Document Type Document Type Troubled Debt Restructurings on Financing Receivables Financing Receivable, Troubled Debt Restructuring [Table Text Block] Originations of loans receivable held-for-sale ("LHFS") Payments for Origination of Mortgage Loans Held-for-sale 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] Retail deposits Pledged Financial Instruments Not Separately Reported Securities for Retail 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 retail 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. Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] OREO, measurement input Other Real Estate Owned, Measurement Input Significant Unobservable Inputs (Level 3) [Member] Fair Value, Inputs, Level 3 [Member] Deposit service fees [Member] Deposit Account [Member] Available-for-sale Securities, One year through five years, Estimated Fair Value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Estimated Selling Costs [Member] Measurement Input, Cost to Sell [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Deferred income tax liabilities, net Deferred Income Tax Liabilities, Net Salaries and employee benefits Labor and Related Expense Name of exchange on which securities are registered Security Exchange Name Proceeds from bank-owned life insurance ("BOLI") death benefit Proceeds from Life Insurance Policy Net change in deposits Increase (Decrease) in Deposits 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. Restricted stock activity, net Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Repurchase of common stock Payments for Repurchase of Common Stock ASSETS: Assets [Abstract] Accounting Policies [Abstract] Accounting Policies [Abstract] Loans and Leases Receivable Disclosure [Abstract] Loans and Leases Receivable Disclosure [Abstract] Borrowings Federal Home Loan Bank Borrowings, Fair Value Disclosure State of principal executive offices location Entity Address, State or Province Earnings Per Share Earnings Per Share Reconciliation [Abstract] Accumulated Other Comprehensive Income Comprehensive Income (Loss) Note [Text Block] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Retained earnings Retained Earnings (Accumulated Deficit) Other comprehensive income (loss), before reclassifications - Cash Flow Hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Q-factor adjustment - Economic Uncertainty [Member] Q-factor adjustment - Economic Uncertainty [Member] Amount of ACL q-factor adjustment related to Economic Uncertainty 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. CASH, CASH EQUIVALENTS, RESTRICTED CASH AND RESTRICTED CASH EQUIVALENTS: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] ACL for loans individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Income allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Taxable Interest Income, Securities, Operating, Taxable Interest rate swaps, notional amount Derivative Liability, Notional Amount Preferred stock, $.01 par value; 100,000,000 shares authorized, no shares issued or outstanding Preferred Stock, Value, Issued One- to Four-Family Segment [Member] Residential Portfolio Segment [Member] 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. Interest rate swaps, collateral posted Collateral Already Posted, Aggregate Fair Value Common stock, par value Common Stock, Par or Stated Value Per Share Impaired loans with related allowance, Recorded Investment Impaired Financing Receivable, with Related Allowance, Recorded Investment Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition 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. Balance at October 1, 2020 [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Impaired loans with related allowance, Average Recorded Investment Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Revenue from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Measurement Frequency [Domain] Measurement Frequency [Domain] Advertising and promotional Advertising Expense Impaired loans with no related allowance, Unpaid Principal Balance Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Net change in loans receivable Payments for (Proceeds from) Loans and Leases Current Loans Financing Receivable, Not Past Due 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. Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Statement [Line Items] Statement [Line Items] Forecast [Member] Forecast [Member] Deferred income tax liabilities, net Increase (Decrease) in Deferred Income Taxes 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 Net EPS: Earnings Per Share, Basic and Diluted [Abstract] FHLB Advances, Term Debt Instrument, Term Q-factor adjustment - Special Mention Loans [Member] Q-factor adjustment - Special Mention Loans [Member] Amount of ACL q-factor adjustment related to special mention loans Measurement Input Type [Domain] Measurement Input Type [Domain] Statement [Table] Statement [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] 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. Delinquent Loans Financing Receivable, Past Due [Table Text Block] Preferred stock, shares issued Preferred Stock, Shares Issued Federal Reserve Bank of Kansas City ("FRB of Kansas City") Pledged Financial Instruments, Not Separately Reported, Securities for Other Debt Facilities Net charge-offs Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery Fair Value, Nonrecurring [Member] Fair Value, Nonrecurring [Member] Weighted Average [Member] Weighted Average [Member] Credit Quality Indicators Financing Receivable Credit Quality Indicators [Table Text Block] Securities Marketable Securities, Policy [Policy Text Block] Originated [Member] One To Four Family Loans Originated [Member] One To Four Family Loans Originated [Member] Smaller Reporting Company indicator Entity Small Business Commercial Segment [Member] Commercial Portfolio Segment [Member] Loans receivable, measurement input Loans Receivable, Measurement Input Value of input used by financial institution to measure loans receivable at fair value Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Borrowed Funds Debt Disclosure [Text Block] Total interest and dividend income Interest and Dividend Income, Operating Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] Amendment Flag Amendment Flag Schedule Of Earnings Per Share, Basic And Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Impaired loans with related allowance, Interest Income Recognized Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Income taxes payable/receivable, net Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable Loans receivable, allowance for credit losses ACL Loans and Leases Receivable, Allowance Schedule Of Fair Value Assets Measured On A Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Interest rate swaps, amount reclassified from AOCI Amount reclassified from AOCI - Cash Flow Hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities 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. Financing receivable, nonaccrual loans Financing Receivable, Nonaccrual Entity Central Index Key Entity Central Index Key Measurement Frequency [Axis] Measurement Frequency [Axis] 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 FHLB Advances, Effective Interest Rate Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Effective Interest Rate at Period End States the effective interest rate applicable to Federal Home Loan Bank advances outstanding as of the Balance Sheet date. Financial Instruments [Domain] Financial Instruments [Domain] Allowance for Credit Losses and Reserve for Off-Balance Sheet Credit Exposures Credit Loss, Financial Instrument [Policy Text Block] Schedule Of Carrying Amounts And Estimated Fair Values Of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Impaired loans with related allowance, Unpaid Principal Balance Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] 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 Accounts payable and accrued expenses Accounts Payable and Other Accrued Liabilities 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. Non-taxable Interest Income, Securities, Operating, Tax Exempt Consumer Segment [Member] Consumer Portfolio Segment [Member] FHLB stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Available-for-sale securities, amortized cost Available-for-sale Securities, Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Marketable Securities [Line Items] Marketable Securities [Line Items] Available-for-sale Securities, Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Loans receivable Interest and Fee Income, Loans and Leases Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Interest-earning deposits Interest-bearing Deposits in Banks and Other Financial Institutions Effect of dilutive stock options Weighted Average Number Diluted Shares Outstanding Adjustment Fiscal Year 2019 Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Average Common Shares Outstanding [Member] Average Common Shares Outstanding [Member] Average common shares outstanding NON-INTEREST INCOME: Noninterest Income [Abstract] Unrealized Gains (Losses) on Cash Flow Hedges [Member] Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Amortization of intangible assets Amortization of Intangible Assets Proceeds from sales of LHFS Proceeds from Sale of Mortgage Loans Held-for-sale Interest rate swaps, fair value Derivative, Fair Value, Net 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) Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure TOTAL ASSETS Assets Cash and cash equivalents Interest Income, Deposits with Financial Institutions Scenario [Axis] Scenario [Axis] Title of security class Title of 12(b) Security Financial Asset, Current [Member] Financing Receivable, Current [Member] Financing receivables that are less than days past due. Operating lease liabilities obtained Operating Lease Liability Obtained Amount of increase in lease liability recognized Depreciation and amortization of premises and equipment Depreciation, Nonproduction Income taxes payable, net Accrued Income Taxes, Current Unrealized gains (losses) on AFS securities arising during the period, net of taxes of $(409) and $145 Other comprehensive income (loss), before reclassifications - AFS Securities OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Lack of Marketability [Member] Measurement Input, Discount for Lack of Marketability [Member] Recorded investment in loans individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment 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] Commercial Real Estate [Member] Commercial Real Estate Portfolio Segment [Member] Common stock committed to be released for allocation - ESOP Employee Stock Ownership Plan (ESOP), Compensation Expense Total interest expense Interest Expense Federal Home Loan Bank Topeka ("FHLB") stock, at cost Federal Home Loan Bank Stock Provision for credit losses on off-balance sheet credit exposures Provision for credit losses Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Accrued interest, AFS debt securities Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss Schedule Of Estimated Fair Value And Gross Unrealized Losses Of Securities In Continuous Unrealized Loss Position Unrealized Gain (Loss) on Investments [Table Text Block] Cumulative effect adjustment - adoption of CECL Accounting Standards Update and Change in Accounting Principle [Table Text Block] Product and Service [Axis] Product and Service [Axis] 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 Total liabilities Liabilities Financing Receivable, by Credit Quality Indicator [Domain] Internal Credit Assessment [Domain] Mortgage-backed securities ("MBS") Interest Income, Securities, Mortgage Backed Proceeds from borrowings Proceeds from FHLBank Borrowings, Financing Activities Accrued interest, loans receivable - balance sheet location Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible List] FHLB stock FHLB stock dividends Dividend Income, Operating Other Comprehensive Income Components [Domain] Other Comprehensive Income Location [Domain] Carrying value of residential OREO Real Estate Acquired Through Foreclosure Net income available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Fair Value, Inputs, Level 1 [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Impaired loans, Average Recorded Investment Impaired Financing Receivable, Average Recorded Investment Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] 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 ACL Beginning Balance Ending Balance ACL Financing Receivable, Allowance for Credit Loss Debt Instrument [Axis] Debt Instrument [Axis] Additional Paid-In Capital [Member] Additional Paid-in Capital [Member] NET INTEREST INCOME Interest Income (Expense), Net Deposits Interest Expense, Deposits Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Other assets Other Assets Interest rate swaps Derivative Liability 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] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Common stock, shares outstanding Common Stock, Shares, Outstanding Proceeds from sale of other real estate owned ("OREO") Proceeds from Sale of Foreclosed Assets Schedule of Investments [Line Items] Schedule of Investments [Line Items] Number of Contracts Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Home Equity [Member] Home Equity Line of Credit [Member] NON-INTEREST EXPENSE: Noninterest Expense [Abstract] Common stock, shares authorized Common Stock, Shares Authorized Stock options exercised Proceeds from Stock Options Exercised Impaired Loans Impaired Financing Receivables [Table Text Block] Change in advance payments by borrowers for taxes and insurance Increase (Decrease) in Advance Payments by Borrowers for Taxes and Insurance Estimated Fair Value [Member] Estimate of Fair Value Measurement [Member] Impaired loans, Related ACL Impaired Financing Receivable, Related Allowance Income Statement [Abstract] Income Statement [Abstract] AOCI [Member] AOCI Attributable to Parent [Member] Deposits Deposits, Domestic Schedule Of Contractual Maturities Investments Classified by Contractual Maturity Date [Table Text Block] FHLB Advances, Interest Rate Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End Payment of FHLB prepayment penalties Payments of Debt Restructuring Costs Occupancy, net Occupancy, Net Insurance commissions [Member] Insurance Services [Member] Services provided in the capacity of an agent between the Company's customer and the insurance carrier MBS [Member] Residential Mortgage Backed Securities [Member] Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Preferred stock, par value Preferred Stock, Par or Stated Value Per Share GSE Debentures [Member] US Government-sponsored Enterprises Debt Securities [Member] Scenario [Domain] Scenario [Domain] Impaired loans with no related allowance, Average Recorded Investment Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Purchase of premises and equipment Payments to Acquire Property, Plant, and Equipment Telephone number - Area code City Area Code Period End Date Document Period End Date Replacement FHLB Advances [Member] Replacement FHLB Advances [Member] Replacement FHLB Advances [Member] Amortized cost of loans in process of foreclosure Mortgage Loans in Process of Foreclosure, Amount Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest INCOME BEFORE INCOME TAX EXPENSE Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Amount reclassified from AOCI Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Loans receivable, net (allowance for credit losses ("ACL") of $26,125 and $31,527) Loans receivable Loans receivable, net Loans and Leases Receivable, Net Amount 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 Stock-based compensation Share-based Payment Arrangement, Noncash Expense Repurchase of common stock Stock Repurchased During Period, Value Commercial and Industrial [Member] Commercial Loan [Member] Pre-Restructured Outstanding Financing Receivable, Troubled Debt Restructuring, Premodification Marketable Securities [Table] Marketable Securities [Table] Cover [Abstract] Cover [Abstract] Measurement Input Type [Axis] Measurement Input Type [Axis] Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Amortized Cost, Estimated Fair Value, And Gross Unrealized Gains And Losses Of AFS Securities Debt Securities, Available-for-sale [Table Text Block] Other comprehensive income (loss), before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Number of Contracts Financing Receivable, Modifications, Number of Contracts ACL and Reserve for Off-Balance Sheet Credit Exposures ACL and Reserve for Off-Balance Sheet Credit Exposures ACL and Reserve for Off-Balance Sheet Credit Exposures Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Interest rate swaps, remaining term to maturity Derivative, Average Remaining Maturity Debt Securities [Member] Debt Securities [Member] Average Committed ESOP Shares Outstanding [Member] Average Committed Employee Stock Ownership Plan Shares Outstanding [Member] Average committed employee stock ownership plan shares outstanding Restricted cash and cash equivalents Restricted Cash and Cash Equivalents Amortization and accretion of premiums and discounts on securities Accretion (Amortization) of Discounts and Premiums, Investments Available-for-sale ("AFS") securities, at estimated fair value (amortized cost of $1,880,972 and $1,529,605) Available-for-sale Securities, Estimated Fair Value Available-for-sale Securities, Estimated Fair Value AFS securities Debt Securities, Available-for-sale Equity Components [Axis] Equity Components [Axis] Changes in unrealized gains (losses) on cash flow hedges, net of taxes of $(1,220) and $(1,741) Other comprehensive income (loss) - Cash Flow Hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Total Delinquent Loans Financing Receivable, Past Due Total non-interest income Noninterest Income Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Minimum [Member] Minimum [Member] Tax impact of cumulative effect adjustment Deferred Tax Assets, Gross Recorded investment in loans collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Federal insurance premium Federal Deposit Insurance Corporation Premium Expense Financing Receivable, Recorded Investment, Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Interactive data current reporting status indicator Entity Interactive Data Current Fair Value Of Financial Instruments Fair Value Disclosures [Text Block] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Recoveries Financing Receivable, Allowance for Credit Loss, Recovery Loans Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Proceeds from calls, maturities and principal reductions of AFS securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale Cumulative effect of adopting ASU [Member] Cumulative effect adjustment - Adoption of CECL [Member] Cumulative Effect, Period of Adoption, Adjustment [Member] Impaired loans, Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Additional paid-in capital Additional Paid in Capital, Common Stock Registrant Name Entity Registrant Name Marketable Securities [Abstract] Marketable Securities [Abstract] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Revolving Line of Credit Financing Receivable, Revolving Investment securities Interest Income, Debt Securities, Operating Repayments on borrowings Payments of FHLBank Borrowings, Financing Activities Pass [Member] Pass [Member] Available-for-sale Securities, One year or less, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Total non-interest expense Noninterest Expense Impaired loans, Recorded Investment Impaired Financing Receivable, Recorded Investment Total securities pledged as collateral Pledged Financial Instruments, Not Separately Reported, Securities State of incorporation Entity Incorporation, State or Country Code Unemployment rate Unemployment Rate US National Unemployment Rate Other Comprehensive Income Components [Axis] Other Comprehensive Income Location [Axis] Accounting Standards Update [Axis] Accounting Standards Update [Axis] 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. Available-for-sale Securities, Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Loans Receivable Financing Receivable, Held-for-investment [Policy Text Block] Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-02 [Member] Zip code of principal executive offices location Entity Address, Postal Zip Code Information technology and related expense Communications and Information Technology Available-for-sale Securities, One year or less, Estimated Fair Value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Proceeds from the redemption of FHLB stock Proceeds from Sale of Federal Home Loan Bank Stock Transition Report indicator Document Transition Report 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 Impaired loans, Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Cash dividends to stockholders Common Stock, Dividends, Per Share, Declared Significant Other Observable Inputs (Level 2) [Member] Fair Value, Inputs, Level 2 [Member] Prior Years Financing Receivable, Originated, More than Five Years before Current Fiscal Year Quarterly Report indicator Document Quarterly Report Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Nonaccrual Loans Financing Receivable, Nonaccrual [Table Text Block] Investment Holdings [Line Items] Investment Holdings [Line Items] INTEREST AND DIVIDEND INCOME: Interest and Dividend Income, Operating [Abstract] Equity [Abstract] Equity [Abstract] Assets, Fair Value Disclosure Assets, Fair Value Disclosure Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Calculated by ACL model [Member] Calculated by ACL model [Member] Amount of ACL calculated by discounted cash flow model Accounting Standards Update 2016-13 [Member] Accounting Standards Update 2016-13 [Member] Office supplies and related expense Supplies and Postage Expense Provision for credit losses Provision for credit losses Provision for Loan, Lease, and Other Losses Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] Diluted weighted average common shares Total diluted average common shares outstanding Weighted Average Number of Shares Outstanding, Diluted Basic earnings per share ("EPS") Basic Earnings Per Share, Basic Unrealized gains (losses) on AFS securities arising during the period, tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax Commission file number Entity File Number Debt Disclosure [Abstract] Debt Disclosure [Abstract] Advance payments by borrowers for taxes and insurance Advance Payments by Borrowers for Taxes and Insurance Investment Holdings [Table] Investment Holdings [Table] Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Post-Restructured Outstanding Financing Receivable, Troubled Debt Restructuring, Postmodification Substandard [Member] Substandard [Member] Restricted cash and cash equivalents, balance sheet location Restricted Cash and Cash Equivalents, Asset, Statement of Financial Position [Extensible List] Common stock, $.01 par value; 1,400,000,000 shares authorized, 138,792,496 and 138,956,296 shares issued and outstanding as of December 31, 2020 and September 30, 2020, respectively Common Stock, Value, Issued Document Fiscal Year Focus Document Fiscal Year Focus 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. Entity current reporting status indicator Entity Current Reporting Status Discounts/unearned loan fees Loans and Leases Receivable, Deferred Income Deposits Deposits, Fair Value Disclosure Purchase of AFS securities Payments to Acquire Debt Securities, Available-for-sale Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Loans receivable, gross Loans and Leases Receivable, before Fees, Gross Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Amount reclassified from AOCI - AFS Securities Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI for Write-down of Securities, Net of Tax Special Mention [Member] Special Mention [Member] CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Common stock, shares issued Common Stock, Shares, Issued Cash and cash equivalents (includes interest-earning deposits of $139,031 and $172,430) Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Other non-interest income Noninterest Income, Other FHLB Advances, Prepayment Penalties Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties Debt Instrument [Line Items] Debt Instrument [Line Items] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total stockholders' equity Balance Balance Cumulative effect adjustment Stockholders' Equity Attributable to Parent TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity Accumulated other comprehensive (loss) income ("AOCI"), net of tax Beginning balance Ending balance Accumulated Other Comprehensive Income (Loss), Net of Tax Changes in unrealized gains (losses) on cash flow hedges, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax City of principal executive offices location Entity Address, City or Town Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair Value, Hierarchy [Axis] Fair Value Hierarchy and NAV [Axis] Accrued interest, AFS debt securities - balance sheet location Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible List] Financial Instrument [Axis] Financial Instrument [Axis] Accounting Standards Update [Domain] Accounting Standards Update [Domain] Antidilutive stock options, excluded from the diluted average common shares outstanding calculation Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Equity Component [Domain] Equity Component [Domain] Other comprehensive income (loss) - AFS Securities OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax Cash dividends paid Payments of Dividends LIABILITIES: Liabilities [Abstract] Premises and equipment, net Property, Plant and Equipment, Net IRS identification number Entity Tax Identification Number 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. NET INCOME Net income Net Income (Loss) Attributable to Parent Changes in: Increase (Decrease) in Operating Capital [Abstract] Provision for credit losses Financing Receivable, Credit Loss, Expense (Reversal) Other comprehensive income (loss), net of tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Summary Of Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Other non-interest expense Other Noninterest Expense Impaired loans with no related allowance, Interest Income Recognized Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Available-for-sale Securities, One year through five years, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Current Fiscal Year End Date Current Fiscal Year End Date Earnings Per Share [Abstract] Earnings Per Share [Abstract] NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES Interest Income (Expense), after Provision for Loan Loss Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Fiscal Year 2017 Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year STOCKHOLDERS' EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Document Fiscal Period Focus Document Fiscal Period Focus Loans individually evaluated for loss Loans receivable Loans Receivable, Fair Value Disclosure Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] ACL for loans collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Current Fiscal Year Financing Receivable, Year One, Originated, Current Fiscal Year Filer category Entity Filer Category Common Stock [Member] Common Stock [Member] Product and Service [Domain] Product and Service [Domain] Reserve for off-balance sheet credit exposures Beginning Balance Ending Balance Off-Balance Sheet, Credit Loss, Liability Borrowings FHLB Advances, Amount Long-term Federal Home Loan Bank Advances Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Cash dividends to stockholders Dividends, Cash Recorded Investment Financing Receivable, Troubled Debt Restructuring, Subsequent Default 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 Municipal Bonds [Member] Municipal Bonds [Member] Total Amortized Cost Financing Receivable, before Allowance for Credit Loss Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Fiscal Year 2020 Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year Doubtful [Member] Doubtful [Member] Basic weighted average common shares Total basic average common shares outstanding Weighted Average Number of Shares Outstanding, Basic Unrealized Gains (Losses) on AFS Securities [Member] AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Including Noncontrolling Interest [Member] Carrying Amount [Member] Reported Value Measurement [Member] Operating lease right-of-use assets obtained Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] INCOME TAX EXPENSE Income Tax Expense (Benefit) Beginning of period End of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Diluted EPS Diluted Earnings Per Share, Diluted Telephone number Local Phone Number Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Domain] Other [Member] Consumer Loan [Member] OREO Other Real Estate Financing Receivable, nonaccrual loans with no ACL Financing Receivable, Nonaccrual, No Allowance 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. Address of principal executive offices location Entity Address, Address Line One ESOP activity Stock Issued During Period, Value, Employee Stock Ownership Plan Other assets, net Increase (Decrease) in Other Operating Assets Emerging Growth Company indicator Entity Emerging Growth Company Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Borrowings Interest Expense, Borrowings Amount reclassified from AOCI, deferred income taxes Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Interest income on investment securities Interest and Dividend Income, Securities, Operating FHLB advances, variable rate Federal Home Loan Bank, Advances, Maturities Summary, Floating Rate Accrued interest, loans receivable Financing Receivable, Accrued Interest, after Allowance for Credit Loss Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Maximum [Member] Maximum [Member] Preferred stock, shares authorized Preferred Stock, Shares Authorized Retained Earnings [Member] Retained Earnings [Member] Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Measurement Basis [Axis] Measurement Basis [Axis] Schedule Of Taxable And Non-taxable Components Of Interest Income Interest Income and Interest Expense Disclosure [Table Text Block] Charge-offs Financing Receivable, Allowance for Credit Loss, Writeoff Impaired loans with no related allowance, Recorded Investment Impaired Financing Receivable, with No Related Allowance, Recorded Investment 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] Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Fiscal Year 2018 Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year Allowance for Credit Losses Financing Receivable, Allowance for Credit Loss [Table Text Block] Trading symbol Trading Symbol Total Recorded Investment Total Recorded Investment Loans and Leases Receivable, Net of Deferred Income Construction [Member] Construction Loans [Member] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Prepaid FHLB Advances [Member] Prepaid FHLB Advances [Member] Prepaid FHLB Advances [Member] Earnings Per Share Earnings Per Share [Text Block] INTEREST EXPENSE: Interest Expense [Abstract] Shell company indicator Entity Shell Company Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Fair Value, Recurring [Member] Fair Value, Recurring [Member] Loans Receivable And Allowance For Credit Losses Financing Receivables [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract]