Subordinated Borrowings [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Subordinated Debt Subordinated Debt [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Subordinated notes Subordinated Debt Subordinated debt issued, gross Subordinated Debt Issued, Gross Subordinated Debt Issued, Gross Proceeds from issuance of subordinated debt Proceeds from Issuance of Subordinated Long-term Debt Debt instrument, interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Debt instrument, maturity date Debt Instrument, Maturity Date Debt issuance costs Payments of Debt Issuance Costs Debt instrument, unamortized discount Debt Instrument, Unamortized Discount Condensed Financial Information of Parent Company Only Disclosure [Abstract] Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Reportable Legal Entities Reportable Legal Entities [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Parent Company Parent Company [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income to net cash provided by (used for) operating activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Provision for credit losses Provision for Loan, Lease, and Other Losses Losses on available-for-sale securities, net Available-for-sale Securities, Gross Realized Gain (Loss) Gain on early extinguishment of debt Gain (Loss) on Extinguishment of Debt Depreciation and amortization Depreciation, Amortization and Accretion, Net Deferred income tax (benefit) expense Deferred Income Tax Expense (Benefit) Stock-based compensation expense Share-based Compensation Excess tax benefits from stock-based compensation arrangements Excess Tax Benefit from Share-based Compensation, Operating Activities Increase in other assets Increase (Decrease) in Other Operating Assets Increase in other liabilities Increase (Decrease) in Other Operating Liabilities Equity in undistributed net income of subsidiaries Income (Loss) from Subsidiaries, Net of Tax Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities Investing Activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Capital contributions to subsidiaries, net Payments to Acquire Additional Interest in Subsidiaries Net cash paid for acquisitions, net Payments to Acquire Businesses, Net of Cash Acquired Other investing activity, net Payments for (Proceeds from) Other Investing Activities Net Cash Used for Investing Activities Net Cash Provided by (Used in) Investing Activities Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] (Decrease) increase in subordinated notes, other borrowings and junior subordinated debt, net Proceeds from (Repayments of) Other Debt Proceeds from the issuance of subordinated notes, net Excess tax benefits from stock-based compensation arrangements Excess Tax Benefit from Share-based Compensation, Financing Activities Proceeds from the issuance of common stock, net Proceeds from Issuance of Common Stock Net proceeds from issuance of Series D Preferred Stock Proceeds from Issuance of Preferred Stock and Preference Stock Issuance of common shares resulting from exercise of stock options, employee stock purchase plan and conversion of common stock warrants Issuance Of Common Shares Resulting From Exercise Of Stock Options Employee Stock Purchase Plan And Conversion Of Common Stock Warrants Issuance Of Common Shares Resulting From Exercise Of Stock Options, Employee Stock Purchase Plan And Conversion Of Common Stock Warrants. Dividends paid Payments of Dividends Common stock repurchases Payments for Repurchase of Common Stock Net Cash Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Net (Decrease) Increase in Cash and Cash Equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and Cash Equivalents at Beginning of Period Cash and Cash Equivalents, at Carrying Value Cash and Cash Equivalents at End of Period Property, Plant and Equipment [Abstract] Summary of Premises and Equipment Property, Plant and Equipment [Table Text Block] Disclosures Pertaining to Servicing Assets and Servicing Liabilities [Abstract] Servicing Asset at Fair Value, Amount [Roll Forward] Servicing Asset at Fair Value, Amount [Roll Forward] Balance at beginning of year Servicing Asset at Fair Value, Amount Additions from loans sold with servicing retained Servicing Assets At Fair Value, Additions From Loans Sold With Servicing Retained Servicing Assets At Fair Value, Additions From Loans Sold With Servicing Retained Additions from acquisitions Servicing asset at fair value, Additions from Acquisitions Servicing asset at fair value, Additions from Acquisitions Estimate of changes in fair value due to: Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions [Abstract] Payoffs and paydowns Servicing Asset at Fair Value, Disposals Changes in valuation inputs or assumptions Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions Fair value at end of year Unpaid principal balance of mortgage loans serviced for others Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement Regulatory Capital Requirements [Abstract] Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Lake Forest Bank Lake Forest Bank [Member] Lake Forest Bank Hinsdale Bank Hinsdale Bank [Member] Hinsdale Bank [Member] Wintrust Bank Wintrust Bank [Member] Wintrust Bank [Member] Libertyville Bank Libertyville Bank [Member] Libertyville Bank [Member] Barrington Bank Barrington Bank [Member] Barrington Bank [Member] Crystal Lake Bank Crystal Lake Bank [Member] Crystal Lake Bank [Member] Northbrook Bank Northbrook Bank [Member] Northbrook Bank [Member] Schaumburg Bank Schaumburg Bank [Member] Schaumburg Bank [Member] Village Bank Village Bank [Member] Village Bank [Member] Beverly Bank Beverly Bank [Member] Beverly Bank [Member] Town Bank Town Bank [Member] Town Bank [Member] Wheaton Bank Wheaton Bank [Member] Wheaton Bank [Member] State Bank of the Lakes State Bank Of Lakes [Member] State Bank Of The Lakes [Member] Old Plank Trail Bank Old Plank Trail Bank [Member] Old Plank Trail Bank [Member] St. Charles Bank St Charles Bank [Member] St. Charles Bank [Member] Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Total Capital to Risk Weighted Assets, Amount Capital Total Capital to Risk Weighted Assets, Ratio Capital to Risk Weighted Assets Total Capital to Risk Weighted Assets, To Be Well Capitalized by Regulatory Definition, Amount Capital Required to be Well Capitalized Total Capital to Risk Weighted Assets, To Be Well Capitalized by Regulatory Definition, Ratio Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital to Risk Weighted Assets, Amount Tier One Risk Based Capital Tier 1 Capital to Risk Weighted Assets, Ratio Tier One Risk Based Capital to Risk Weighted Assets Tier 1 Capital to Risk Weighted Assets, To Be Well Capitalized by Regulatory Definition, Amount Tier One Risk Based Capital Required to be Well Capitalized Tier 1 Capital to Risk Weighted Assets, To Be Well Capitalized by Regulatory Definition, Ratio Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Common Equity Tier 1 Capital to Risk Weighted Assets, Amount Common Equity Tier One Risk Based Capital Common Equity Tier One Risk Based Capital Common Equity Tier 1 Capital to Risk Weighted Assets, Ratio Common Equity Tier One Risk Based Capital To Risk Weighted Assets Common Equity Tier One Risk Based Capital To Risk Weighted Assets Common Equity Tier 1 Capital to Risk Weighted Assets, To Be Well Capitalized by Regulatory Definition, Amount Common Equity Tier One Risk Based Capital Required To Be Well Capitalized Common Equity Tier One Risk Based Capital Required To Be Well Capitalized Common Equity Tier 1 Capital to Risk Weighted Assets, To Be Well Capitalized by Regulatory Definition, Ratio Common Equity Tier One Capital Required to be Well Capitalized to Risk Weighted Assets Common Equity Tier One Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Leverage Ratio, Amount Tier One Leverage Capital Tier 1 Leverage Ratio, Ratio Tier One Leverage Capital to Average Assets Tier 1 Leverage Ratio, To Be Well Capitalized by Regulatory Definition, Amount Tier One Leverage Capital Required to be Well Capitalized Tier 1 Leverage Ratio, To Be Well Capitalized by Regulatory Definition, Ratio Tier One Leverage Capital Required to be Well Capitalized to Average Assets Receivables [Abstract] Allowance for Covered Loan Losses [Roll Forward] Allowance for Covered Loan Losses [Roll Forward] Allowance for Covered Loan Losses [Roll Forward] Balance at beginning of period Loans and Leases Receivable, Allowance, Covered Allowance for covered loan losses transferred to allowance for loan losses subsequent to loss share expiration Allowance for Covered Loan Losses Subsequent to Loss Share Allowance for Covered Loan Losses Subsequent to Loss Share Provision for covered loan losses before benefit attributable to FDIC loss share agreements Provision For Covered Loan Losses Before Benefit Attributable To Fdic Loss Share Agreements Provision for covered loan losses before benefit attributable to FDIC loss share agreements Benefit attributable to FDIC loss share agreements Benefit Attributable To Federal Deposit Insurance Corporation Loss Share Agreements Benefit Attributable To Federal Deposit Insurance Corporation Loss Share Agreements Net provision for covered loan losses and transfer from allowance for covered loan losses to allowance for loan losses Net Provision For Covered Loan Losses Net provision for covered loan losses Increase/decrease in FDIC indemnification liability/asset Increase In Fdic Indemnification Asset Increase in FDIC indemnification asset Loans charged-off Covered Loans Charged Off Covered loans charged-off Recoveries of loans charged-off Recoveries Of Covered Loans Charged Off Recoveries of covered loans charged-off Net recoveries Covered Loans Net Charge Offs Covered loans Net charge-offs Balance at end of period Advances from Federal Home Loan Banks [Abstract] Federal Home Loan Bank Advances Federal Home Loan Bank Advances, Disclosure [Text Block] Consolidated Capital Ratios Consolidated Capital Ratios [Table Text Block] Consolidated Capital Ratios [Table Text Block] Actual Capital Amounts And Ratios Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Debt Disclosure [Abstract] Notes payable Notes Payable Short-term borrowings Short-term Debt Other Other Long-term Debt Secured borrowings Secured Debt Total other borrowings Other Borrowings Income Tax Disclosure [Abstract] Current income taxes: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Total current income taxes Current Income Tax Expense (Benefit) Deferred income taxes: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Total deferred income taxes Total income tax expense Income Tax Expense (Benefit) Income Statement [Abstract] Interest income Interest and Dividend Income, Operating [Abstract] Interest and fees on loans Interest and Fee Income, Loans and Leases Interest bearing deposits with banks Interest Income, Deposits with Financial Institutions Federal funds sold and securities purchased under resale agreements Interest Income, Federal Funds Sold and Securities Purchased under Agreements to Resell Investment securities Interest and Dividend Income, Securities, Operating Trading account securities Interest and Dividend Income, Securities, Operating, Trading or Measured at Fair Value Federal Home Loan Bank and Federal Reserve Bank stock Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock Brokerage customer receivables Interest Income On Brokerage Customer Receivables Interest Income on Brokerage customer receivables. Total interest income Interest and Dividend Income, Operating Interest expense Interest Expense [Abstract] Interest on deposits Interest Expense, Deposits Interest on Federal Home Loan Bank advances Interest Expense, Federal Home Loan Bank and Federal Reserve Bank Advances, Long-term Interest on other borrowings Interest Expense, Borrowings Interest on subordinated notes Interest Expense, Subordinated Notes and Debentures Interest on junior subordinated debentures Interest Expense, Junior Subordinated Debentures Total interest expense Interest Expense Net interest income Interest Income (Expense), Net Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Non-interest income Noninterest Income [Abstract] Wealth management Brokerage Trust And Asset Management Revenue Brokerage Trust And Asset Management Revenue Mortgage banking Fees and Commissions, Mortgage Banking Service charges on deposit accounts Fees and Commissions, Depositor Accounts Gains (losses) on investment securities, net Marketable Securities, Realized Gain (Loss) Fees from covered call options Fees From Covered Call Options Fees from covered call options Trading gains (losses), net Trading Gain (Loss) Operating lease income, net Operating Leases, Income Statement, Lease Revenue Other Noninterest Income, Other Operating Income Total non-interest income Noninterest Income Non-interest expense Noninterest Expense [Abstract] Salaries and employee benefits Labor and Related Expense Equipment Equipment Expense Operating lease equipment depreciation Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease Occupancy, net Occupancy, Net Data processing Information Technology and Data Processing Advertising and marketing Marketing and Advertising Expense Professional fees Professional Fees Amortization of other intangible assets Amortization of Intangible Assets FDIC insurance Federal Deposit Insurance Corporation Premium Expense OREO expenses, net Foreclosed Real Estate Expense Other Other Noninterest Expense Total non-interest expense Noninterest Expense Income before taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Net income Preferred stock dividends Preferred Stock Dividends and Other Adjustments Net income applicable to common shares—Basic Net Income (Loss) Available to Common Stockholders, Basic Net income per common share - Basic (usd per share) Earnings Per Share, Basic Net income per common share - Diluted (usd per share) Earnings Per Share, Diluted Cash dividends declared per common share (usd dollars per share) Common Stock, Dividends, Per Share, Declared Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Dilutive potential common shares (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Average common shares and dilutive common shares (in shares) Weighted Average Number of Shares Outstanding, Diluted Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Commercial Commercial Portfolio Segment [Member] Commercial real estate Commercial Real Estate Portfolio Segment [Member] Residential real estate and other Residential Real Estate And Other [Member] Residential Real Estate And Other [Member] Class of Financing Receivable [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable, Type [Domain] Commercial, industrial and other Commercial, Industrial And Other [Member] Commercial, Industrial And Other [Member] Leases Leases [Member] Leases [Member] Commercial construction Construction Loans [Member] Land Land Loans [Member] Land Loans [Member] Office Office Building Loans [Member] Office Loans [Member] Industrial Industrial Loans [Member] Industrial Loans [Member] Retail Retail Loan [Member] Retail Loan [Member] Multi-family Multifamily [Member] Mixed use and other Mixed Use And Other [Member] Mixed Use and Other [Member] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Extension at Below Market Terms Extended Maturity [Member] Reduction of Interest Rate Interest Rate Below Market Reduction [Member] Modification To Interest Only Payments Modification To Interest Only Payments [Member] Modification To Interest- Only Payments [Member] Forgiveness of Debt Principal Forgiveness [Member] Financing Receivables, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Total Count Financing Receivable, Modifications, Number of Contracts Total Balance Financing Receivable, Modifications, Post-Modification Recorded Investment Stockholders' Equity Note [Abstract] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Accumulated unrealized losses on securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Accumulated unrealized losses on derivative instruments Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Gains (losses) on investment securities, net Income before taxes Income tax expense Net income Loans and Leases Receivable Disclosure [Abstract] Loans [Table] Loans [Table] Loans [Table] Home equity Home Equity Loan [Member] Residential real estate Residential Portfolio Segment [Member] Premium finance receivables Premium Finance Receivable [Member] Premium Finance Receivable [Member] Consumer and other Consumer Portfolio Segment [Member] Commercial insurance loans Commercial Insurance Loans [Member] Commercial insurance loans [Member] Life insurance Premium Finance Receivables Life Insurance [Member] Premium Finance Receivables Life Insurance [Member] Loans [Line Items] Loans [Line Items] Loans [Line Items] Loans, net of unearned income, excluding covered loans Loans and Leases Receivable, Net of Deferred Income Covered loans Loans and Leases Receivable, Net Reported Amount, Covered Total loans Loans and Leases Receivable, Net of Deferred Income, Including Covered Loans Loans and Leases Receivable, Net of Deferred Income, Including Covered Loans Total loans, percentage Percentage Of Loans And Leases Receivable Gross Carrying Amount Percentage of Loans and Leases Receivable, Gross, Carrying Amount Covered loans, percentage Percentage Of Covered Loans Percentage of Covered Loans Percentage of Loans Net of Unearned Income Including Covered Loans Percentage of Loans Net of Unearned Income Including Covered Loans Percentage of Loans Net of Unearned Income Including Covered Loans Deposits [Abstract] Time deposits of $250,000 or more Time Deposits, Two Hundred Fifty Thousand Dollars Or More Time Deposits, Two Hundred Fifty Thousand Dollars Or More Fair Value Disclosures [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Nonrecurring Fair Value, Measurements, Nonrecurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [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] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Impaired loans Impaired Financing Receivable, Recorded Investment Other real estate owned Other Real Estate, Foreclosed Assets, and Repossessed Assets Fair value of assets measured on nonrecurring basis Assets, Fair Value Disclosure, Nonrecurring Impaired loans, fair value losses (gains) recognized Impaired Loans Fair Value Losses Recognized Impaired Loans Fair Value Losses Recognized Real estate acquired through oreclosure fair value losses recognized Real Estate Acquired Through Foreclosure Fair Value Losses Recognized Real Estate Acquired Through Foreclosure Fair Value Losses Recognized Fair value losses (gains) recognized Assets Nonrecurring Fair Value Losses Recognized Assets Nonrecurring Fair Value Losses Recognized Federal Home Loan Bank, Advances, Activity for Year [Abstract] Federal Home Loan Bank, Advances [Table] Federal Home Loan Bank, Advances [Table] Federal Home Loan Bank Advances Federal Home Loan Bank Advances [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Weighted Average Weighted Average [Member] Federal Home Loan Bank, Advances [Line Items] Federal Home Loan Bank, Advances [Line Items] Additional borrowings possible Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Federal Home Loan Bank advances having varying put dates Federal Home Loan Bank Advances Having Varying Put Dates Federal Home Loan Bank advances having varying put dates FHLB advances, weighted average interest rate Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End Payment on FHLB Advances Payments for Federal Home Loan Bank Advances Prepayment fees on advances Prepayment Fees on Advances, Net Non-interest bearing Noninterest-bearing Deposit Liabilities NOW and interest bearing demand deposits Deposits, NOW and Interest Bearing Demand Deposits Deposits, NOW and Interest Bearing Demand Deposits Wealth management deposits Wealth Management Deposits Wealth management deposits Money market Deposits, Money Market Deposits Savings Deposits, Savings Deposits Time certificates of deposit Time Deposits Total deposits Deposits Non-interest bearing Non Interest Bearing Percentage Non-interest bearing, percentage NOW and interest bearing demand deposits NOW and Interest Bearing Demand Deposits Percentage NOW and Interest Bearing Demand Deposits Percentage Wealth management deposits Wealth Management Deposits Percentage Wealth management deposits, percentage Money market Percentage of Interest-bearing Domestic Deposits to Deposits, Money Market Savings Percentage of Interest-bearing Domestic Deposits to Deposits, Savings Time certificates of deposit Percentage of Interest-bearing Domestic Deposits to Deposits, Time Deposits Total deposits Deposits Percentage Deposits, Percentage Impaired loans with an allowance for loan loss required, Recorded Investment Impaired Financing Receivable, with Related Allowance, Recorded Investment Impaired loans with no allowance for loan loss required Impaired Financing Receivable, with No Related Allowance, Recorded Investment Total impaired loans Allowance for loan losses related to impaired loans Impaired Financing Receivable, Related Allowance TDRs Financing Receivable, Modifications, Recorded Investment Reduction of interest income from non-accrual loans Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans Interest income recognized on impaired loans Impaired Financing Receivable, Interest Income, Accrual Method Investments, Debt and Equity Securities [Abstract] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Mortgage-backed Asset-backed Securities [Member] Equity securities Equity Securities [Member] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Available-for-sale securities, due in one year or less, Amortized Cost Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis Available-for-sale securities, due in one year or less, Fair Value Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Available-for-sale securities, due in one to five years, Amortized Cost Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis Available-for-sale securities, due in one to five years, Fair Value Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Available-for-sale securities, due in five to ten years, Amortized Cost Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis Available-for-sale securities, due in five to ten years, Fair Value Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Available-for-sale securities, due after ten years, Amortized Cost Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis Available-for-sale securities, due after ten years, Fair Value Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Available-for-sale securities, Amortized Cost Basis Available-for-sale Securities, Amortized Cost Basis Available-for-sale securities, at fair value Available-for-sale Securities Held-to-maturity securities, due in one year or less, Amortized Cost Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount Held-to-maturity securities, due in one year or less, Fair Value Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value Held-to-maturity securities, due in one to five years, Amortized Cost Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount Held-to-maturity securities, due in one to five years, Fair Value Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value Held-to-maturity securities, due in five to ten years, Amortized Cost Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount Held-to-maturity securities, due in five to ten years, Fair Value Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value Held-to-maturity securities, due after ten years, Amortized Cost Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount Held-to-maturity securities, due after ten years, Fair Value Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value Held-to-maturity securities Held-to-maturity Securities Held-to-maturity Securities, Fair Value Held-to-maturity Securities, Fair Value Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] 0.16% advance due January 2016 Zero Point One Six Percentage Advance Due January Two Thousand Sixteen [Member] Zero Point One Six Percentage Advance Due January 2016 [Member] 0.19% advance due January 2016 Zero Point One Nine Percentage Advance Due January Two Thousand Sixteen [Member] Zero Point One Nine Percentage Advance Due January Two Thousand Sixteen [Member] 0.99% advance due February 2016 Zero Point Nine Nine Percentage Advance Due February Two Thousand Sixteen [Member] Zero Point Nine Nine Percentage Advance Due February Two Thousand Sixteen [Member] 1.09% advance due February 2017 One Point Zero Nine Percentage Advance Due February Two Thousand Seventeen [Member] One Point Zero Nine Percentage Advance Due February Two Thousand Seventeen [Member] 1.25% advance due February 2017 One Point Two Five Percentage Advance Due February Two Thousand Seventeen [Member] One Point Two Five Percentage Advance Due February Two Thousand Seventeen [Member] 3.47% advance due November 2017 Three Point Four Seven Percentage Advance Due November Two Thousand Seventeen [Member] Three Point Four Seven Percentage Advance Due November Two Thousand Seventeen [Member] 0.89% advance due December 2017 Zero Point Eight Nine Percentage Advance Due December Two Thousand Seventeen [Member] Zero Point Eight Nine Percentage Advance Due December Two Thousand Seventeen [Member] 1.49% advance due February 2018 One Point Four Nine Percentage Advance Due Feburary Two Thousand Eighteen [Member] One Point Four Nine Percentage Advance Due Feburary Two Thousand Eighteen [Member] 1.31% advance due August 2018 One Point Three One Percentage Advance Due August Two Thousand Eighteen [Member] One Point Three One Percentage Advance Due August Two Thousand Eighteen [Member] 1.89% advance due August 2020 One Point Eight Nine Percentage Advance Due August Two Thousand Twenty [Member] One Point Eight Nine Percentage Advance Due August Two Thousand Twenty [Member] 4.18% advance due February 2022 Four Point One Eight Percentage Advance Due February Two Thousand Twenty Two [Member] Four Point One Eight Percentage Advance Due February Two Thousand Twenty Two [Member] Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Federal Home Loan Bank advances Long-term Federal Home Loan Bank Advances Debt instrument, interest rate, stated percentage Debt instrument, maturity date Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Due Date Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series C - $1,000 liquidation value; 126,257 and 126,287 shares issued and outstanding at December 31, 2016 and 2015, respectively Series C Preferred Stock [Member] Series D - $25 liquidation value; 5,000,000 shares issued and outstanding at December 31 2016 and December 31, 2015 Series D Preferred Stock [Member] Statement [Line Items] Statement [Line Items] Assets Assets [Abstract] Cash and due from banks Cash and Due from Banks Federal funds sold and securities purchased under resale agreements Federal Funds Sold and Securities Purchased under Agreements to Resell Interest bearing deposits with banks Interest-bearing Deposits in Banks and Other Financial Institutions Available-for-sale securities, at fair value Held-to-maturity securities, at amortized cost ($607.6 million and $878.1 million fair value at December 31, 2016 and 2015, respectively) Trading account securities Trading Securities Federal Home Loan Bank and Federal Reserve Bank stock Federal Home Loan Bank Stock and Federal Reserve Bank Stock Brokerage customer receivables Receivables from Brokers-Dealers and Clearing Organizations Mortgage loans held-for-sale Loans Held-for-sale, Fair Value Disclosure Allowance for loan losses Loans and Leases Receivable, Allowance Allowance for covered loan losses Net loans Loans and Leases Receivable, Net Reported Amount, Covered and Not Covered Premises and equipment, net Property, Plant and Equipment, Net Lease investments, net Property Subject to or Available for Operating Lease, Net Accrued interest receivable and other assets Interest Receivable and Other Assets Goodwill Goodwill Other intangible assets Other Intangible Assets, Net Total assets Assets Liabilities and Shareholders' Equity Liabilities and Equity [Abstract] Deposits: Non-interest bearing Interest bearing Interest-bearing Deposit Liabilities Other borrowings Subordinated notes Junior subordinated debentures Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust Trade date securities payable Trade Date Securities Payable Trade Date Securities Payable. Accrued interest payable and other liabilities Accounts Payable and Other Accrued Liabilities Total liabilities Liabilities Shareholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, no par value; 20,000,000 shares authorized: Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred stock, Series C and Series D Preferred Stock, Value, Issued Common stock, no par value; $1.00 stated value; 100,000,000 shares authorized at December 31, 2016 and 2015; 51,978,289 shares issued at December 31, 2016 and 48,468,894 shares issued at December 31, 2015 Common Stock, Value, Issued Surplus Additional Paid in Capital Treasury stock, at cost, 97,749 shares at December 31, 2016 and 85,615 shares at December 31, 2015 Treasury Stock, Value Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and shareholders’ equity Liabilities and Equity Mortgage Servicing Rights Transfers and Servicing of Financial Assets [Text Block] Deferred tax assets: Deferred Tax Assets, Gross [Abstract] Allowance for credit losses Deferred Tax Assets Allowance For Credit Losses Deferred Tax Assets Allowance For Credit Losses Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation Net unrealized losses on securities included in other comprehensive income Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross Covered assets Deferred Tax Assets, Covered Assets Deferred Tax Assets, Covered Assets Stock-based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Federal net operating loss carryforward Deferred Tax Assets, Operating Loss Carryforwards, Domestic Other real estate owned Deferred Tax Assets Other Real Estate Owned Deferred tax assets other real estate owned Loans - purchase accounting adjustments Deferred Tax Asset Discount On Purchased Loans Deferred Tax Asset Discount On Purchased Loans Foreign net operating loss carryforward Deferred Tax Assets, Operating Loss Carryforwards, Foreign Mortgage banking recourse obligation Deferred Tax Assets Mortgage Banking Recourse Obligation Deferred tax assets mortgage banking recourse obligation Nonaccrued interest Deferred Tax Assets Nonaccrued Interest Deferred tax assets nonaccrued interest AMT credt carryforward Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax Net unrealized losses on derivatives included in other comprehensive income Deferred Tax Assets Net Unrealized Losses On Derivatives Included In Other Comprehensive Income Deferred tax assets net unrealized losses on derivatives included in other comprehensive income Other Deferred Tax Assets, Other Total gross deferred tax assets Deferred Tax Assets, Gross Deferred tax liabilities: Deferred Tax Liabilities, Gross [Abstract] Premises and equipment Deferred Tax Liabilities, Property, Plant and Equipment Equipment leasing Deferred Tax Liabilities, Leasing Arrangements Goodwill and intangible assets Deferred Tax Liabilities, Goodwill and Intangible Assets Capitalized servicing rights Deferred Tax Liabilities, Mortgage Servicing Rights Deferred loan fees and costs Deferred Tax Liabilities Deferred Loan Fees And Costs Deferred tax liabilities deferred loan fees and costs Fair value adjustments on loans Deferred Tax Liabilities, Fair Value Adjustment on Loans Deferred Tax Liabilities, Fair Value Adjustment on Loans Net unrealized gains on derivatives included in other comprehensive income Deferred Tax Liabilities, Net Unrealized Losses On Derivatives Included In Other Comprehensive Income Deferred Tax Liabilities, Net Unrealized Losses On Derivatives Included In Other Comprehensive Income FHLB stock dividends Deferred Tax Liabilities FHLB Stock Dividends Deferred tax liabilities fhlb stock dividends Other Deferred Tax Liabilities, Other Total gross deferred liabilities Deferred Tax Liabilities, Gross Net deferred tax assets Deferred Tax Assets, Net Share-based Compensation [Abstract] Stock Options Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at beginning of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Options outstanding in acquired plans (in shares) Share Based Compensation Arrangement By Share Based Payment Conversion Of Options Of Acquired Company Share Based Compensation Arrangement By Share Based Payment Conversion Of Options Of Acquired Company Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited or canceled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding at end of the period (in shares) Exercisable (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Vested or expected to vest (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number Stock Options, Weighted Average Strike Price [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at beginning of the period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Options outstanding in acquired plans (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Conversion Of Options Of Acquired Company Weighted Average Exercise Price Share Based Compensation Arrangement By Share Based Payment Conversion Of Options Of Acquired Company Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited or canceled (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding at end of the period (in dollars per share) Exercisable (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Vested or expected to vest (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Stock Options Additional Disclosures Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Outstanding, Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Outstanding, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Exercisable, Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Exercisable, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Vested or expected to vest, Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term Vested or expected to vest, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Quarterly Financial Information Disclosure [Abstract] Quarterly Financial Summary (Unaudited) Quarterly Financial Information [Text Block] Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust [Abstract] Summary of the Company's Junior Subordinated Debentures Schedule of Subordinated Borrowing [Table Text Block] Leases [Abstract] 2017 - Payments Operating Leases, Future Minimum Payments Due, Next Twelve Months 2018 - Payments Operating Leases, Future Minimum Payments, Due in Two Years 2019 - Payments Operating Leases, Future Minimum Payments, Due in Three Years 2020 - Payments Operating Leases, Future Minimum Payments, Due in Four Years 2021 - Payments Operating Leases, Future Minimum Payments, Due in Five Years 2022 and thereafter - Payments Operating Leases, Future Minimum Payments, Due Thereafter Total minimum future amounts - Payments Operating Leases, Future Minimum Payments Due 2017 - Receipts Operating Leases, Future Minimum Payments Receivable, Current 2018 - Receipts Operating Leases, Future Minimum Payments Receivable, in Two Years 2019 - Receipts Operating Leases, Future Minimum Payments Receivable, in Three Years 2020 - Receipts Operating Leases, Future Minimum Payments Receivable, in Four Years 2021 - Receipts Operating Leases, Future Minimum Payments Receivable, in Five Years 2022 and thereafter - Receipts Operating Leases, Future Minimum Payments Receivable, Thereafter Total minimum future amounts - Receipts Operating Leases, Future Minimum Payments Receivable Summary of Outstanding FHLB Advances Schedule Of Federal Home Loan Bank Advances By Obligation [Table text block] Schedule Of Federal Home Loan Bank Advances By Obligation [Table text block] Cash Investment in and receivable from subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Loans, net of unearned income Less: Allowance for loan losses Net Loans Loans and Leases Receivable, Net Amount Goodwill Other assets Other Assets Total assets Other liabilities Other Liabilities Shareholders' equity Business Combinations [Abstract] FDIC Indemnification Asset [Roll Forward] FDIC Indemnification Asset [Roll Forward] Balance at beginning of period FDIC Indemnification Liability (Asset) FDIC Indemnification Liability (Asset) Additions from acquisitions FDIC Indemnification Asset, Acquisitions Additions from reimbursable expenses FDIC Indemnification Asset, Additional Estimated Losses Amortization FDIC Indemnification Assets, Amortization FDIC Indemnification Assets, Amortization Changes in expected reimbursements from the FDIC for changes in expected credit losses FDIC Indemnification Asset, Period Increase (Decrease) Payments received from the FDIC FDIC Indemnification Asset, Cash Payments Received Balance at end of period - Liability Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate Risk-free rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected option life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Federal Agency Borrowings Federal Agency Borrowings [Member] Borrowings from certain federal agencies. Federal Reserve Bank Advances Federal Reserve Bank Advances [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Bank acquisitions Bank Acquisitions [Member] Bank Acquisitions [Member]. Loans and leases receivable, deferred income Loans and Leases Receivable, Deferred Income Deferred discounts, finance charges and Interest Included in receivables Deferred Discounts, Finance Charges and Interest and Other Adjustments Included in Receivables Deferred Discounts, Finance Charges and Interest and Other Adjustments Included in Receivables Loans pledged as collateral Loans Pledged as Collateral Accretion to interest income Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion Premises and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Receivables Acquired with Deteriorated Credit Quality [Axis] Receivables Acquired with Deteriorated Credit Quality [Axis] Receivables Acquired with Deteriorated Credit Quality [Domain] Receivables Acquired with Deteriorated Credit Quality [Domain] Receivables Acquired with Deteriorated Credit Quality Receivables Acquired with Deteriorated Credit Quality [Member] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Allowance for Loan Losses [Roll Forward] Allowance for Loan and Lease Losses [Roll Forward] Allowance for loan losses at beginning of period Other adjustments Financing Receivable Allowance For Credit Losses Other Adjustments Financing Receivable Allowance For Credit Losses Other Adjustments Reclassification to/from allowance for unfunded lending-related commitments Reclassification To From Allowance For Unfunded Lending Related Commitments Reclassification to/from allowance for unfunded lending-related commitments Charge-offs Financing Receivable, Allowance for Credit Losses, Write-downs Recoveries Financing Receivable, Allowance for Credit Losses, Recovery Provision for credit losses Provision for Loan and Lease Losses Allowance for loan losses at period end Allowance for unfunded lending-related commitments at period end Allowance For Unfunded Lending Related Commitments Allowance for unfunded lending related commitments Allowance for credit losses at period end Financing Receivable, Allowance for Credit Losses Allowance for credit losses, Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Allowance for credit losses, Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Loans, Individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Loans, Collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans Allowance for Credit Losses [Text Block] Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] American Homestead Mortgage, LLC (AHM) American Homestead Mortgage, LLC (AHM) [Member] American Homestead Mortgage, LLC (AHM) [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Business acquisition, date of acquisition agreement Business Acquisition, Effective Date of Acquisition Residential mortgage loans originations Mortgage Loan Originations Mortgage Loan Originations Regulatory Agency [Axis] Regulatory Agency [Axis] Regulatory Agency [Domain] Regulatory Agency [Domain] Federal Reserve Bank Federal Reserve Bank [Member] Federal Reserve Bank [Member] Cash dividends paid to parent Company by consolidated subsidiaries Cash Dividends Paid to Parent Company by Consolidated Subsidiaries Amount available to be paid as dividends without prior regulatory approval Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval Cash reserve requirement Cash Reserve Requirement Cash Reserve Requirement Minimum ratio of qualifying total capital to risk-weighted assets Capital Required for Capital Adequacy to Risk Weighted Assets Common Equity Tier 1 capital required for capital adequacy to risk weighted assets Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 risk based capital required for capital adequacy to risk weighted assets Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 leverage capital required for capital adequacy to average assets Tier One Leverage Capital Required for Capital Adequacy to Average Assets Ratios required for the banks to be well capitalized, Total Capital to Risk-Weighted Assets Ratios required for the banks to be well capitalized, Tier1 Capital to Risk-Weighted Assets Ratio required for the banks to be well capitalized, Common Equity Tier 1 Capital to Risk-Weighted Assets Ratios required for the banks to be well capitalized, Tier 1 Leverage Ratio Goodwill and Intangible Assets Disclosure [Abstract] Estimated - 2017 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Estimated - 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Two Estimated - 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Three Estimated - 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Four Estimated - 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Five Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [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] Award Date [Axis] Award Date [Axis] Award Date [Domain] Award Date [Domain] Granted in Two Thousand Fifteen Granted in Two Thousand Fifteen [Member] Granted in Two Thousand Fifteen [Member] Granted Prior To Two Thousand Fifteen Granted Prior To Two Thousand Fifteen [Member] Granted Prior To Two Thousand Fifteen [Member] Granted in Two Thousand and Thirteen and Two Thousand and Fourteen Granted In Two Thousand And Thirteen And Two Thousand And Fourteen [Member] Granted In Two Thousand And Thirteen And Two Thousand And Fourteen [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Cash Incentive And Retention Plan Cash Incentive And Retention Plan [Member] Cash Incentive and Retention Plan [Member] Directors Deferred Fee And Stock Plan Directors Deferred Fee And Stock Plan [Member] Directors Deferred Fee And Stock Plan [Member] HPK Financial Corporation HPK Financial Corporation [Member] HPK Financial Corporation [Member] Diamond Bancorp, Inc. Diamond Bancorp, Inc [Member] Diamond Bancorp, Inc [Member] Minimum Minimum [Member] Maximum Maximum [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Two Thousand And Fifteen Plan Two Thousand And Fifteen Plan [Member] [Member] Two Thousand And Fifteen Plan [Member] [Member] Two Thousand And Seven Plan And Two Thousand And Fifteen Plan Two Thousand And Seven Plan And Two Thousand And Fifteen Plan [Member] Two Thousand And Seven Plan And Two Thousand And Fifteen Plan [Member] Nineteen Ninety Seven Plan Nineteen Ninety Seven Plan [Member] Nineteen Ninety Seven Plan [Member] Restricted Stock Restricted Stock [Member] Ltip Awards Ltip Awards [Member] LTIP Awards [Member] Performance Shares Performance Shares [Member] Employee Stock Employee Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Shares granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Shares vested in period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Option term Share Based Compensation By Share Based Payment Award Options Term Share based compensation by share based payment award, options term. Percentage award payout Percentage Of Performance Based Award Payouts Percentage of performance based award payouts. Allocated Share-based Compensation Expense Allocated Share-based Compensation Expense Tax benefit Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Modification expense Allocated Sharebased Compensation Expense Modification Of Performance Measurement Allocated Sharebased Compensation Expense Modification Of Performance Measurement Grants in period 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 Fair value granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Tax benefit realized Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options Cash received from exercise Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options Percentage Of Awards Paid In Performance Shares Percentage Of Awards Paid In Performance Shares Percentage Of Awards Paid In Performance Shares Maximum number of shares that could be issued based on the grants made to date (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Excess Tax Benefit Over Estimate Excess Tax Benefit Over Estimate Excess Tax Benefit Over Estimate Unrecognized compensation Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Fair value vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Deferred Compensation Arrangement with Individual, Compensation Expense Deferred Compensation Arrangement with Individual, Compensation Expense Deferred Compensation Arrangement with Individual, Distributions Paid Deferred Compensation Arrangement with Individual, Distributions Paid Deferred Compensation, Cash Awards, Outstanding Deferred Compensation, Cash Awards, Outstanding Deferred Compensation, Cash Awards, Outstanding Defined Contribution Plan, Employer Discretionary Contribution Amount Defined Contribution Plan, Employer Discretionary Contribution Amount Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent Stock Issued During Period, Shares, Employee Stock Purchase Plans Stock Issued During Period, Shares, Employee Stock Purchase Plans Employee Stock Purchase Plan, Compensation Expense Employee Stock Purchase Plan, Compensation Expense Employee Stock Purchase Plan, Compensation Expense Employee Stock Ownership Plan (ESOP), Number of Committed-to-be-Released Shares Employee Stock Ownership Plan (ESOP), Number of Committed-to-be-Released Shares Employee Stock Ownership Plan (ESOP), Shares in ESOP Employee Stock Ownership Plan (ESOP), Shares in ESOP Defined Benefit Plan, Number Of Participants Defined Benefit Plan, Number Of Participants Defined Benefit Plan, Number Of Participants Defined Benefit Plan, Benefit Obligation Defined Benefit Plan, Benefit Obligation Defined Benefit Plan, Fair Value of Plan Assets Defined Benefit Plan, Fair Value of Plan Assets Pension Expense Pension Expense Deferred Compensation Arrangement with Individual, Shares Issued Deferred Compensation Arrangement with Individual, Shares Issued Deferred Compensation, Shares To Be Issued Deferred Compensation, Shares To Be Issued Deferred Compensation, Shares To Be Issued Deferred Compensation Arrangement with Individual, Common Stock Reserved for Future Issuance Deferred Compensation Arrangement with Individual, Common Stock Reserved for Future Issuance Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative [Table] Derivative [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash flow hedging Cash Flow Hedging [Member] Interest Rate Derivatives By Type [Axis] Interest Rate Derivatives By Type [Axis] Interest Rate Derivatives By Type [Axis] Interest Rate Derivatives By Type [Domain] Interest Rate Derivatives By Type [Domain] Interest Rate Derivatives By Type [Domain] Interest Rate Swap, $250 million, July 2019 Interest Rate Swap Two Hundred Fifty Million Notional July Two Thousand Nineteen Maturity [Member] Interest Rate Swap Two Hundred Fifty Million Notional July Two Thousand Nineteen Maturity [Member] Interest Rate Swap, $275 million, August 2019 Interest Rate Swap, Two Hundred Seventy-Five Million Notional Amount, August Two Thousand Nineteen Maturity [Member] Interest Rate Swap, Two Hundred Seventy-Five Million Notional Amount, August Two Thousand Nineteen Maturity [Member] Total Interest Rate Swaps Total Interest Rate Swap [Member] Total Interest Rate Swap [Member] Interest Rate Cap $50 million Notional September 2017 Maturity Interest Rate Cap Fifty Million Notional September Two Thousand Seventeen Maturity [Member] Interest Rate Cap Fifty Million Notional September Two Thousand Seventeen Maturity [Member] Interest Rate Cap $40 million Notional September 2017 Maturity Interest Rate Cap Forty Million Notional September Two Thousand Seventeen Maturity [Member] Interest Rate Cap Forty Million Notional September Two Thousand Seventeen Maturity [Member] Total Interest Rate Cap Total Interest Rate Cap [Member] Total Interest Rate Cap [Member] Interest rate swaps and caps Interest Rate Swaps And Caps [Member] Interest Rate Swaps And Caps [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as hedging instrument Designated as Hedging Instrument [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Derivative [Line Items] Derivative [Line Items] Derivative, notional amount Derivative, Notional Amount Fair Value Asset (Liability) Interest Rate Derivatives, at Fair Value, Net Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Bond Pricing Bond Pricing [Member] Bond Pricing [Member] Discounted Cash Flow Discounted Cash Flow [Member] Discounted Cash Flow [Member] Appraisal Value Appraisal Value [Member] Appraisal Value [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Loans Held For Investment Loans Held For Investment [Member] Loans Held For Investment [Member] Loans Held for Investment Constant Prepayment Rate Loans Held for Investment Constant Prepayment Rate [Member] Loans Held for Investment Constant Prepayment Rate [Member] Mortgage Servicing Rights Discount Rate Input Mortgage Servicing Rights Discount Rate Input [Member] Mortgage Servicing Rights Discount Rate Input Mortgage Servicing Rights Prepayment Rate Input Mortgage Servicing Rights Prepayment Rate Input [Member] Mortgage Servicing Rights Prepayment Rate Input [Member] Mortgage Servicing Rights, Cost of Servicing Mortgage Servicing Rights, Cost of Servicing [Member] Mortgage Servicing Rights, Cost of Servicing [Member] Mortgage Servicing Rights, Cost of Servicing Delinquent Mortgage Servicing Rights, Cost of Servicing Delinquent [Member] Mortgage Servicing Rights, Cost of Servicing Delinquent [Member] Derivative Financial Instruments, Assets Derivative Financial Instruments, Assets [Member] Impaired Financing Receivable By Type [Axis] Impaired Financing Receivable By Type [Axis] Impaired Financing Receivable By Type [Axis] Impaired Financing Receivable By Type [Domain] Impaired Financing Receivable By Type [Domain] Impaired Financing Receivable By Type [Domain] Impaired Loans Impaired Loans [Member] Impaired Loans [Member] Other Real Estate Owned Other Real Estate Owned [Member] Other Real Estate Owned [Member] Major Types of Debt and Equity Securities [Axis] Municipal Municipal Bonds [Member] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] Available-for-sale Securities Loans held-for-investment Loans Held for Investment. Fair Value Disclosure Loans Held for Investment. Fair Value Disclosure Mortgage servicing rights Derivative Assets Derivative Asset, Fair Value, Amount Not Offset Against Collateral Valuation Methodology Fair Value Measurements, Valuation Techniques Significant Unobservable Input Fair Value Measurements, Significant Assumptions Range of Inputs Level 3 Fair Value Measurements Range of Inputs Level 3 Fair Value Measurements Range of Inputs Range of Inputs Fair Value Input Cost of Servicing Current Loan Fair Value Input Cost of Servicing Current Loan Weighted Average of Inputs Fair Value Input, Cost of Servicing, Delinquent Fair Value Input, Cost of Servicing, Delinquent Impact to valuation from an increased or higher input value Fair Value Measurements, Changes in Significant Assumptions Range of Inputs - Discount Rate Fair Value Inputs, Discount Rate Range of Inputs - Prepayment Rate Fair Value Inputs, Prepayment Rate Credit discount Fair Value Inputs, Entity Credit Risk Pull Through Rate, Derivatives Pull Through Rate, Derivatives Pull Through Rate, Derivatives Fair value inputs, discount for lack of marketability Fair Value Inputs, Discount for Lack of Marketability Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment by Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Buildings and leasehold improvements Buildings And Leasehold Improvemenets [Member] Buildings And Leasehold Improvemenets. Furniture, equipment, and computer software Furniture Equipment And Computer Software [Member] Furniture Equipment And Computer Software Construction in progress Construction in Progress [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Premises and equipment, gross Property, Plant and Equipment, Gross Less: Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total premises and equipment, net Deposits Deposit Liabilities Disclosures [Text Block] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Fair value hedging Fair Value Hedging [Member] Interest Rate Contract Interest Rate Contract [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Amount of Gain or (Loss) Recognized in Income on Derivative Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments Amount of Gain or (Loss) Recognized in Income on Hedged Item Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge Income Statement Gain/ (Loss) due to Hedge Ineffectiveness Gain (Loss) on Fair Value Hedge Ineffectiveness, Net Schedule of Goodwill [Table] Schedule of Goodwill [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 deposit intangibles Core Deposits [Member] Customer list intangibles Customer Lists [Member] Business Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Community banking Community Banking [Member] Community Banking [Member] Specialty finance Specialty Finance [Member] Specialty Finance [Member] Wealth management Wealth Management [Member] Wealth Management [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill increase Goodwill, Period Increase (Decrease) Finite-lived intangibles, useful life Finite-Lived Intangible Asset, Useful Life Minimum Lease Commitments Operating Leases Disclosure [Text Block] Disclosure of operating leases as a lessee and lessor. Statement of Stockholders' Equity [Abstract] Series C preferred stock Series D preferred stock Preferred stock Preferred Stock [Member] Common stock Common Stock [Member] Surplus Additional Paid-in Capital [Member] Treasury stock Treasury Stock [Member] Retained earnings Retained Earnings [Member] Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance at beginning of period Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Cash dividends declared on common stock Dividends, Common Stock, Cash Dividends on preferred stock Dividends, Preferred Stock, Cash Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Issuance of stock Stock Issued During Period, Value, New Issues Conversion of Series C Preferred Stock to common stock Stock Issued During Period, Value, Conversion of Convertible Securities Common stock issued for: Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Acquisitions Stock Issued During Period, Value, Acquisitions Exercise of stock options and warrants Stock Issued During Period Value Stock Options And Warrants Exercised Stock Issued During Period Value Stock Options And Warrants Exercised. Restricted stock awards Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Employee stock purchase plan Stock Issued During Period, Value, Employee Stock Purchase Plan Director compensation plan Stock Issued During Period, Value, Issued for Services Balance at end of period Stock Compensation Plans and Other Employee Benefit Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Subsequent Events Subsequent Events [Text Block] Effective income tax rate reconciliation, at Federal satutory income tax rate, percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Income tax expense based upon the Federal statutory rate on income before income taxes Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Increase (decrease) in tax resulting from: Effective Income Tax Rate Reconciliation, Amount [Abstract] Tax-exempt interest, net of interest expense disallowance Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount State taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Income earned on bank owned life insurance Increase (Decrease) In Tax Resulting From Income Earned On Bank Owned Life Insurance Increase (decrease) in tax resulting from income earned on bank owned life insurance Meals, entertainment and related expenses Effective Income Tax Rate Reconciliation, Nondeductible Expense, Meals and Entertainment, Amount Foreign subsidiary, net Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Tax benefits related to tax credit investments Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Loans Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Assets Other Assets [Member] Other Liabilities Other Liabilities [Member] Not designed as hedging instrument Not Designated as Hedging Instrument [Member] Interest Rate Derivatives Interest Rate Lock Commitments Interest Rate Lock Commitments [Member] Forward commitments to sell mortgage loans Forward Commitments To Sell Mortgage Loans [Member] Forward Commitments to Sell Mortgage Loans [Member] Foreign Exchange Contract Foreign Exchange Contract [Member] Derivative liabilities Derivative Liability, Fair Value, Amount Not Offset Against Collateral Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Segments [Axis] Community Banking Wealth Management First Community Financial Corporation First Community Financial Corporation [Member] First Community Financial Corporation [Member] GE Capital Franchise Finance GE Capital Franchise Finance [Member] GE Capital Franchise Finance [Member] Generations Bancorp Inc Generations Bancorp Inc [Member] Generations Bancorp Inc Community Financial Shares Inc. Community Financial Shares Inc. [Member] Community Financial Shares Inc. [Member] Suburban Illinois Bancorp Suburban Illinois Bancorp [Member] Suburban Illinois Bancorp [Member] North Bank North Bank [Member] North Bank [Member] Delavan Bancshares Delavan Bancshares [Member] Delavan Bancshares [Member] Talmer Bank & Trust Talmer Bank & Trust [Member] Talmer Bank & Trust [Member] THE National Bank THE National Bank [Member] THE National Bank [Member] Urban Partnership Bank, Stone Park Branch Urban Partnership Bank, Stone Park Branch [Member] Urban Partnership Bank, Stone Park branch [Member] FDIC Assisted FDIC Assisted [Member] FDIC Assisted [Member] Policy Billing Services Inc. And Equity Premium Finance Inc. Policy Billing Services Inc. And Equity Premium Finance Inc. [Member] Policy Billing Services Inc. And Equity Premium Finance Inc. [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Date of acquisition