Loans and Leases Receivable Disclosure [Abstract] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] One- to Four-Family Segment [Member] Residential Portfolio Segment [Member] Commercial Real Estate Segment [Member] Commercial Portfolio Segment [Member] Consumer Segment [Member] Consumer Portfolio Segment [Member] Class of Financing Receivable [Axis] Class of Financing Receivable, Type [Axis] Financing Receivable, Recorded Investment, Class of Financing Receivable [Domain] Class of Financing Receivable, Type [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. Home Equity [Member] Home Equity Line of Credit [Member] Other [Member] Consumer Loan [Member] Financing Receivable, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Number of Contracts Financing Receivable, Modifications, Number of Contracts Pre-Restructured Outstanding Financing Receivable, Modifications, Pre-Modification Recorded Investment Post-Restructured Outstanding Financing Receivable, Modifications, Post-Modification Recorded Investment Statement of Stockholders' Equity [Abstract] Cash dividends to stockholders Common Stock, Dividends, Per Share, Declared Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Financing Receivable, by Credit Quality Indicator [Domain] Internal Credit Assessment [Domain] Doubtful [Member] Doubtful [Member] Loans Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] 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. 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 Loans and Leases Receivable, Net Amount ACL maintained for impaired loans Impaired Financing Receivable, Related Allowance ACL maintained for loans individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Fair Value Disclosures [Abstract] 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] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] GSE Debentures [Member] US Government-sponsored Enterprises Debt Securities [Member] MBS [Member] Residential Mortgage Backed Securities [Member] Municipal Bonds [Member] Municipal Bonds [Member] Trust Preferred Securities [Member] Trust Preferred Securities [Member] A collateralized debt obligation backed by a shared pool of trust preferred securities. Issuers include companies in highly regulated industries such as banks, insurance companies and regulated utilities as well as some general corporate issuers. Most are rated by one or more of the standard rating agencies. 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 Available-for-sale Securities Interest Rate Swaps Derivative Asset Assets Assets, Fair Value Disclosure Interest Rate Swaps Derivative Liability Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Financing Receivable, Recorded Investment [Line Items] Financing Receivable, Recorded Investment [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. Marketable Securities [Abstract] Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Other than temporary impairments, amount Other than Temporary Impairment Losses, Investments Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Line Items] Debt Securities, Available-for-sale [Line Items] Proceeds received from sale of AFS securities Proceeds from Sale of Debt Securities, Available-for-sale Gain on sale of AFS securities Available-for-sale Securities, Gross Realized Gains 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] Changes in unrealized gains (losses) on AFS securities, net of taxes of $437, $345, $1,756 and $1,374 Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax Changes in unrealized gains (losses) on cash flow hedges, net of taxes of $9, $0, $(1,858) and $0 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 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 Originations of loans receivable held-for-sale (LHFS) Payments for Origination of Mortgage Loans Held-for-sale Proceeds from sales of LHFS Proceeds from Sale of Mortgage Loans Held-for-sale 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 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 Compensation Changes in deferred income tax liabilities, net Increase (Decrease) in Deferred Income Taxes Changes in cash collateral received from derivative counterparty, net Increase (Decrease) Cash Collateral from Counterparties Changes in: Increase (Decrease) in Operating Capital [Abstract] Other assets, net Increase (Decrease) in Other Operating Assets Income taxes payable, net Increase (Decrease) in Income Taxes Payable 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 Available-for-sale Securities 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 sale of AFS securities Proceeds from Sale of Available-for-sale 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 increase 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 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 Net change in short-term borrowings Proceeds from (Repayments of) Short-term Debt 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 Excess tax benefits from stock options Excess Tax Benefit from Share-based Compensation, Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities NET DECREASE IN CASH AND CASH EQUIVALENTS Cash and Cash Equivalents, Period Increase (Decrease) CASH AND CASH EQUIVALENTS: Cash and Cash Equivalents, at Carrying Value [Abstract] Beginning of period Cash and Cash Equivalents, at Carrying Value End of period SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Loans transferred to LHFS Transfer of Portfolio Loans and Leases to Held-for-sale Fair Value, Measurements, Nonrecurring [Member] Fair Value, Measurements, 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] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other Income [Member] Other Income [Member] Proceeds received from sale of AFS securities Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Gain on sale of AFS securities Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Proceeds from principal repayments (Decreases) increases in net unrealized losses included in OCI Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Loans individually evaluated for impairment Loans Receivable, Fair Value Disclosure 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 Estimated fair value of deposits Deposits, Fair Value Disclosure Special Mention [Member] Special Mention [Member] Substandard [Member] Substandard [Member] Financing receivable, total recorded investment Loans and Leases Receivable, Net of Deferred Income Statement of Financial Position [Abstract] ASSETS: Assets [Abstract] Cash and cash equivalents (includes interest-earning deposits of $174,490 and $340,748) Securities: Available-for-sale (AFS), at estimated fair value (amortized cost of $556,257 and $410,541) Held-to-maturity (HTM), at amortized cost (estimated fair value of $654,965 and $833,009) Debt Securities, Held-to-maturity Loans receivable, net (allowance for credit losses (ACL) of $8,344 and $8,398) Federal Home Loan Bank Topeka (FHLB) stock, at cost Federal Home Loan Bank Stock Premises and equipment, net Property, Plant and Equipment, Net Other assets Other Assets TOTAL ASSETS Assets LIABILITIES: Liabilities [Abstract] Deposits Deposits, Domestic FHLB borrowings Long-term Federal Home Loan Bank Advances Repurchase agreements Securities Sold under Agreements to Repurchase 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, 138,256,735 and 138,223,835 shares issued and outstanding as of June 30, 2018 and September 30, 2017, 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 Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (AOCI), net of tax Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders' equity Stockholders' Equity Attributable to Parent TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity Accounting Policies [Abstract] Summary Of Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Changes in unrealized gains (losses) on AFS securities, deferred income taxes Other Comprehensive Income (Loss), Securities, Available-for-sale, 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 Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Deposit Account [Member] Deposit Account [Member] Statement [Line Items] Statement [Line Items] INTEREST AND DIVIDEND INCOME: Interest and Dividend Income, Operating [Abstract] Loans receivable Interest and Fee Income, Loans and Leases Cash and cash equivalents Interest Income, Deposits with Financial Institutions Mortgage-backed securities (MBS) Interest Income, Securities, Mortgage Backed FHLB stock Investment securities Interest and Dividend Income, Securities, Operating Total interest and dividend income Interest and Dividend Income, Operating INTEREST EXPENSE: Interest Expense [Abstract] FHLB borrowings Interest Expense, Federal Home Loan Bank and Federal Reserve Bank Advances, Long-term Deposits Interest Expense, Deposits Repurchase agreements Interest Expense, Securities Sold under Agreements to Repurchase 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 NON-INTEREST INCOME: Noninterest Income [Abstract] Retail fees and charges Revenue from Contract with Customer, Including Assessed Tax Income from bank-owned life insurance (BOLI) Bank Owned Life Insurance Income 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 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. 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. Advertising and promotional Advertising Expense Federal insurance premium Federal Deposit Insurance Corporation Premium Expense Office supplies and related expense Supplies and Postage 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) Earnings Per Share, Basic Diluted EPS Earnings Per Share, Diluted Dividends declared per share Basic weighted average common shares Weighted Average Number of Shares Outstanding, Basic Diluted weighted average common shares Weighted Average Number of Shares Outstanding, Diluted Income Tax Disclosure [Table] Income Tax Disclosure [Table] Income Tax Disclosure [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Forecast [Member] Scenario, Forecast [Member] Income Tax Disclosure [Line Items] Income Tax Disclosure [Line Items] [Line Items] for Income Tax Disclosure [Table] Federal corporate income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Revaluation of net deferred tax liability Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Impairment of low income housing partnership investments Affordable Housing Project Investment, Write-down, Amount Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing receivable, nonaccrual loans Financing Receivable, Recorded Investment, Nonaccrual Status Investment Holdings [Table] Investment Holdings [Table] 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 Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses Available-for-sale Securities, 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 Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Estimated Fair Value Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Held-to-maturity Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Estimated Fair Value Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value Held-to-maturity Securities, Continuous Unrealized Loss Position, Equal to or Greater Than 12 Months, Unrealized Losses Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Equity [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] AOCI [Member] AOCI Attributable to Parent [Member] 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] Accumulated Net Investment Gain (Loss) Attributable to 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) Other Comprehensive Income (Loss), Net of Tax Reclassification of certain income tax effects related to adoption of ASU 2018-02 Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect Amount of increase (decrease) in accumulated other comprehensive income (AOCI) for reclassification to retained earnings of tax effect from remeasurement of deferred tax pursuant to Tax Cuts and Jobs Act. Ending balance Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Financing Receivables, Period Past Due [Domain] Financing Receivables, 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. Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Financing receivable, total delinquent loans Financing Receivable, Recorded Investment, Past Due Financing receivable, current loans Financing Receivable, Recorded Investment, Current Financing receivable, total recorded investment 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 Past Due Financing Receivables [Table Text Block] Recorded Investment in Loans, Nonaccrual Schedule of Financing Receivables, Non Accrual Status [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 Troubled Debt Restructurings on Financing Receivables [Table Text Block] Impaired Loans by Class Impaired Financing Receivables [Table Text Block] Allowance for Credit Losses Allowance for Credit Losses on Financing Receivables [Table Text Block] Interest-earning deposits Interest-bearing Deposits in Banks and Other Financial Institutions Available-for-sale securities, amortized cost Available-for-sale Securities, Amortized Cost Basis Held-to-maturity securities, estimated fair value Debt Securities, Held-to-maturity, Fair Value 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 Fair Value Of Financial Instruments Fair Value Disclosures [Text Block] Debt Securities [Member] Debt 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, 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, Estimated Fair Value Held-to-maturity Securities, One year or less, Amortized Cost Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Held-to-maturity Securities, One year through five years, Amortized Cost Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Held-to-maturity Securities, Amortized Cost Held-to-maturity Securities, One year or less, Estimated Fair Value Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Held-to-maturity Securities, One year through five years, Estimated Fair Value Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Held-to-maturity Securities, Estimated Fair Value Basis of Presentation Basis of Accounting, 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 Income Taxes Income Tax, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Document And Entity Information [Abstract] Document and entity information [Abstract] Entity Registrant Name Entity Registrant Name Trading Symbol Trading Symbol Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Earnings Per Share [Abstract] Schedule Of Earnings Per Share, Basic And Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] 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 HTM securities Loans receivable FHLB stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Interest rate swaps Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Deposits FHLB borrowings Federal Home Loan Bank Borrowings, Fair Value Disclosure Repurchase agreements Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure Interest rate swaps Available-for-sale Securities, Gross Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale Securities, Gross Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Securities, Estimated Fair Value Schedule of Held-to-maturity Securities [Table] Debt Securities, Held-to-maturity [Table] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Held-to-maturity Securities, Gross Unrealized Gains Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain Held-to-maturity Securities, Gross Unrealized Losses Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Held-to-maturity securities, Estimated Fair Value 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 Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Recorded Investment Impaired Financing Receivable, Recorded Investment Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Taxable Interest Income, Securities, Operating, Taxable Non-taxable Interest Income, Securities, Operating, Tax Exempt Interest income on investment securities 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 Effect of dilutive stock options Weighted Average Number Diluted Shares Outstanding Adjustment Total diluted average common shares outstanding Net EPS: Earnings Per Share, Basic and Diluted [Abstract] Basic Diluted Antidilutive stock options, excluded from the diluted average common shares outstanding calculation Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Earnings Per Share Earnings Per Share [Text Block] Loans Receivable And Allowance For Credit Losses Financing Receivables [Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Class of Financing Receivable [Domain] Construction [Member] Construction Loans [Member] Permanent [Member] Commercial Loan [Member] Loans receivable, gross Loans and Leases Receivable, before Fees, Gross Total real estate loans Loans and Leases Receivable, Total Real Estate, Gross Total (gross) amount of real estate loans, including unamortized fees, discounts, expenses, and premiums, and undisbursed loan funds. ACL Discounts/unearned loan fees Loans and Leases Receivable, Deferred Income Premiums/deferred costs Loans And Leases Receivable Premiums Deferred Costs Loans And Leases Receivable Premiums Deferred Costs Loans receivable, net 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] Balance Other comprehensive income (loss), net of tax Reclassification of certain tax effects related to adoption of Accounting Standards Update (ASU) 2018-02 ESOP activity, net 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 Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Cumulative effect of adopting ASU 2016-09 Cumulative Effect on Retained Earnings, Net of Tax Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Cash dividends to stockholders Dividends, Cash Balance Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Beginning Balance Financing Receivable, Allowance for Credit Losses Charge-offs Financing Receivable, Allowance for Credit Losses, Write-downs Recoveries Financing Receivable, Allowance for Credit Losses, Recovery Provision for credit losses Provision for Loan, Lease, and Other Losses Ending Balance Average Recorded Investment, No Related Allowance Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Average Recorded Investment, Allowance Recorded Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized, No Related Allowance Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Interest Income Recognized, Allowance Recorded Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Other Comprehensive Income Comprehensive Income (Loss) Note [Text Block] Disclosure of Repurchase Agreements [Abstract] Repurchase Agreements Repurchase Agreements, Resale Agreements, Securities Borrowed, and Securities Loaned Disclosure [Text Block] 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, Recorded Investment The balance of financing receivables that were individually evaluated for impairment. ACL for loans collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [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 Year Two [Member] Maturity Year Two [Member] Maturity period in second fiscal year following the reporting date for repurchase agreements and similar transactions, for example, but not limited to, securities lending arrangements. Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Repurchase Agreements, Description of Potential Risks Repurchase Agreements, Securities Lending Transactions, and Repurchase-to-Maturity Transactions Accounted for as Secured Borrowings, Description of Potential Risks Weighted average rate of repurchase agreements Assets Sold under Agreements to Repurchase, Interest Rate Amortized Cost, Estimated Fair Value, And Gross Unrealized Gains And Losses Of AFS Securities Available-for-sale Securities [Table Text Block] Amortized Cost, Estimated Fair Value, And Gross Unrealized Gains And Losses Of HTM Securities Debt Securities, Held-to-maturity [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. 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] Number of Contracts Financing Receivable, Modifications, Subsequent Default, Number of Contracts Recorded Investment Financing Receivable, Modifications, Subsequent Default, Recorded Investment