dollars per share) Share Price Acquired finite-lived intangible assets weighted average useful life Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Additional cost expensed Business Combination, Acquisition Related Costs Operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Net gain/(loss) on sale of assets Gain (Loss) on Disposition of Assets for Financial Service Operations Net depreciation, amortization and accretion Depreciation, Amortization and Accretion, Net Increase in other assets Increase (Decrease) in Other Operating Assets Increase in other liabilities Increase (Decrease) in Other Operating Liabilities Net amortization on marketable securities Accretion (Amortization) of Discounts and Premiums, Investments Noncash write-down of real estate owned Impairment of Real Estate Deferred income tax expense Deferred Income Tax Expense (Benefit) Origination of loans held-for-sale Payments for Origination and Purchases of Loans Held-for-sale Proceeds from sale of loans held-for-sale Proceeds from Sale of Loans Held-for-sale Noncash compensation expense related to stock benefit plans Share-based Payment Arrangement, Noncash Expense Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Purchase of marketable securities available-for-sale Payments to Acquire Debt Securities, Available-for-sale Proceeds from maturities and principal reductions of marketable securities held-to-maturity Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Proceeds from maturities and principal reductions of marketable securities available-for-sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Proceeds from sale of marketable securities available-for-sale Proceeds from Sale of Debt Securities, Available-for-sale Proceeds from bank-owned life insurance Proceeds from Life Insurance Policy Loan originations Originations of Loans Receivable Held for Investment The cash outflow associated with loans originated and held for investment purposes during the period. Proceeds from loan maturities and principal reductions Proceeds from Principal Repayments on Loans and Leases Held-for-investment Proceeds from sale of loans held for investment Proceeds from Sale of Mortgage Loans Held-for-sale Net proceeds of Federal Home Loan Bank stock Payments to Acquire Federal Home Loan Bank Stock Proceeds from sale of real estate owned Proceeds from Sale of Foreclosed Assets Sale of real estate owned for investment, net Net Income (Loss) from Real Estate Investment Partnership, Attributable to Parent Purchase of premises and equipment Payments to Acquire Property, Plant, and Equipment Acquisitions, net of cash received Payments to Acquire Businesses, Net of Cash Acquired Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Increase in deposits, net Increase (Decrease) in Deposits Net increase in short-term borrowings Proceeds from Short-term Debt Increase in advances by borrowers for taxes and insurance Increase (Decrease) in Advance Payments by Borrowers for Taxes and Insurance Cash dividends paid Payments of Dividends Proceeds from stock options exercised Proceeds from Stock Options Exercised Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Net increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents at end of period Cash paid during the period for: Cash Paid During Period for [Abstract] Interest on deposits and borrowings (including interest credited to deposit accounts of $32,893 and $20,927, respectively) Cash Paid for Interest on Deposits and Borrowings This element represents the interest paid on deposits and borrowings during the reporting period. Income taxes Income Taxes Paid Business acquisitions: Business Acquisitions [Abstract] Fair value of assets acquired Noncash or Part Noncash Acquisition, Value of Assets Acquired Northwest Bancshares, Inc. common stock issued Stock Issued Cash paid Liabilities assumed Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed) Non-cash activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Loan foreclosures and repossessions Transfer of Other Real Estate and Other Repossessed Personal Property Value of real estate and repossessed personal property transferred in noncash transactions during the reporting period. Sale of real estate owned financed by the Company Sale and Financing of Other Real Estate Owned Loans originated by the Company to finance the sale of OREO.