Cash and Cash Equivalents [Abstract] Required minimum average reserve balance based on the amount of deposits held with the Federal Reserve Bank Required Minimum Average Cash Reserve Maintained with Federal Reserve Bank The required minimum average cash reserve maintained with the Federal Reserve Bank based on the amount of deposits held with the Federal Reserve Bank. Condensed Financial Information of Parent Company Only Disclosure [Abstract] Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Parent Parent Company [Member] Condensed financial statements of the Parent Condensed Financial Statements, Captions [Line Items] Income Revenues [Abstract] Cash Dividends Paid to Parent Company by Consolidated Subsidiaries and Interest Income Cash Dividends Paid to Parent Company by Consolidated Subsidiaries and Interest Income Represents cash dividends paid to parent company by consolidated subsidiaries and interest income. Investment Securities Gains (Losses), Net Gain (Loss) on Sale of Securities, Net Other Income Other Income Total Income Revenues Noninterest Expense Noninterest Expense [Abstract] Intercompany Salaries and Services Intercompany Salaries and Services Expenses Represents the amount of expenses incurred on intercompany salaries and services. Other Expenses Other Expenses Total Noninterest Expense Noninterest Expense Income Before Income Tax Benefit and Equity in Undistributed Income of Subsidiaries Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income Tax Benefit (Expense) Income Tax Expense (Benefit) Equity in Undistributed Income of Subsidiaries Equity in Undistributed Income of Subsidiaries Represents equity in undistributed income of subsidiaries. Net Income Net Income (Loss) Available to Common Stockholders, Basic Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Offsetting [Abstract] Offsetting Assets and Liabilities [Table] Offsetting Assets and Liabilities [Table] Offsetting Assets and Liabilities [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Institutional Counterparties Institutional Counterparties [Member] Institutional Counterparties [Member] Private Institutions Private Institutions [Member] Private Institutions [Member] Government Entities Government Entities [Member] Government Entities [Member] Derivative, by Nature [Axis] Derivative Instrument [Axis] Derivative, Name [Domain] Derivative Contract [Domain] Interest Rate Swap Agreements Interest Rate Swap [Member] Offsetting Assets and Liabilities [Line items] Offsetting Assets and Liabilities [Line Items] [Line Items] for Offsetting Assets and Liabilities [Table] Derivative Liability, Fair Value of Collateral Derivative Liability, Fair Value of Collateral Net liability positions, aggregate fair value Derivative, Net Liability Position, Aggregate Fair Value Securities Sold under Agreements to Repurchase, Fair Value of Collateral Securities Sold under Agreements to Repurchase, Fair Value of Collateral Assets: Offsetting Assets [Abstract] Offsetting Assets [Abstract] Derivative Assets, Gross Amounts Recognized in the Statements of Condition Derivative Asset, Fair Value, Gross Asset Derivative Assets, Gross Amounts Offset in the Statements of Condition Derivative Asset, Fair Value, Gross Liability Derivative Assets, Net Amount Presented in the Statements of Condition Derivative Asset, Fair Value, Amount Not Offset Against Collateral Derivative Assets, Not Offset in the Statements of Condition - Netting Adjustments Derivative Asset, Not Offset, Policy Election Deduction Gross Amounts Not Offset in the Statements of Condition - FV of collateral pledged Derivative, Collateral, Obligation to Return Securities Derivative Assets, Net Amount Derivative Asset, Fair Value, Amount Offset Against Collateral Liabilities: Offsetting Liabilities [Abstract] Offsetting Liabilities [Abstract] Derivative Liability, Gross Amounts Recognized in the Statements of Condition Derivative Liability, Fair Value, Gross Liability Derivative Liability, Gross Amounts Offset in the Statements of Condition Derivative Liability, Fair Value, Gross Asset Derivative Liability, Net Amounts Presented in the Statements of Condition Derivative Liability, Fair Value, Amount Not Offset Against Collateral Derivative Liability, Not Offset in the Statements of Condition - Netting Adjustments Derivative Liability, Not Offset, Policy Election Deduction Derivative Liability, Not Offset in the Statements of Condition - FV of collateral pledged Derivative, Collateral, Right to Reclaim Securities Derivative Liabilities, Net Amount Derivative Liability, Fair Value, Amount Offset Against Collateral Repurchase Agreements, Gross Amounts of Recognized Liabilities Securities Sold under Agreements to Repurchase, Gross Repurchase Agreements, Gross Amounts Offset in the Statements of Condition Securities Sold under Agreements to Repurchase, Asset Repurchase Agreements, Net Amounts of Liabilities Presented in the Statements of Condition Securities Sold under Agreements to Repurchase Repurchase Agreements, Fair Value of Collateral Pledged Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities Securities Sold under Agreements to Repurchase, Net Amount Offset Against Collateral Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments Equity Method Investments [Table Text Block] Accounting Policies [Abstract] Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract] Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] 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] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Low-income housing partnerships Low-income housing partnerships [Member] Low-income housing partnerships [Member] Solar energy partnerships Solar energy partnerships [Member] Solar energy partnerships [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Period over which tax credits or benefits are generally recognized (in years) Variable Interest Entities Tax Credit or Benefit Recognition Period Represents the period over which tax credits or benefits arising from variable interest entities are recognized. Unfunded commitments to fund low-income housing partnerships Qualified Affordable Housing Project Investments, Commitment Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Loans and Leases Nonperforming Loans and Leases Nonperforming [Abstract] -- None. No documentation exists for this element. -- Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable Type [Domain] Receivable [Domain] Commercial Commercial Portfolio Segment [Member] Residential mortgage and home equity loan Residential Mortgage and Home Equity [Member] Residential mortgage represents a loan to an individual to purchase or refinance residential real estate such as a home, in which the real estate itself serves as collateral for the loan. Home equity represents the revolving, open-end loan extended under a line of credit and secured by the borrower's residential property. Home Equity Home Equity Line of Credit [Member] Automobile and Other consumer Automobile Loan and Consumer Other Financing Receivable [Member] Automobile loan represents a loan to an individual to finance the purchase of a car. Other loans include class of financing receivables related to other consumer financing receivables. Credit Cards Credit Card Receivable [Member] Commercial and Industrial Commercial and Industrial Loans [Member] Class of financing receivables related to commercial and industrial loans. Range [Axis] Range [Axis] Range [Domain] Range [Domain] Maximum Maximum [Member] Loan and lease portfolio Accounts, Notes, Loans and Financing Receivable [Line Items] Loans and Leases Loans and Leases [Abstract] -- None. No documentation exists for this element. -- Number of portfolio segments of loans and leases (commercial and consumer) Number of Portfolio Segments of Loans and Leases Represents the number of portfolio segments of loans and leases (commercial and consumer) in determining the allowance. Number of classes of loans and leases determined by management Number of Classes of Loans and Leases Represents the number of classes of loans and leases determined by the management namely, commercial and industrial, commercial mortgage, construction, lease financing, residential mortgage, home equity, automobile and other. Non-Performing Loans and Leases Loans and Leases Modified as Trouble Debt Restructuring [Abstract] Loans and Leases Modified as Trouble Debt Restructuring Minimum maturity period to be considered to place loans and leases on non-accrual status (in days) Minimum Past Due for Loans and Leases to be Placed on Nonaccrual Status Represents the minimum period for which the loans and leases are past due for placing them on non-accrual status. Minimum maturity period to be considered for loans and leases to be charged off (in days) Minimum Past Due for Loans to be Charged-Off. Represents the minimum period for which the loans are past due to be charged-off. Combined loan-to-value ratio, considered in determining whether the entire outstanding balance on the loan is to be charged-off or not (as a percent) Loans and Leases Receivable, Ratio of Nonperforming Loans to Collateral Value This item represents the loan to collateral ratio, represented as a percentage that was considered as one of the potential factors in reaching a conclusion that the entire outstanding balance is to be charged-off or not. Loans modified in a troubled debt restructuring Troubled Debt Restructuring Note, Debtor [Abstract] Period during which non-accrual loan that has been modified in a troubled debt restructuring remains on non-accrual status (in months) Period During Which Non Accrual Loan Modified in Trouble Debt Restructuring Remains on Non Accrual Status Represents the period during which non accrual loan that has been modified in a troubled debt restructuring remains on non accrual status, to demonstrate that the borrower is able to meet the terms of the modified loan. Number of components of company's reserve for credit losses Number of Components of Reserve for Credit Losses Represents the number of components of company's reserve for credit losses that is, the allowance and reserve for unfunded commitments. Cash and Cash Equivalents Maximum original maturity period of cash and cash equivalents (in days) Maximum Original Maturity Period of Cash and Cash Equivalents Represents the maximum original maturity period of cash and cash equivalents. Loans and Leases and Allowance for Loan and Lease Losses [Abstract] Loans and Leases and Allowance for Loan and Lease Losses Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Consumer Consumer Portfolio Segment [Member] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Commercial and Industrial Commercial and Industrial [Member] Class of financing receivables related to commercial and industrial financing receivables. Commercial Mortgage Commercial Real Estate [Member] Construction Construction Loans [Member] Lease Financing Finance Leases Portfolio Segment [Member] Residential Mortgage Residential Mortgage [Member] Automobile Automobile Loan [Member] Other Consumer Loan [Member] Loans and Leases Loans and Leases Receivable, Net of Deferred Income Unearned income on loans and leases Loans and Leases Receivable, Deferred Income Commercial loans and residential mortgage loans pledged to secure an undrawn FRB line of credit Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Other Arrangements Residential mortgage loans pledged under a blanket pledge arrangement to secure FHLB advance Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt Net gains related to sales of residential mortgage loans Gain (Loss) on Sale of Mortgage Loans Schedule of condensed statements of income Condensed Income Statement [Table Text Block] Schedule of condensed statements of condition Condensed Balance Sheet [Table Text Block] Schedule of condensed statements of cash flows Condensed Cash Flow Statement [Table Text Block] Consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure Mortgage Loans in Process of Foreclosure, Amount Borrowings Disclosure Abstract Borrowings Disclosure Abstract Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Long-term Repurchase Agreements with Government Entities Long-term Repurchase Agreements with Government Entities [Member] Long-term Repurchase Agreements with Government Entities [Member] Long-term Repurchase Agreements with Private Institutions Long-term Repurchase Agreements with Private Institutions [Member] Represents the long-term securities sold under agreements to repurchase with private institutions. Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Funds Purchased Federal Funds Purchased [Member] Securities Sold Under Agreements to Repurchase Securities Sold under Agreements to Repurchase [Member] Short-term Borrowings Short-term Debt [Line Items] Securities Sold Under Agreements to Repurchase Amounts Outstanding Short-term Debt Weighted Average Interest Rate (as a percent) Short-term Debt, Weighted Average Interest Rate Income Statement [Abstract] Interest Income Interest and Dividend Income, Operating [Abstract] Interest and Fees on Loans and Leases Interest and Fee Income for Loans and Leases The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans, (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases, (3) amortization of deferred leasing fees and deferred lease origination costs, and (4) amortization of deferred loan origination fees and costs. Income on Investment Securities Interest and Dividend Income, Securities, by Classification [Abstract] Available-for-Sale Interest and Dividend Income, Securities, Operating, Available-for-sale Held-to-Maturity Interest Income, Securities, Operating, Held-to-maturity Deposits Interest Income, Deposits with Financial Institutions Funds Sold Interest Income, Federal Funds Sold Other Other Interest and Dividend Income Total Interest Income Interest and Dividend Income, Operating Interest Expense Interest Expense [Abstract] Deposits Interest Expense, Deposits Securities Sold Under Agreements to Repurchase Interest Expense, Securities Sold under Agreements to Repurchase Funds Purchased Interest Expense, Federal Funds Purchased Short-term Borrowings Interest Expense, Other Short-term Borrowings Other Debt Interest Expense, Long-term Debt Total Interest Expense Interest Expense Net Interest Income Interest Income (Expense), Net Provision for Credit Losses Provision for Loan and Lease Losses Net Interest Income After Provision for Credit Losses Interest Income (Expense), after Provision for Loan Loss Noninterest Income Noninterest Income [Abstract] Trust and Asset Management Fees and Commissions, Fiduciary and Trust Activities Mortgage Banking Mortgage Banking Income The noninterest income derived from mortgage banking activities. Includes fees earned from servicing held in portfolio loans as well as loans sold in the secondary market, gains and losses on the sale of mortgage loans to investors, activities related to mortgage servicing rights, and gains and losses resulting from mortgage-related derivative financial instruments. Service Charges on Deposit Accounts Service Charges on Deposit Accounts Includes amounts charged depositors for: (1) maintenance of their accounts (maintenance charges); (2) failure to maintain specified minimum balances on account; (3) exceeding the number of checks or transactions allowed to be processed in a given period; (4) checks drawn on no minimum balance deposit accounts; (5) withdrawals from nontransaction deposit accounts; (6) closing savings accounts before a specified minimum period of time has elapsed; (7) accounts which have remained inactive for extended periods of time or which have become dormant; (8) checks drawn against insufficient funds that the bank assesses regardless of whether it decides to pay, return or hold the check; (9) issuing stop payment orders; (10) certifying checks; (11) accumulating or disbursing funds deposited in IRAs or Keogh Plan accounts when not handled by the bank's trust department; and (12) penalties assessed on the early withdrawal of time deposits. Excludes amounts charged depositors for use of automated teller machines or remote service units. Fees, Exchange, and Other Service Charges Fees, Exchange, and Other Service Charges The noninterest income derived from the following: (1) fees and services from debit card services; (2) fees charged depositors for use of automated teller machines; (3) merchant service activity; (4) annual fees from loans; (5) other fees and service charges. Annuity and Insurance Insurance Commissions and Fees Bank-Owned Life Insurance Bank Owned Life Insurance Income Other Noninterest Income, Other Operating Income Total Noninterest Income Noninterest Income Salaries and Benefits Labor and Related Expense Net Occupancy Occupancy, Net Net Equipment Equipment Expense Data Processing Communications and Information Technology Professional Fees Professional Fees FDIC Insurance Federal Deposit Insurance Corporation Premium Expense Other Other Noninterest Expense Income Before Provision for Income Taxes Provision for Income Taxes Net Income Net Income (Loss) Attributable to Parent Basic Earnings Per Share (in dollars per share) Earnings Per Share, Basic Diluted Earnings Per Share (in dollars per share) Earnings Per Share, Diluted Dividends Declared Per Share (in dollars per share) Common Stock, Dividends, Per Share, Declared Basic Weighted Average Shares (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted Weighted Average Shares (in shares) Weighted Average Number of Shares Outstanding, Diluted Net affordable housing tax credit investments and related unfunded commitments Amortization Method Qualified Affordable Housing Project Investments Affordable Housing Tax Credit Investments, Unfunded Commitments [Abstract] Affordable Housing Tax Credit Investments and Related Unfunded Commitments [Abstract] Affordable Housing Tax Credit Investments and Related Unfunded Commitments [Abstract] 2018 Qualified Affordable Housing Project Investments, Commitment Payments, Remainder of Fiscal Year Qualified Affordable Housing Project Investments, Commitment Payments, Remainder of Fiscal Year 2019 Qualified Affordable Housing Project Investments, Commitment Payments, Year Two Qualified Affordable Housing Project Investments, Commitment Payments, Year Two 2020 Qualified Affordable Housing Project Investments, Commitment Payments, Year Three Qualified Affordable Housing Project Investments, Commitment Payments, Year Three 2021 Qualified Affordable Housing Project Investments, Commitment Payments, Year Four Qualified Affordable Housing Project Investments, Commitment Payments, Year Four 2022 Qualified Affordable Housing Project Investments, Commitment Payments, Year Five Qualified Affordable Housing Project Investments, Commitment Payments, Year Five Thereafter Qualified Affordable Housing Project Investments, Commitment Payments, After Year Five Qualified Affordable Housing Project Investments, Commitment Payments, After Year Five Total Unfunded Commitments Investments in Affordable Housing Projects [Abstract] Investments in Affordable Housing Projects [Abstract] Effective Yield Method [Abstract] Effective Yield Method [Abstract] Effective Yield Method [Abstract] Tax Credits and Other Tax Benefits Recognized Affordable Housing Tax Credits and Other Tax Benefits, Amount Amortization Expense in Provision for Income Taxes Amortization Method Qualified Affordable Housing Project Investments, Amortization Proportional Amortization Method [Abstract] Proportional Amortization Method [Abstract] Proportional Amortization Method [Abstract] Tax credits and other tax benefits recognized Affordable Housing Tax Credits, Proportional Amortization Method Affordable Housing Tax Credits, Proportional Amortization Method Amortization Expense in Provision for Income Taxes Proportional Amortization Method, Qualified Affordable Housing Project Investments, Amortization Proportional Amortization Method, Qualified Affordable Housing Project Investments, Amortization Fair Value Disclosures [Abstract] Fair Value of Assets and Liabilities Fair Value Disclosures [Text Block] Premises and Equipment Property, Plant and Equipment [Abstract] 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] Building Building [Member] Equipment Equipment [Member] Premises and Equipment Property, Plant and Equipment [Line Items] Estimated useful lives (in years) Property, Plant and Equipment, Useful Life Pension and Postretirement Benefit Plans Pension and Postretirement Benefit Plans [Abstract] -- None. No documentation exists for this element. -- Number of company's pension plans Number of Pension Plans Represents the number of Company's pension plans. Minimum percentage of net acturial gain (loss) will be amortized in net periodic benefit cost Minimum Percentage of Net Acturial Gain (Loss) to be Amortized in Net Periodic Benefit Cost Represents the minimum percentage of net actuarial gain (loss) to be amortized in net periodic benefit costs. Income Taxes Income Taxes [Abstract] -- None. No documentation exists for this element. -- Minimum percentage of likelihood of tax position being realized upon ultimate settlement according to management's judgment Minimum Percentage of Likelihood of Tax Position Being Realized Upon Ultimate Settlement Represents the minimum percentage of likelihood of tax position being realized upon ultimate settlement, if the tax position meets the more likely than not recognition threshold. Advertising Costs Marketing and Advertising Expense [Abstract] Advertising costs Advertising Expense Earnings Per Share [Abstract] Reconciliation of the weighted average number of common shares outstanding for computing diluted earnings per share and antidilutive stock options and restricted stock outstanding Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Debt Disclosure [Abstract] Schedule of Other Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Annual Maturities of Long-Term Debt, Exclusive of Capital Lease Obligations Schedule of Maturities of Long Term Debt Excluding Capital Lease Obligations [Table Text Block] Tabular disclosure of the combined aggregate amount of maturities and sinking fund requirements for long-term borrowings, excluding capital lease obligations, for each of the five years and after five years following the date of the latest balance sheet date presented. Stockholders' Equity Note [Abstract] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Bank Subsidiaries [Member] Minimum required capital amounts and ratios for well capitalized institutions and the actual capital amounts [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Shareholders' Equity Stockholders' Equity Attributable to Parent Common Equity Tier One Capital Common Equity Tier One Capital A measurement of a bank's core equity capital compared with its total risk-weighted assets. Tier 1 Capital Tier One Risk Based Capital Total Capital Capital Well Capitalized Minimum Common Equity Tier One Ratio (as a percent) Common Equity Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets The Common Equity Tier One ratio required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Common Equity Tier One Ratio Common Equity Tier One Risk Based Capital To Risk Weighted Assets Common Equity Tier 1 capital divided by risk weighted assets as defined by regulations. Well Capitalized Minimum Tier 1 Capital Ratio (as a percent) Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital Ratio (as a percent) Tier One Risk Based Capital to Risk Weighted Assets Well Capitalized Minimum Total Capital Ratio (as a percent) Capital Required to be Well Capitalized to Risk Weighted Assets Total Capital Ratio (as a percent) Capital to Risk Weighted Assets Well Capitalized Minimum Tier 1 Leverage Ratio (as a percent) Tier One Leverage Capital Required to be Well Capitalized to Average Assets Tier 1 Leverage Ratio (as a percent) Tier One Leverage Capital to Average Assets Dividends Dividends, Common Stock [Abstract] Number of prior calendar years considered for payment of dividends in excess of the sum of net income Number of Prior Calender Years Considered for Payment of Dividends in Excess of Net Income Requiring Advanced Approval from Banks Regulator Represents the number of prior calendar years considered for payment of dividends in excess of net income, for which advanced approval from the Bank's regulator is required. Common Stock Repurchase Program Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract] Number of shares of common stock repurchased Treasury Stock, Shares, Acquired Amount returned to shareholders on stock repurchase Treasury Stock, Value, Acquired, Cost Method Average cost of shares repurchased (in dollars per share) Treasury Stock Acquired, Average Cost Per Share Treasury Stock Value Acquired Cost Method Share Repurchase Program Treasury Stock Value Acquired Cost Method Share Repurchase Program Equity impact of the cost of common stock that were repurchased during the period. Recorded using the cost method related to the common stock repurchase program. Schedule of Assets Sold under Agreements to Repurchase [Table] Schedule of Assets Sold under Agreements to Repurchase [Table] Securities sold under repurchase agreements Assets Sold under Agreements to Repurchase [Line Items] Repurchase agreements, Weighted average interest rate (as a percent) Long-term Debt, Weighted Average Interest Rate Repurchase agreements, Weighted average maturity period (in days or years) Weighted Average Maturity for Securities Sold under Agreements to Repurchase Represents the weighted average maturity for securities sold under agreements to repurchase. Repurchase agreements, Decreased weighted average maturity period if agreements terminated at earlier specified dates (in years) Weighted Average Maturity for Securities Sold under Agreements to Repurchase Decreased, if Agreements Terminated at Earlier Specified Dates Represents the decreased weighted average maturity for securities sold under agreements to repurchase if agreements are terminated at earlier specified dates. Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income 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] Share-Based Compensation Share-based Compensation Net Losses (Gains) on Investment Securities Gain (Loss) on Investments Equity in Undistributed Income of Subsidiaries Net Change in Other Assets and Other Liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Capital Distribution from BOHC Inv Fund Payments for (Proceeds from) Businesses and Interest in Affiliates Capital Contributions to the Bank Payments of Distributions to Affiliates Proceeds from Sales of Investment Securities Proceeds from Sale of Available-for-sale Securities Purchase of Investment Securities Held-to-Maturity Securities Payments to Acquire Held-to-maturity Securities Net Cash Provided by (Used in) Investing Activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from Issuance of Common Stock Proceeds from Issuance of Common Stock Repurchase of Common Stock Payments for Repurchase of Common Stock Cash Dividends Paid Payments of Ordinary Dividends, Common Stock Net Cash Provided by (Used in) Financing Activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net Change 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 Schedule of minimum required capital amounts and ratios for well capitalized institutions and the actual capital amounts and ratios for the Company and the Bank Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Components of other comprehensive income Comprehensive Income (Loss) [Table Text Block] Schedule of accumulated other comprehensive income (loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Reclassification out of accumulated other comprehensive income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Segment Reporting [Abstract] Business Segments Segment Reporting Disclosure [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of the notional amount and fair value of the derivative financial instruments Schedule of Derivative Instruments [Table Text Block] Derivative financial instruments, their fair values, and balance sheet location Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Derivative financial instruments and the amount and location of the net gains or losses recognized in the statements of income Derivative Instruments, Gain (Loss) [Table Text Block] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Financing Receivable, by Credit Quality Indicator [Domain] Internal Credit Assessment [Domain] Pass Pass [Member] Special Mention Special Mention [Member] Classified Substandard [Member] Recorded investment in loans and leases by class and by credit quality indicator Financing Receivable, Recorded Investment [Line Items] Number of days past due for loans and leases in classified credit quality indicator Financing Receivable, Number of Days Past Due for Loans and Leases, to be Classified as Classified Credit quality Indicator Represents the number of days past due for loans and leases to be classified as classified credit quality indicator. Maximum current loan-to-value ratio for residential mortgage and home equity loans to be considered as pass (as a percent) Financing Receivable, Credit Quality Current Loan to Value Ratio Percentage, Maximum Represents the maximum current loan-to-value ratio for residential mortgage and home equity loans to be considered as pass. Number of months up to which residential and home equity loans may be considered classified, even if they are current as to principal and interest (in months) Financing Receivable, Modified Residential Mortgage and/or Home Equity Loans, Maximum Number of Months Categorized as Classified Credit Quality Indicator If Principal and Interest are Current Number of months up to which residential mortgage and home equity loans may be considered classified, even if they are current as to principal and interest. Following a period of demonstrated performance in accordance with contractual terms, the loan may be removed. Total Recorded Investment in Loans and Leases Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Schedule of other assets Schedule of Other Assets [Table Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Derivative [Table] Derivative [Table] Visa Conversion Rate Swap Agreement Visa Conversion Rate Swap Agreement [Member] Visa Class B to Class A Conversion Rate Swap Agreement [Member] Derivative [Line Items] Derivative [Line Items] Liability Derivatives Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Statement, Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Retail Banking Retail Banking [Member] This element represents selected financial information of the retail banking business segment. Commercial Banking Commercial Banking [Member] This element represents selected financial information of the commercial banking business segment. Investment Services Investment Services [Member] This element represents selected financial information of the investment services business segment. Treasury and Other Treasury and Other [Member] This element represents selected financial information of the treasury business segment. Business segment financial information Segment Reporting Information [Line Items] Federal and State Effective Tax Rate used for Segment Reporting Federal and State Effective Tax Rate Used for Segment Reporting The combined Federal and State Effective Tax Rate Used for Segment Reporting purposes. Number of branch locations through which products and services are delivered to customers Number of Branch Locations through which Products and Services Delivered to Customers The number of branch locations through which products and services are delivered to customers. Number of A T M s through which products and services delivered to customers Number of A T M s through which Products and Services Delivered to Customers The number of ATMs through which products and services are delivered to customers. Net Interest Income Net Interest Income After Provision for Credit Losses Noninterest Income Noninterest Expense Income Before Provision for Income Taxes Provision for Income Taxes Net Income Total Assets Assets Commitments and Contingencies Disclosure [Abstract] Rental expense Operating Leases, Rent Expense, Net [Abstract] Minimum Rentals Operating Leases, Rent Expense, Minimum Rentals Sublease Rental Income Operating Leases, Rent Expense, Sublease Rentals Total Operating Leases, Rent Expense, Net Future minimum payments for capital leases Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 Capital Leases, Future Minimum Payments Due, Next Twelve Months 2019 Capital Leases, Future Minimum Payments Due in Two Years 2020 Capital Leases, Future Minimum Payments Due in Three Years 2021 Capital Leases, Future Minimum Payments Due in Four Years 2022 Capital Leases, Future Minimum Payments Due in Five Years Thereafter Capital Leases, Future Minimum Payments Due Thereafter Total Future Minimum Lease Payments Capital Leases, Future Minimum Payments Due Amounts Representing Interest Capital Leases, Future Minimum Payments, Interest Included in Payments Present Value of Net Future Minimum Lease Payments Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Future minimum payments for operating leases Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2019 Operating Leases, Future Minimum Payments, Due in Two Years 2020 Operating Leases, Future Minimum Payments, Due in Three Years 2021 Operating Leases, Future Minimum Payments, Due in Four Years 2022 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Future Minimum Lease Payments Operating Leases, Future Minimum Payments Due Minimum future rental income receivable under subleases from non-cancelable operating leases Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals Compensation and Retirement Disclosure [Abstract] Employee Benefits Pension and Other Postretirement Benefits Disclosure [Text Block] Other Commitments [Table] Other Commitments [Table] Other Commitments [Axis] Other Commitments [Axis] Other Commitments [Domain] Other Commitments [Domain] Unfunded Commitments to Extend Credit Commitments to Extend Credit [Member] Standby Letters of Credit Standby Letters of Credit [Member] Commercial Letters of Credit Letter of Credit [Member] Standby and Commercial Letters of Credit Standby and Commercial Letteres of Credit [Member] Standby and Commercial Letteres of Credit [Member] Minimum Minimum [Member] Credit Commitments [Line Items] Other Commitments [Line Items] Credit Commitments Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability Assets secured for standby letters of credit Assets Secured for Standby Letters of Credit Represents the value of assets secured for the standby letters of credit. Standby and commercial letters of credit, remaining term (in months) Standby and Commercial Letters of Credit Remaining Term Represents the remaining term of standby and commercial letters of credit. Premises and Equipment Property, Plant and Equipment Disclosure [Text Block] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Interest Rate Lock Commitments Interest Rate Lock Commitments [Member] Forward Commitments Forward Contracts [Member] Foreign Exchange Contracts Foreign Exchange Contract [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Mortgage Banking Income Mortgage Banking Income [Member] Details pertaining to noninterest income derived from mortgage banking activities. Other Noninterest Income Other Income [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Net Gains (Losses) Recognized in the Statements of Income Derivative, Gain (Loss) on Derivative, Net Disclosure of Compensation Related Costs, Share-based Payments [Abstract] 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 Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Stock Options Employee Stock Option [Member] Restricted Stock Restricted Stock [Member] Service-Based Restricted Stock Service-Based Restricted Stock [Member] Service-Based Restricted Stock [Member] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Share-based Compensation [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Vesting period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Total shares authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Shares available for future grants of stock options or restricted stock Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Compensation Expense Allocated Share-based Compensation Expense Income Tax Benefit Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Restricted Stock Share Based Compensation Arrangement by Share Based Payment Award, Equity Instruments Other than Options, Restricted Stock [Abstract] -- None. No documentation exists for this element. -- Unrecognized compensation cost related to unvested restricted stock Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted average period during which unrecognized compensation cost is expected to be recognized (in years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Unvested at the beginning of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Unvested at the end of the period (in shares) Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Unvested at the beginning of the period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Unvested at the end of the period (in dollars per share) Grant Date Fair Value of Restricted Stock that Vested During the Year Share Based Compensation Arrangement by Share Based Payment Award, Equity Instruments Other than Options Grant Date Fair Value [Abstract] -- None. No documentation exists for this element. -- Vested (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Stock Options [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at the beginning of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited ( in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding at the end of the period (in shares) Vested and Exercisable at the end of the period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at the beginning of the period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, 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 ( in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding at the end of the period (in dollars per share) Vested and Exercisable at the end of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted Average Remaining Contractual Term Share Based Compensation Arrangement by Share Based Payment Award, Options, Weighted Average Remaining Contractual [Abstract] -- None. No documentation exists for this element. -- Outstanding at the end of the period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Vested and Exercisable at the end of period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract] Outstanding at the end of the period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Vested and Exercisable at the end of the period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Stock options activity Share Based Compensation Arrangement by Share Based Payment Award, Stock Options Activity [Abstract] Share Based Compensation Arrangement by Share Based Payment Award, Options, Intrinsic Value Cash Received Tax Benefits Realized for Deductions Related to Stock Options Exercised and Total Fair Value of Stock Options Vested Intrinsic Value of Stock Options Exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Cash Received from Stock Options Exercised Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options Tax Benefits Realized from Stock Options Exercised Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options Interest Rate Swap Agreements Receive Fixed/Pay Variable Swaps Receive Fixed or Pay Variable Swap [Member] Represents the receive fixed or pay variable interest rate swap agreements. Interest Rate Swap Agreements Pay Fixed/Receive Variable Swaps Pay Fixed or Receive Variable Swap [Member] Represents the pay fixed or receive variable interest rate swap agreements. Derivative Financial Instruments Not Designated as Hedging Instruments Derivatives, Fair Value [Line Items] Notional Amount Derivative, Notional Amount Fair Value Derivative, Fair Value, Net Borrowings Borrowings Disclosure [Text Block] The disclosure of funds purchased, securities sold under agreements to repurchase, and short-term borrowings. Schedule of compensation expense and the related income tax benefit recognized for all share-based awards Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block] Schedule of activity for restricted stock Schedule of Nonvested Share Activity [Table Text Block] Schedule of activity for restricted stock units Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Schedule of activity related to stock options Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary of certain stock option activity of the Company Schedule of Share Based Compensation Arrangement by Share Based Payment Award Options Intrinsic Value Cash Received and Fair Value of Shares Vested During the Period [Table Text Block] Tabular disclosure of the total intrinsic value of options exercised (or share units converted), cash received from stock options exercised, tax benefits realized for deductions related to stock options exercised, and the total fair value of shares vested during the year. Share-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Other Assets Other Assets Disclosure [Text Block] Investments, Debt and Equity Securities [Abstract] Federal Home Loan Bank Stock Federal Home Loan Bank Stock Federal Reserve Bank Stock Federal Reserve Bank Stock Total Federal Home Loan Bank Stock and Federal Reserve Bank Stock Investment Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Financial Instruments Owned and Pledged as Collateral [Table] Financial Instruments Owned and Pledged as Collateral [Table] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Maturity Up To 90 Days [Member] Maturity Up To 90 Days [Member] Maturity Up To 90 Days [Member] Maturity 91 To 365 Days [Member] Maturity 91 To 365 Days [Member] Maturity 91 To 365 Days [Member] Maturity 1 To 3 Years [Member] Maturity 1 To 3 Years [Member] Maturity 1 To 3 Years [Member] Maturity After 3 Years [Member] Maturity After 3 Years [Member] Maturity After 3 Years [Member] Financial Instruments Owned and Pledged as Collateral by Type [Axis] Financial Instruments Owned and Pledged as Collateral by Type [Axis] Financial Instruments Owned and Pledged as Collateral, Type [Domain] Financial Instruments Owned and Pledged as Collateral, Type [Domain] Debt Securities Issued by the U.S. Treasury and Government Agencies Debt Securities Issued by United States Treasury and Government Agencies [Member] This category includes investments in debt securities issued by the United States Department of the Treasury and U.S. Government Agencies. Such securities may include treasury bills (short-term maturities - one year or less), treasury notes (intermediate term maturities - two to ten years), treasury bonds (long-term maturities - ten to thirty years), and debt securities issued by the Government National Mortgage Association (Ginnie Mae). Debt Securities Issued by States and Political Subdivisions US States and Political Subdivisions Debt Securities [Member] Residential - Government Agencies Residential Mortgage-Backed Securities issued by U.S. government agencies [Member] Debt securities collateralized by residential real estate mortgage loans issued by U.S. government agencies such as the Government National Mortgage Association (GNMA) [Member] Residential - U.S. Government Sponsored Enterprises Residential Mortgage-Backed Securities Issued by U.S. Government Sponsored Enterprises [Member] Debt securities collateralized by residential real estate mortgage loans issued by U.S. government-sponsored enterprises. [Member] Securities Sold under Agreements to Repurchase Document and Entity Information Document and Entity Information Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Other Debt Long-term Debt [Text Block] Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Financing Receivables, Period Past Due [Domain] 30 to 59 Days Past Due Financing Receivables, 30 to 59 Days Past Due [Member] 60 to 89 Days Past Due Financing Receivables, 60 to 89 Days Past Due [Member] Past Due 90 Days or More Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Aging Analysis of Accruing and Non-Accruing Loans and Leases Financing Receivable, Recorded Investment, Past Due [Line Items] Days Past Due Financing Receivable, Recorded Investment, Past Due Non-Accrual Financing Receivable, Recorded Investment, Nonaccrual Status Total Past Due and Non-Accrual Financing Receivable, Recorded Investment Past Due and Nonaccrual Status Recorded investment in financing receivables that are past due and of nonaccrual status as of the balance sheet date. Current Financing Receivable, Recorded Investment, Current Total Loans and Leases Non-Accrual Loans and Leases that are Current Financing Receivable Recorded Investment Nonaccrual Status, Current Represents nonaccrual loans that are not past due 30 days or more; however, full payment of principal and interest is still not expected. Number of days non-accrual loans and leases are not past due Financing Receivable Recorded Investment, Nonaccrual Status, Current, Number of Days Not Past Due Represents the number of days that the nonaccrual loans that are not past due. Schedule of details of short-term borrowings Schedule of Short-term Debt [Table Text Block] Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value Inputs, Assets, Quantitative Information [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Mortgage Servicing Rights Servicing Contracts [Member] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Discounted Cash Flow Discounted Cash Flow Technique [Member] Discounted cash flow approach valuation technique used to measure fair value. Pricing Model Pricing Model Technique [Member] Pricing model approach valuation technique used to measure fair value. Level 3 Assets and Liabilities, Fair Value and Fair Value Unobservable Inputs Fair Value Inputs, Assets, Quantitative Information [Line Items] Weighted Average Constant Prepayment Rate (as a percent) Fair Value Inputs, Prepayment Rate Weighted Average Discount Rate (as a percent) Fair Value Inputs, Discount Rate Weighted Average Closing Ratio (as a percent) Fair Value Inputs Closing Ratio Represents the percentage of loans currently in a lock position which management estimates will ultimately close. Weighted Average Credit Factor (as a percent) Fair Value Inputs, Entity Credit Risk Mortgage Servicing Rights, at Fair Value Mortgage Servicing Rights Fair Value Disclosure This element represents the assets reported on a recurring or nonrecurring basis on the balance sheet at period end at fair value. Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Credit Rating, Moody's [Axis] Credit Rating, Moody's [Axis] External Credit Rating, Moody's [Domain] External Credit Rating, Moody's [Domain] Moody's, Aa2 or Better Rating Moody's, Aa2 or Better Rating [Member] Moody's, Aa2 or Better Rating [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Municipal Debt Securities Municipal Debt Securities [Member] Municipal Debt Securities [Member] Hawaiian Municipal Debt Securities Hawaiian Municipal Debt Securities [Member] Hawaiian Municipal Debt Securities [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Geographic Concentration Risk Geographic Concentration Risk [Member] Investment Concentration Risk Investment Concentration Risk [Member] Investment Concentration Risk [Member] Investment Geographic Region [Axis] Investment Geographic Region [Axis] Investment Geographic Region [Domain] Investment Geographic Region [Domain] HAWAII HAWAII Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] General Obligation Bond General Obligation Bond [Member] General Obligation Bond [Member] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Debt Securities Issued by State and Political Subdivision, State of Hawaii Investments, Fair Value Disclosure Concentration Risk, Percentage Concentration Risk, Percentage Municipal Debt Securities Issued by One Single State or Political Subdivision as Percentage of Total Fair Value of Entire Municipal Debt Securities Threshold Municipal Debt Securities Issued by One Single State or Political Subdivision as Percentage of Total Fair Value of Entire Municipal Debt Securities Threshold Municipal Debt Securities Issued by One Single State or Political Subdivision as Percentage of Total Fair Value of Entire Municipal Debt Securities Threshold Selected business segment financial information Schedule of Segment Reporting Information, by Segment [Table Text Block] Assets Assets [Abstract] Cash with Bank of Hawaii Cash with Subsidiaries Represents the cash with Bank of Hawaii. Investment Securities Held-to-Maturity Held-to-maturity Securities Goodwill Goodwill Income Taxes Receivable and Deferred Tax Assets Taxes Receivable and Deferred Taxes Represents the taxes receivable and deferred taxes. Other Assets Other Assets Equity in Net Assets of Subsidiaries Equity in Net Assets of Subsidiaries Represents intercompany ownership interest in subsidiaries. Total Assets Liabilities Liabilities [Abstract] Income Taxes Payable Accrued Income Taxes Other Liabilities Other Liabilities Total Liabilities Liabilities Total Liabilities and Shareholders' Equity Liabilities and Equity Schedule of Other Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Other Debt, Type [Axis] Long-term Debt, Type [Axis] Other Debt, Type [Domain] Long-term Debt, Type [Domain] Federal Home Loan Bank Advance Federal Home Loan Bank Advances [Member] Non-Recourse Debt Secured Debt [Member] Capital Lease Obligations Capital Lease Obligations [Member] Federal Reserve Bank Advance Federal Reserve Bank Advances [Member] Other Debt Debt Instrument [Line Items] Federal Home Loan Bank Advances Long-term Federal Home Loan Bank Advances Non-Recourse Debt Non-Recourse Debt Federal Home Loan Bank, Advances, Weighted Average Interest Rate (as a percent) Federal Home Loan Bank, Advances, Weighted Average Interest Rate Capital Lease Obligations Capital Lease Obligations Total Long-term Debt and Capital Lease Obligations Maximum percentage of the total assets that can be borrowed from the FHLB by the entity Federal Home Loan, Bank Advances General Debt Obligations, Disclosures Maximum Borrowing Capacity as Percentage of Total Assets Represents the maximum borrowing capacity from the Federal Home Loan Bank system, expressed as a percentage of the entity's total assets, provided the entity is able to pledge an adequate amount of qualified assets to secure the borrowings. Undrawn line of credit with the FHLB or FRB Line of Credit Facility, Maximum Borrowing Capacity Lease term (in years) Capital Lease Obligations Term Represents the lease term under capital lease obligations. Fixed lease payments through December 2022 Debt Instrument, Periodic Payment Fair Value Measurements, Recurring and Nonrecurring [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, Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Other Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Debt Securities Issued by the U.S. Treasury and Government Agencies US Treasury and Government Agencies [Member] This category includes investments in debt securities issued by the United States Department of the Treasury and U.S. Government Agencies. Such securities may include treasury bills (short-term maturities - one year or less), treasury notes (intermediate term maturities - two to ten years), treasury bonds (long-term maturities - ten to thirty years), and debt securities issued by the Government National Mortgage Association (Ginnie Mae). Debt Securities Issued by Corporations Corporate Debt Securities [Member] Mortgage-Backed Securities Collateralized Mortgage Backed Securities [Member] Residential - Government Agencies Residential - U.S. Government Sponsored Enterprises Commercial - Government Agencies Commercial Mortgage-Backed Securities Issued by Government Agencies [Member] Debt securities collateralized by commercial real estate mortgage loans issued by U.S. government agencies such as the Government National Mortgage Association (GNMA) [Member] Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets: Assets, Fair Value Disclosure [Abstract] Available-for-Sale: Fair Value Available-for-sale Securities Loans Held for Sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group Mortgage Servicing Rights Servicing Asset at Fair Value, Amount Other Assets Other Assets, Fair Value Disclosure Derivative Assets Derivative Asset Total Assets Measured at Fair Value on a Recurring Basis Assets, Fair Value Disclosure Liabilities: Liabilities, Fair Value Disclosure [Abstract] Derivative Liabilities Derivative Liability Total Liabilities Measured at Fair Value on a Recurring Basis Financial and Nonfinancial Liabilities, Fair Value Disclosure Qualitative and Quantitative Information, Transferor's Continuing Involvement [Table] Qualitative and Quantitative Information, Transferor's Continuing Involvement [Table] Financial Instrument [Axis] Financial Instrument [Axis] Types of Financial Instruments [Domain] Financial Instruments [Domain] Representations and Warranties Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items] Unpaid principal balance of mortgage loans sold Continuing Involvement with Transferred Financial Assets, Principal Amount Outstanding Number of mortgage loans repurchased Number of Mortgage Loans Repurchased Number of Mortgage Loans Repurchased Unpaid principal balance of repurchased mortgage loan Cash Flows Between Transferor and Transferee, Purchases of Previously Transferred Financial Assets Number of Mortgage Loans Repurchased, Pending Number of Mortgage Loans Repurchased, Pending Number of Mortgage Loans Repurchased, Pending Number of Mortgage Loans Repurchased due to Loan Servicing Activities Number of Mortgage Loans Repurchased due to Loan Servicing Activities Number of Mortgage Loans Repurchased due to Loan Servicing Activities Number of Mortgage Loans Repurchased due to Loan Servicing Activities, Pending Number of Mortgage Loans Repurchased due to Loan Servicing Activities, Pending Number of Mortgage Loans Repurchased due to Loan Servicing Activities, Pending Current residential mortgage loans serviced for investors as percentage of total Current Residential Mortgage Loans Serviced for Third Parties as Percentage of Total Residential Mortgage Loans Serviced for Third Parties that were Current as a Percentage of Total Residential Mortgage Loans Serviced for Third Parties. 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] Debt Securities Issued by Government Agencies US Government Agencies Debt Securities [Member] Investment Securities Available-for-Sale, Debt Maturities [Abstract] Available-for-sale Securities, Debt Maturities [Abstract] Available-for-Sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Rolling Maturity [Abstract] Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost, Rolling Maturity [Abstract] Due in One Year or Less Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Due After One Year Through Five Years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Due After Five Years Through Ten Years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Due After Ten Years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Available-for-Sale, Total Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Available-for-Sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract] Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturity [Abstract] Due in One Year or Less Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Due After One Year Through Five Years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Due After Five Years Through Ten Years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Due After Ten Years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value Fair Value, Total Available-for-sale Securities, Debt Maturities, Single Maturity Date Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed Securities: Amortized Cost Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed-Securities: Fair Value Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value Available-for-Sale: Amortized Cost Available-for-sale Securities, Amortized Cost Basis Schedule of Held-to-Maturity Securities [Table] Schedule of Held-to-maturity Securities [Table] Commercial - Government Agencies Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Investment Securities Held-to-Maturity, Debt Maturities [Abstract] Held-to-maturity Securities, Debt Maturities [Abstract] Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Rolling Maturity [Abstract] Held-to-maturity Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract] Due in One Year or Less Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Due After One Year Through Five Years Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Due After Five Years Through Ten Years Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Due After Ten Years Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost Amortized Cost, Total Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturities [Abstract] Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturity [Abstract] Due in One Year or Less Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Due After One Year Through Five Years Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Due After Five Years Through Ten Years Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Due After Ten Years Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Fair Value Fair Value, Total Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value Held-to-Maturity: Mortgage-Backed-Securities: Amortized Cost Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Net Carrying Amount Held-to-Maturity: Mortgage-Backed-Securities: Fair Value Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Fair Value Held-to-Maturity: Amortized Cost Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment Held-to-Maturity: Fair Value Held-to-maturity Securities, Fair Value Carrying value of investment securities which were pledged to secure deposits of gov't entities and repos Carrying Value of Investment Securities Pledged The carrying value, as of the date of each statement of financial position presented, of investment securities, classified as available for sale or held to maturity, which are owned but transferred to serve as collateral to secure deposits of government entities and securities sold under agreements to repurchase, and payment of the related debt obligation, primarily a secured borrowing or repurchase agreement. Statement of Cash Flows [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Impairment of Equipment Held for Sale Impairment of Long-Lived Assets to be Disposed of Depreciation and Amortization Depreciation, Nonproduction Amortization of Deferred Loan and Lease Fees Amortization of Deferred Loan Origination Fees, Net Amortization and Accretion of Premiums/Discounts on Investment Securities, Net Accretion (Amortization) of Discounts and Premiums, Investments Benefit Plan Contributions Pension and Other Postretirement Benefit Contributions Deferred Income Taxes Deferred Income Tax Expense (Benefit) Net Gains (Losses) on Sale of Loans and Leases Gain (Loss) on Sale of Loans and Leases Proceeds from Sales of Loans Held for Sale Proceeds from Sale of Loans Held-for-sale Originations of Loans Held for Sale Payments for Origination and Purchases of Loans Held-for-sale Net Tax Benefits from Share-based Compensation Net Tax Benefits from Share-based Compensation boh-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense Tax Benefits from Share-Based Compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Investment Securities Available-for-Sale: Available-for-sale Securities [Abstract] Proceeds from Prepayments and Maturities Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Proceeds from Sales Purchases Payments to Acquire Available-for-sale Securities Investment Securities Held-to-Maturity: Proceeds from Sale and Maturity of Held-to-maturity Securities [Abstract] Proceeds from Prepayments and Maturities Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Purchases Net Change in Loans and Leases Payments for (Proceeds from) Loans and Leases Proceeds from Sale of Loans and Leases Held-for-investment Proceeds from Sale of Loans and Leases Held-for-investment Premises and Equipment, Net Payments for (Proceeds from) Productive Assets Financing Activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Net Change in Deposits Increase (Decrease) in Deposits Net Change in Short-Term Borrowings Proceeds from (Repayments of) Short-term Debt Proceeds from Long-Term Debt Proceeds from Issuance of Long-term Debt Repayments of Other Debt Repayments of Long-term Debt Tax Benefits from Share-Based Compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Net Cash Provided by (Used in) Financing Activities Net Change in Cash and Cash Equivalents Net Cash Provided by (Used in) Continuing Operations Supplemental Information Supplemental Cash Flow Information [Abstract] Cash Paid for Interest Interest Paid Cash Paid for Income Taxes Income Taxes Paid Non-Cash Investing and Financing Activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Transfer from Loans to Foreclosed Real Estate Real Estate Owned, Transfer from Real Estate Owned Transfer of Loans to Loans Held for Sale Transfer of Portfolio Loans and Leases to Held-for-sale Held-to-Maturity Securities [Abstract] Held-to-maturity Securities [Abstract] Held-to-Maturity: Amortized Cost Held-to-Maturity: Gross Unrealized Gains Held-to-maturity Securities, Accumulated Unrecognized Holding Gain Held-to-Maturity: Gross Unrealized Losses Held-to-maturity Securities, Accumulated Unrecognized Holding Loss Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment Debt Securities Issued by the U.S. Treasury and Government Agencies Debt Securities Issued by States and Political Subdivisions Debt Securities Issued by Corporations Mortgage-Backed Securities Available-for-Sale Securities [Abstract]: Available-for-Sale: Amortized Cost Available-for-Sale: Gross Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-Sale: Gross Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-Sale Credit commitments Other Commitments [Table Text Block] Schedule of rental expense Schedule of Rent Expense [Table Text Block] Schedule of future minimum payments for capital leases and non-cancelable operating leases Schedule of Future Minimum Lease Payments for Capital and Non Cancelable Operating Leases [Table Text Block] Tabular disclosure of future minimum lease payments for capital and non-cancelable operating leases as of the date of the latest balance sheet presented, in aggregate and for each of the five succeeding fiscal years, with separate deductions from the total for the amount representing executor costs, including any profit thereon, included in the minimum lease payments and for the amount of the imputed interest necessary to reduce the net minimum lease payments to its present value and having initial or remaining noncancelable lease terms in excess of one year and the total minimum rentals to be received in the future under noncancelable subleases as of the balance sheet date. Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Pension Benefits Pension Plan [Member] Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Cash Cash [Member] Equity Security - Mutual Funds: Large-Cap Large Cap [Member] Represents the investment in large-cap equity securities by mutual funds. Equity Security - Mutual Funds: Mixed-Cap Mixed Cap [Member] Represents the investment in mixed-cap equity securities by mutual funds. Equity Security - Mutual Funds: International International [Member] Represents the investment in international equity securities by mutual funds. Equity Security - Mutual Funds: Emerging Market Emerging Market [Member] Represents the investment in emerging market equity securities by mutual funds. Common Stock Common Stock [Member] Fixed Income - Mutual Funds Fixed Income Funds [Member] Defined benefit pension plan disclosure Defined Benefit Plan Disclosure [Line Items] Fair value of plan assets Defined Benefit Plan, Fair Value of Plan Assets Schedule of Defined Benefit Plan Assumptions Used in Calculating Net Periodic Benefit Cost [Table Text Block] Schedule of Defined Benefit Plan Assumptions Used in Calculating Net Periodic Benefit Cost [Table Text Block] Tabular disclosure of the assumptions used to determine the net benefit cost for pension plans and/or other employee benefit plans, including assumed discount rates, rate increase in compensation and expected long-term rates of return on plan assets. Schedule of reconciliation of changes in the benefit obligation and the fair value of plan assets, as well as the funded status recognized in the consolidated statements of condition for the pension plans and postretirement benefit plan Schedule of Net Funded Status [Table Text Block] Schedule of amounts recognized in accumulated other comprehensive income (loss) Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block] Schedule of components of net periodic benefit cost Schedule of Net Benefit Costs [Table Text Block] Schedule of assumptions used to determine the benefit obligations/net periodic cost Schedule of Defined Benefit Plan Assumptions Used in Calculating Benefit Obligation [Table Text Block] Tabular disclosure of the assumptions used to determine the benefit obligation for pension plans and/or postretirement benefit plans, including assumed discount rates, rate increase in compensation and expected long-term rates of return on plan assets. Schedule of impact of one percent change in the health care cost trend rate assumption Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block] Schedule of expected benefits to be paid in each of the next five years and in the aggregate for the five years thereafter Schedule of Expected Benefit Payments [Table Text Block] Schedule of the fair values of the retirement plan assets by asset category Schedule of Allocation of Plan Assets [Table Text Block] Asset Derivatives Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value Schedule of premises and equipment Property, Plant and Equipment [Table Text Block] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Excess retirement Plan Pension Plans, Nonqualified Defined Benefit [Member] A defined benefit pension plan which covered employees of the Company and participating subsidiaries who met certain eligibility requirements. Any pension plan that is not a defined contribution pension plan is a defined benefit pension plan. Postretirement Benefits Other Postretirement Benefit Plan [Member] Employee benefits Number of defined benefit plans Defined Benefit Plan Number Represents the number of defined benefit pension plans. Accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Retirees' age and above which Medicare supplemental plan subsidy is provided (in years) Defined Benefit Plan, Minimum Age of Retirees to Be Provided with Medicare Supplemental Plan Subsidy Represents the age of retirees and above to whom Medicare supplemental plan subsidy is provided. Limit on annual credit provided in HRA to eligible employees Defined Benefit Plan Annual Credit Limit Provided into HRA Represents the annual credit limit under health reimbursement account program to eligible employees. Reconciliation of changes in benefit obligations Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Benefit Obligation at Beginning of Year Defined Benefit Plan, Benefit Obligation Service Cost Defined Benefit Plan, Service Cost Interest Cost Defined Benefit Plan, Interest Cost Defined Benefit Plan, Plan Amendments Defined Benefit Plan, Plan Amendments Actuarial Losses (Gains) Defined Benefit Plan, Actuarial Gain (Loss) Benefit Obligation at End of Year Reconciliation of changes in fair value of plan assets Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair Value of Plan Assets at Beginning of Year Actual Return on Plan Assets Defined Benefit Plan, Actual Return on Plan Assets Employer Contributions Defined Benefit Plan, Contributions by Employer Employer Benefits Paid Defined Benefit Plan, Benefits Paid Fair Value of Plan Assets at End of Year Funded Status at End of Year Defined Benefit Plan, Funded Status of Plan Participants contributions Defined Benefit Plan, Contributions by Plan Participants Amounts Recognized in Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract] Net Actuarial Gains (Losses) Defined Benefit Plan, Accumulated Other Comprehensive Income Net Gains (Losses), after Tax Prior Service Credit Defined Benefit Plan, Accumulated Other Comprehensive Income Net Prior Service Cost (Credit), after Tax Total Amounts Recognized in Accumulated Other Comprehensive Income, Net of Tax Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Other Comprehensive Income, Before Tax: Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract] Net Unrealized Gains (Losses) Arising During the Period Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax (Gain) Loss on Sale, before Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Amortization of Unrealized Holding (Gains) Losses on HTM Securities Other Comprehensive Income Reclassification Adjustment for Amortization of Held To Maturity holding Gainsbefore Tax Other Comprehensive Income Reclassification Adjustment for Amortization of holding Gains for Securities Held-To-Maturity before Tax Net Unrealized Gains (Losses) on Investment Securities Other Comprehensive Income, Unrealized Losses on Investment Securities, Before Tax Gross appreciation or the gross loss in value of the total of unsold available-for-sale securities, net of pre-tax reclassification adjustments for gains or losses realized upon the sale of securities and amortization of Available-for-Sale holding gains moved to Held-to-Maturity. Net Actuarial Gains (Losses) Arising During the Period Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax Amortization of Net Actuarial Losses (Gains) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax Amortization of Prior Service Credit, before tax Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax Defined Benefit Plans, Net Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent Other Comprehensive Income (Loss) Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Other Comprehensive Income, Tax Effect: Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract] Net Unrealized Gains Arising During the Period Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax (Gain) Loss on Sale, Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Amortization of Unrealized Holding (Gains) Losses on HTM Securities The tax effect of other comprehensive income reclassification for amortization of holding gains/losses on HTM Securities, tax effect. The tax effect of other comprehensive income reclassification for amortization of holding gains/losses on HTM Securities. Net Unrealized Gains (Losses) on Investment Securities Tax effect on Unrealized gain/loss on Investment Securities Tax effect on unrealized gain/loss on available-for-sale securities, net or tax effect of reclassification adjustments for gains or losses realized upon the sale of securities and amortization of available-for-sale holdings gains moved to Held-to_maturity. Net Actuarial Gains (Losses) Arising During the Period Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax Amortization of Net Actuarial Losses (Gains) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Tax Amortization of Prior Service Credit Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), Tax Defined Benefit Plans, Net Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Parent Other Comprehensive Income (Loss) Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Other Comprehensive Income, Net of Tax: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Net Unrealized Gains (Losses) Arising During the Period Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax (Gain) Loss on Sale, Net of Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Amortization of Unrealized Holding (Gains) Losses on HTM Securities after Tax Other Comprehensive Income Reclassification Adjustment for Amortization of Gains on Held To Maturity Securities after Tax Other Comprehensive Income Reclassification Adjustment for Amortization of Holding Gains on Held To Maturity Securities after Tax Net Unrealized Gains (Losses) on Investment Securities Net Unrealized Gain/Loss on Investment Securities, net of tax Amount after tax and reclassification adjustments or gain or loss in value of unsold Available- for-Sale securities and amortization of Available-for-Sale holding gains moved to Held-to-Maturity. Net Actuarial Losses Arising During the Period Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Amortization of Net Actuarial Losses (Gains) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax Amortization of Prior Service Credit Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), Net of Tax Defined Benefit Plans, Net Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent Other Comprehensive Income (Loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Gross Gains on Sales of Investment Securities Gain on Sale of Investment Securities, Gross The gross gain realized from the sale, exchange, redemption, or retirement of investment securities. Gross Losses on Sales of Investment Securities Loss on Sale of Investment Securities Gross The gross loss on the sale, exchange, redemption, or retirement of investment securities. Net Gains on Sales of Investment Securities Tax on Sale of Investment Securities Tax on Sale of Investment Securities Represents the income tax expense related to the Company's net realized gains on the sale of investments securities. Commitments, Contingencies, and Guarantees Commitments Contingencies and Guarantees [Text Block] Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Less Than 12 Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Less Than 12 Months, Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 Months or Longer, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value 12 Months or Longer, Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Total Gross Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Held-to-Maturity Securities, Continuous Unrealized Loss Position [Abstract] Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract] Less Than 12 Months, Fair Value Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Less than 12 Months, Gross Unrealized Losses Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 Months or Longer, Fair Value Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value 12 Months or Longer, Gross Unrealized Losses Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total, Fair Value Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value Total Gross Unrealized Losses Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss Number of Investment Securities in Unrealized Loss Position Number of Investment Securities in Unrealized Loss Position This element represents the number of investment securities that were in an unrealized loss position as of the balance sheet date. Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Denominator for Basic Earnings Per Share (in shares) Dilutive Effect of Equity Based Awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Denominator for Diluted Earnings Per Share (in shares) Antidilutive Stock Options and Restricted Stock Outstanding (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Transfers and Servicing of Financial Assets [Abstract] Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table] Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table] Key assumptions used in estimating the fair value of mortgage servicing rights Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items] Weighted-Average Constant Prepayment Rate (as a percent) Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Prepayment Speed Weighted-Average Life (in years) Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Weighted Average Life Weighted-Average Note Rate (as a percent) Assumption for Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities Note Rate The weighted average note rate of securitized assets. This is used as a key input in measuring the fair value of assets or liabilities that relate to a transferor's continuing involvement, if any, as of the date of the latest statement of financial position presented. Weighted-Average Discount Rate (as a percent) Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Discount Rate Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Minimum Information related to loans modified as a TDR Financing Receivable, Modifications [Line Items] Default period past due following modification of loans in TDR (in days) Financing Receivable Modifications Made Default Period Represents the number of days past due following modification of loans in a troubled debt restructuring, when a loan is considered to be in default. Number of Contracts, TDRs that Defaulted Financing Receivable, Modifications, Subsequent Default, Number of Contracts Recorded Investment (as of period ended), TDRs that Defaulted Financing Receivable, Modifications, Subsequent Default, Recorded Investment Balance Sheet Offsetting Offsetting Assets and Liabilities [Text Block] Offsetting Assets and Liabilities [Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Amount Reported Value Measurement [Member] Fair value Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial Instruments - Assets Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Held-to-Maturity, Fair Value Loans Loans Receivable, Fair Value Disclosure Financial Instruments - Liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Time Deposits Fair value, time deposits Fair value of time deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts. Securities Sold Under Agreements to Repurchase Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure Other Debt Long Term Debt, Excluding Capital Lease Obligations, Fair Value The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. This element excludes the capital lease obligations. Defined Contribution Plans Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] Number of company contribution components, Retirement Savings Plan Defined Contribution Plans, Number of Components of Company Contribution Represents the number of company contribution components in addition to employee contributions. Fixed percentage of employer's contribution based on eligible compensation Defined Contribution Plan, Fixed Percentage of Employers Contribution Based on Eligible Compensation Represents the fixed percentage of employer's contribution based on eligible compensation. Employee contribution limit per calendar year (as a percent of compensation) Defined Contribution Plan, Employee Contribution Limit Percentage of Compensation The limit of annual employee contributions to the plan per calendar year as a percentage of eligible compensation. Employee's contribution matched by employer (in dollars) Defined Contribution Plan, Employee Contribution Amount Matched by Employer The dollar value of employee contributions to the plan matched by the employer. Employer match of employee contributions upto 2% of eligible compensation Defined Contribution Plan, Employer Match Level One Represents the employer matching contribution of the first level of employee contributions. Percentage of eligible compensation, matched $1.25 for by employer for each dollar amount contributed by participants Defined Contribution Plan, Employer Match Employee Contribution Level One Represents the first level of employee contributions of dollar one which are matched by the employer. Employer match of employee contributions over 2% upto 5% of eligible compensation Defined Contribution Plan, Employer Match Level Two Represents the employer matching contribution of the second level of employee contributions. Percentage of eligible compensation, matched $0.50 for by employer for each dollar amount contributed by participants, low end of range Defined Contribution Plan, Employer Match, Employee Contribution Level Two Low End of Range Represents the low end of the range of second level of employee contributions of dollar one, which are matched by the employer. Percentage of eligible compensation, matched $0.50 for by employer for each dollar amount contributed by participants, high end of range Defined Contribution Plan, Employer Match Employee Contribution Level Two High End of Range Represents the high end of the range of second level of employee contributions of dollar one, which are matched by the employer. Total expense for all components of the company's defined contribution plans Defined Contribution Plan, Cost Recognized Affordable Housing Projects Tax Credit Partnerships Affordable Housing Program [Text Block] Deposits [Abstract] Time deposits classified according to the contractual maturities Time Deposits, Fiscal Year Maturity [Abstract] 2018 Time Deposit Maturities, Next Twelve Months 2019 Time Deposit Maturities, Year Two 2020 Time Deposit Maturities, Year Three 2021 Time Deposit Maturities, Year Four 2022 Time Deposit Maturities, Year Five Thereafter Time Deposit Maturities, after Year Five Total Time Deposits Time deposits with balances of $100,000 or more, classified according to the contractual maturities Contractual Maturities, Time Deposits, $100,000 or More [Abstract] Three Months or Less Contractual Maturities, Time Deposits, $100,000 or More, Three Months or Less Over Three Months through Six Months Contractual Maturities, Time Deposits, $100,000 or More, Three Months Through Six Months Over Six Months through Twelve Months Contractual Maturities, Time Deposits, $100,000 or More, Six Months Through 12 Months Over Twelve Months Contractual Maturities, Time Deposits, $100,000 or More, after 12 Months Total Time Deposits, $100,000 or More Government entity deposits Deposits Governmental Entities The aggregate amount of deposits of governmental entities, which require collateralization by acceptable investment securities of the company. Interest Income from Investment Securities, Taxable Interest Income, Securities, Operating, Taxable Interest Income from Investment Securities, Non-Taxable Interest Income, Securities, Operating, Tax Exempt Total Interest Income from Investment Securities Interest Income, Operating Statement of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net of Tax: Net Unrealized Gains (Losses) on Investment Securities Defined Benefit Plans, Net Other Comprehensive Income (Loss) Comprehensive Income Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Deposits Deposit Liabilities Disclosures [Text Block] Land Loans Land Loan [Member] A loan for land. Recorded Investment (narrative) Financing Receivable, Modifications, Recorded Investment Available Commitments to Lend Additional Funds on Loans Modified as TDR Available commitments under Revolving Credit Lines, Modified as TDR Available commitments under revolving credit lines that have been modified as TDRs. Period of Time Loan Being Fully amortized Period of Time Loan Being Fully Amortized Period of Time Loan Being Fully Amortized Extending balloon payments Extending Balloon Payments Period of modification related to loans that have been modified in a troubled debt restructuring where the balloon payment is extended. Number of Contracts Financing Receivable, Modifications, Number of Contracts Recorded Investment (as of period end) Financing Receivable, Modifications, Post-Modification Recorded Investment Increase in Allowance (as of period end) Financing Receivable Modifications, Impact on Allowance Represents the modification impact on allowance at the end of the period. Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Capital Surplus Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Treasury Stock Treasury Stock [Member] Statement [Line Items] Statement [Line Items] Increase (decrease) in shareholders' equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance at Beginning of Period Beginning Balance (in shares) Common Stock, Shares, Outstanding Share-Based Compensation Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Common Stock Issued under Purchase and Equity Compensation Plans and Related Tax Benefits Stock Issued During Period, Value, Purchase and Equity Compensation Plans Value of stock issued during the period as a result of purchase and equity compensation plans. Common Stock Issued under Purchase and Equity Compensation Plans and Related Tax Benefits (in shares) Stock Issued During Period, Shares, Purchase and Equity Compensation Plans Number of shares issued during the period as a result of purchase and equity compensation plans. Common Stock Repurchased Common Stock Repurchased (in shares) Cash Dividends Declared ($1.80 per share) Dividends, Common Stock, Cash Balance at End of Period Ending Balance (in shares) Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] Analysis of mortgage servicing rights accounted for under the fair value measurement method Schedule of Servicing Assets at Fair Value [Table Text Block] Analysis of mortgage servicing rights accounted for under the amortization method Servicing Asset at Amortized Cost [Table Text Block] Schedule of key data and assumptions used in estimating the fair value of mortgage servicing rights Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table Text Block] Schedule of sensitivity analysis of the fair value of mortgage servicing rights Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] Reduction of swap liabilities resulting from variation margin payments Reduction of swap liabilities resulting from variation margin payments The amount of reduction of swap liabilities resulting from variation margin payments. Balances 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] Changes in Level 3 assets and liabilities measured at fair value on a recurring basis Fair Value Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Tabular disclosure of the fair value measurement of assets and liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income, and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issuances, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset and liability. Summary of the significant unobservable inputs Fair Value Inputs, Assets, Quantitative Information [Table Text Block] Assets and liabilities measured at fair value on a nonrecurring basis Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of difference between the aggregate fair value and the aggregate unpaid principal balance of the Company's residential mortgage loans held for sale Fair Value, Option, Quantitative Disclosures [Table Text Block] Schedule of carrying amount, fair value, and fair value hierarchy of financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Earnings Per Share Earnings Per Share [Text Block] Schedule of Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Investment Securities Schedule of Available For Sale Securities and Held To Maturity [Table Text Block] This item represents the entire disclosure related to reconciling the amortized cost basis and aggregate fair value of the entity's available-for-sale and held-to-maturity investment securities. Schedule of Analysis of the Contractual Maturities of Investment Securities Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of Gross Gains and Losses from Sale of Investment Securities Gain (Loss) on Investments [Table Text Block] Schedule of Investment Securities in an Unrealized Loss Position Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of Interest Income from Taxable and Non-Taxable Investment Securities. Interest Income From Taxable And Non-Taxable Investment Securities [Table Text Block] Interest income from taxable and non-taxable investment securities. Schedule of Carrying Value of the Company's Federal Home Loan Bank and Federal Reserve Bank Schedule of Carrying Value of Company's Federal Home Loan Bank and Federal Reserve Bank [Table Text Block] Schedule of Carrying Value of Company's Federal Home Loan Bank and Federal Reserve Bank [Table Text Block] Fair Value, Option, Quantitative Disclosures [Table] Fair Value, Option, Quantitative Disclosures [Table] Residential Mortgage Loans Held For Sale Residential Mortgage Held For Sale [Member] A loan to an individual to purchase or refinance residential real estate such as a home, in which the real estate itself serves as collateral for the loan, that will be sold to other entities. Fair Value Option Fair Value, Option, Quantitative Disclosures [Line Items] Aggregate Fair Value Loans Held-for-sale, Fair Value Disclosure Aggregate Unpaid Principal Fair Value Option Loans Held for Sale Aggregate Unpaid Principal Represents the aggregate unpaid principal balance of loans held for sale for which the fair value option was elected. Aggregate Fair Value less Aggregate Unpaid Principal Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables Schedule of Loan and Lease portfolio Schedule of Aggregate Carrying Amount of Loans and Leases [Table Text Block] Tabular disclosure of the aggregate carrying amount of all categories of loans and leases held in portfolio, net of unearned income, net of deferred loan fees or costs, and any direct principal charge-offs. Schedule of Portfolio Segment and Balance in Allowance Disaggregated on the Basis of Impairment Measurement Method Allowance for Credit Losses on Financing Receivables [Table Text Block] Schedule of Recorded Investment in Loans and Leases by Class and by Credit Quality Indicator Financing Receivable Credit Quality Indicators [Table Text Block] Schedule of Aging Analysis by Class of Loan and Lease Portfolio Past Due Financing Receivables [Table Text Block] Schedule of Information Related to Impaired Loans Impaired Financing Receivables [Table Text Block] Schedule of the Average Recorded Investment and Interest Income Recognized on Impaired Loans Schedule of Average Recorded Investment and Interest Income Recognized on Impaired Loans [Table Text Block] Tabular disclosure of the average recorded investment and interest income recognized on impaired financing receivables. Schedule of Loans Modified in a TDR and TDRs that Defaulted During the Period Within 12 mos of Modification Date Troubled Debt Restructurings on Financing Receivables [Table Text Block] Restrictions on Cash Cash and Cash Equivalents Disclosure [Text Block] Statement of Financial Position [Abstract] Common Stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common Stock, authorized shares Common Stock, Shares Authorized Common Stock, issued shares Common Stock, Shares, Issued Common Stock, outstanding shares Treasury Stock, Shares Treasury Stock, Shares Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Use of Estimates in the Preparation of Financial Statements Use of Estimates, Policy [Policy Text Block] Consolidation Consolidation, Policy [Policy Text Block] Variable Interest Entities Consolidation, Variable Interest Entity, Policy [Policy Text Block] Investment Securities Investment, Policy [Policy Text Block] Other-Than-Temporary Impairments of Investment Securities Other than Temporary Impairments of Investment Securities [Policy Text Block] Disclosure of accounting policy for other-than-temporary impairments of investment securities. Loans Held for Sale Loans Held For Sale [Policy Text Block] Disclosure of accounting policy for valuation and recording of gain or loss and fees, for residential mortgage loans and commercial loans. Loans and Leases Finance, Loans and Leases Receivable, Policy [Policy Text Block] Non-Performing Loans and Leases Loans and Leases Receivable, Nonperforming Loan and Lease, Policy [Policy Text Block] Impaired Loans Impaired Financing Receivable, Policy [Policy Text Block] Loans Modified in a Troubled Debt Restructuring Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block] Reserve for Credit Losses Reserves for Credit Losses [Policy Text Block] The entire disclosure for allowances and reserves for credit losses. Allowance for Loan and Lease Losses Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Reserve for Unfunded Commitments Reserve for Unfunded Commitments [Policy Text Block] Disclosure of accounting policy for reserve for unfunded commitments which is a component of other liabilities and represents the estimate for probable credit losses inherent in unfunded commitments to extend credit. Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Premises and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Foreclosed Real Estate Loans and Leases Receivable, Real Estate Acquired Through Foreclosure, Policy [Policy Text Block] Mortgage Servicing Rights Mortgage Servicing Rights [Policy Text Block] Disclosure of accounting policy for Mortgage Servicing Rights (MSRs). Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Non-Marketable Equity Securities Securities Owned Not Readily Marketable, Policy [Policy Text Block] Securities Sold Under Agreements to Repurchase Securities Sold under Agreements to Repurchase [Policy Text Block] Disclosure of accounting policy of securities that are sold under the agreement to repurchase the same or identical securities. Pension and Postretirement Benefit Plans Pension and Other Postretirement Plans, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Treasury Stock Stockholders' Equity, Policy [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Share-Based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Advertising Costs Advertising Cost, Policy, Expensed Advertising Cost [Policy Text Block] International Operations International Operations [Policy Text Block] Disclosure of accounting policy with respect to classification of international operations as domestic. Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Accounting Standards Adopted in the Current Year or Pending Adoption New Accounting Pronouncements, Policy [Policy Text Block] Investment Income [Table] Investment Income [Table] Visa Class B Restricted Securities Visa Class B Restricted Securities [Member] Visa Class B Restricted Securities [Member] Visa Class A Unrestricted Securities Visa Class A Unrestricted Securities [Member] Visa Class A Unrestricted Securities [Member] Net Investment Income [Line Items] Net Investment Income [Line Items] Conversion ratio to Class A shares Conversion Ratio of Convertible Securities Conversion Ratio of Convertible Securities Net Gains on Sales of Investment Securities Sale of investment securities, shares Sale of Investment Securities, Shares Sale of Investment Securities, Shares Equity securities remaining, shares Equity Securities, Shares Equity Securities, Shares Net periodic benefit cost for pension plans and the postretirement benefit plan Defined Benefit Plan, Net Periodic Benefit Cost [Abstract] Expected Return on Plan Assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of Prior Service Credit Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of Net Actuarial Losses (Gains) Defined Benefit Plan, Amortization of Gains (Losses) Net Periodic Benefit Cost Defined Benefit Plan, Net Periodic Benefit Cost Estimated amount expected to be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost in next fiscal year Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year [Abstract] Net actuarial loss Defined Benefit Plan, Future Amortization of Gain (Loss) Net gain and prior service credit Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year Weighted average assumptions used to determine the benefit obligations Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] Discount Rate (as a percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Health Care Cost Trend Rate Assumed For Next Year (as a percent) Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year Ultimate health care cost trend rate (as a percent) Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Year that reaches the ultimate health care cost trend rate Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate Weighted average assumptions used to determine the net periodic benefit cost Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Discount rate (as a percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected Long-Term Rate of Return on Plan Assets (as a percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Health Care Cost Trend Rate (as a percent) Defined Benefit Plan, Health Care Cost, Trend Rate Assumed The assumed health care cost trend rate to calculate net periodic benefit cost. A one percent change in the health care cost trend rate assumption impact on cost Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract] Effect of one percentage increase on the total of service and interest cost components of net periodic postretirement benefit cost Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components Effect of one percentage increase on the postretirement benefit obligation Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation Effect of one percentage decrease on the total of service and interest cost components of net periodic postretirement benefit cost Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components Effect of one percentage decrease on the postretirement benefit obligation Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Expected benefits to be paid in each of the next five years and in the aggregate for the five years thereafter Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract] 2015 Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months 2016 Defined Benefit Plan, Expected Future Benefit Payments, Year Two 2017 Defined Benefit Plan, Expected Future Benefit Payments, Year Three 2018 Defined Benefit Plan, Expected Future Benefit Payments, Year Four 2019 Defined Benefit Plan, Expected Future Benefit Payments, Year Five Years 2020-2024 Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year Schedule of Servicing Assets at Amortized Value [Table] Servicing Asset at Amortized Cost [Table] Mortgage servicing rights including fair value of mortgage servicing rights accounted for under the amortization method, net of a valuation allowance Servicing Asset at Amortized Cost [Line Items] Change in Carrying Value of Mortgage Servicing Rights Accounted for Under the Amortization Method, Net of a Valuation Allowance Servicing Asset at Amortized Cost, Balance [Roll Forward] Balance at beginning of Year Servicing Asset at Amortized Cost Servicing Rights that Resulted From Asset Transfers Servicing Asset at Amortized Cost, Additions Amortization Servicing Asset at Amortized Cost, Amortization Valuation Allowance Provision Valuation Allowance for Impairment of Recognized Servicing Assets, Additions (Deductions) for Expenses (Recoveries) Balance at end of Year Valuation Allowance [Roll Forward] Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward] Balance at Beginning of Year Valuation Allowance for Impairment of Recognized Servicing Assets, Balance Valuation Allowance Provision Balance at End of Year Fair Value: Fair Value of Mortgage Servicing Rights Accounted for under Amortization Method [Abstract] Represents the fair value of mortgage servicing rights at the beginning and ending of the period accounted for under the amortization method. Balance at Beginning of Year Servicing Asset at Amortized Cost, Fair Value Balance at End of Year Schedule of Servicing Assets at Fair Value [Table] Schedule of Servicing Assets at Fair Value [Table] Servicing Assets at Fair Value [Line Items] Servicing Assets at Fair Value [Line Items] Change in fair value of the mortgage servicing rights accounted for under the fair value measurement method Servicing Asset at Fair Value, Amount [Roll Forward] Balance at Beginning of Year Changes in Fair Value: Servicing Asset at Fair Value, Amount [Abstract] -- None. No documentation exists for this element. -- Due to Change in Valuation Assumptions Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions Due to Payoffs Servicing Asset at Fair Value, Other Changes in Fair Value Total Changes in Fair Value of Mortgage Servicing Rights Servicing Asset at Fair Value, Period Increase (Decrease) Balance at End of Year Premises Land and Building [Member] Capital leases Leaseholds and Leasehold Improvements [Member] Cost Property, Plant and Equipment, Gross Accumulated Depreciation and Amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Net Book Value Property, Plant and Equipment, Net Depreciation and amortization (including capital lease amortization) included in noninterest expense Depreciation, Depletion and Amortization Impairment charge Asset Impairment Charges Interest-Bearing Deposits in Other Banks Interest-bearing Deposits in Banks and Other Financial Institutions Funds Sold Funds Sold Amount represents balances maintained with the Federal Reserve Bank. Investment Securities Marketable Securities [Abstract] Held-to-Maturity (Fair Value of $3,894,121 and $3,827,527) Allowance for Loan and Lease Losses Loans and Leases Receivable, Allowance Net Loans and Leases Loans and Leases Receivable, Net Amount Total Earning Assets Earning Assets Aggregate total of all income-earning assets owned by the entity. Cash and Due From Banks Cash and Due from Banks Premises and Equipment, Net Accrued Interest Receivable Interest Receivable Foreclosed Real Estate Real Estate Acquired Through Foreclosure Mortgage Servicing Rights Mortgage Servicing Rights: The total of mortgage servicing rights, both those carried at fair value and those carried at amortized cost. Mortgage servicing rights consist of an asset representing the present value of estimated future revenues from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements. Rights may be obtained via (1) acquisition or assumption of a servicing obligation that does not relate to financial assets of the servicer or its consolidated affiliates; or (2) by originating loans and then transferring the loans in a transaction that meets the requirements for sale accounting. Bank-Owned Life Insurance Bank Owned Life Insurance Deposits Noninterest-Bearing Demand Noninterest-bearing Deposit Liabilities Interest-Bearing Demand Interest Bearing Demand Deposit Liabilities The amount of money in accounts that bear interest and that the depositor is entitled to withdraw at any time without prior notice. Includes both domestic and foreign depositors. Savings Deposits, Savings Deposits Time Total Deposits Deposits Funds Purchased Federal Funds Purchased Other Debt Retirement Benefits Payable Pension and Other Postretirement Defined Benefit Plans, Liabilities Accrued Interest Payable Interest Payable Taxes Payable and Deferred Taxes Taxes Payable and Deferred Taxes Obligations related to taxes payable and deferred taxes. Taxes payable includes the carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, excise, and other taxes. Deferred taxes includes the cumulative amount for all deferred tax liabilities as of the balance sheet date arising from temporary differences between accounting income in accordance with generally accepted accounting principles and tax-basis income that will result in future taxable income exceeding future accounting income. Commitments, Contingencies, and Guarantees (Note 20) Commitments and Contingencies Shareholders' Equity Stockholders' Equity Attributable to Parent [Abstract] Common Stock ($.01 par value; authorized 500,000,000 shares; issued / outstanding: December 31, 2017 - 57,959,074 / 42,401,443 and December 31, 2016 - 57,856,672 / 42,635,978) Common Stock, Value, Issued Capital Surplus Additional Paid in Capital, Common Stock Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Income (Loss), Net of Tax Retained Earnings Retained Earnings (Accumulated Deficit) Treasury Stock, at Cost (Shares: December 31, 2017 - 15,557,631 and December 31, 2016 - 15,220,694) Treasury Stock, Value Total Shareholders' Equity Total Liabilities and Shareholders' Equity Schedule of the Company's Provision for Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of significant components of the Company's Deferred Tax Liabilities and Assets Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of reconciliation of the statutory federal income tax rate to the Company's Effective Tax Rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of reconciliation of the Company's Liability for Unrecognized Tax Benefits Summary of Income Tax Contingencies [Table Text Block] Components of Other Assets Other Assets [Abstract] Federal Home Loan Bank and Federal Reserve Bank Stock Derivative Financial Instruments Low-Income Housing and Other Equity Investments Low Income Housing and Other Equity Investments Assets Represents low-income housing and other equity investments included in other assets. Deferred Compensation Plan Assets Deferred Compensation Plan Assets Prepaid Expenses Prepaid Expense Accounts Receivable Accounts Receivable, Net Other Other Assets, Miscellaneous Total Other Assets Schedule of Repurchase Agreements - by maturity date and collateral type Schedule of Repurchase Agreements [Table Text Block] Schedule of assets and liabilities subject to an enforceable master netting arrangement Offsetting Assets and Liabilities [Table Text Block] Offsetting Assets and Liabilities [Table Text Block] Bank of Hawaii Corporation Financial Statements Condensed Financial Information of Parent Company Only Disclosure [Text Block] Equity Securities Equity Securities [Member] Equity Securities, Domestic Equity Securities, Domestic [Member] Equity Securities, Domestic [Member] Equity Securities, International Equity Securities, International [Member] Equity Securities, International [Member] Fixed Income Securities Fixed Income Securities [Member] Cash Cash and Cash Equivalents [Member] Defined Benefit Plan by Index Categories [Axis] Defined Benefit Plan by Index Categories [Axis] Categorization based on indexes. Defined Benefit Plan by Index Categories [Domain] Defined Benefit Plan by Index Categories [Domain] Categories based on the types of indexes. S&P 500 Index MSCI USA IMI Index [Member] [Domain] boh_MSCI USA IMI Index [Member] [Domain] MSCI EAFE Index Morgan Stanley Capital International Europe Australasia and Far East Index [Member] Represents the details pertaining to Morgan Stanley Capital International Europe, Australasia and Far East (MSCI EAFE) Index. Barclays Capital Aggregate Bond Index Barclays Capital Aggregate Bond Index [Member] Represents the Barclays Capital Aggregate Bond Index, which is a component of benchmark index. Performance benchmark (as a percent) Defined Benefit Plan, Performance Percentage Benchmark Performance percentage benchmarked to indexes. Target plan asset allocations Defined Benefit Plan, Target Plan Asset Allocations Asset allocation guidelines Defined Benefit Plan, Assets, Target Allocations [Abstract] Fixed income securities, percentage of variable component in strategic targets (as a percent) Defined Benefit Plan, Target Allocation, Percentage of Assets, Debt Securities Variable Component Target allocation percentage of variable component in strategic targets, of investments in debt securities to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position. Effect of market fluctuations in cash flow on target allocation limits (as a percent) Defined Benefit Plan, Target Allocation Percentage Increase Decrease Due to Market Fluctuations or Cash Flow Effect Represents the breach limits allowed for each asset class due to market fluctuations or cash flows. Period during which asset allocation is expected to conform to range limits (in days) Defined Benefit Plan, Target Allocation Expected Period to Conform to Range Limits Effected by Market Fluctuation or Cash Flows Represents the period during which the asset allocation affected by market fluctuations is expected to conform to range limits. Mortgage Servicing Rights Transfers and Servicing of Financial Assets [Text Block] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Commercial Mortgage [Member] Commercial Mortgage [Member] Class of financing receivables related to commercial mortgage financing receivables. Impaired Loans Information: Financing Receivable, Impaired [Line Items] Impaired Loans with No Related Allowance, Recorded Investment Impaired Financing Receivable, with No Related Allowance, Recorded Investment Impaired Loans with No Related Allowance, Unpaid Principal Balance Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Impaired Loans with Related Allowance, Recorded Investment Impaired Financing Receivable, with Related Allowance, Recorded Investment Impaired Loans with Related Allowance, Unpaid Principal Balance Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Related Allowance for Loan Losses Impaired Financing Receivable, Related Allowance Recorded Investment Impaired Financing Receivable, Recorded Investment Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Impaired Loans with No Related Allowance, Average Recorded Investment Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Impaired Loans with No Related Allowance, Interest Income Recognized Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Impaired Loans with Related Allowance, Average Recorded Investment Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Impaired Loans with Related Allowance, Interest Income Recognized Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Schedule of time deposits with contractual maturities Schedule of Time Deposit Contractual Maturities [Table Text Block] Tabular disclosure of time deposits, classified with respect to their maturities. Schedule of time deposits with balances of $100,000 or more with contractual maturities Schedule of Time Deposit with Balances of Dollar 100000 or More with Contractual Maturities [Table Text Block] Tabular disclosure of time deposits with balances of 100,000 dollars or more, along with contractual maturities. Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table] Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table] Sensitivity analysis of fair value of mortgage servicing rights to changes in certain key assumptions Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items] Constant Prepayment Rate Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact in Prepayment Speed [Abstract] -- None. No documentation exists for this element. -- Decrease in fair value from 25 basis points ("bps") adverse change Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact from 25 Basis Points Adverse Change in Prepayment Speed The hypothetical financial impact of 25 basis points' adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. Decrease in fair value from 50 bps adverse change Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact from 50 Basis Points Adverse Change in Prepayment Speed The hypothetical financial impact of 50 basis points' adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. Discount Rate Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact in Discount Rate [Abstract] -- None. No documentation exists for this element. -- Decrease in fair value from 25 bps adverse change Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact from 25 Basis Points Adverse Change in Discount Rate The hypothetical financial impact of a 25 basis points adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. Decrease in fair value from 50 bps adverse change Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact from 50 Basis Points Adverse Change in Discount Rate The hypothetical financial impact of a 50 basis points adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date. Non-Recourse Debt and Federal Home Loan Bank Advance Non-Recourse Debt and Federal Home Loan Bank Advance [Member] Non-Recourse Debt and Federal Home Loan Bank Advance [Member] Annual Maturities of Other Debt Exclusive of Capital Lease Obligations Maturities of Long-term Debt [Abstract] 2018 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2019 Long-term Debt, Maturities, Repayments of Principal in Year Two 2020 Long-term Debt, Maturities, Repayments of Principal in Year Three 2021 Long-term Debt, Maturities, Repayments of Principal in Year Four 2022 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Total Long-term Debt Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Debt Security Category [Axis] Debt Security Category [Axis] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain] Available-for-sale Securities Available-for-sale Securities [Member] Held-to-maturity Securities Held-to-maturity Securities [Member] Unrealized Gains and Losses on Net Investment Securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Defined Benefit Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Other Comprehensive Income (Loss) Before Reclassification OCI, before Reclassifications, Net of Tax, Attributable to Parent Amounts Reclassified from Accumulated Other Comprehensive Income Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Fair Value, Mortgage Servicing Rights Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Mortgage Servicing Rights, Beginning Balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Fair Value, Mortgage Servicing Rights, Realized and Unrealized Net Gains (Losses) Included in Net Income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Fair Value, Mortgage Servicing Rights, Ending Balance Fair Value, Mortgage Service Rights, Total Unrealized Net Gains (Losses) Included in Net Income Related to Assets Still Held Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Fair Value, Net Derivative Assets and Liabilities, Beginning Balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Fair Value, Net Derivative Assets and Liabilities, Realized and Unrealized Net Gains (Losses) Included in Net Income Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Fair Value, Net Derivative Assets and Liabilities, Transfers to Loans Held for Sale Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers to Loans Held For Sale This element represents transfers to loans held for sale which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3). Fair Value, Net Derivative Assets and Liabilities, Ending Balance Fair Value, Net Derivative Assets and Liabilities,Total Unrealized Net Gains (Losses) Included in Net Income Related to Assets Still Held Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Unrealized Gain (Loss) Included in Net Income Related to Assets Still Held Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those net derivative assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3). Variation margin payments for swap liabilities Variation margin payments for swap liabilities Variation margin payments for swap liabilities Loans and Leases and the Allowance for Loan and Lease Losses Loans and Leases and Allowance for Loan and Lease Losses [Text Block] The disclosure of Loans and Leases and the Allowance for Loan and Lease Losses includes: (1) balances in the entity's classes of loans and leases as of period end; (2) roll forward of the entity's Allowance for Loan and Lease Losses by portfolio segment; (3) balances in the entity's classes of loans and leases by internal credit quality indicators as of period end; (4) an aging analysis of the entity's classes of loans and leases as of period end; (5) balances of impaired loans by the entity's classes of loans as of period end; and (6) information related to the average recorded investment and interest income recognized on impaired loans for the periods presented. Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Allowance for Loan and Lease Losses Financing Receivable, Allowance for Credit Losses [Line Items] Allowance for Loan and Lease Losses: Financing Receivable, Allowance for Credit Losses [Roll Forward] Balance at the Beginning of Period Financing Receivable, Allowance for Credit Losses Loans and Leases Charged-Off Financing Receivable, Allowance for Credit Losses, Write-downs Recoveries on Loans and Leases Previously Charged-Off Allowance for Loan and Lease Loss, Recovery of Bad Debts Net Loans and Leases Recovered (Charged-Off) Allowance for Loan and Lease Losses Write-offs, Net Balance at End of Period Allowance for Loan and Lease Losses: Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract] Individually Evaluated for Impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Collectively Evaluated for Impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Total Recorded Investment in Loans and Leases: Loans and Leases Receivable Investment [Abstract] -- None. No documentation exists for this element. -- Individually Evaluated for Impairment Financing Receivable, Individually Evaluated for Impairment Collectively Evaluated for Impairment Financing Receivable, Collectively Evaluated for Impairment Unrecognized Tax Benefits Income Tax Uncertainties [Abstract] Reconciliation of liability for Unrecognized Tax Benefits Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Unrecognized Tax Benefits at the Beginning of Year Unrecognized Tax Benefits Gross Increases, Related to Tax Positions Taken in a Prior Period Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Gross Decreases, Related to Tax Positions Taken in a Prior Period Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Gross Increases, Related to Current Period Tax Positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Settlements with Taxing Authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Lapse of Statute of Limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Unrecognized Tax Benefits at the End of Year Amount related to unrecognized tax benefits that if reversed would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Interest and penalties expense/(benefit) related to the liability for unrecognized tax benefits Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Accrued interest and penalties related to the liability for unrecognized tax benefits Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability, Provisional Income Tax (Expense) Benefit Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability, Provisional Income Tax (Expense) Benefit Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability, Provisional Income Tax (Expense) Benefit Components of the Company's provision for income taxes Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Total Current Current Income Tax Expense (Benefit) Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Total Deferred Provision for Income Taxes Net tax charge/(benefit) recorded directly to consolidated shareholders' equity Income Tax Effects Allocated Directly to Equity Significant components of the Company's Deferred Tax Liabilities and Assets Components of Deferred Tax Assets and Liabilities [Abstract] Deferred Tax Liabilities: Deferred Tax Liabilities, Gross [Abstract] Accrued Pension Cost Deferred Tax Liabilities, Accrued Pension Cost The amount as of the balance sheet date of the estimated future tax effects attributable to accrued pension cost. Federal Home Loan Bank Stock Deferred Tax Liabilities, Federal Home Loan Bank Stock The amount as of the balance sheet date of the estimated future tax effects attributable to Federal Home Loan Bank (FHLB) stock. Federal Home Loan Bank stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Lease Transactions Deferred Tax Liabilities, Leasing Arrangements Energy Tax Credits Deferred Tax Liabilities, Energy Tax Credits The amount as of the balance sheet date of the estimated future tax effects attributable to energy tax credits. Investment in Variable Interest Entities Deferred Tax Liabilities, Investment in Unincorporated Entities The tax effect as of the balance sheet date of the amount of the estimated future tax additions attributable to a difference between the tax and GAAP basis of a company’s investment in unincorporated entities which will increase future taxable income when such basis difference reverses. Deferred Loan Fees Deferred Tax Liabilities, Financing Arrangements Originated Mortgage Servicing Rights Deferred Tax Liabilities, Mortgage Servicing Rights Other Deferred Tax Liabilities, Other Gross Deferred Tax Liabilities Deferred Tax Liabilities, Gross Deferred Tax Assets: Deferred Tax Assets, Gross [Abstract] Accelerated Depreciation Deferred Tax Assets, Accelerated Depreciation The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to accelerated depreciation which can only be realized if sufficient taxable income is generated in future periods to enable the deduction to be taken. Allowance for Loan Losses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Provision for Loan Losses Minimum Pension Liability Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions Accrued Expenses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Postretirement Benefit Obligations Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits Capital Lease Expenses Deferred Tax Assets, Capital Lease Expenses The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to capital lease expenses which can only be realized if sufficient taxable income is generated in future periods to enable the deduction to be taken. Restricted Stock Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Net Unrealized Losses on Investment Securities Deferred Tax Assets, Other Comprehensive Loss Deductible State and Local Taxes Deferred Tax Assets, State Taxes Other Deferred Tax Assets, Other Gross Deferred Tax Assets Before Valuation Allowance Deferred Tax Assets, Gross Valuation Allowance Deferred Tax Assets, Valuation Allowance Gross Deferred Tax Assets After Valuation Allowance Deferred Tax Assets, Net of Valuation Allowance Net Deferred Tax Liabilities Deferred Tax Liabilities, Net Base year reserves included in retained earnings boh_DeferredTaxLiabilityNotRecognizedTemporaryDifferenceUndistributedEarningsofDomesticSubsidiaries The amount of the temporary difference for which a deferred tax liability has not been recognized because of the exceptions to comprehensive recognition of deferred taxes related to undistributed earnings of domestic subsidiaries. Unrecognized deferred federal income tax liability Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Domestic Subsidiaries Reconciliation of the Statutory Federal Income Tax Rate to the Company's Effective Tax Rate Effective Income Tax Rate Reconciliation, Percent [Abstract] Statutory Federal Income Tax Rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Increase (Decrease) in Income Tax Rate Resulting From: Effective Income Tax Rate Reconciliation, Increase (Decrease) in Income Tax Rate [Abstract] -- None. No documentation exists for this element. -- State Taxes, Net of Federal Income Tax (Percent) Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Tax Reserve Adjustments (Percent) Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Percent Low-Income Housing Investments (Percent) Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent Investment Tax Credits (Percent) Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent Bank-Owned Life Insurance (Percent) Effective Income Tax Rate Reconciliation, Bank Owned Life Insurance, Percent Effective Income Tax Rate Reconciliation, Bank Owned Life Insurance, Percent Tax-Exempt Income (Percent) Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent Excess Tax Benefits - Stock Compensation (Percent) Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent Deferred Tax Adjustment for Tax Rate Change (Percent) Effective Income Tax Rate Reconciliation,Tax Cuts and Jobs Act of 2017, Percent Effective Income Tax Rate Reconciliation,Tax Cuts and Jobs Act of 2017, Percent Other (Percent) Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective Tax Rate (as a percent) Effective Income Tax Rate Reconciliation, Percent Residential Mortgage Loans Serviced for Third Parties Residential Mortgage Loans Serviced for Third Parties This element represents the amount of residential mortgage loans serviced for third parties. Servicing income, including late and ancillary fees Contractually Specified Servicing Fees, Late Fees, and Ancillary Fees Earned in Exchange for Servicing Financial Assets Reclassification Out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Amortization of Unrealized Gains(Losses) of Investment Securities Transferred from AFS to HTM [Member] Amortization of Unrealized Gains(Losses) of Investment Securities Transferred from AFS to HTM [Member] Amortization of Unrealized Gains(Losses) of Investment Securities Transferred from AFS to HTM [Member] Sale of Investment Securities Available-for-Sale Sale of Investment Securities Available-for-Sale [Member] Sale of Investment Securities Available-for-Sale [Member] Amortization of Defined Benefit Pension Items Prior Service Credit Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Net Actuarial Losses Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] 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] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Investment Income, Interest Investment Income, Interest Available-for-sale Securities, Gross Realized Gain (Loss) Available-for-sale Securities, Gross Realized Gain (Loss) Salaries and Benefits Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest