Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Subordinated notes Subordinated Debt Maximum Maximum [Member] Financing receivable, held for sale Financing Receivable, Held-for-Sale Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Title of 12(b) Security Title of 12(b) Security Total earnings applicable to common shares Net Income (Loss) Available to Common Stockholders, Diluted Carrying value Reported Value Measurement [Member] Subsequent Event Subsequent Event [Member] Customer-related noninterest income from other sources Revenue Not from Contract with Customer, Excluding Interest Income Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Net loan and lease charge-offs (recoveries) Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff (Recovery) Adjustment to Compensation, Amount Adjustment to Compensation Amount Pledged Status [Axis] Pledged Status [Axis] Financial Instrument [Axis] Financial Instrument [Axis] Financial liabilities: Financial Liabilities Fair Value Disclosure [Abstract] Segment Reporting [Abstract] Common stock ($0.001 par value; authorized 350,000 shares; issued and outstanding 145,939 and 147,653 shares) and additional paid-in capital Common stock and additional paid in capital Common Stocks, Including Additional Paid in Capital Revenue Recognition and Deferred Revenue [Abstract] Loans added to held for sale Financing Receivable, Reclassification to Held-for-Sale LEASES Lessee, Finance Leases [Text Block] Derivative Instrument [Axis] Derivative Instrument [Axis] Total loans Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract] Agriculture loan servicing Servicing Asset at Fair Value, Amount Total unfunded lending commitments Total Unfunded Lending Commitments Total Unfunded Lending Commitments Held-to-maturity Interest Income, Debt Securities, Held-to-Maturity Measurement Frequency [Axis] Measurement Frequency [Axis] Shares repurchased (in dollars per share) Shares Acquired, Average Cost Per Share Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Office buildings and agriculture production Office Buildings And Agriculture Production [Member] Office Buildings And Agriculture Production Doubtful Doubtful [Member] Sales-type or direct financing leases Sales-type and Direct Financing Leases, Lease Receivable Leases [Abstract] Other comprehensive income, net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Interest rate reduction Contractual Interest Rate Reduction [Member] Total loans and leases Total loans Total loans Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Fee, and Loan in Process Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Available-for-sale, total Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Amounts reclassified from AOCI Reclassification out of Accumulated Other Comprehensive Income [Member] Loans acquired in purchase of California branches, net (at time of purchase) Loans Assumed Summary of TDRs (Accruing and Nonaccruing) Categorized by Loan Class and Modification Type Financing Receivable, Modified [Table Text Block] Gross charge-offs by year of loan origination Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract] Terminated or redesignated, unamortized basis adjustments, assets Terminated And Redesignated Swaps, Unamortized Basis Adjustments, Assets Terminated And Redesignated Swaps, Unamortized Basis Adjustments, Assets Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Operating leases Lessee, Operating Lease, Description [Abstract] Number of reportable segments Number of Reportable Segments Schedule of Basis Adjustments for Hedged Items Schedule of Derivative Instruments [Table Text Block] Total debt securities Investment securities Available-for-sale Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss Subsequent Events Subsequent Events, Policy [Policy Text Block] Loss to be reclassified within the next 12 months into interest income Cash Flow Hedge Gain (Loss) to be Reclassified within 12 Months Securities Sold under Agreements to Repurchase Securities Sold under Agreements to Repurchase [Member] Entity Address, City or Town Entity Address, City or Town Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Receivables [Abstract] Statement of Financial Position [Abstract] Number of branches owned Number of Branches Owned Number of Branches Owned 2026 2025 Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Net gains from valuation adjustments of loans carried at fair value Fair Value, Option, Credit Risk, Gains (Losses) on Assets Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] 90+ days past due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Total debt securities Debt Securities, Available-for-Sale, Maturity, Weighted Average Yield Debt Securities, Available-for-Sale, Maturity, Weighted Average Yield Subsequent Event Type [Axis] Subsequent Event Type [Axis] Schedule of Long-Term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Distributed earnings applicable to common shares Distributed Earnings 30-89 days past due Financial Asset, 30 to 89 Days Past Due [Member] Financial Asset, 30 to 89 Days Past Due Investment Income [Table] Investment Income [Table] Segment Reporting Segment Reporting [Table Text Block] 1-4 family residential One Through Four Family Residential [Member] One through four Family Residential [Member] Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Single family residential Single Family Residential [Member] Single Family Residential Schedule of Lease Maturity Analysis Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Allowance for loan and lease losses Balance at beginning of period Balance at end of period Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Document Period End Date Document Period End Date Savings and money market Deposits, Savings and Money Market Deposits, Savings and Money Market Preferred stock outstanding (in shares) Preferred Stock, Shares Outstanding Debt instrument face amount Debt Instrument, Face Amount Basic: Earnings Per Share, Basic [Abstract] 2028 Lessee, Operating Lease, Liability, to be Paid, Year Two Revolving loans converted to term loans amortized cost basis Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan Due after five years through ten years Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, After Year 5 Through 10 Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, After Year 5 Through 10 Available-for-sale, gross losses Debt Securities, Available-for-Sale, Realized Loss Share repurchase program, increase in authorized amount Share Repurchase Program, Increase In Authorized Amount Share Repurchase Program, Increase In Authorized Amount Due in one year or less Debt Securities, Available-for-Sale, Weighted Average Yield, Maturity, Year One LEASES Lessor, Operating Leases [Text Block] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Due after ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Agency securities Agency Securities [Member] Income tax expense (benefit) included in other comprehensive income Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Finance leases Finance Lease, Weighted Average Remaining Lease Term Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Construction and other consumer real estate Construction And Other Consumer Real Estate [Member] Construction And Other Consumer Real Estate [Member] Credit-related expense Credit And Collection Services Credit and collection services. Percentage of total loans Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage NET EARNINGS PER COMMON SHARE Earnings Per Share [Text Block] Net earnings per common share: Earnings Per Share [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total allowance for credit losses Financing Receivable And Off Balance Sheet Liability, Allowance For Credit Loss Financing Receivable And Off Balance Sheet Liability, Allowance For Credit Loss Total liabilities Liabilities Trading securities, at fair value Trading securities Debt Securities, Trading, and Equity Securities, FV-NI Trading Symbol Trading Symbol Weighted-average interest rate reduction (in percentage points) Financing Receivable, Modified, Weighted-Average Interest Rate Decrease from Modification Available-for-sale, at fair value Available-for-sale Debt Securities, Available-for-Sale, Excluding Accrued Interest Allowance for loan losses Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward] Purchases of premises and equipment Payments to Acquire Property, Plant, and Equipment Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Company Selected Measure Name Company Selected Measure Name Purchases of investment securities available-for-sale Payments to Acquire Debt Securities, Available-for-Sale Available-for-sale, Unrealized Gains, Other Available-for-sale, Unrealized Gains, Other [Member] Available-for-sale, Unrealized Gains, Other Income Tax Disclosure [Abstract] Interest on deposits Interest Expense, Deposits Diluted: Earnings Per Share, Diluted [Abstract] Schedule of Gains (Losses) Recognized From Derivatives Not Designated as Accounting Hedges Derivatives Not Designated as Hedging Instruments [Table Text Block] 2026 2025 Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction CASH FLOWS FROM OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Due after ten years Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year 10 Dividends on common stock (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Transfers out Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Less common and preferred dividends Dividends U.S. Treasury, agencies, and corporations U.S. Treasury securities US Treasury Securities [Member] Financing Receivable, Modifications [Line Items] Financing Receivable, Modified [Line Items] Terminated or redesignated, unamortized basis adjustments, debt Terminated And Redesignated Swaps, Unamortized Basis Adjustments, Debt Terminated And Redesignated Swaps, Unamortized Basis Adjustments, Debt Schedule of Assets and Liabilities Measured at Fair Value by Class on a Recurring Basis Using Level 3 Inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Unfunded lending commitments on troubled debt restructuring Financing Receivable, Modified, Commitment to Lend Related cash disbursements for operating leases Operating Lease, Payments Award Timing Predetermined Award Timing Predetermined [Flag] Interest income: Interest and Dividend Income, Operating [Abstract] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Level 1 Fair Value, Inputs, Level 1 [Member] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Total income from loans sold Gain (Loss) on Sale of Financing Receivable Dilutive effect of stock options (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table] Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table] Reserve for unfunded lending commitments Off-Balance-Sheet, Credit Loss, Liability [Roll Forward] Number of states in which entity operates Number of States in which Entity Operates Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Hedged items Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge Office and industrial buildings Office And Industrial Buildings [Member] Office And Industrial Buildings Long-term debt Long-Term Debt, Fair Value Plan Name [Domain] Plan Name [Domain] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Retail and business banking fees Products And Services, Retail And Business Banking Fees [Member] Products And Services, Retail And Business Banking Fees ROU assets, net of amortization Operating Lease, Right-of-Use Asset Number of civil cases Number of Civil Cases Number of Civil Cases Due in one year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Fair Value Disclosures [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Commercial account fees Commercial account fees Commercial account fees INVESTMENT SECURITIES Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Interest on securities Investment Income, Debt Securities Excluding Trading Securities, Operating Investment Income, Debt Securities Excluding Trading Securities, Operating Expiration Date Trading Arrangement Expiration Date Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] Held-to-maturity Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain Amortized cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Proceeds from the issuance of common stock Proceeds from Issuance of Common Stock Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Hedges of fixed-rate liabilities Hedges Of Fixed-Rate Liabilities [Member] Hedges Of Fixed-Rate Liabilities CASH FLOWS FROM INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segments [Domain] Segments [Domain] Net increase in trading securities Increase (Decrease) in Debt Securities, Trading PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Nonaccrual Nonaccrual [Member] Nonaccrual Loans held for sale (includes $51 and $71 of loans carried at fair value) Loans held for sale Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Finance leases Finance Lease, Weighted Average Discount Rate, Percent Debt instrument stated interest rate Debt Instrument, Interest Rate, Stated Percentage Dividends on common stock Dividends, Common Stock, Cash Total shareholders’ equity Balance at beginning of period Balance at end of period Accumulated other comprehensive loss Equity, Attributable to Parent Interest on fair value hedges Other Noninterest Income/(Expense) Derivative Instrument, Noninterest Income (Expense) Derivative instrument noninterest income (expense) ASSETS Assets [Abstract] Payment deferral Payment Deferral [Member] Other noninterest-bearing investments Other Investments Summary of Outstanding Loan Balances (Accruing and Nonaccruing) Categorized by Credit Quality Indicators Financing Receivable Credit Quality Indicators [Table Text Block] Fair Value, Nonrecurring Fair Value, Nonrecurring [Member] Professional and legal services Professional Fees Insider Trading Policies and Procedures [Line Items] Due after ten years Debt Securities, Weighted Average Yield, Maturity, After Year 10 Debt Securities, Weighted Average Yield, Maturity, After Year 10 Deferred income tax expense Deferred Income Tax Expense (Benefit) Other noninterest income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Noninterest Income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Noninterest Income Commercial real estate: Commercial Real Estate Portfolio Segment [Member] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Schedule of Investment Securities Summary of Investment Securities [Table Text Block] Summary of Investment Securities [Table Text Block] Number of branches Number of Branches Number of Branches Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount LEASES Lessor, Direct Financing Leases [Text Block] Entity Central Index Key Entity Central Index Key Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Accrued interest receivable written off Financing Receivable, Accrued Interest, Writeoff Hedges of floating-rate liabilities Hedges Of Floating-Rate Liabilities [Member] Hedges Of Floating-Rate Liabilities Commitments, Guarantees, and Contingent Liabilities [Abstract] Guarantees, Commitments And Contingencies [Abstract] Pledging Purpose [Axis] Pledging Purpose [Axis] Net gains on equity securities Increase (Decrease) in Equity Securities, FV-NI Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Dividends on preferred stock Dividends, Preferred Stock, Cash Derivatives designated as accounting hedges: Designated as Hedging Instrument [Member] Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Average yield Debt Securities, Available-for-Sale, Weighted Average Yield, Maturity [Abstract] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Financing Receivable, Modified [Table] Amortized cost basis with no allowance Financing Receivable, Excluding Accrued Interest, Nonaccrual, No Allowance Accumulated other comprehensive income (loss) Total AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Carrying amount of hedged assets Hedged Asset, Fair Value Hedge Standby letters of credit Letters Of Credit Standby Letters of credit standby. Dividends paid on common and preferred stock Payments of Dividends Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Statement [Line Items] Statement [Line Items] Total assets Assets Derivative, notional amount, not yet effective Derivative, Notional Amount, Not Yet Effective Derivative, Notional Amount, Not Yet Effective Private equity investments Private equity investments Private Equity Funds [Member] Maturity or term extension Extended Maturity [Member] Total interest expense Interest Expense, Operating Dividends and other income Investment Income, Net Schedule of Lease Related Assets and Liabilities Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Operating Segments Operating Segments [Member] Available-for-sale Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Other comprehensive income (loss) before reclassifications, net of tax OCI, before Reclassifications, Net of Tax, Attributable to Parent Occupancy and equipment, net Occupancy, Net PEO PEO [Member] Noninterest-bearing demand Noninterest-Bearing Deposit Liabilities Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Number of AFS investment securities in an unrealized loss position Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions Retained earnings Retained Earnings [Member] Noninterest income Noninterest Income, Adjusted Noninterest Income, Adjusted Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, outstanding shares (in shares) Balance at beginning of period (in shares) Balance at end of period (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Schedule of Carrying Values and Estimated Fair Values Fair Value, by Balance Sheet Grouping [Table Text Block] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Due after five years through ten years Debt Securities, Weighted Average Yield, Maturity, After Year 5 Through 10 Debt Securities, Weighted Average Yield, Maturity, After Year 5 Through 10 Diluted (in dollars per share) Net earnings per common share (in dollars per share) Earnings Per Share, Diluted Total Financing Receivable, Modified, after 12 Months Other interest rate derivatives Other Contract [Member] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Deposit insurance and regulatory expense Federal Deposit Insurance Corporation Premium Expense Zions Bank Zions Bank Segment [Member] Zions Bank Segment [Member] 2023 2022 Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Total noninterest income from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Other real estate expense, net Other Revenue (Expense) from Real Estate Operations Small Business Administration loan-backed securities Small Business Administration Loan Backed Securities [Member] Small Business Administration Loan-Backed Securities [Member] Federal funds and other short-term borrowings 1 Federal Funds Purchased and Securities Sold under Agreements to Repurchase Bank common stock repurchased Shares repurchased Stock Repurchased During Period, Value Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Accounting Standards Update and Change in Accounting Principle Accounting Standards Update and Change in Accounting Principle [Table Text Block] Cost of investments sold Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Total income statement impact Derivative, Gain (Loss) on Derivative, Net Collateral Held [Axis] Collateral Held [Axis] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Arizona ARIZONA Revolving loans amortized cost basis Financing Receivable, Excluding Accrued Interest, Revolving Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] CB&T California Bank And Trust Segment [Member] California Bank And Trust Segment [Member] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Summary of Changes in the Allowance for Credit Losses Financing Receivable, Allowance for Credit Loss [Table Text Block] Common stock, shares issued (in shares) Common Stock, Shares, Issued Fair value of assets, beginning balance Fair value of assets, ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Due in one year or less Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Schedule of Off Balance Sheet Financial Instruments Schedule of Guarantor Obligations [Table Text Block] Series A Floating-Rate Non-Cumulative Perpetual Preferred Stock Series A Floating-Rate Non-Cumulative Perpetual Preferred Stock [Member] Series A Floating-Rate Non-Cumulative Perpetual Preferred Stock Available-for-sale, 12 Months or more Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Product and Service [Domain] Product and Service [Domain] Capital markets fees and income Products And Services, Capital Markets And Foreign Exchange Fees [Member] Products And Services, Capital Markets And Foreign Exchange Fees California CALIFORNIA Due after one year through five years Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five Noninterest expense: Noninterest Expense [Abstract] Undistributed earnings applicable to common shares Undistributed Earnings (Loss) Available to Common Shareholders, Basic Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Total available-for-sale Debt Securities, Available For Sale, Excluding Accrued Interest [Member] Debt Securities, Available For Sale, Excluding Accrued Interest Financing receivable, modified, subsequent default (less than) Financing Receivable, Modified, Subsequent Default 2029 Lessee, Operating Lease, Liability, to be Paid, Year Three Due in one year or less Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, Year One Termination Date Trading Arrangement Termination Date Other Commitments [Axis] Other Commitments [Axis] Weighted average remaining lease term (years) Weighted Average Remaining Lease Term [Abstract] Weighted Average Remaining Lease Term Schedule of Interest Income by Security Type Tax and Nontaxable Interest Income by Investment Type [Table Text Block] [Table Text Block] for Tax and Nontaxable Interest Income by Investment Type [Table] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Hedges of floating-rate assets Hedges Of Floating-Rate Assets [Member] Hedges Of Floating-Rate Assets Other liabilities: Other Liabilities [Abstract] Fair Value as of Grant Date Award Grant Date Fair Value Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Total investment securities Gross Unrealized Gains of Investment Securities Recognized in OCI Gross Unrealized Gains of Investment Securities Recognized in OCI Net unamortized purchase premiums, discounts, and deferred loan fees and cost Financing Receivable, Unamortized Loan Cost (Fee) and Purchase Premium (Discount) Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Retail and business banking fees Retail and business banking fees Retail and business banking fees Total debt securities Debt Securities, Held-to-Maturity, Maturity, Weighted Average Yield Debt Securities, Held-to-Maturity, Maturity, Weighted Average Yield Available-for-sale, less than 12 Months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Total customer-related noninterest income Revenues Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Schedule of Assets and Liabilities Measured at Fair Value by Class on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Investment securities: Marketable Securities [Abstract] All Award Types Award Type [Domain] 2026 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year FAIR VALUE Fair Value Disclosures [Text Block] Amortized cost Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date [Abstract] Customer-facing interest rate derivatives Interest Rate Swaps For Customers [Member] Interest Rate Swaps For Customers [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Asset Pledged as Collateral Asset Pledged as Collateral [Member] Geographical [Axis] Geographical [Axis] Summary of Derivative Instruments [Abstract] Loan-related fees and income Loan-related fees and income The net gain or loss from the sale of loans, and related servicing income. Allowance for credit loss on HTM securities (less than) Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest Home equity credit line Home Equity Line of Credit [Member] Other assets 1 Other Assets Amegy Amegy Corporation Segment [Member] Amegy Corporation Segment [Member] Carrying amount of hedged liabilities Hedged Liability, Fair Value Hedge Noninterest income: Noninterest Income [Abstract] Cash and due from banks at beginning of period Cash and due from banks at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Threshold period past due Financing Receivable, Threshold Period Past Due Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Non-NEOs Non-NEOs [Member] Allowance for Credit Losses Credit Loss, Financial Instrument [Policy Text Block] LEASES Lessee, Operating Leases [Text Block] Municipal Municipal [Member] Municipal [Member] Due after five years through ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Long-Term Debt, Type [Domain] Long-Term Debt, Type [Domain] Bank common stock repurchased Payments for Repurchase of Common Stock Gross unrealized losses Debt Securities, Unrealized Loss [Abstract] Debt Securities, Unrealized Loss Range [Axis] Statistical Measurement [Axis] Schedule of Derivative Gains (Losses) Deferred in OCI or Recognized in Earnings Derivative Instruments, Gain (Loss) [Table Text Block] Award Type Award Type [Axis] Effective portion of derivative gain/(loss) deferred in AOCI Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Consumer: Consumer Portfolio Segment [Member] Product and Service [Axis] Product and Service [Axis] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Stock, par value $0.001 Common stock shares (in thousands) Common Stock [Member] Semi-trailers and semi-tractors Sem-Trailers Semi-Tractors [Member] Sem-Trailers Semi-Tractors Investment securities Total investment securities Debt Securities, Maturity, Allocated And Single Maturity Date, Amortized Cost Debt Securities, Maturity, Allocated And Single Maturity Date, Amortized Cost Operating lease expense Operating Lease, Cost 2022 2021 Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff Multiple modification types Multiple Modification Types [Member] Multiple modification types LONG-TERM DEBT AND SHAREHOLDERS' EQUITY Debt And Stockholders' Equity Note Disclosure [Text Block] Debt And Stockholders' Equity Note Disclosure Derivative Contract [Domain] Derivative Contract [Domain] Colorado COLORADO Total past due Financial Asset, Past Due [Member] Total liabilities and shareholders’ equity Liabilities and Equity Goodwill and intangibles Intangible Asset, Including Goodwill, after Accumulated Amortization Stock options Share-Based Payment Arrangement, Option [Member] Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Fair Value by Asset Class [Axis] Asset Class [Axis] Schedule of Fair Value Hedges Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Tabular List, Table Tabular List [Table Text Block] Purchases of investment securities held-to-maturity Payments to Acquire Held-to-Maturity Securities Name Awards Close in Time to MNPI Disclosures, Individual Name Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Total average loans Average Loans And Leases Average loans and leases. Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Wealth management fees Products And Services, Wealth Management Fees [Member] Products And Services, Wealth Management Fees Preferred stock, without par value; authorized 4,400 shares Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Weighted average LTV Loan-To-Value Ratio, Weighted Average Loan-To-Value Ratio, Weighted Average Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Less undistributed earnings applicable to nonvested shares Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Hedging Designation [Axis] Hedging Designation [Axis] Total assets Total assets Assets, Fair Value Disclosure Long-term debt Total Long-Term Debt and Lease Obligation Number of branches leased Number of Branches Leased Number of Branches Leased Name Measure Name Liabilities for Guarantees on Long-Duration Contracts [Table] Liabilities for Guarantees on Long-Duration Contracts [Table] Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Interest and fees on loans Interest and fees on loans; Interest on short- and long-term borrowings Interest and Fee Income, Financing Receivable Accumulated paid-in capital Additional Paid-in Capital [Member] Income before income taxes Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Domestic Due after five years through ten years Debt Securities, Available-for-Sale, Weighted Average Yield, Maturity, after Year 5 Through 10 Netting Derivative Asset, Subject to Master Netting Arrangement, Gross Liability and Collateral, Obligation to Return Cash, Offset Net change in loans and leases Payments for (Proceeds from) Other Loans and Leases Accrued interest receivable Interest Receivable Name Trading Arrangement, Individual Name 4.48% Fixed-To-Floating Senior Notes 4.48% Fixed-To-Floating Senior Notes [Member] 4.48% Fixed-To-Floating Senior Notes Securities gains (losses), net Debt and Equity Securities, Gain (Loss) Company Selected Measure Amount Company Selected Measure Amount Deferred compensation plan assets Deferred Compensation Plan Assets, Fair Value Disclosure Deferred Compensation Plan Assets, Fair Value Disclosure Net activity under employee plans and related tax benefits (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Operating leases Operating Lease, Weighted Average Remaining Lease Term Non-PEO NEO Non-PEO NEO [Member] Principal balance of loans sold, serviced loans Principal Balance of Loans Sold, Serviced Loans Principal Balance of Loans Sold, Serviced Loans Total noninterest expense Noninterest Expense Award Timing Method Award Timing Method [Text Block] Net increase in cash and due from banks Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Par value of hedged liabilities Derivative Liability, Notional Amount Net income Net income for the period Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Schedule of Basic and Diluted Earnings per Common Share Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Idaho IDAHO Schedule of Financing Receivables Past Due [Table] Financing Receivable, Past Due [Table] Restatement Determination Date: Restatement Determination Date [Axis] Schedule of Changes in Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Unrealized loss amortization associated with the securities transferred from AFS to HTM OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), after Tax Losses from fair value changes Fair Value, Option, Changes in Fair Value, Gain (Loss) NSB Nevada State Bank Segment [Member] Nevada State Bank Segment [Member] Hedges of fixed-rate assets Hedges of Fixed-Rate Assets [Member] Hedges of Fixed-Rate Assets Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] New Mexico NEW MEXICO Weighted average common shares outstanding during the period: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Range [Domain] Statistical Measurement [Domain] Related allowance Financing Receivable, Excluding Accrued Interest, Nonaccrual, Related Allowance Financing Receivable, Excluding Accrued Interest, Nonaccrual, Related Allowance Summary of Collateral-Dependent Loans Collateral-Dependent Loans [Table Text Block] Collateral-Dependent Loans Document Fiscal Year Focus Document Fiscal Year Focus Sales-type or direct financing leases income Sales-type and Direct Financing Leases, Profit (Loss) Less: Offsetting derivative instruments Derivative Liability, Subject to Master Netting Arrangement, Asset Offset Less: Cash collateral pledged/received Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Offset Total deposits Deposits Bankcard and other revolving plans Bankcard And Other Revolving Plans [Member] Bankcard And Other Revolving Plans [Member] 2027 Lessee, Operating Lease, Liability, to be Paid, Year One Schedule of Long-term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Net earnings applicable to common shareholders Net Income (Loss) Available To Common Shareholders Net Income (Loss) Available To Common Shareholders Unfunded lending commitments Unused Commitments to Extend Credit Restatement Determination Date Restatement Determination Date Less: Cash collateral pledged/received Derivative Asset, Subject to Master Netting Arrangement, Collateral, Obligation to Return Cash, Offset Against Derivative Asset Estimated fair value Debt Securities, Fair Value [Abstract] Debt Securities, Fair Value Other Other Noninterest Expense LOANS, LEASES, AND ALLOWANCE FOR CREDIT LOSSES Financing Receivables [Text Block] Amendment Flag Amendment Flag Nevada NEVADA Marketable Securities [Line Items] Marketable Securities [Line Items] Available-for-sale Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Financial Standby Letters of Credit [Member] Schedule of Amount of Gross Unrealized Losses for Debt Securities and Estimated Fair Value Debt Securities, Available-for-Sale [Table Text Block] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Other real estate owned Other Real Estate, Foreclosed Assets, and Repossessed Assets Entity Address, State or Province Entity Address, State or Province Nonaccrual loans that are current Nonaccrual loans that are current Financing Receivable, Excluding Accrued Interest, Nonaccrual PEO Total Compensation Amount PEO Total Compensation Amount ASSETS Assets, Fair Value Disclosure [Abstract] Notional amount Derivative, Notional Amount Basic shares (in shares) Weighted average common shares outstanding (in shares) Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] 2030 Lessee, Operating Lease, Liability, to be Paid, Year Four Interest-bearing deposits Interest-Bearing Deposits in Banks and Other Financial Institutions Finance leases Lessee, Finance Lease, Description [Abstract] Debt and Equity Securities, FV-NI [Line Items] Investments [Abstract] Interest income Financing Receivable, Nonaccrual, Interest Income Total noninterest income Total noninterest income Noninterest Income Time Time deposits Time Deposits Document Information [Line Items] Document Information [Line Items] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Basis of Accounting Basis of Accounting, Policy [Policy Text Block] Class of Stock [Axis] Class of Stock [Axis] Net earnings applicable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-Maturity [Table] Taxable VS Nontaxable Income [Axis] Taxable VS Nontaxable Income [Axis] Taxable VS Nontaxable Income [Axis] Construction and land development Construction And Land Development [Member] Construction And Land Development [Member] Loans and leases (including loans held for sale), net of allowance Financing Receivable, After Allowance For Credit Loss And Held-For-Sale, Not Part of Disposal Group Financing Receivable, After Allowance For Credit Loss And Held-For-Sale, Not Part of Disposal Group Loans held for investment, net of allowance Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Recent Accounting Pronouncements and Developments New Accounting Pronouncements, Policy [Policy Text Block] Total average deposits Average Deposits Average deposits. 2024 2023 Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Net cash provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Amount of hedging Derivative, Amount of Hedged Item Security Exchange Name Security Exchange Name Netting Derivative Liability, Subject to Master Netting Arrangement, Gross Asset and Collateral, Right to Reclaim Cash, Offset Agriculture production and industrial buildings Agriculture Production And Industrial Buildings [Member] Agriculture Production And Industrial Buildings Total debt securities Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date Bank-owned life insurance Bank-owned life insurance [Member] Bank-owned life insurance [Member] Total liabilities Liabilities, Fair Value Disclosure Nontaxable Nontaxable [Member] Nontaxable [Member] Available-for-sale, 12 months or more, estimated fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer ROU assets, net of amortization Finance Lease, Right-of-Use Asset, after Accumulated Amortization Statement of Comprehensive Income [Abstract] Marketable Securities [Table] Marketable Securities [Table] Name Outstanding Recovery, Individual Name Deferred losses AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Schedule of Anti-Dilutive Stock Awards Schedule of Weighted Average Number of Shares [Table Text Block] Amortized cost Debt Securities, Amortized Cost [Abstract] Debt Securities, Amortized Cost Liabilities for Guarantees on Long-Duration Contracts [Line Items] Liabilities for Guarantees on Long-Duration Contracts [Line Items] Interest on short- and long-term borrowings Interest Expense, Borrowings Geographical [Domain] Geographical [Domain] Card fees Products And Services, Card Fees [Member] Products And Services, Card Fees Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Oregon OREGON Past due loans classification, minimum number of days principal or interest unpaid Past Due Loans Classification, Minimum Number Of Days Principal Or Interest Unpaid Past Due Loans Classification, Minimum Number Of Days Principal Or Interest Unpaid Due after one year through five years Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year One Through Five Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Marketing and business development Marketing and Business Development Expense Marketing and Business Development Expense Amounts reclassified from AOCI, net of tax Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Total investment securities Gross Unrealized Losses of Investment Securities Recognized in OCI Gross Unrealized Losses of Investment Securities Recognized in OCI Total investment securities Debt Securities, Excluding Trading Securities Debt Securities, Excluding Trading Securities Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table] Noncash activities: Noncash Investing and Financing Items [Abstract] Pension and post-retirement Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, by Asset Class [Domain] Asset Class [Domain] Purchases and sales of other noninterest-bearing investments Net change in other noninterest-bearing investments Net change in other noninterest-bearing investments Total investment securities Estimated Fair Value of Investment Securities Estimated Fair Value of Investment Securities Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Diluted shares (in shares) Weighted average diluted common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Capital markets fees and income Capital Market Fees And Income Capital Market Fees And Income Entity Emerging Growth Company Entity Emerging Growth Company Mortgage loans in process of foreclosure Mortgage Loans in Process of Foreclosure, Amount Loans and leases, net of unearned income and fees 1 Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Underlying Security Market Price Change Underlying Security Market Price Change, Percent Premises, equipment and software, net Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Other direct expenses Other Direct Expenses Other Direct Expenses DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Derivative Instruments and Hedging Activities Disclosure [Text Block] Held-to-maturity Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss Less imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Derivatives Other liabilities Derivative Liability, Subject to Master Netting Arrangement, before Offset Amortized cost basis with allowance Financing Receivable, Excluding Accrued Interest, Nonaccrual, With Allowance Financing Receivable, Excluding Accrued Interest, Nonaccrual, With Allowance Provision for unfunded lending commitments Provision for unfunded lending commitments Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Securities sold, not yet purchased Financial Instruments Sold, Not yet Purchased, at Fair Value Customer-related noninterest income Noninterest income, Customer-related Noninterest income, Customer-related Organization, Consolidation and Presentation of Financial Statements [Abstract] Total lease payments Lessee, Operating Lease, Liability, to be Paid Loans sold from held for sale Proceeds from Sale, Loan, Held-for-Sale Par value of hedged items Derivative Asset, Notional Amount Principal forgiveness Principal Forgiveness [Member] Loans held for investment reclassified to loans held for sale, net Transfer Of Portfolio Loans And Leases To Held-For-Sale And Transfer Of Loans Held-For-Sale To Portfolio Loans, Net Transfer Of Portfolio Loans And Leases To Held-For-Sale And Transfer Of Loans Held-For-Sale To Portfolio Loans, Net 2024 2023 Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff Collateral Held [Domain] Collateral Held [Domain] Other Other Debt Securities Available-For-Sale [Member] Other Debt Securities Available-For-Sale Other expenses associated with operating leases Operating Leases, Other Expenses Operating Leases, Other Expenses All Executive Categories All Executive Categories [Member] Washington WASHINGTON Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] 90+ days past due Financing Receivable, Excluding Accrued Interest, 90 Days or More Past Due, Still Accruing Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Past due loans classification, minimum number of delinquent monthly payments Past Due Loans Classification, Minimum Number Of Delinquent Monthly Payments Past Due Loans Classification, Minimum Number Of Delinquent Monthly Payments OPERATING SEGMENT INFORMATION Segment Reporting [Text Block] Proceeds from sales, maturities, and paydowns of investment securities available-for-sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Investment securities, available-for-sale Investments, Fair Value Disclosure Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Preferred stock dividends Other Preferred Stock Dividends and Adjustments Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Utah UTAH Accrued interest receivable Financing Receivable, Accrued Interest, after Allowance for Credit Loss Other liabilities 1 Other Liabilities Noncustomer-related noninterest income Noninterest Income, Other Operating Income Schedule of Financing Receivable, Allowance for Credit Losses [Table] Financing Receivable, Allowance for Credit Loss [Table] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Owner-occupied Owner Occupied [Member] Owner Occupied [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-Maturity Securities [Line Items] Available-for-sale, gross gains Debt Securities, Available-for-Sale, Realized Gain Amortized cost Financing Receivable, Individually Evaluated for Credit Loss Exercise Price Award Exercise Price Held-to-maturity, at amortized cost (fair value: $8,440 and $8,940) Held-to-maturity Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss Fair Value, Recurring Fair Value, Recurring [Member] Segment Reporting [Line Items] Segment Reporting [Line Items] Share repurchase program, authorized amount Share Repurchase Program, Authorized, Amount Financing receivable, commitments threshold for evaluating individually Financing Receivable, Excluding Accrued Interest, Commitment Threshold For Measuring Individually Financing Receivable, Excluding Accrued Interest, Commitment Threshold For Measuring Individually Document Quarterly Report Document Quarterly Report Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items] Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] Texas TEXAS Municipal securities US States and Political Subdivisions Debt Securities [Member] Special Mention Special Mention [Member] 2023 2022 Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Preferred stock, liquidation preference (in dollars per share) Preferred Stock, Liquidation Preference Per Share Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Equity Component [Domain] Equity Component [Domain] Realized gains (losses) in the statement of income Securities gains (losses), net Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Foreign exchange derivatives Foreign Exchange Contract [Member] Performance Performance Guarantee [Member] Adoption Date Trading Arrangement Adoption Date Commercial letters of credit Commercial Letters Of Credit Commercial Letters Of Credit Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Lease liabilities Total Operating Lease, Liability Finance lease obligations Finance Lease, Liability Held-to-maturity, estimated fair value Held-to-maturity investment securities Debt Securities, Held-to-Maturity, Fair Value Other, net Proceeds from (Payment for) Other Financing Activity Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Commercial: Commercial Portfolio Segment [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Other noninterest-bearing investments Other Noninterest Bearing Investments Fair Value Disclosure Other noninterest bearing investments fair value disclosure. Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Operating lease income Operating Lease, Lease Income Financing Receivables, Period Past Due [Domain] Financial Asset, Aging [Domain] Restricted stock and restricted stock units Restricted Stock Units (RSUs) [Member] All Adjustments to Compensation All Adjustments to Compensation [Member] Modified, principal forgiveness (current year approximately, prior year less than) Financing Receivable, Excluding Accrued Interest, Modified in Period, Principal Amount Forgiven Financing Receivable, Excluding Accrued Interest, Modified in Period, Principal Amount Forgiven Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Land Acquisition and Development Land Acquisition And Development [Member] Land Acquisition And Development Pledging Purpose [Domain] Pledging Purpose [Domain] Net decrease (increase) in loans held for sale Increase (Decrease) in Loan, Held-for-Sale Income Statement [Abstract] Shareholders’ equity: Equity, Attributable to Parent [Abstract] Document Transition Report Document Transition Report Change in other liabilities Increase (Decrease) in Operating Liabilities Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Derivatives Increase (Decrease) in Fair Value of Interest Rate Fair Value Hedging Instruments Other Commitments [Domain] Other Commitments [Domain] Due after ten years Debt Securities, Available-for-Sale, Weighted Average Yield, Maturity, after Year 10 City Area Code City Area Code Wyoming WYOMING Provision for credit losses: Allowance for Credit Loss [Abstract] Gross unrealized gains Debt Securities, Unrealized Gain [Abstract] Debt Securities, Unrealized Gain Document Information [Table] Document Information [Table] Commercial account fees Products And Services, Commercial Account Fees [Member] Products And Services, Commercial Account Fees Name Forgone Recovery, Individual Name Total provision for credit losses Provision for credit losses Provision for credit losses Financing Receivable And Off Balance Sheet Liability, Credit Loss, Expense (Reversal) Financing Receivable And Off Balance Sheet Liability, Credit Loss, Expense (Reversal) Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Total interest income Interest and Dividend Income, Operating Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Due after ten years Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10 Card fees Card fees Card fees Net decrease in money market investments Payments for (Proceeds from) Short-Term Investments Change in other assets Increase (Decrease) in Other Operating Assets Other customer-related fees Products And Services, Other Customer-Related Fees [Member] Products And Services, Other Customer-Related Fees Net increase (decrease) in deposits Increase (Decrease) in Deposits Amortized cost Debt Securities, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract] Debt Securities, Maturity, Allocated and Single Maturity Date, Amortized Cost Due after five years through ten years Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 5 through 10 Less: Offsetting derivative instruments Derivative Asset, Subject to Master Netting Arrangement, Liability Offset Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Series A Preferred Stock Series A Preferred Stock [Member] Revolving loans gross charge-offs Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff Net unrealized gains (losses) on investment securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Net change in unrealized gains on investment securities OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Cash Flow Hedging Cash Flow Hedging [Member] LIABILITIES Liabilities, Fair Value Disclosure [Abstract] Commercial and industrial Commercial And Industrial [Member] Commercial And Industrial [Member] Other Corporate Reconciling Items And Eliminations [Member] Corporate Reconciling Items And Eliminations Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] COMMITMENTS, GUARANTEES AND CONTINGENT LIABILITIES Commitments Contingencies and Guarantees [Text Block] Weighted-average term extension (in months) Financing Receivable, Modified, Weighted-Average Term Increase from Modification CASH FLOWS FROM FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Interest on money market investments Interest Income, Money Market Deposits Money market investments: Restricted Cash and Investments [Abstract] Net Investment Income [Line Items] Net Investment Income [Line Items] Financial Instruments [Domain] Financial Instruments [Domain] 2022 2021 Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Derivatives Total net derivatives presented on balance sheet Derivative Asset LEASES Lessor, Sales-type Leases [Text Block] Underlying Securities Award Underlying Securities Amount Fair value Estimate of Fair Value Measurement [Member] REVENUE FROM CONTRACTS WITH CUSTOMERS Revenue from Contract with Customer [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Extended Maturity and Interest Rate Reduction Extended Maturity and Interest Rate Reduction [Member] Taxable VS Nontaxable Income [Domain] Taxable VS Nontaxable Income [Domain] [Domain] for Taxable VS Nontaxable Income [Axis] Cash Cash Due in one year or less Debt Securities, Weighted Average Yield, Maturity, Year One Debt Securities, Weighted Average Yield, Maturity, Year One Preferred stock Preferred Stock [Member] Other, net Payment for (Proceeds from) Other Investing Activity Operating leases Operating Lease, Weighted Average Discount Rate, Percent Undistributed earnings Undistributed Earnings, Basic Segment Reporting [Table] Segment Reporting [Table] Amortized cost basis Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount Reserve for unfunded lending commitments Balance at beginning of period Balance at end of period Off-Balance-Sheet, Credit Loss, Liability Schedule of Lease Expense Lease, Cost [Table Text Block] Vectra Vectra Bank Colorado Segment [Member] Vectra Bank Colorado Segment [Member] Total debt securities Debt Securities, Maturity, Weighted Average Yield Debt Securities, Maturity, Weighted Average Yield Agency guaranteed mortgage-backed securities Agency Guaranteed Mortgage Backed Securities [Member] Agency Guaranteed Mortgage-Backed Securities [Member] All Trading Arrangements All Trading Arrangements [Member] Available-for-sale, less than 12 Months, estimated fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Due after ten years Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, After Year 10 Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, After Year 10 Current Fiscal Year End Date Current Fiscal Year End Date Due after one year through five years Debt Securities, Available-for-Sale, Weighted Average Yield, Maturity, after Year One Through Five Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Provision for loan and lease losses Provision for loan losses Financing Receivable, Excluding Accrued Interest, Credit Loss Expense (Reversal) Derivative [Line Items] Derivative [Line Items] Other customer-related fees Other customer-related fees Other customer-related fees Technology, telecom, and information processing Communications and Information Technology Bank common stock repurchased (in shares) Common stock repurchased (in shares) Stock Repurchased During Period, Shares Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Entity File Number Entity File Number Office building Office Building [Member] Net change in short-term borrowed funds Proceeds from (Repayments of) Short-Term Debt Net activity under employee plans and related tax benefits Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Schedule of Contractual Maturities Debt Securities Investments Classified by Contractual Maturity Date [Table Text Block] Average yield Debt Securities, Weighted Average Yield, Maturity [Abstract] Debt Securities, Weighted Average Yield, Maturity Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Senior notes Senior Notes Measure: Measure [Axis] Interest-bearing: Interest-Bearing Deposit Liabilities [Abstract] Accruing Substandard Accruing Substandard [Member] Accruing Substandard Equity Components [Axis] Equity Components [Axis] Net cash paid for income taxes Income Tax Paid, after Refund Received Entity Interactive Data Current Entity Interactive Data Current Due after one year through five years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Entity Small Business Entity Small Business Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Net interest income Net interest income Interest Income (Expense), Operating MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Document Type Document Type Acquisition of California branches, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Proceeds from the issuance of long-term debt Proceeds from Issuance of Long-Term Debt Local Phone Number Local Phone Number Summary of Derivative Instruments by Hedge Designation [Abstract] Summary of Derivative Instruments by Hedge Designation [Abstract] Due after five years through ten years Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year 5 Through 10 Average yield Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity [Abstract] Collateral Dependent Loans Collateral Dependent Loans [Member] Collateral Dependent Loans Pledged Status [Domain] Pledged Status [Domain] Due after one year through five years Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, After Year One Through Five Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, After Year One Through Five Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Other debt securities Available-for-sale, Other debt securities [Member] Available-for-sale, Other debt securities [Member] Executive Category: Executive Category [Axis] LIABILITIES AND SHAREHOLDERS’ EQUITY LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities and Equity [Abstract] Indirect/allocated expenses Noninterest Expense, Indirect And Allocated Expenses Noninterest Expense, Indirect And Allocated Expenses Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Net change in cash flow hedge derivatives Amount of gain/(loss) reclassified from AOCI into income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Other Other Consumer Loans [Member] Other Consumer Loans PEO Name PEO Name Weighted average discount rate Weighted Average Discount Rate [Abstract] Weighted Average Discount Rate Net unrealized gains (losses) on derivatives and other Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] 5.24% Fixed-To-Floating Senior Notes 5.24% Fixed-To-Floating Senior Notes [Member] 5.24% Fixed-To-Floating Senior Notes Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Cash and due from banks Cash and Due from Banks Summary of Past Due Loans (Accruing and Nonaccruing) Financing Receivable, Past Due [Table Text Block] Current Financial Asset, Not Past Due [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Debt Instrument [Line Items] Debt And Equity [Abstract] Debt And Equity BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Measurement Frequency [Domain] Measurement Frequency [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Share-based compensation Share-Based Payment Arrangement, Noncash Expense Interest expense: Interest Expense, Operating and Nonoperating [Abstract] Salaries and employee benefits Labor and Related Expense Total lease expense Lease, Cost Change in deferred compensation Stockholders' Equity, Change In Deferred Compensation Stockholders' Equity, Change In Deferred Compensation Fed funds and other short-term borrowings: Fed Funds And Other Short-Term Borrowings [Abstract] Fed Funds And Other Short-Term Borrowings Proceeds from maturities and paydowns of investment securities held-to-maturity Proceeds from Maturities, Prepayments and Calls of Held-to-Maturity Securities Schedule of Derivative Amounts Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Basic (in dollars per share) Net earnings per common share (in dollars per share) Earnings Per Share, Basic Insider Trading Arrangements [Line Items] Deposits acquired in purchase of California branches (at time of purchase) Noncash Or Part Noncash Acquisition, Deposits Acquired Noncash Or Part Noncash Acquisition, Deposits Acquired Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged items Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease) Customer commodity derivatives Commodity Contract [Member] Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Asset Pledged as Collateral without Right Asset Pledged as Collateral without Right [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Recoveries Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Unrealized loss amortization associated with the securities transferred from AFS to HTM, before tax OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), before Tax Nonaccrual loans that are current Financial Asset, 1 to 29 Days Past Due [Member] 2025 2024 Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Equity Awards Adjustments Equity Awards Adjustments [Member] Federal funds sold and securities purchased under agreements to resell Federal Funds Sold and Securities Purchased under Agreements to Resell Hedging Relationship [Domain] Hedging Relationship [Domain] Deferred tax assets Deferred Tax Assets, Net Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Revolving loans converted to term loans gross charge-offs Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan, Writeoff Pass Pass [Member] Plan Name [Axis] Plan Name [Axis] Summary of Major Portfolio Segment and Specific Loan Class Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Interest on securities Interest Income, Debt Securities, Operating Multifamily apartments Multifamily Apartments [Member] Multifamily Apartments Other debt securities Other Debt Obligations [Member] Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged items Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease) Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] Loans Held For Sale Loans Held For Sale [Table Text Block] Loans Held For Sale Schedule of Realized Gain (Loss) Schedule of Realized Gain (Loss) [Table Text Block] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Hedging Designation [Domain] Hedging Designation [Domain] Class of Stock [Domain] Class of Stock [Domain] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Taxable Taxable [Member] Taxable [Member] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Available-for-sale Interest Income, Debt Securities, Available-for-Sale, Operating INCOME TAXES Income Tax Disclosure [Text Block] Real estate acquired through foreclosure (prior year less than) Real Estate Acquired Through Foreclosure Other, net Other Noncash Income (Expense) Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Wealth management fees Wealth Management Fees Wealth Management Fees Entity Filer Category Entity Filer Category Available-for-sale, total, estimated fair value Debt Securities, Available-for-Sale, Unrealized Loss Position Stock Compensation Plan Zion's Stock Compensation Plan [Member] Zion's Stock Compensation Plan Thereafter Lessee, Operating Lease, Liability, To Be Paid, After Year Four Lessee, Operating Lease, Liability, To Be Paid, After Year Four Financing Receivables, Period Past Due [Axis] Financial Asset, Aging [Axis] Derivatives not designated as hedging instruments Not Designated as Hedging Instrument [Member] Deposits: Deposits [Abstract] Unrealized securities gains, net Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Derivatives Total net derivatives presented on balance sheet Derivative Liability Senior notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Income taxes Less: Income tax expense (benefit) Income Tax Expense (Benefit) Fair Value Hedging Fair Value Hedging [Member] Consolidation Consolidation, Policy [Policy Text Block] Total Total Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff NBAZ National Bank Of Arizona Segment [Member] National Bank of Arizona Segment [Member] Financing receivable, commitments threshold for risk classification approach Financing Receivable, Commitments Threshold For Risk Classification Approach Financing Receivable, Commitments Threshold For Risk Classification Approach Term Term [Member] Term [Member] RECENT ACCOUNTING PRONOUNCEMENTS Accounting Standards Update and Change in Accounting Principle [Text Block] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Due in one year or less Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, Year One Debt Securities, Amortized Cost, Maturity, Allocated And Single Maturity Date, Year One Fixed-Rate Available For Sale Securities Fixed-Rate Available For Sale Securities [Member] Fixed-Rate Available For Sale Securities Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Statement [Table] Statement [Table] Due after one year through five years Debt Securities, Weighted Average Yield, Maturity, After Year One Through Five Debt Securities, Weighted Average Yield, Maturity, After Year One Through Five 2025 2024 Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Summary of Nonaccrual Loans Financing Receivable, Nonaccrual [Table Text Block] TCBNW The Commerce Bank Northwest Segment [Member] The Commerce Bank Northwest Segment Ag loan servicing Servicing Contracts [Member] Derivatives Other assets Derivative Asset, Subject to Master Netting Arrangement, before Offset Purchased credit derivatives Purchased Credit Derivative [Member] Purchased Credit Derivative Loans held for sale Loan, held for sale fair value Loan, Held-for-Sale, Fair Value Disclosure Derivative Instruments and Hedging Activities Disclosure [Abstract]