Summary of Assets and Liabilities measured at estimated fair value on a recurring basis Fair Value, Net Asset (Liability) [Abstract] Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Receivable Type [Axis] Receivable Type [Axis] Intrinsic value of options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Troubled debt restructurings Financing Receivable, Troubled Debt Restructuring [Table Text Block] State and municipal US States and Political Subdivisions Debt Securities [Member] Securities held to maturity transferred to available for sale Securities held to maturity transferred to available for sale Securities held to maturity transferred to available for sale Proceeds from calls of securities held to maturity Proceeds From Calls Of Held-To-Maturity Securities Proceeds From Calls Of Held-To-Maturity Securities Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Subordinated Notes Subordinated Debt [Member] Total non-performing loans Non Performing Loans Total Total non performing loans. Net accretion of debt issuance costs and amortization of premium on borrowings Amortization of Debt Discount (Premium) February 2017 February 2017 [Member] February 2017 Tier 1 risk-based capital required for minimum capital adequacy, fully phased-in, ratio Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets, Fully Phased-In Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets, Fully Phased-In Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Cash paid for acquisition, net Payments for (Proceeds from) Businesses and Interest in Affiliates Accrued interest Financing Receivable, Accrued Interest, before Allowance for Credit Loss Annual effective tax rate adjustment Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount A Standard & Poor's, A Rating [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Estimated fair value greater than carrying value, percent Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount Compensation and benefits Labor and Related Expense Tier 1 common equity, actual, ratio Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual Preferred stock Preferred Stock [Member] Current Fiscal Year End Date Current Fiscal Year End Date Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items] Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items] Unused borrowing capacity Debt Instrument, Unused Borrowing Capacity, Amount BOLI income Income Tax Reconciliation, Bank Owned Life Insurance Income Income Tax Reconciliation, Bank Owned Life Insurance Income CMOs/Other MBS CMOs/Other MBS Collateralized Mortgage Obligations [Member] Performance Shares Performance Shares [Member] Beginning balance (USD per share) Ending balance (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Variable Rate [Domain] Variable Rate [Domain] Gross realized losses Debt Securities, Available-for-sale, Realized Loss Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Restricted stock awards, net Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Loans evaluated for impairment by segment Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract] ASSETS: Assets: Assets [Abstract] Sterling National Bank Subsidiaries [Member] Cover page. Cover [Abstract] Operating cash flows from operating leases Operating Lease, Payments Document Type Document Type Period of loan term eligible for inclusion in Tier 2 capital decreases Period Of Loan Term Eligible For Inclusion In Tier Two Capital Decreases Period Of Loan Term Eligible For Inclusion In Tier Two Capital Decreases Accumulated Other Comprehensive Income Comprehensive Income (Loss) Note [Text Block] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] 2021 Lessee, Operating Lease, Liability, to be Paid, Year One Purchase of treasury stock (in shares) Treasury Stock, Shares, Acquired Beginning balance (in shares) Ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Accumulated other comprehensive loss, tax expense (benefit) AOCI Tax, Attributable to Parent 2024 Lessee, Operating Lease, Liability, to be Paid, Year Four Proceeds from calls of securities available for sale Proceeds From Calls Of Available-For-Sale Securities Proceeds From Calls Of Available-For-Sale Securities Estimated fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Total unrecognized stock-based compensation expense Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Preferred stock (par value $0.01 per share; 10,000,000 shares authorized; 135,000 shares issued and outstanding at June 30, 2020 and December 31, 2019) Preferred Stock, Value, Issued Proceeds from calls Proceeds from Sale of Held-to-maturity Securities Residential mortgage portfolio segment Residential Portfolio Segment [Member] Common stock, par value (USD per share) Common Stock, Par or Stated Value Per Share Schedule of debt securities held-for-sale allowance for credit loss rollforward Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table Text Block] Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Derivative Instruments and Hedges, Assets [Abstract] Derivative Instruments and Hedges, Assets [Abstract] Impaired loans with an allowance recorded, recorded investment Impaired Financing Receivable, with Related Allowance, Recorded Investment Advertising and promotion Marketing and Advertising Expense Purchases of low income housing tax credits Payments to Acquire Affordable Housing Tax Credit Payments to Acquire Affordable Housing Tax Credit Measurement Frequency [Domain] Measurement Frequency [Domain] Total securities pledged Restricted Investments Current loans Financing Receivable, Not Past Due Taxi medallions Taxi Medallions [Member] Taxi Medallions Available-for-sale, five to ten years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Statement [Line Items] Statement [Line Items] Measurement Input, Appraised Value Measurement Input, Appraised Value [Member] Class of Stock [Domain] Class of Stock [Domain] Total borrowings, rate Long-term Debt, Weighted Average Interest Rate, at Point in Time One to two years, rate Long Term Debt Maturities Weighted Average Interest Rate In Rolling Year Two Long term debt maturities weighted average interest rate in rolling year two. Measurement Input Type [Domain] Measurement Input Type [Domain] Stock awards vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Statement [Table] Statement [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Sterling National Bank Sterling National Bank [Member] Sterling National Bank [Member] Asset-based lending Asset-Based Lending [Member] Asset-Based Lending [Member] Net charge-offs Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method Allowance for Loan and Lease Losses [Roll Forward] Fair Value Measurements, Nonrecurring Fair Value, Nonrecurring [Member] Charge offs from TDR's Charge Offs From Troubled Debt Restructurings Charge Offs From Troubled Debt Restructurings Depositary Shares, Each Representing 1/40th Interest In A Share Of 6.50% Non-Cumulative Perpetual Preferred Stock, Series A Depositary Shares, Each Representing 1/40th Interest In A Share Of 6.50% Non-Cumulative Perpetual Preferred Stock, Series A [Member] Depositary Shares, Each Representing 1/40th Interest In A Share Of 6.50% Non-Cumulative Perpetual Preferred Stock, Series A [Member] Schedule of debt Long-term Debt, by Category, Current and Noncurrent [Abstract] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Borrowings Debt Disclosure [Text Block] Held to maturity Payments to Acquire Held-to-maturity Securities Brokered Deposits [Domain] Brokered Deposits [Domain] Brokered Deposits [Domain] Proceeds from sales of loans held for sale Proceeds from Sale of Loans Held-for-sale Total interest and dividend income Interest and Dividend Income, Operating Unpaid principal balance of loans acquired Loans And Leases Receivable, Unpaid Principal Balance Loans And Leases Receivable, Unpaid Principal Balance Weighted average common shares: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Commercial and industrial Commercial and Industrial Sector [Member] Beginning balance (in shares) Ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Amounts reclassified from AOCI Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Held-to-maturity, five to ten years, fair value Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Net accretion of purchase discount and amortization of net deferred loan costs Accretion (Amortization) of Discounts and Premiums, Loans Accretion (Amortization) of Discounts and Premiums, Loans Measurement Frequency [Axis] Measurement Frequency [Axis] Financing Receivable Financing Receivable [Member] Financial Instruments [Domain] Types of Financial Instruments [Domain] Financial Instruments [Domain] Allowance for Credit Loss Credit Loss, Financial Instrument [Policy Text Block] Carrying amounts and estimated fair value of financial assets and liabilities Fair Value, by Balance Sheet Grouping [Table Text Block] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Fair value, 12 months or longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Financial Asset, Other than Financial Asset Acquired with Credit Deterioration Financial Asset, Other than Financial Asset Acquired with Credit Deterioration [Member] Local Phone Number Local Phone Number Schedule of Classification of Deposits [Line Items] Schedule of Classification of Deposits [Line Items] Schedule of classification of deposits. Securities non-taxable Interest Income, Securities, Operating, Tax Exempt Number of contracts Financing Receivable, Number Of Contracts Financing Receivable, Number Of Contracts Unrecognized stock-based compensation, stock options Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Loans and loan fees Interest and Fee Income, Loans and Leases Fair value, total Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value Woodforest National Bank Woodforest National Bank [Member] Woodforest National Bank [Member] Common-equivalent shares due to the dilutive effect of stock options and unvested performance share grants (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment 2018 Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year Income Statement Location [Domain] Income Statement Location [Domain] 2022 Lessee, Operating Lease, Liability, to be Paid, Year Two Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Held-to-maturity securities Held-to-maturity Securities [Member] 2023 Lessee, Operating Lease, Liability, to be Paid, Year Three Plan Name [Axis] Plan Name [Axis] Real estate Real Estate Sector [Member] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Tier 1 risk-based capital, actual, capital amount Banking Regulation, Tier One Risk-Based Capital, Actual Total assets Assets Unrecognized losses, 12 months or longer Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Beginning balance (in shares) Ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Redemptions of FHLB and FRB stock, net Payments for (Proceeds from) Federal Home Loan Bank Stock Loans evaluated by segment, Individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] CRE Commercial Real Estate Portfolio Segment [Member] Federal Home Loan Bank (“FHLB”) and Federal Reserve Bank (“FRB”) stock, at cost Federal Home Loan Bank Stock Equity-based stock compensation benefit Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount Outstanding loans and leases held by acquiree at acquisition date Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Assets Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Non-performing loans: Non Performing Assets [Abstract] Non performing assets: Total liabilities Liabilities Entity Address, City or Town Entity Address, City or Town Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Paycheck Protection Program Lending Facility Lines of Credit, Fair Value Disclosure Interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Fair value, total Debt Securities, Available-for-sale, Unrealized Loss Position Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Level 1 inputs Fair Value, Inputs, Level 1 [Member] Uncertain tax position reserve Effective Income Tax Reconciliation, Uncertain Tax Positions, Amount Effective Income Tax Reconciliation, Uncertain Tax Positions, Amount Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Held to maturity Proceeds From Maturities And Prepayments Of Held-To-Maturity Securities Proceeds From Maturities And Prepayments Of Held-To-Maturity Securities Fair value, less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Non-vested stock awards/stock units outstanding - Number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Credit Rating, Standard & Poor's [Axis] Credit Rating, Standard & Poor's [Axis] Greater than five years, rate Long Term Debt Maturities Weighted Average Interest Rate In Rolling After Year Five Long term debt maturities weighted average interest rate in rolling after year five. Payroll finance Payroll Finance [Member] Payroll Finance [Member] Stock awards vested (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value Additional paid-in capital Additional Paid-in Capital [Member] Net interest income Interest Income (Expense), Net Deposits Interest Expense, Deposits Preferred stock dividend Preferred Stock Dividends and Other Adjustments Financial assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Other assets Total other assets Other Assets Held-to-maturity, one year or less, amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Other adjustments (principally net changes in other assets and other liabilities) Other Operating Activities, Cash Flow Statement Balance (in shares) Balance (in shares) Shares, Issued Non-vested stock awards/performance units Non-vested Stock Awards and Performance Units [Member] Non-vested Stock Awards and Performance Units [Member] AA Standard & Poor's, AA Rating [Member] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Axis] Net gain on called securities Debt and Equity Securities Called, Gain (Loss) Debt and Equity Securities Called, Gain (Loss) Fair value, 12 months or longer Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value Debt Securities, Held-to-maturity, Credit Quality Indicator [Table] Debt Securities, Held-to-maturity, Credit Quality Indicator [Table] Tier 1 capital to RWA: Banking Regulation, Tier One Risk-Based Capital [Abstract] Brokered Deposits [Axis] Brokered Deposits [Axis] Brokered deposits. Restructuring and integration costs Business Combination, Integration Related Costs Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Abstract] Beginning balance (USD per share) Ending balance (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Investment securities available for sale: Investment Securities Available For Sale [Abstract] Investment securities available for sale. Common stock, shares authorized (in shares) Common Stock, Shares Authorized Schedule of compliance with regulatory capital requirements under banking regulations Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Proceeds from stock option exercises Proceeds from Stock Options Exercised Portfolio loan originations, net Payments for Loan originations Cash outflows for the origination of new loans during the period. Components of loan portfolio, excluding loans held for sale Loans and Leases Receivable, Net Amount [Abstract] Uncertain Tax Positions [Roll Forward] Uncertain Tax Positions [Roll Forward] Uncertain Tax Positions Income Statement [Abstract] Income Statement [Abstract] Accumulated other comprehensive (loss) income AOCI Attributable to Parent [Member] Summary of amortized cost and fair value of investment securities available for sale by remaining period to contractual maturity Investments Classified by Contractual Maturity Date [Table Text Block] Debt securities, held-to-maturity, allowance for credit loss Balance at December 31, 2019 Total ACL - HTM at June 30, 2020 Debt Securities, Held-to-maturity, Allowance for Credit Loss Other real estate owned Other Real Estate, Foreclosed Assets, and Repossessed Assets Accrued interest receivable Interest Receivable Public sector finance Public Sector Finance [Member] Public Sector Finance [Member] Held-to-maturity, greater than ten years, fair value Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Use of Estimates Use of Estimates, Policy [Policy Text Block] Multi-family Real Estate Commercial Mortgage CBL [Member] Real estate commercial mortgage CBL. Provision for credit losses - held to maturity securities Provision for credit loss expense recorded in the six months ended June 30, 2020 Debt Securities, Held-to-maturity, Credit Loss Expense (Reversal) Debt Security Category [Axis] Debt Security Category [Axis] Amortized cost Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract] Financial Instruments Owned and Pledged as Collateral [Table] Financial Instruments Owned and Pledged as Collateral [Table] Goodwill Noncash or Part Noncash Acquisition, Goodwill Acquired Noncash or Part Noncash Acquisition, Goodwill Acquired Consolidated Entities [Axis] Consolidated Entities [Axis] 3.50% Senior Notes Senior Notes, 3.50% [Member] Senior Notes, 3.50% [Member] Tier 1 common equity required for minimum capital adequacy, fully phased-in, capital amount Tier One Common Capital Required For Capital Adequacy, Fully Phased-In Tier One Common Capital Required For Capital Adequacy, Fully Phased-In Accrued interest receivable Noncash or Part Noncash Acquisition, Interest Receivable Acquired Noncash or Part Noncash Acquisition, Interest Receivable Acquired Tier 1 (core) capital required for minimum capital adequacy, fully phased-in, capital amount Tier One Leverage Capital Required For Capital Adequacy, Fully Phased-In Tier One Leverage Capital Required For Capital Adequacy, Fully Phased-In Purchases of premises and equipment Payments to Acquire Property, Plant, and Equipment Document Information [Line Items] Document Information [Line Items] Entity Tax Identification Number Entity Tax Identification Number Business assets Business Assets [Member] Business Assets Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Litigation accrual Loss Contingency Accrual Tier 1 (core) capital required for minimum capital adequacy, fully phased-in, ratio Tier One Leverage Capital Required For Capital Adequacy To Average Assets, Fully Phased-In Tier One Leverage Capital Required For Capital Adequacy To Average Assets, Fully Phased-In Unrealized losses, total Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Summary of derivatives Summary of Credit Derivatives [Abstract] Loans formally in process of foreclosure Mortgage Loans in Process of Foreclosure, Amount Municipal deposits Municipal Deposits Municipal deposits. Customer lists Customer Lists [Member] Income before income tax expense Income before income tax expense Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Trading Symbol Trading Symbol Total risk-based capital required for minimum capital adequacy, fully phased-in, ratio Capital Required For Capital Adequacy To Risk Weighted Assets, Fully Phased-In Capital Required For Capital Adequacy To Risk Weighted Assets, Fully Phased-In Tier 1 common equity required to be well capitalized, capital amount Banking Regulation, Common Equity Tier One Risk-Based Capital, Well Capitalized, Minimum Federal Home Loan Bank advances, loss realized Federal Home Loan Bank Advances, Loss Realized Federal Home Loan Bank Advances, Loss Realized Legal Entity [Axis] Legal Entity [Axis] Fair value measurement input Impaired Loans, Measurement Input Impaired Loans, Measurement Input Less than one year, rate Long Term Debt Maturities Weighted Average Interest Rate In Next Rolling Twelve Months Long term debt maturities weighted average interest rate in next rolling twelve months. Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Summary of securities available for sale Debt Securities, Available-for-sale [Table Text Block] Number Financing Receivable, Modifications, Number of Contracts Canceled/expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Expirations Reclassification adjustment for net realized (gains) losses included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Greater than five years, amount Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Non-Accrual TDRs Non Accrual Loans Under Troubled debt restructurings Non accrual loans. Total risk-based capital, ratio Banking Regulation, Total Risk-Based Capital Ratio, Actual Unrecognized losses, total Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss City Area Code City Area Code Securities available for sale, at estimated fair value Securities available for sale Fair value of available-for-sale securities transfered from held to maturity Debt Securities, Available-for-sale Other liability balances Other Liabilities, Other Other Liabilities, Other Title of 12(b) Security Title of 12(b) Security Past due loans Financing Receivable, Past Due Customer interest rate swap Customer Interest Rate Swap [Member] Customer interest rate swap. Proceeds from sale of commercial loans Proceeds from Collection of Finance Receivables Consolidated Entities [Domain] Consolidated Entities [Domain] Loans evaluated by segment, Collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Industry Sector [Domain] Industry Sector [Domain] 90 days past due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] FDIC insurance and regulatory assessments Federal Deposit Insurance Corporation Premium Expense Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Forfeited (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Third-party interest rate swap Third Party Interest Rate Swap [Member] Third party interest rate swap. Fair Value Measurements Fair Value Disclosures [Text Block] Purchases of securities: Payments to Acquire Investments [Abstract] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Interest rate swap Interest Rate Swap [Member] Repurchase agreements Securities Sold under Agreements to Repurchase Cumulative Effect, Period of Adoption, Adjustment Impact of CECL adoption Cumulative Effect, Period of Adoption, Adjustment [Member] Held-to-maturity, one to five years, amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Business Acquisition [Line Items] Business Acquisition [Line Items] Non-interest bearing demand Demand Deposit Accounts Impairment related to financial centers and real estate consolidation strategy Asset Impairment Charges Stock options outstanding - Weighted average exercise price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Repayments of term FHLB borrowings Payments of FHLBank Borrowings, Financing Activities Pass Pass [Member] Available-for-sale, one year or less, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Cash dividends paid - common stock Payments of Ordinary Dividends, Common Stock Cash on deposit as swap collateral / net of settlement Cash On Deposit As Swap Collateral And Settlement Cash On Deposit As Swap Collateral And Settlement Redemption of bank owned life insurance, pending settlement Payments for (Proceeds from) Life Insurance Policies Schedule of other liabilities Other Liabilities [Table Text Block] Information technology Information Technology and Data Processing Real Estate [Domain] Real Estate [Domain] Core deposits Core Deposits [Member] Securities pledged for borrowings at FHLB and other institutions, and securities pledged for municipal deposits and other purposes Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block] Cash dividends declared, preferred Dividends, Preferred Stock, Cash Communications Communication Increased borrowing capacity by pledging securities Market Value Of Mortgage Not Required To Be Pledged Market value of mortgage not required to be pledged. Gross realized (losses) Debt Securities, Held To Maturity, Sold, Realized Loss Debt Securities, Held To Maturity, Sold, Realized Loss Accounting Standards Update [Axis] Accounting Standards Update [Axis] Federal Home Loan Bank advances Federal Home Loan Bank Advances Gross unrealized losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Accounting Standards Update 2017-12 Accounting Standards Update 2017-12 [Member] Accrued interest receivable on securities Accrued Interest Receivables, Securities, Fair Value Disclosure Accrued interest receivables fair value disclosure. Deposits [Abstract] Deposits [Abstract] Goodwill Goodwill Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Total other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Net (decrease) in short-term FHLB borrowings Payments Of Short Term FHLBank Borrowings, Financing Activities Payments Of Short Term FHLBank Borrowings, Financing Activities Held-to-maturity, without single maturity date, fair value Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Fair Value Asset write-downs, retention and severance compensation and other restructuring charges Restructuring Costs and Asset Impairment Charges Loans individually evaluated for impairment by segment of loans Loans Individually Evaluated For Impairment By Segment Of Loans [Abstract] Loans individually evaluated for impairment by segment of loans. Credit Derivatives [Line Items] Credit Derivatives [Line Items] Brokered deposits Noninterest-bearing Domestic Deposit, Brokered Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Schedule of additional analysis of non-accrual loans Financing Receivable, Nonaccrual [Table Text Block] Unrealized (loss) on transfer of securities held to maturity to available for sale OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment and Tax Interest and dividend income: Interest and Dividend Income, Operating [Abstract] Equity [Abstract] Equity [Abstract] Total assets Assets, Fair Value Disclosure Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items] Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items] Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-maturity [Table] Canceled/expired (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Cancellations in Period Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Cancellations in Period Entity Central Index Key Entity Central Index Key Schedule of goodwill and intangible assets Schedule of Intangible Assets and Goodwill [Table Text Block] Emerging Growth Company Entity Emerging Growth Company Granted (USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Credit Derivatives Contract Type [Domain] Derivative Contract [Domain] Future amortization expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Diluted (in shares) Weighted average common shares for computation of diluted EPS (in shares) Weighted Average Number of Shares Outstanding, Diluted Letters of credit Letter of Credit [Member] Loss Unlikely to be Collected Financing Receivable [Member] Subordinated Notes Subordinated Debt Other Income and Expenses [Abstract] Other Income and Expenses [Abstract] Commitment to fund low income housing tax credit investments Qualified Affordable Housing Project Investments, Commitment Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period List of company's brokered deposits Schedule of List of Brokered Deposits [Table Text Block] Schedule of list of brokered deposits. Held-to-maturity, with a stated maturity date, fair value Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value Low income housing tax credits and other benefits Effective Income Tax Rate Reconciliation, Tax Credit, Low Income Housing, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Low Income Housing, Amount Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Recorded investment, Post-modification Financing Receivable, Troubled Debt Restructuring, Postmodification Substandard Substandard [Member] Cash dividends paid - preferred stock Payments of Ordinary Dividends, Preferred Stock and Preference Stock Uncertain tax positions beginning of period Uncertain tax positions at June 30, 2020 Unrecognized Tax Benefits Common stock (par value $0.01 per share; 310,000,000 shares authorized at June 30, 2020 and December 31, 2019; 229,872,925 shares issued at June 30, 2020 and December 31, 2019; 194,458,805 and 198,455,324 shares outstanding at June 30, 2020 and December 31, 2019, respectively) Common Stock, Value, Issued Investment management fees Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] 2022 Finite-Lived Intangible Asset, Expected Amortization, Year Two External Credit Rating, Standard & Poor's [Domain] External Credit Rating, Standard & Poor's [Domain] Available-for-sale securities Available-for-sale Securities [Member] Schedule of Credit Derivatives [Table] Schedule of Credit Derivatives [Table] Available for sale Payments to Acquire Debt Securities, Available-for-sale Net unrealized holding (loss) gain on securities transferred to held to maturity Net Unrealized Holding Gain (Loss) On Securities Transferred To Held-to-maturity [Member] Net Unrealized Holding Gain (Loss) On Securities Transferred To Held-to-maturity [Member] Performance measurement period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Measurement Period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Measurement Period Residential mortgage loans transferred from held for sale to portfolio Transfer of Loans Held-for-sale to Portfolio Loans Vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Special mention Special Mention [Member] Common stock, shares issued (in shares) Common Stock, Shares, Issued Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Present value of lease liabilities Operating Lease, Liability Net deferred tax liability Deferred Tax Liabilities, Net Basis of Financial Statement Presentation and Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Debt Instrument [Line Items] Debt Instrument [Line Items] Total stockholders’ equity Balance, beginning Balance, ending Total stockholders’ equity Stockholders' Equity Attributable to Parent Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Total consideration paid Business Combination, Consideration Transferred Total other securities Securities Investment [Member] Total ACL - loans Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease) Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Certificates of deposit Time Deposits Bank owned life insurance (“BOLI”) Bank Owned Life Insurance 2025 Lessee, Operating Lease, Liability, to be Paid, Year Five Other assets Other Assets [Member] Financial Instrument [Axis] Financial Instrument [Axis] Accounting Standards Update [Domain] Accounting Standards Update [Domain] Warehouse lending Warehouse Lending [Member] Warehouse lending [Member] Acquired Financial Asset Acquired and No Credit Deterioration [Member] Held-to-maturity, with a stated maturity date, amortized cost Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost Other comprehensive income, before tax: Other Comprehensive Income (Loss), before Tax [Abstract] Held-to-maturity, greater than ten years, amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Tier 1 common equity, actual, capital amount Banking Regulation, Common Equity Tier One Risk-Based Capital, Actual Schedule of collateral-dependent financing receivables Schedule Of Collateral-Dependent Financing Receivables [Table Text Block] Schedule Of Collateral-Dependent Financing Receivables Valuation allowance Deferred Tax Assets, Valuation Allowance LIABILITIES: Liabilities: Liabilities [Abstract] Entity Address, Address Line One Entity Address, Address Line One Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Financing Receivable Payment Deferrals Financing Receivable, Payment Deferral CARES Act [Table Text Block] Financing Receivable, Payment Deferral CARES Act 2023 Finite-Lived Intangible Asset, Expected Amortization, Year Three Entity Address, State or Province Entity Address, State or Province Remainder of 2020 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Other comprehensive income, net of tax Other comprehensive income Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax Available-for-sale, greater than ten years, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Other Total other non-interest expense Other Noninterest Expense Weighted average fixed rate  Derivative, Average Fixed Interest Rate Available-for-sale, one to five years, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Earnings per common share: Earnings Per Share [Abstract] Earnings Per Share [Abstract] Financial liabilities: Financial Liabilities [Abstract] Financial Liabilities [Abstract] Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Factored receivables Factored receivables Factored Receivables [Member] A loan related to factored receivables. Loans held for sale Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Net unrealized holding gain (loss) on retirement plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Increase to allowance for credit losses due to TDR's subsequently defaulted Financing Receivable, Allowance For Credit Loss, Troubled Debt Restructurings, Defaults Financing Receivable, Allowance For Credit Loss, Troubled Debt Restructurings, Defaults 2016 Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year STOCKHOLDERS’ EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Net non-cash assets acquired Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed) Entity Interactive Data Current Entity Interactive Data Current 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Five Certificates of deposit Certificates of Deposit [Member] Net increase (decrease) in other borrowings Proceeds from (Repayments of) Other Debt Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Available-for-sale, with a stated maturity date, amortized cost Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Schedule of stock-based compensation expense associated with stock options and non-vested stock awards Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Common stock Common Stock [Member] Loss on prepayment of FHLB borrowings Loss On Prepayment Of Federal Home Loan Bank Borrowings Loss On Prepayment Of Federal Home Loan Bank Borrowings Securities sold to raise liquidity Debt Securities, Held-to-maturity, Sold, Amount ACL - loans - (adjustment related to purchase credit impaired loan mark)1 Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Other asset balances Other Assets, Other Other Assets, Other Stock options & other stock transactions, net APIC, Share-based Payment Arrangement, Recognition and Exercise Fair value Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract] Money market Money Market Deposits [Member] Money market deposits. Charge for asset write-downs, retention and severance Asset Impairment, Severance, And Retention Charges Asset Impairment, Severance, And Retention Charges Income tax expense (benefit) on realized net gains / (losses) Tax Expense (Benefit) Of Securities Gains Tax expense (benefit) of securities gains Amortized cost Debt Securities, Held-to-maturity, Maturity, Amortized Cost, Net [Abstract] Accounts receivable management / factoring commissions and other fees Accounts Receivable Management Fees, Factoring Commissions And Other Related Fees Accounts receivable / factoring commissions and other related fees TDRs modified and subsequently defaulted Financing Receivable, Troubled Debt Restructuring, Subsequent Default Unusual or Infrequent Item, or Both [Domain] Unusual or Infrequent Item, or Both [Domain] Senior Notes Senior Notes Senior Notes Interest rate Debt Instrument, Interest Rate, Stated Percentage Two to three years, amount Long-term Debt, Maturities, Repayments of Principal in Rolling Year Three Portfolio loans Total  loans Financing Receivable, before Allowance for Credit Loss Accrued interest receivable, reversed against interest income Financing Receivables, Accrued Interest Receivable Reversed Against Net Income Financing Receivables, Accrued Interest Receivable Reversed Against Net Income Period past due at time of acquisition to determine PCD classification Financing Receivable, Threshold Period Past Due, Writeoff Payment Deferral Payment Deferral [Member] Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Liabilities assumed: Noncash or Part Noncash Acquisition, Value of Liabilities Assumed [Abstract] Net (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Securities reclassified from held to maturity to available for sale OCI, Debt Securities, Available-for-Sale, Transfer from Held-to-Maturity, Gain (Loss), before Adjustment, after Tax Acquisitions Business Combination Disclosure [Text Block] Financial assets: Financial Assets [Abstract] Financial Assets [Abstract] Change in unrealized holding gains on securities available for sale OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Stock-based compensation plans Employee Stock Ownership Plan (ESOP) And Stock Based Compensation Expense Employee Stock Ownership Plan (ESOP) And Stock Based Compensation Expense Stock options Share-based Payment Arrangement, Option [Member] Available for Sale Available for sale: Debt Securities, Available-for-sale [Abstract] Fair value, less than 12 months Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Treasury stock, shares (in shares) Treasury Stock, Shares Income tax expense on realized net gains Tax expense held to maturity security gains Tax expense held to maturity security gains Proceeds from maturities and other principal payments on securities: Proceeds from Sale, Maturity and Collection of Investments [Abstract] Collateral Collateral Pledged [Member] Acquisition, development and construction (“ADC”) Acquisition, Development And Construction [Member] Acquisition Development And Construction [Member] Interest payments Interest Paid, Excluding Capitalized Interest, Operating Activities Available-for-sale, pledged as collateral Debt Securities, Available-for-sale, Restricted Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Annualized net charge-offs to average loans outstanding: Net Charge Offs To Average Gross Loans Annualized Net charge offs to average gross loans annualized. Non-cash assets acquired: Noncash or Part Noncash Acquisition, Value of Assets Acquired [Abstract] Additional paid-in capital Additional Paid in Capital 2021 Finite-Lived Intangible Asset, Expected Amortization, Year One Class of Stock [Axis] Class of Stock [Axis] Summary of derivatives Schedule of Derivative Instruments [Table Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] Accounting Standards Update and Change in Accounting Principle [Table] Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Residential mortgage Residential Mortgage [Member] Diluted (USD per share) Earnings Per Share, Diluted Proceeds from sales of securities available for sale Proceeds from sales Proceeds from Sale of Debt Securities, Available-for-sale Schedule of unrecognized tax benefits roll forward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Granted (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Granted In Period Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Granted In Period Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] List of Company's Brokered deposits List of Company's Brokered Deposits [Abstract] List of company's brokered deposits. Acquisitions: Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed) [Abstract] Schedule of debt Schedule of Debt [Table Text Block] Non-accrual loans with no ACL Financing Receivable, Nonaccrual, No Allowance Tier 1 (core) capital, actual, capital amount Banking Regulation, Tier One Leverage Capital, Actual Equipment financing Equipment Financing Receivables [Member] A loan related to equipment finance receivable. Total risk-based capital, actual, capital amount Banking Regulation, Total Capital, Actual Maximum Maximum [Member] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Loans held for sale Loans Held-for-sale, Fair Value Disclosure Cash dividends declared, common Dividends, Common Stock, Cash Document Information [Table] Document Information [Table] Other Other Investment Securities [Member] Other investment securities. Mortgage escrow funds Mortgage Escrow Funds Fair Value Disclosure Mortgage escrow funds fair value disclosure. 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] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Deferred fees, deferred costs and purchase counting adjustments Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums Municipal Deposits Municipal Deposits [Member] Municipal deposits. Available-for-sale, with a stated maturity date, fair value Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Non Investment Grade Non-rated External Credit Rating, Non Investment Grade [Member] Amortization of premium on certificates of deposit Accretion (Amortization) Of Discounts And Premiums, Certificates Of Deposit Accretion (Amortization) Of Discounts And Premiums, Certificates Of Deposit Basis spread Derivative, Basis Spread on Variable Rate 2017 Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Corporate and Other Corporate Debt Securities And Other Investment Securities [Member] Corporate Debt Securities And Other Investment Securities Other earning assets Other Interest and Dividend Income Non-maturity deposits Non Maturity Deposits Fair Value Disclosure Non maturity deposits fair value disclosure. Cash Paid as STM Derivative, Collateral, Right to Reclaim Cash Two to three years, rate Long Term Debt Maturities Weighted Average Interest Rate In Rolling Year Three Long term debt maturities weighted average interest rate in rolling year three. Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Held-to-maturity, without single maturity date, amortized cost Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Amortized Cost Equipment Equipment [Member] Low income housing tax credit investments Amortization Method Qualified Affordable Housing Project Investments Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Portfolio Loans Financing Receivables [Text Block] Tier 1 common equity required for minimum capital adequacy, phase-in schedule, ratio Tier One Common Capital Required For Capital Adequacy To Risk Weighted Assets, Fully Phased-In Tier One Common Capital Required For Capital Adequacy To Risk Weighted Assets, Fully Phased-In Canceled/expired (USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Tier 1 common equity required to be well capitalized, ratio Tier One Common Capital Required To Be Well Capitalized To Risk Weighted Assets Tier One Common Capital Required To Be Well Capitalized To Risk Weighted Assets Accrued interest payable on deposits Accrued Interest Payable, Deposits Including Escrow, Fair Value Disclosure Accrued Interest Payable, Deposits Including Escrow, Fair Value Disclosure Revolving loans converted to term Financing Receivable, Revolving, Converted to Term Loan Financing Receivable, Collateral-Dependent Loans [Table] Financing Receivable, Collateral-Dependent Loans [Table] Financing Receivable, Collateral-Dependent Loans [Table] Summary of major classification of deposits Schedule Of Major Classification Of Deposits [Table Text Block] Major classification of deposits. Granted (in shares) Grant of share options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Treasury stock Treasury Stock [Member] Credit Loss Status [Domain] Credit Loss Status [Domain] Fair value Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] Schedule of accumulated other comprehensive income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Stock awards vested (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Gain on sale of residential mortgage loans Gain (Loss) on Sale of Mortgage Loans Level 3 inputs Level 3 inputs Fair Value, Inputs, Level 3 [Member] Derivative assets, fair value Swaps Derivative Asset Number of available for sale securities which were in continuous unrealized loss position for less than 12 months Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Number Of Securities Available for sale securities continuous unrealized loss position less than twelve months number of securities. Total risk-based capital required for minimum capital adequacy, fully phased-in, capital amount Capital Required For Capital Adequacy, Fully Phased-In Capital Required For Capital Adequacy, Fully Phased-In Available-for-sale, one to five years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Loans transferred from held for investment to held for sale Financing Receivable, Reclassification to Held-for-sale Paycheck Protection Program Liquidity Facility Line of Credit [Member] Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] Other intangible assets, net Other intangible assets Intangible Assets, Net (Excluding Goodwill) Unrecognized losses, less than 12 months Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available-for-sale, without single maturity date, fair value Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value Proceeds from bank owned life insurance Proceeds from Life Insurance Policy Entity Address, Postal Zip Code Entity Address, Postal Zip Code Bank pledged mortgages Pledged Assets Separately Reported, Loans Pledged as Collateral, at Fair Value Variable Rate [Axis] Variable Rate [Axis] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Commitments and Contingent liabilities (See Note 15. “Commitments and Contingencies”) Commitments and Contingencies Treasury shares repurchased Payments for Repurchase of Common Stock 2026 and thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five FHLB borrowings Federal Home Loan Bank Borrowings, Fair Value Disclosure Entity Shell Company Entity Shell Company Stock awards vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Tax at federal statutory rate of 21% Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Total other comprehensive income, before tax Other comprehensive income (loss), before tax Other Comprehensive Income (Loss), before Tax Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Retained earnings Retained Earnings (Accumulated Deficit) Right of use asset for operating leases (see Note 15) Operating Lease, Right-of-Use Asset Accrued interest payable on borrowings Accrued Interest Payable, Borrowings, Fair Value Disclosure Accrued Interest Payable, Borrowings, Fair Value Disclosure (Gain) loss on extinguishment of debt Gain (Loss) on Extinguishment of Debt Deposits Deposit Liabilities Disclosures [Text Block] Deposits Total deposits Deposits Unused lines of credit Unused lines of Credit [Member] Income tax payments Income Taxes Paid Stock options & other stock transactions, net (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Period Increase (Decrease) Allowance evaluated by segment, Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Held-to-maturity, five to ten years, amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Available-for-sale, without single maturity date, amortized cost Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost Securities taxable Interest Income, Securities, Operating, Taxable Derivative liability, notional Amount Derivative Liability, Notional Amount Document Quarterly Report Document Quarterly Report Exercisable at end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Certificates of deposit Certificates Of Deposit Fair Value Disclosure Certificates of deposit fair value disclosure. Cumulative Effect, Period of Adoption, Adjusted Balance As reported under CECL Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Unpaid principal balance with no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Entity File Number Entity File Number Business Acquisition [Axis] Business Acquisition [Axis] Gross unrecognized losses Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Impairment of early termination of leases Gain (Loss) on Termination of Lease Deferred income tax (benefit) expense Increase (Decrease) in Deferred Income Taxes EPS: Earnings Per Share, Basic and Diluted [Abstract] Financing Receivable, Collateral-Dependent Loans [Line Items] Financing Receivable, Collateral-Dependent Loans [Line Items] Financing Receivable, Collateral-Dependent Loans Document Fiscal Period Focus Document Fiscal Period Focus Total risk-based capital required to be well capitalized, ratio Banking Regulation, Total Risk-Based Capital Ratio, Well Capitalized, Minimum Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Five Schedule of amounts and status of loans and TDRs Financing Receivable, Past Due [Table Text Block] Available-for-sale, greater than ten years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Financial Instruments Owned and Pledged as Collateral [Line Items] Financial Instruments Owned and Pledged as Collateral [Line Items] Operating leases - equipment and vehicles leased to others Lessor, Operating Lease, Payments to be Received Industry Sector [Axis] Industry Sector [Axis] Federal agencies US Government Agencies Debt Securities [Member] Financing receivable credit quality indicators Financing Receivable Credit Quality Indicators [Table Text Block] Tier 1 risk-based capital required to be well capitalized, ratio Banking Regulation, Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum Business Combinations [Abstract] Business Combinations [Abstract] Commercial loans portfolio segment Commercial Portfolio Segment [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Depreciation expense on operating leases Operating Lease, Depreciation Expense Operating Lease, Depreciation Expense Multi-family Real Estate Loan [Member] Originations of loans held for sale Payments for Origination and Purchases of Loans Held-for-sale External Credit Rating by Grouping [Domain] External Credit Rating by Grouping [Domain] Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] Computation of basic and diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Number of held to maturity securities which were in continuous unrealized loss position for less than 12 months Held To Maturity Securities Continuous Loss Position Less Than Twelve Months Number Of Securities Held To Maturity Securities Continuous Loss Position Less Than Twelve Months Number Of Securities FDIC insurance premium limitation Effective Income Tax Rate Reconciliation, FDIC Insurance Premium Limitation Effective Income Tax Rate Reconciliation, FDIC Insurance Premium Limitation Allowance for credit losses - loans Loans and Leases Receivable, Allowance Amendment Flag Amendment Flag Real estate Real Estate [Member] Paycheck Protection Program Lending Facility Long-term Line of Credit Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Non accrual loans Total Non-accrual Loans Financing Receivable, Nonaccrual Other assets Noncash or Part Noncash Acquisition, Other Assets Acquired Federal Home Loan Bank Borrowings Federal Home Loan Bank Borrowings [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Payroll finance and factoring liabilities Payroll Finance And Factoring Liabilities Payroll Finance And Factoring Liabilities Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Senior Notes Senior Notes [Member] Consumer portfolio segment Consumer Portfolio Segment [Member] Proceeds from sale of residential mortgage loans Proceeds from Sale of Loans Held-for-investment FHLB stock and FRB stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Amortized cost Amortized cost Debt Securities, Available-for-sale, Amortized Cost Gross unrealized gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Total impact of CECL adoption Allowance For Credit Loss, Change In Method, Credit Loss Expense (Reversal) Allowance For Credit Loss, Change In Method, Credit Loss Expense (Reversal) Nonperforming loans Nonperforming Financial Instruments [Member] Income Statement Location [Axis] Income Statement Location [Axis] Net gain (loss) on sale of securities Net (gain) loss on sale of securities Debt and Equity Securities, Gain (Loss) Non-interest income: Noninterest Income [Abstract] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Multi-family Multi-family financing [Member] Multi-family financing [Member] Amortization of intangible assets Amortization of intangible assets Amortization of Intangible Assets Entity Current Reporting Status Entity Current Reporting Status Non-Interest Income and Other Non-Interest Expense Other non-interest expense [Text Block] Other non-interest expense [Text Block] Loss on security calls held to maturity Debt Securities, Held-to-maturity, Sold, Realized Gain (Loss) Other liabilities Total other liabilities Other Liabilities Operational losses Operational Loss Operational Loss Restricted stock awards, net (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Common Stock, Par Value $0.01 Per Share Common Stock, Par Value $0.01 Per Share [Member] Common Stock, Par Value $0.01 Per Share [Member] Schedule of other non-interest expense Other non- interest expense [Table Text Block] Other non- interest expense [Table Text Block] Net (gain) on loans held for sale Gain (Loss) on Sales of Loans, Net Loans 90 days past due and still accruing Loans 90 days or more past due still accruing interest Financing Receivable, 90 Days or More Past Due, Still Accruing Tier 1 (core) capital, ratio Banking Regulation, Tier One Leverage Capital Ratio, Actual Total Finite-Lived Intangible Assets, Net Smaller Reporting Company Entity Small Business Total interest expense Interest Expense Depreciation of premises and equipment Depreciation, Depletion and Amortization Entity Filer Category Entity Filer Category Total loans, net Noncash or Part Noncash Acquisition, Loans and Leases Receivable Acquired Noncash or Part Noncash Acquisition, Loans and Leases Receivable Acquired Schedule of CECL standard adoption impact Accounting Standards Update and Change in Accounting Principle [Table Text Block] Common equity tier 1 to RWA: Tier One Common Equity [Abstract] Tier One Common Equity [Abstract] Advances of term FHLB borrowings Proceeds from FHLBank Borrowings, Financing Activities Weighted-average period total unrecognized compensation cost related to non-vested shares granted Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Total capital to RWA: Banking Regulation, Total Capital [Abstract] Net income available to common stockholders Net income available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Document Fiscal Year Focus Document Fiscal Year Focus ACL - loans Allowance for credit losses Financing receivable, allowance for credit loss Total allowance for loan losses Beginning balance Ending balance Financing Receivable, Allowance for Credit Loss Total non-cash assets acquired Noncash or Part Noncash Acquisition, Value of Assets Acquired Gross realized gains Debt Securities, Available-for-sale, Realized Gain Cash dividends paid, common (usd per share) Common Stock, Dividends, Per Share, Cash Paid Real estate acquired in settlement of loans Real Estate Owned, Transfer to Real Estate Owned Debt Instrument [Axis] Debt Instrument [Axis] Stock awards vested (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Vested In Period Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Vested In Period ACL - off balance sheet credit exposure (recorded in other liabilities) Off-Balance Sheet, Credit Loss, Liability, Change in Method, Credit Loss Expense (Reversal) Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract] Residential mortgage loans servicing Residential Loan Servicing Residential Loan Servicing Class of Stock [Line Items] Class of Stock [Line Items] Number of held to maturity securities which were in continuous unrealized loss position for 12 months or more Held To Maturity Securities Continuous Loss Position More Than Twelve Months Number Of Securities Held To Maturity Securities Continuous Loss Position More Than Twelve Months Number Of Securities Purchase of treasury stock Treasury Stock, Value, Acquired, Cost Method Swap liabilities (see Note 9) 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] State and local income taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Insurance & surety bond premium Insurance and Surety Bond Premium Expense Insurance and Surety Bond Premium Expense Net increase in mortgage escrow funds Payments for (Proceeds from) Deposit on Loan TDRs modified and subsequently defaulted, number Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Non-interest expense: Noninterest Expense [Abstract] Number of available for sale securities which were in continuous unrealized loss position for 12 months or more Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Number Of Securities Available for sale securities continuous unrealized loss position twelve months or longer number of securities. Sale of securities Schedule of Realized Gain (Loss) [Table Text Block] Impaired financing receivables Impaired Financing Receivables [Table Text Block] Impairment on fixed assets Impairment of Long-Lived Assets Held-for-use Tax exempt interest, net of disallowed interest Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Document Period End Date Document Period End Date Entity Registrant Name Entity Registrant Name Estimate of Fair Value Measurement Estimate of Fair Value Measurement [Member] Repayment of Senior Notes Repayments of Senior Debt 2024 Finite-Lived Intangible Asset, Expected Amortization, Year Four Increase in cash surrender value of bank owned life insurance Life Insurance, Corporate or Bank Owned, Change in Value Occupancy and office operations Occupancy, Net Allowance for credit losses (“ACL”) - loans Financing Receivable, Change in Method, Credit Loss Expense (Reversal) Loans classified as TDRs Past due TDRs Financing Receivable, Troubled Debt Restructuring Total residential MBS Residential Mortgage Backed Securities [Member] Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Schedule of Classification of Deposits [Table] Schedule of Classification of Deposits [Table] Schedule of classification of deposits. Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent By period to maturity: Long-term Debt, Rolling Maturity [Abstract] Preferred stock, par value (USD per share) Preferred Stock, Par or Stated Value Per Share Schedule of effective income tax rate reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Collateral [Axis] Collateral Held [Axis] Accretion of net unrealized loss on securities transferred to held to maturity Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) On Securities Transferred To Held To Maturity Arising During Period, before Tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) On Securities Transferred To Held To Maturity Arising During Period, before Tax Other comprehensive income before reclassification OCI, before Reclassifications, Net of Tax, Attributable to Parent Originated Financial Asset Originated [Member] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Tier 1 risk-based capital, ratio Banking Regulation, Tier One Risk-Based Capital Ratio, Actual Portfolio loans, net Loans and Leases Receivable, Net Amount Small Business Administration Paycheck Protection Program Small Business Administration Paycheck Protection Program [Member] Small Business Administration Paycheck Protection Program Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Recorded investment, Pre-modification Financing Receivable, Troubled Debt Restructuring, Premodification Measurement Input Type [Axis] Measurement Input Type [Axis] Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table] Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table] AAA Standard & Poor's, AAA Rating [Member] Entity [Domain] Entity [Domain] Tax rate adjustment benefit due to CARES Act NOL carryback Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), CARES Act Net Operating Loss Carryback Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), CARES Act Net Operating Loss Carryback Total borrowings, amount Long-term debt Long-term Debt Average maturity (in years) Derivative, Average Remaining Maturity Money market Deposits, Money Market Deposits Net amortization of premiums on securities Accretion (Amortization) of Discounts and Premiums, Investments Net loss (gain) from write-downs and sales of other real estate owned Gains (Losses) on Sales of Other Real Estate Award Date [Domain] Award Date [Domain] Equity Components [Axis] Equity Components [Axis] Total liabilities assumed Noncash or Part Noncash Acquisition, Value of Liabilities Assumed Total non-interest income Noninterest Income Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Minimum Minimum [Member] Allowance for Credit Losses - Loans Allowance for Credit Losses [Text Block] Receivables [Abstract] Receivables [Abstract] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Interest bearing demand Deposits, Negotiable Order of Withdrawal (NOW) Award Date [Axis] Award Date [Axis] Unrecognized stock-based compensation, non-vested stock awards/performance units Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Held-to-maturity securities pledged as collateral Debt Securities, Held-to-maturity, Restricted Tier 1 (core) capital required to be well capitalized, capital amount Banking Regulation, Tier One Leverage Capital, Well Capitalized, Minimum Premium paid for loans receivable, percentage of gross loans Business Combination, Premium Paid For Loans Receivable, Percent Of Gross Loans Business Combination, Premium Paid For Loans Receivable, Percent Of Gross Loans Restricted stock compensation expense Restricted Stock or Unit Expense Exercised (USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Paycheck Protection Program Liquidity Facility Paycheck Protection Program Liquidity Facility [Member] Paycheck Protection Program Liquidity Facility Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Recoveries Financing Receivable, Allowance for Credit Loss, Recovery Summary of Company's stock option activity Share-based Payment Arrangement, Option, Activity [Table Text Block] Securities available for sale with unrealized losses, by length of time in continuous unrealized loss position Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Held-to-maturity, fair value Held-to-maturity, fair value Securities held to maturity Debt Securities, Held-to-maturity, Fair Value Remainder of 2020 Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item, or Both [Axis] Other borrowings Other Borrowings Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Interest bearing demand Interest-bearing Deposits [Member] Revolving loans Financing Receivable, Revolving Proceeds from sale of premises and equipment Proceeds from Sale of Property, Plant, and Equipment Savings Deposits, Savings Deposits Lending-related instruments Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset Unrecognized stock-based compensation expense Share-based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Total non-interest expense Noninterest Expense Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Other liabilities Noncash or Part Noncash Acquisition, Other Liabilities Assumed Total lease payments Lessee, Operating Lease, Liability, to be Paid Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain] Tier 1 risk-based capital required for minimum capital adequacy, fully phased-in, capital amount Tier One Risk Based Capital Required For Capital Adequacy, Fully Phased-In Tier One Risk Based Capital Required For Capital Adequacy, Fully Phased-In 30-59 days past due Financial Asset, 30 to 59 Days Past Due [Member] Loan commissions and fees Fees And Commissions, Loans Fees And Commissions, Loans (Gain) on security calls available for sale Debt Securities, Available-for-sale, Realized Gain (Loss) Available-for-sale, one year or less, 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] Unrealized losses, 12 months or longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Level 2 inputs Fair Value, Inputs, Level 2 [Member] Available-for-sale, five to ten years, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Available for sale Proceeds From Maturities And Prepayments Of Debt Securities, Available-For-Sale Proceeds From Maturities And Prepayments Of Debt Securities, Available-For-Sale Estimated fair value on nonrecurring basis Fair Value Measurements, Nonrecurring [Table Text Block] One to two years, amount Long-term Debt, Maturities, Repayments of Principal in Rolling Year Two Prior Financing Receivable, Originated, More than Five Years before Current Fiscal Year Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Derivative assets, notional amount Derivative Asset, Notional Amount Accounting Standards Update 2016-13 Accounting Standards Update 2016-13 [Member] Other liabilities Other Liabilities [Member] Cumulative Effect, Period Of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] PCI Loans Financial Asset Acquired with Credit Deterioration [Member] Schedule of debt securities held-for-sale amortized cost by credit quality indicator Debt Securities, Held-to-maturity, Credit Quality Indicator [Table Text Block] Basic (USD per share) Earnings Per Share, Basic Canceled/expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Collateral [Domain] Collateral Held [Domain] Mortgage escrow funds Advance Payments by Borrowers for Taxes and Insurance Stock-based compensation expense Share-based Payment Arrangement, Expense Net unrealized holding (loss) gain on available for sale securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] Low income housing investment amortization expense Effective Income Tax Rate Reconciliation, Tax Credit, Low Income Housing Amortization Expense, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Low Income Housing Amortization Expense, Amount Forfeited (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Forfeitures in Period Share-Based Compensation Arrangement By Share-Based Payment Award, Forfeitures in Period Balance Sheet Location [Axis] Balance Sheet Location [Axis] Deposit fees and service charges Revenue from Contract with Customer, Including Assessed Tax Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Santander Bank, N.A Santander Bank, N.A [Member] Santander Bank, N.A [Member] Stock-based compensation expense, income tax benefit Share-based Payment Arrangement, Expense, Tax Benefit CRE Commercial Real Estate [Member] Components of loan portfolio excluding loans held for sale Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Amortization of low income housing tax credits Amortization Method Qualified Affordable Housing Project Investments, Amortization Recognition and Retention Plan Recognition and Retention Plan [Member] Recognition and Retention Plan [Member] Professional fees Professional Fees Retirement Benefits [Abstract] Retirement Benefits [Abstract] Receivable [Domain] Receivable [Domain] Proceeds from sales of other real estate owned Proceeds from Sale of Other Real Estate Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Exercised (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Exercised In Period Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available For Grant, Exercised In Period Threshold period considered past due Debt Securities, Held-to-maturity, Threshold Period Past Due Granted (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value FHLB Borrowings FHLB borrowings Federal Home Loan Bank Advances [Member] Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Schedule of off-balance-sheet financial instruments Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block] Other Noninterest Income, Other Tier 1 leverage ratio: Banking Regulation, Tier One Leverage Capital [Abstract] Cash and due from banks Cash and Due from Banks Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total liabilities and stockholders’ equity Liabilities and Equity Accumulated other comprehensive income, net of tax expense of $33,847 at June 30, 2020 and $15,361 at December 31, 2019 Accumulated Other Comprehensive Income (Loss), Net of Tax Income Taxes Income Tax Disclosure [Text Block] Agency-backed Agency Securities [Member]