Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Unrealized gains (losses) on AFS securities arising during the period, net of taxes of $145 and $(1,133) Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Changes in unrealized gains (losses) on cash flow hedges, net of taxes of $(1,741) and $3,128 Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Marketable Securities [Abstract] Public unit deposits Pledged Financial Instruments, Not Separately Reported, Securities for Public Unit Deposits The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for public unit deposits, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party. Repurchase agreements Pledged Financial Instruments, Not Separately Reported, Securities for Repurchase Agreements Federal Reserve Bank of Kansas City (FRB of Kansas City) Pledged Financial Instruments, Not Separately Reported, Securities for Other Debt Facilities Total securities pledged as collateral Pledged Financial Instruments, Not Separately Reported, Securities Loans and Leases Receivable Disclosure [Abstract] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] One- to Four-Family Segment [Member] Residential Portfolio Segment [Member] Commercial Segment [Member] Commercial Portfolio Segment [Member] Consumer Segment [Member] Consumer Portfolio Segment [Member] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Financing Receivable, Recorded Investment, Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Originated [Member] One To Four Family Loans Originated [Member] One To Four Family Loans Originated [Member] Correspondent Purchased [Member] One To Four Family Loans Correspondent Purchased [Member] Correspondent purchased loan secured by residential real estate as a single family home or a multi-unit dwelling of two to four units. Bulk Purchased [Member] One To Four Family Loans Bulk Purchased [Member] Bulk purchased loan secured by residential real estate as a single family home or a multi-unit dwelling of two to four units. Commercial Real Estate [Member] Commercial Real Estate Portfolio Segment [Member] Commercial and Industrial [Member] Commercial Loan [Member] Home Equity [Member] Home Equity Line of Credit [Member] Other [Member] Consumer Loan [Member] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] Financial Asset, 30 to 89 Days Past Due [Member] Financing Receivables, 30 to 89 Days Past Due [Member] Financing receivables that are more than 29 days past due but fewer than 90 days past due. Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Financing receivable, total delinquent loans Financing Receivable, Past Due Financing receivable, current loans Financing Receivable, Not Past Due Financing receivable, total recorded investment Loans and Leases Receivable, Net of Deferred Income Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Statement of Financial Position [Abstract] Interest-earning deposits Interest-bearing Deposits in Banks and Other Financial Institutions Loans receivable, allowance for credit losses Loans and Leases Receivable, Allowance Preferred stock, par value Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued Preferred Stock, Shares Issued Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Unrealized gains (losses) on AFS securities arising during the period, deferred income taxes Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Changes in unrealized gains (losses) on cash flow hedges, deferred income taxes Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Financing Receivable, Impaired [Line Items] 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 Impaired loans, Recorded Investment Impaired Financing Receivable, Recorded Investment Impaired loans, Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Impaired loans, Related ACL Impaired Financing Receivable, Related Allowance Accounting Policies [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash and cash equivalents Restricted Cash and Cash Equivalents Restricted cash and cash equivalents, balance sheet location Restricted Cash and Cash Equivalents, Asset, Statement of Financial Position [Extensible List] Right-of-use asset, amount Operating Lease, Right-of-Use Asset Lease liability, amount Operating Lease, Liability Cumulative effect of adopting Accounting Standards Update Cumulative Effect on Retained Earnings, Net of Tax Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Earnings Per Share Reconciliation Effect On Basic Earnings Per Share [Axis] Earnings Per Share Reconciliation Effect On Basic Earnings Per Share [Axis] Earnings Per Share Reconciliation, Effect On Basic Earnings Per Share [Axis] Earnings Per Share Reconciliation Effect On Basic Earnings Per Share [Domain] Earnings Per Share Reconciliation Effect On Basic Earnings Per Share [Domain] Earnings Per Share Reconciliation Effect On Basic Earnings Per Share [Domain] Average Common Shares Outstanding [Member] Average Common Shares Outstanding [Member] Average common shares outstanding Average Committed ESOP Shares Outstanding [Member] Average Committed Employee Stock Ownership Plan Shares Outstanding [Member] Average committed employee stock ownership plan shares outstanding Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Earnings Per Share Earnings Per Share Reconciliation [Abstract] Income allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Net income available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Total basic average common shares outstanding Weighted Average Number of Shares Outstanding, Basic Effect of dilutive stock options Weighted Average Number Diluted Shares Outstanding Adjustment Total diluted average common shares outstanding Weighted Average Number of Shares Outstanding, Diluted Net EPS: Earnings Per Share, Basic and Diluted [Abstract] Basic Earnings Per Share, Basic Diluted Earnings Per Share, Diluted Antidilutive stock options, excluded from the diluted average common shares outstanding calculation Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Leases [Abstract] 2020 Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months 2021 Lessee, Operating Lease, Liability, Payments, Due Year Two 2022 Lessee, Operating Lease, Liability, Payments, Due Year Three 2023 Lessee, Operating Lease, Liability, Payments, Due Year Four 2024 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total future minimum lease payments Lessee, Operating Lease, Liability, Payments, Due Amounts representing interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of net future minimum lease payments Revenue from Contract with Customer [Abstract] Revenue Recognition Revenue from Contract with Customer [Text Block] Equity [Abstract] Accumulated Other Comprehensive Income Comprehensive Income (Loss) Note [Text Block] Leases Lessee, Operating Leases [Text Block] Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Financing receivable, nonaccrual loans Financing Receivable, Nonaccrual Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Operating leases, remaining term Lessee, Operating Lease, Term of Contract Right-of-use asset, balance sheet location Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Lease liability, balance sheet location Operating Lease, Liability, Statement of Financial Position [Extensible List] Operating leases, weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Operating leases, weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Operating lease expense Operating Lease, Cost Variable lease expense Variable Lease, Cost Short-term lease expense Short-term Lease, Cost Cash paid for amounts included in the measurement of lease liabilities Operating Lease, Payments Taxable Interest Income, Securities, Operating, Taxable Non-taxable Interest Income, Securities, Operating, Tax Exempt Interest income on investment securities Interest and Dividend Income, Securities, Operating Schedule Of Earnings Per Share, Basic And Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] 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 Impaired loans, Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Impaired loans, Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Weighted average credit score Weighted Average Credit Score Weighted Average Credit Score Weighted average LTV Weighted Average Loan To Value Ratio Weighted Average Loan To Value Ratio. Schedule of Future Minimum Payments for Operating Leases Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of Future Minimum Rental Commitments Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Beginning Balance Financing Receivable, Allowance for Credit Loss Charge-offs Financing Receivable, Allowance for Credit Loss, Writeoff Recoveries Financing Receivable, Allowance for Credit Loss, Recovery Provision for credit losses Provision for Loan, Lease, and Other Losses Ending Balance Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] 2020 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2021 Operating Leases, Future Minimum Payments, Due in Two Years 2022 Operating Leases, Future Minimum Payments, Due in Three Years 2023 Operating Leases, Future Minimum Payments, Due in Four Years 2024 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Future minimum rental commitments, total Operating Leases, Future Minimum Payments Due Investment Holdings [Table] Investment Holdings [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Debt Securities [Member] Debt Securities [Member] MBS [Member] Residential Mortgage Backed Securities [Member] Investment Holdings [Line Items] Investment Holdings [Line Items] Available-for-sale Securities, One year or less, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Available-for-sale Securities, One year through five years, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Available-for-sale Securities, Five years through ten years, Amortized Cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Available-for-sale Securities, Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Available-for-sale Securities, One year or less, Estimated Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Available-for-sale Securities, One year through five years, Estimated Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Available-for-sale Securities, Five years through ten years, Estimated Fair Value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Available-for-sale Securities, Estimated Fair Value Debt Securities, Available-for-sale Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] GSE Debentures [Member] US Government-sponsored Enterprises Debt Securities [Member] Municipal Bonds [Member] Municipal Bonds [Member] Schedule of Available-for-sale Securities [Line Items] Debt Securities, Available-for-sale [Line Items] Available-for-sale Securities, Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Available-for-sale Securities, Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Securities, Estimated Fair Value Debt Disclosure [Abstract] Borrowed Funds Debt Disclosure [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Class of Financing Receivable [Domain] Construction [Member] Construction Loans [Member] Loans Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Loans receivable, gross Loans and Leases Receivable, before Fees, Gross ACL Discounts/unearned loan fees Loans and Leases Receivable, Deferred Income Premiums/deferred costs Loans And Leases Receivable Premiums Deferred Costs Amount of deferred premiums over face amounts of purchased and acquired loans and unamortized costs incurred to originate loans. Loans receivable, net Loans and Leases Receivable, Net Amount Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Financing Receivable, by Credit Quality Indicator [Domain] Internal Credit Assessment [Domain] Doubtful [Member] Doubtful [Member] Loan-to-value ratio securing commercial real estate loans, maximum Loan To Value Ratio For Securing Commercial Real Estate Loans Maximum Loan To Value Ratio For Securing Commercial Real Estate Loans Maximum Debt service coverage ratio for commercial real estate loans, minimum Debt Service Coverage Ratio For Commercial Real Estate Loans Minimum For commercial real estate loans, the minimum acceptable debt service coverage ratio. Loan-to-value ratio securing commercial construction loans, maximum Loan to Value Ratio for Securing Commercial Construction Loans Maximum For commercial construction loans, the maximum acceptable loan to value ratio Recorded investment of loans in process of foreclosure Mortgage Loans in Process of Foreclosure, Amount Carrying value of residential OREO Real Estate Acquired Through Foreclosure Loans receivable Fair Value Disclosures [Abstract] Schedule Of Fair Value Assets Measured On A Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule Of Carrying Amounts And Estimated Fair Values Of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Statement of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest 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] FHLB stock dividends Dividend Income, Operating Provision for credit losses Provision for Loan and Lease Losses Amortization and accretion of premiums and discounts on securities Accretion (Amortization) of Discounts and Premiums, Investments Depreciation and amortization of premises and equipment Depreciation, Nonproduction Amortization of intangible assets Amortization of Intangible Assets Amortization of deferred amounts related to FHLB advances, net Amortization of Deferred Amounts Related to fhlb Advances, Net Includes amortization of deferred gains and prepayment penalties related to FHLB advances or derivatives related to FHLB advances. Common stock committed to be released for allocation - ESOP Employee Stock Ownership Plan (ESOP), Compensation Expense Stock-based compensation Share-based Payment Arrangement, Noncash Expense Changes in: Increase (Decrease) in Operating Capital [Abstract] Unrestricted cash collateral (provided to)/received from derivative counterparties, net Increase (Decrease) Cash Collateral from Counterparties Other assets, net Increase (Decrease) in Other Operating Assets Income taxes payable/receivable, net Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable Deferred income tax liabilities, net Increase (Decrease) in Deferred Income Taxes Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchase of AFS securities Payments to Acquire Debt Securities, Available-for-sale Proceeds from calls, maturities and principal reductions of AFS securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Proceeds from calls, maturities and principal reductions of HTM securities Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Proceeds from the redemption of FHLB stock Proceeds from Sale of Federal Home Loan Bank Stock Purchase of FHLB stock Payments to Acquire Federal Home Loan Bank Stock Net change in loans receivable Payments for (Proceeds from) Loans and Leases Purchase of premises and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sale of other real estate owned (OREO) Proceeds from Sale of Foreclosed Assets Proceeds from bank-owned life insurance (BOLI) death benefit Proceeds from Life Insurance Policy Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Cash dividends paid Payments of Dividends Net change in deposits Increase (Decrease) in Deposits Proceeds from borrowings Proceeds from FHLBank Borrowings, Financing Activities Repayments on borrowings Payments of FHLBank Borrowings, Financing Activities Change in advance payments by borrowers for taxes and insurance Increase (Decrease) in Advance Payments by Borrowers for Taxes and Insurance Stock options exercised Proceeds from Stock Options Exercised Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities NET DECREASE IN CASH, CASH EQUIVALENTS, RESTRICTED CASH AND RESTRICTED CASH EQUIVALENTS Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect CASH, CASH EQUIVALENTS, RESTRICTED CASH AND RESTRICTED CASH EQUIVALENTS: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] Beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents End of period SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Operating lease right-of-use assets obtained Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Operating lease liabilities obtained Operating Lease Liability Obtained Amount of increase in lease liability recognized Statement of Stockholders' Equity [Abstract] Cash dividends to stockholders Common Stock, Dividends, Per Share, Declared Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Recurring [Member] Fair Value, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) [Member] Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] AFS securities Interest rate swaps Derivative Liability Schedule of Investments [Line Items] Schedule of Investments [Line Items] Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-In Capital [Member] Additional Paid-in Capital [Member] Unearned Compensation ESOP [Member] Employee Stock Ownership Plan [Member] A plan where shares of company stock are allocated to qualified employees based on the proportion of their qualifying compensation to total qualifying compensation. Funds are borrowed by the ESOP from the Company to purchase the Company's common stock and repaid from the Bank's contributions and dividends paid on unallocated ESOP shares. The shares pledged as collateral are reported as a reduction of stockholders' equity at cost. As ESOP shares are committed to be released from collateral each quarter, the Company records compensation expense based on the average market price of the Company's stock during the quarter. Additionally, the shares become outstanding for earnings per share ("EPS") computations once they are committed to be released. Retained Earnings [Member] Retained Earnings [Member] AOCI [Member] AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Balance Stockholders' Equity Attributable to Parent Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax ESOP activity Stock Issued During Period, Value, Employee Stock Ownership Plan Restricted stock activity, net Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Cash dividends to stockholders Dividends, Cash Balance Summary Of Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Number of Contracts Financing Receivable, Modifications, Number of Contracts Pre-Restructured Outstanding Financing Receivable, Troubled Debt Restructuring, Premodification Post-Restructured Outstanding Financing Receivable, Troubled Debt Restructuring, Postmodification Number of Contracts Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Recorded Investment Financing Receivable, Troubled Debt Restructuring, Subsequent Default Other than temporary impairments, amount Other than Temporary Impairment Losses, Investments Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Amount [Member] Reported Value Measurement [Member] Estimated Fair Value [Member] 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] Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Loans receivable Loans Receivable, Fair Value Disclosure FHLB stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Deposits Deposits, Fair Value Disclosure Borrowings Federal Home Loan Bank Borrowings, Fair Value Disclosure Summary of Loans Receivable Summary Of Loans Receivable By Category [Table Text Block] Tabular disclosure of the various types of loans receivable and for each the gross carrying value as of the balance sheet date. Recorded Investment in Loans, Past Due Financing Receivable, Past Due [Table Text Block] Recorded Investment in Loans, Nonaccrual Financing Receivable, Nonaccrual [Table Text Block] Recorded Investment in Classified Loans Financing Receivable Credit Quality Indicators [Table Text Block] Weighted Average Loan-to-Value and Credit Score Information Financing Receivable Credit Quality Indicator Loan To Value And Credit Scores [Table Text Block] Financing Receivable Credit Quality Indicator Loan To Value And Credit Scores Troubled Debt Restructurings on Financing Receivables Financing Receivable, Troubled Debt Restructuring [Table Text Block] Impaired Loans by Class Impaired Financing Receivables [Table Text Block] Allowance for Credit Losses Financing Receivable, Allowance for Credit Loss [Table Text Block] Income Statement [Abstract] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Deposit service fees [Member] Deposit Account [Member] Insurance commissions [Member] Insurance Services [Member] Services provided in the capacity of an agent between the Company's customer and the insurance carrier INTEREST AND DIVIDEND INCOME: Interest and Dividend Income, Operating [Abstract] Loans receivable Interest and Fee Income, Loans and Leases Mortgage-backed securities (MBS) Interest Income, Securities, Mortgage Backed FHLB stock Investment securities Interest Income, Debt Securities, Operating Cash and cash equivalents Interest Income, Deposits with Financial Institutions Total interest and dividend income Interest and Dividend Income, Operating INTEREST EXPENSE: Interest Expense [Abstract] Deposits Interest Expense, Deposits Borrowings Interest Expense, Borrowings Total interest expense Interest Expense NET INTEREST INCOME Interest Income (Expense), Net PROVISION FOR CREDIT LOSSES NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES Interest Income (Expense), after Provision for Loan Loss NON-INTEREST INCOME: Noninterest Income [Abstract] Revenue from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Other non-interest income Noninterest Income, Other Total non-interest income Noninterest Income NON-INTEREST EXPENSE: Noninterest Expense [Abstract] Salaries and employee benefits Labor and Related Expense Information technology and related expense Communications and Information Technology Occupancy, net Occupancy, Net Advertising and promotional Advertising Expense Regulatory and outside services Regulatory And Professional Fees Fees charged for services from professionals such as lawyers and accountants, and fees paid to regulators for conducting regulatory examinations. Deposit and loan transaction costs Deposit And Loan Transaction Costs Expense paid for miscellaneous loan fees that are not deferred, and fees related to deposit transactions, such as debit card processing, electronic banking, and ATM networks. Office supplies and related expense Supplies and Postage Expense Federal insurance premium Federal Deposit Insurance Corporation Premium Expense Other non-interest expense Other Noninterest Expense Total non-interest expense Noninterest Expense INCOME BEFORE INCOME TAX EXPENSE Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest INCOME TAX EXPENSE Income Tax Expense (Benefit) NET INCOME Basic earnings per share (EPS) Diluted EPS Basic weighted average common shares Diluted weighted average common shares Interest rate swaps, notional amount Derivative Liability, Notional Amount FHLB advances, variable rate Federal Home Loan Bank, Advances, Maturities Summary, Floating Rate Interest rate swaps, remaining term to maturity Derivative, Average Remaining Maturity Interest rate swaps, fair value Derivative, Fair Value, Net Interest rate swaps, amount reclassified from AOCI Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Interest rate swaps, amount of hedge ineffectiveness recognized Loss on Cash Flow Hedge Ineffectiveness Interest rate swaps, future amount to be reclassified from AOCI Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Interest rate swaps, collateral posted Collateral Already Posted, Aggregate Fair Value Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Net Presentation of Cash Flows Related to Borrowings Net Presentation of Cash Flows Related to Borrowings [Policy Text Block] Disclosure of accounting policy for net presentation of cash flows related to borrowings Leases Lessee, Leases [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Interchange network charges Interchange Network Charges Transaction related costs paid in order to participate in debit card payment networks Loans Receivable And Allowance For Credit Losses Financing Receivables [Text Block] Amortized Cost, Estimated Fair Value, And Gross Unrealized Gains And Losses Of AFS Securities Debt Securities, Available-for-sale [Table Text Block] Schedule Of Estimated Fair Value And Gross Unrealized Losses Of Securities In Continuous Unrealized Loss Position Unrealized Gain (Loss) on Investments [Table Text Block] Schedule Of Contractual Maturities Investments Classified by Contractual Maturity Date [Table Text Block] Schedule Of Taxable And Non-taxable Components Of Interest Income Interest Income and Interest Expense Disclosure [Table Text Block] Schedule Of Carrying Value Of Securities Pledged As Collateral Schedule Of Carrying Value Of Securities Pledged As Collateral Table Text Block Schedule Of Carrying Value Of Securities Pledged As Collateral. Special Mention [Member] Special Mention [Member] Substandard [Member] Substandard [Member] Financing receivable, total recorded investment Recorded investment in loans collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Recorded investment in loans individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment ACL for loans collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment ACL for loans individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Cover page. Document Type Document Type Quarterly Report indicator Document Quarterly Report Period End Date Document Period End Date Transition Report indicator Document Transition Report Commission file number Entity File Number Registrant Name Entity Registrant Name State of incorporation Entity Incorporation, State or Country Code IRS identification number Entity Tax Identification Number Address of principal executive offices location Entity Address, Address Line One City of principal executive offices location Entity Address, City or Town State of principal executive offices location Entity Address, State or Province Zip code of principal executive offices location Entity Address, Postal Zip Code Telephone number - Area code City Area Code Telephone number Local Phone Number Title of security class Title of 12(b) Security Trading symbol Trading Symbol Name of exchange on which securities are registered Security Exchange Name Entity current reporting status indicator Entity Current Reporting Status Interactive data current reporting status indicator Entity Interactive Data Current Filer category Entity Filer Category Smaller Reporting Company indicator Entity Small Business Emerging Growth Company indicator Entity Emerging Growth Company Shell company indicator Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag ASSETS: Assets [Abstract] Cash and cash equivalents (includes interest-earning deposits of $46,427 and $198,809) Available-for-sale (AFS) securities, at estimated fair value Loans receivable, net (allowance for credit losses (ACL) of $9,435 and $9,226) Federal Home Loan Bank Topeka (FHLB) stock, at cost Federal Home Loan Bank Stock Premises and equipment, net Property, Plant and Equipment, Net Income taxes receivable, net Income Taxes Receivable Other assets Other Assets TOTAL ASSETS Assets LIABILITIES: Liabilities [Abstract] Deposits Deposits, Domestic Borrowings Long-term Federal Home Loan Bank Advances Advance payments by borrowers for taxes and insurance Advance Payments by Borrowers for Taxes and Insurance Income taxes payable, net Accrued Income Taxes, Current Deferred income tax liabilities, net Deferred Tax Liabilities, Net Accounts payable and accrued expenses Accounts Payable and Other Accrued Liabilities Total liabilities Liabilities STOCKHOLDERS' EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $.01 par value; 100,000,000 shares authorized, no shares issued or outstanding Preferred Stock, Value, Issued Common stock, $.01 par value; 1,400,000,000 shares authorized, 141,502,665 and 141,440,030 shares issued and outstanding as of December 31, 2019 and September 30, 2019, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Unearned compensation, Employee Stock Ownership Plan (ESOP) Unearned ESOP Shares Cost Cost of unearned shares that qualify as permanent equity that are held by an employee stock ownership plan (ESOP) Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive (loss) income (AOCI), net of tax Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders' equity TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity Fair Value Of Financial Instruments Fair Value Disclosures [Text Block] Fair Value, Nonrecurring [Member] Fair Value, Nonrecurring [Member] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Estimated Selling Costs [Member] Measurement Input, Cost to Sell [Member] Lack of Marketability [Member] Measurement Input, Discount for Lack of Marketability [Member] Weighted Average [Member] Weighted Average [Member] Loans individually evaluated for impairment Loans receivable, measurement input Loans Receivable, Measurement Input Value of input used by financial institution to measure loans receivable at fair value OREO Other Real Estate OREO, measurement input Other Real Estate Owned, Measurement Input Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Other Comprehensive Income Components [Axis] Other Comprehensive Income Location [Axis] Other Comprehensive Income Components [Domain] Other Comprehensive Income Location [Domain] Unrealized Gains (Losses) on AFS Securities [Member] AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Unrealized Gains (Losses) on Cash Flow Hedges [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Beginning balance Other comprehensive income (loss), before reclassifications OCI, before Reclassifications, Net of Tax, Attributable to Parent Amount reclassified from AOCI Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Other comprehensive income (loss) Ending balance