Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Revision of Prior Period [Axis] Revision of Prior Period [Axis] Expected Return on Plan Assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Award Timing Predetermined Award Timing Predetermined [Flag] Entity File Number Entity File Number Capital Surplus [Member] Additional Paid-in Capital [Member] Agency mortgage-backed securities Financial Instruments Owned Agency Mortgage backed Securities At Fair Value The fair value as of the balance sheet date of firm holdings in Agency mortgage-backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the agency mortgage-backed security). Tabular List, Table Tabular List [Table Text Block] Income tax (expense) benefit Other Comprehensive Income (Loss), Tax Derivative Instruments [Abstract] Derivative Instruments [Abstract] Derivative Instruments [Abstract] Loans charged off Financing Receivable, Allowance for Credit Loss, Writeoff Share Based Compensation Award, Performance Stock Unit, Grants in Period, Weighted Avg Grant Date Fair Value Share Based Compensation Award, Performance Stock Unit, Grants in Period, Weighted Avg Grant Date Fair Value Share Based Compensation Award, Performance Stock Unit, Grants in Period, Weighted Avg Grant Date Fair Value Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Contractual amount of letters of credit, guaranteed maximum potential future payments Guarantor Obligations, Maximum Exposure, Undiscounted Debt Securities [Member] Debt Securities [Member] Goodwill and Intangible Assets [Line Items] Goodwill [Line Items] Goodwill [Line Items] Fair Value, by Balance Sheet Grouping [Axis] Measurement Basis [Axis] Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Revenue from Contract with Customer [Text Block] Revenue from Contract with Customer [Text Block] Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Derivatives subject to master netting agreements Derivative Subject to Master Netting Agreement [Member] Derivatives Subject to Master Netting Agreement [Member] February 23, 2023 February 23, 2023 Interest Rate Floor [Member] February 23, 2023 Interest Rate Floor Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Interest rate caps Interest Rate Cap [Member] Adjustment to Compensation, Amount Adjustment to Compensation Amount Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Non-Agency Mortgage-Backed Securities [Member] Non-agency mortgage-backed securities Non Agency Mortgage Backed Securities [Member] Non-agency mortgage-backed securities [Member] Proceeds from sale of investments, total, including pending trades Total proceeds from sales of investments including pending trades Amount of proceeds from sale of investments in available for sale debt securities, equity securities, and other investments. Includes pending transactions for which cash has not yet been received. Employee Stock Option Share-Based Payment Arrangement, Option [Member] Financing Receivable, after Allowance for Credit Loss Financing Receivable, after Allowance for Credit Loss Summary of Cash Flow Hedge Activity [Table] Summary of Cash Flow Hedge Activity [Table] Summary of Cash Flow Hedge Activity [Table] Consumer Loan [Member] Consumer Loan [Member] Cash dividends per share, Common Stock, Cash Dividends, Common Stock, Cash Total Commerce Bancshares, Inc. stockholders' equity Equity, Attributable to Parent Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Insider Trading Policies and Procedures [Line Items] Financing Receivable at acquisition on purchased seasoned loans, Excluding Accrued Interest, after Allowance for Credit Loss Financing Receivable at acquisition on purchased seasoned loans, Allowance for Credit Loss, Excluding Accrued Interest Financing Receivable at acquisition on purchased seasoned loans, Allowance for Credit Loss, Excluding Accrued Interest Common Stock, Shares Authorized Common Stock, Shares Authorized Long Lived Assets Nonrecurring Basis Gains Losses Long Lived Assets Nonrecurring Basis Gains Losses Represents the gains and losses on long-lived assets measured on a nonrecurring basis during the period(s) presented. Assets Sold under Agreements to Repurchase [Line Items] Assets Sold under Agreements to Repurchase [Line Items] Contract with Customer, Asset and Liability [Table] Contract with Customer, Asset and Liability [Table] Disclosure of information about accounts receivable due from contracts with customers. Interest and fees on loans Interest and fees on loans [Member] Interest and fees on loans Derivative Instruments (Balance Sheet Offsetting) [Abstract] Derivative Instruments (Balance Sheet Offsetting) [Abstract] Derivative Instruments - Balance Sheet Offsetting [Abstract] Unpaid Principal Balance on Personal Real Estate Loans Held for Sale Unpaid Principal Balance on Personal Real Estate Loans Held for Sale Unpaid Principal Balance on Personal Real Estate Loans Held for Sale LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Cover page. Cover [Abstract] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] CECL Model Inputs CECL Model Inputs [Table Text Block] CECL Model Inputs Maximum [Member] Maximum [Member] Loans transferred to foreclosed real estate Real Estate Owned, Transfer to Real Estate Owned Less non-controlling interest expense (income) Net Income (Loss) Attributable to Noncontrolling Interest Net Amount Finite-Lived Intangible Assets, Net Debt Securities, Available-for-sale, Unrealized Loss Position Debt Securities, Available-for-Sale, Unrealized Loss Position Restricted Stock Restricted Stock [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Credit Quality Information [Abstract] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Financing Receivable, Credit Quality Indicator [Table] Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Less income allocated to nonvested restricted stock awards Income allocated to unvested restricted stockholders Dividends and undistributed income allocated to unvested restricted stockholders Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Location, Statement of Financial Position, Balance [Axis] Location, Statement of Financial Position, Balance [Axis] Location, Statement of Financial Position, Balance Interest on deposits with banks Interest Income, Deposits with Financial Institutions Financing Receivable, Modified, Weighted Average Term Increase from Modification Financing Receivable, Modified, Weighted Average Term Increase from Modification Equity Securities without Readily Determinable Fair Value, Additions, Annual Amount Equity Securities without Readily Determinable Fair Value, Additions, Annual Amount Equity Securities without Readily Determinable Fair Value, Additions, Annual Amount Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Summary Investment Holdings Summary Investment Holdings [Table Text Block] Schedule of Revenue by Major Customers, by Reporting Segments [Table] Schedule of Revenue by Major Customers, by Reporting Segments [Table] Diluted income per common share: Diluted Income Per Common Share [Member] Diluted income per common share [Member] Sales of premises and equipment Proceeds from Sale of Property, Plant, and Equipment Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Segments Operating Segments [Member] Total investment securities Total investment securities Sum of Available for Sale, Trading and Non-Marketable securities. Less non-controlling interest (income) expense Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Total interest expense Interest Expense, Operating Financing Receivable, Modified in Period, to Total Financing Receivables, Percentage Financing Receivable, Modified in Period, to Total Financing Receivables, Percentage Document Fiscal Period Focus Document Fiscal Period Focus Balance January 1 Balance June 30, 2026 Intangible Assets, Net (Including Goodwill) Other non-interest income (1) Revenue Not In Scope of ASC 606 [Member] Revenue Not In Scope of ASC 606 [Member] Percent of Revenue not in scope of ASC 606 Percent of Revenue not in scope of ASC 606 Percent of total revenue not within the scope of ASC 606 Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Award Timing Method Award Timing Method [Text Block] Business Real Estate Loan [Member] Business Real Estate Loan [Member] Business Real Estate Loan [Member] Award Type [Axis] Award Type [Axis] Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Hedging Relationship [Domain] Hedging Relationship [Domain] Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis Fair Value Level Three Measurement Disclosures [Table Text Block] Fair Value Level Three Measurement Disclosures [Table Text Block] Business Combination, Pro Forma Information Business Combination, Pro Forma Information [Table Text Block] Deposit account charges and other fees Deposit fee revenue Deposit fee revenue Derivative, Maturity Date Derivative, Contract End Date Trading Symbol Trading Symbol Entity Address, City or Town Entity Address, City or Town Basic income per common share: Basic Income Per Common Share [Member] Basic income per common share [Member] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Equity Securities Sold, Average Price Equity Securities Sold, Average Price Equity Securities Sold, Average Price Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Schedule Of Earnings Per Share Basic And Diluted [Table] Schedule Of Earnings Per Share Basic And Diluted [Table] Schedule Of Earnings Per Share Basic And Diluted [Table] Business Combination, Consideration Transferred Business Combination, Consideration Transferred Schedule of Financing Receivables, Purchased Seasoned Loans Schedule of Financing Receivables, Purchased Seasoned Loans [Table Text Block] Schedule of Financing Receivables, Purchased Seasoned Loans Credit risk participation agreements Credit Risk Participation Agreements [Member] Credit Risk Participation Agreements Entity Emerging Growth Company Entity Emerging Growth Company Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number 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] Restricted Cash and Cash Equivalent Restricted Cash and Cash Equivalent Equity Securities without Readily Determinable Fair Value Equity Securities without Readily Determinable Fair Value [Table Text Block] Total non-interest income Non-interest income Noninterest Income NON-INTEREST EXPENSE Noninterest Expense [Abstract] State and municipal obligations Financial Instruments, Owned, State and Municipal Government Obligations, at Fair Value Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Cash and due from banks Cash and Due from Banks Assets, Fair Value Financial Instruments Assets, Fair Value Financial Instruments Fair value estimates are made at a specific point in time based on relevant market information. They do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for many of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, risk characteristics and economic conditions. These estimates are subjective, involve uncertainties, and cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Percentage decrease requiring a review for impairment Percentage Decrease In Fair Value Below Amortized Cost The percent of decrease in the fair value of securities below amortized cost requiring a review for possible impairment. Financial Asset Acquired and No Credit Deterioration Financial Asset Acquired and No Credit Deterioration [Member] 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] Standby letters of credit, net liability Guarantor Obligations, Current Carrying Value Residential Real Estate Acquired Through Foreclosure through Obtaining Physical Possession Residential Real Estate Acquired Through Foreclosure through Obtaining Physical Possession Residential Real Estate Acquired Through Foreclosure through Obtaining Physical Possession Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Equity Securities Sold, Shares Equity Securities Sold, Shares Equity Securities Sold, Shares Nonvested Share Awards [Roll Forward] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Interest on investment securities Interest and Dividend Income, Securities, Operating Less income taxes Income Tax Expense (Benefit) Other assets Other Assets Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Designated as Hedging Instrument [Member] Designated as Hedging Instrument [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] Unrealized gains (losses) on cash flow hedge derivatives Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Derivative Liability, Amount Offset by Asset Derivative Liability, Amount Offset by Asset Amount of the asset offset against the fair value of gross derivative liabilities on the balance sheet. Schedule of Guarantor Obligations [Table] Guarantor Obligation [Table] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Antidilutive securities excluded from EPS [Domain] Antidilutive securities excluded from EPS [Domain] Antidilutive securities excluded from EPS [Domain] Goodwill, Acquired During Period Goodwill, Acquired During Period Cash Paid in Acquisition, Net of Cash Received Payments to Acquire Businesses, Net of Cash Acquired All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Derivative, Premium Paid Derivative, Premium Paid Other Noninterest Income, Other Operating Income Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Reserve Bank Debt Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Reserve Bank Debt The carrying amount, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of FRB debt obligations, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party. Net cash provided by (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Pension Loss Pension Loss [Member] The total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost. [Member] Financing Receivable, Modified, Payment Deferral Financing Receivable, Modified, Weighted Average Term Increase for Monthly Payments Financing Receivable, Modified, Payment Deferral Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Total repurchase agreements, subject to master netting arrangements Repurchase agreement [Member] Repurchase agreement [Member] Recoveries on Loans Financing Receivable, Allowance for Credit Loss, Recovery Net interest income Net interest income Interest Income (Expense), Operating Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Securities or Other Assets Sold under Agreements to Repurchase, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Derivative Liability, Fair Value, Gross Liability Derivative Liability, Subject to Master Netting Arrangement, before Offset Liabilities Assumed Liabilities Assumed Business Combination Acquisition Exchange Ratio on Common Stock Business Combination Acquisition Exchange Ratio on Common Stock Business Combination Acquisition Exchange Ratio on Common Stock Statement, Equity Components [Axis] Equity Components [Axis] Three Years before Current Fiscal Year Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Number of Reportable Segments Number of Reportable Segments Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period Entity Address, State or Province Entity Address, State or Province Substandard [Member] Substandard [Member] Total interest income Interest and Dividend Income, Operating Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Special Mention [Member] Special Mention [Member] Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] Interest rate floor trade date [Domain] Interest rate floor trade date [Domain] Interest rate floor trade date [Domain] Loans Loans Receivable, Fair Value Disclosure Individual: Individual [Axis] Summary Classification Of Held For Investment Loan Portfolio Schedule Of Held To Maturity Loans By Classification [Table Text Block] Schedule of held to maturity loans by classification. Share-Based Payment Arrangement, Stock Appreciation Right, Activity Share-Based Payment Arrangement, Stock Appreciation Right, Activity [Table Text Block] Total resale agreements, subject to master netting arrangements Resale agreement [Member] Resale agreement [Member] Financing Receivable, Modified, Past Due Financing Receivable, Modified, Past Due [Table Text Block] HFS Loans on non accrual status HFS Loans on non accrual status HFS Loans on non accrual status Investment Securities [Abstract] Investment Securities [Abstract] Investment Securities Disclosure Risk Participation Agreement [Member] Risk Participation Agreement [Member] Risk Participation Agreement [Member] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Entity Interactive Data Current Entity Interactive Data Current Valuation Technique Fair Value, Market Comparable Companies, Valuation Techniques Fair value, market comparable companies, valuation techniques. Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Modified [Line Items] Lessor, Components of Lease Income [Table Text Block] Components of Lease Income [Table Text Block] Components of Lease Income [Table Text Block] Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] INTEREST INCOME Interest and Dividend Income, Operating [Abstract] Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, Collateral, Obligation to Return Security Not Offset Total non-interest expense Non-interest expense Noninterest Expense Nature of Revenue [Domain] Nature of Revenue [Domain] [Domain] for Nature of Revenue [Axis]. In scope of ASC 606 versus not within the scope of ASC 606. Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Payment Deferral Payment Deferral [Member] Current or Less than 30 Days Past Due Financing Receivable Recorded Investment Current or Less than 30 days Past Due Financing Receivable, Recorded Investment, Current or Less than 30 days Past Due Personal Real Estate Loan [Member] Personal Real Estate Loan [Member] Personal Real Estate Loan [Member] Locations, Statement of Income, Balance [Domain] Locations, Statement of Income, Balance [Domain] Locations, Statement of Income, Balance [Domain] NON-INTEREST INCOME Noninterest Income [Abstract] Ownership [Domain] Ownership [Domain] Segments [Abstract] Segments [Abstract] Segments [Abstract] Net income attributable to Commerce Bancshares, Inc. Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest Valuation Allowance SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer Repayments of securities purchased under agreements to resell Proceeds from Securities Purchased under Agreements to Resell Net increase (decrease) in federal funds purchased and securities sold under agreements to repurchase Increase (Decrease) in Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Net Entity Central Index Key Entity Central Index Key PEO Name PEO Name Segment Reporting Information, Intersegment Revenue Revenues 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] Fair Value, Balance Sheet Grouping [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Risk Category of Loans in Commercial Portfolio Financing Receivable Credit Quality Indicators [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Non-interest bearing Non-interest bearing deposits Noninterest-Bearing Deposit Liabilities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Schedule Of Fair Values Of Derivative Instruments Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Class of Stock [Domain] Class of Stock [Domain] Financing Receivable, Modified in Period, Ninety Days Past Due Financing Receivable, Modified in Previous 12 months, Ninety Days Past Due Financing Receivable, Modified in Previous 12 months, Ninety Days Past Due 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Three Foreclosed real estate Real Estate Acquired Through Foreclosure Total Financing Receivable, before Allowance for Credit Loss Amounts reclassified to current earnings from accumulated other comprehensive income Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Gross Carrying Amount Finite-Lived Intangible Assets, Gross 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] Entity Address, Address Line One Entity Address, Address Line One Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Assets Sold under Agreements to Repurchase, Repurchase Liability Assets Sold under Agreements to Repurchase, Repurchase Liability Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Business Combination, Pro Forma Information, Nonrecurring Adjustment [Domain] Business Combination, Pro Forma Information, Nonrecurring Adjustment [Domain] Ownership [Axis] Ownership [Axis] Loans And Allowance For Loan Losses [Line Items] Loans and Leases Receivable Disclosure [Line Items] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Bank card transaction fees Bank Card Transaction Fees [Member] Fees earned from the issuance of debit and credit cards to the Company's retail and commercial banking customers who use the cards to purchase goods and services from merchants through an electronic payment system. Fair Value as of Grant Date Award Grant Date Fair Value Private equity investments Financial Instruments, Owned, Principal Investments, at Fair Value Derivative Instrument Detail [Abstract] Derivative Instrument Detail [Abstract] Four Years before Current Fiscal Year Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Liabilities held in trust for deferred compensation plan Deferred Compensation Liability, Current and Noncurrent Financing Receivable, Modified, Subsequent Default [Line Items] Financing Receivable, Modified, Subsequent Default [Line Items] Loans And Allowance For Loan Losses [Line Items] Loans And Allowance For Loan Losses [Line Items] Loans And Allowance For Loan Losses [Line Items] Summary Of Changes In Goodwill And Other Intangible Assets [Table] Summary Of Changes In Goodwill And Other Intangible Assets [Table] Summary Of Changes In Goodwill And Other Intangible Assets [Table] Salaries and employee benefits Labor and Related Expense Net effect of the assumed exercise of stock-based awards - based on the treasury stock method using the average market price for the respective periods Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested Options Forfeited, Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested Options Forfeited, Number of Shares Locations, Statement of Income, Balance [Axis] Locations, Statement of Income, Balance [Axis] Location, Statement of Income, Balance Purchases of investment securities (A) Payments to Acquire Investments Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Document Quarterly Report Document Quarterly Report Fair Value, Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Interest Receivable, Current Interest Receivable, Current Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Government-sponsored enterprise obligations US Government-sponsored Enterprises Debt Securities [Member] Guarantees Guarantees [Text Block] Business Loan [Member] Business Loan [Member] Business Loan [Member] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Deposit fee revenue by segment Deposit fee revenue by segment Portion of deposit fee revenue recorded in segment. Sales of Equity Securities Without Readily Determinable Fair Value Sales of Equity Securities Without Readily Determinable Fair Value Sales during the period of equity securities without a readily determinable fair value. Investments, Total Investments Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Agency mortgage-backed securities Agency Mortgage Backed Securities [Member] Agency mortgage-backed securities [Member] Debt Securities, Available-for-Sale, Planned Sale, Amortized Cost Debt Securities, Available-for-Sale, Planned Sale, Amortized Cost Amortized cost of available for sale debt securities that the Company sold as part of its plan to reposition a portion of its available for sale debt securities portfolio. Derivative Asset, Fair Value of Collateral Derivative Asset, Fair Value of Collateral Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Derivative Instrument, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Derivative Instrument, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Non-PEO NEO Non-PEO NEO [Member] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), Adjustments, before Tax Allowance for Credit Losses Debt Securities, Available-for-Sale, Allowance for Credit Loss Business Combination, Pro Forma Information [Table] Business Combination, Pro Forma Information [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Overnight and continuous Maturity Overnight [Member] Financing Receivable, Allowance for Credit Loss Financing Receivable, Allowance for Credit Loss Award Type [Domain] Award Type [Domain] Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Non-controlling interest Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Greater than 90 days Maturity Greater than 90 Days [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Compensation Amount Outstanding Recovery Compensation Amount Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Foreign exchange contracts Foreign Exchange Contract [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Trust fees Trust Fees [Member] Fees earned from providing trust and asset management services to both private client and institutional trust customers including asset custody, investment advice, and reporting and administrative services. MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Income per common share [Domain] Income per common share [Domain] [Domain] for Income per common share [Axis] Trading Activities, Gain and Losses, by Type, by Income Statement Location [Table] Trading Activity, Gain (Loss) [Table] Certificates of deposit of less than $100,000 Time Deposits, Less than $100,000 Loans Nonrecurring Basis Gains (Losses) Loans Nonrecurring Basis Gains Losses Represents the gains and losses on loans measured on a nonrecurring basis during the period(s) presented. Discount accretion Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion Derivative Liability, Not Offset, Policy Election Deduction Derivative Liability, Subject to Master Netting Arrangement, Deduction of Financial Instrument Not Offset Accumulated Other Comprehensive Income (Loss) Beginning balance Ending balance Accumulated Other Comprehensive Income (Loss), Net of Tax Fair Value Of Financial Instruments [Abstract] Fair Value Of Financial Instruments [Abstract] Fair Value of Financial Instruments [Abstract] Financial Instruments [Domain] Financial Instruments [Domain] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Minimum [Member] Minimum [Member] Business Combinations, Recognized Asset Acquired, Other Assets Business Combinations, Recognized Asset Acquired, Other Assets Business Combinations, Recognized Asset Acquired, Other Assets Net interest income after credit losses Interest Income (Expense), after Provision for Loan Loss Capitalized interest/dividends Capitalized Interest Or Dividends Capitalized interest or dividends during the period. Financial Impacts of Loan Modifications and Deferrals [Line Items] Financial Impacts of Loan Modifications and Deferrals [Line Items] Financial Impacts of Loan Modifications and Deferrals [Line Items] Company Selected Measure Name Company Selected Measure Name Proceeds from sales of other investments, including pending trades Proceeds from sales of other investments including pending trades Amount of proceeds from sale of investments classified as other. Includes pending transactions for which cash has not yet been received. Fair Value Measurement [Domain] Fair Value Measurement [Domain] Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax Collateral Dependent Loans, Amortized Cost Collateral Dependent Loans, Amortized Cost Collateral Dependent Loans, Amortized Cost Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Current period other comprehensive income (loss), before tax Other Comprehensive Income (Loss), before Tax Stock Appreciation Rights (SARs) [Member] Stock Appreciation Rights (SARs) [Member] Net Income (Loss) Available to Common Stockholders, Diluted Net Income (Loss) Available to Common Stockholders, Diluted Collateral [Domain] Collateral Held [Domain] Net increase (decrease) in other borrowings Net Increase (Decrease) in Short-Term Borrowings The net cash inflow or outflow for short-term borrowings having initial term of repayment within one year or the normal operating cycle, if longer. Goodwill and Intangible Assets [Roll Forward] Goodwill [Roll Forward] 90 Days Past Due and Still Accruing Financing Receivable, 90 Days or More Past Due, Still Accruing Business Combination Acquisition Exchange Ratio on Preferred Stock Business Combination Acquisition Exchange Ratio on Preferred Stock Business Combination Acquisition Exchange Ratio on Preferred Stock Weighted average diluted common shares outstanding Weighted Average Number of Shares Outstanding, Diluted Loan fees and sales Loan fees and sales Loan Fees and Sales. Loan fees and sales include 1) gain/(loss) on sales of loans; 2) loan commitment fees; 3) mortgage banking revenue; 4) miscellaneous other loan fees Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Derivative [Table] Derivative [Table] Entity Small Business Entity Small Business Document Transition Report Document Transition Report Underlying Securities Award Underlying Securities Amount Other comprehensive income (loss) before reclassifications to current earnings Other Comprehensive Income (Loss), before Reclassifications, before Tax Available-for-sale Securities, Gains realized on sales Debt Securities, Available-for-Sale, Realized Gain Certificates of deposit of $100,000 and over Time Deposits, $100,000 or More Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date Business Combination, Recognized Liability Assumed, Other Borrowings Business Combination, Recognized Liability Assumed, Other Borrowings Business Combination, Recognized Liability Assumed, Other Borrowings Financing Receivable, Modified in Period, Current Financing Receivable, Modified in the Previous 12 months, Current Financing Receivable, Modified in the Previous 12 months, Current Net increase (decrease) in certificates of deposit Increase (Decrease) in Time Deposits Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Derivative Asset, Fair Value, Amount Offset Against Collateral Derivative Asset, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Total equity Balance Balance Equity, Including Portion Attributable to Noncontrolling Interest Legal Proceedings [Abstract] Legal Proceedings [Abstract] Legal Proceedings [Abstract] Fair value other securities adjustments, net Fair Value Adjustments Other Securities Fair value adjustments on other securities. Document Type Document Type Significant Unobservable Inputs (Level 3) Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Common Stock Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Capital surplus Additional Paid in Capital Product and Service [Axis] Product and Service [Axis] Operating Lease Income [Axis] Operating Lease Income [Axis] Operating Lease Income [Axis] Components Of Other Comprehensive Income [Axis] Components Of Other Comprehensive Income [Axis] Components Of Other Comprehensive Income [Axis] Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff Financing Receivable, Excluding Accrued Interest, Revolving, Writeoff Proceeds from sales of loans held for sale Proceeds from Sale, Loan, Held-for-Sale Finite-Lived Intangible Assets Acquired Finite-Lived Intangible Assets Acquired Statistical Measurement [Axis] Statistical Measurement [Axis] Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Interest and fees on loans Interest and Fee Income, Loan and Lease, Held-in-Portfolio Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Proceeds from FHLBank Borrowings, Financing Activities Proceeds from FHLBank Borrowings, Financing Activities Net Income (Loss) Available to Common Stockholders, Basic Net Income (Loss) Available to Common Stockholders, Basic Pension (Narrative) [Abstract] Pension (Narrative) [Abstract] Pension (Narrative) [Abstract] Interest Rate Floor [Member] Interest Rate Floor Interest Rate Floor [Member] Financial Standby Letter Of Credit [Member] Financial Standby Letter of Credit [Member] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Financing Receivable, Modified in Period, Thirty to Eighty Nine Days Past Due Financing Receivable, Modified in Previous 12 months, Thirty to Eighty Nine Days Past Due Financing Receivable, Modified in Previous 12 months, Thirty to Eighty Nine Days Past Due Business Combination, Price Per Share Business Combination, Price Per Share Quoted Prices in Active Markets for Identical Assets (Level 1) Level 1 Fair Value, Inputs, Level 1 [Member] Payments of FHLBank Borrowings, Financing Activities Payments of FHLBank Borrowings, Financing Activities Debt Securities, Available-for-Sale, Planned Sale, Yield Debt Securities, Available-for-Sale, Planned Sale, Yield Estimated yield of the available for sale debt securities sold as part of the Company's plan to reposition a portion of its available for sale debt securities portfolio. Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement Interest/Fees Forgiven Interest/Fees Forgiven [Member] Interest/Fees Forgiven Net income per common share — diluted Diluted income per common share Earnings Per Share, Diluted Deposit insurance Federal Deposit Insurance Corporation Premium Expense Loans held for sale Financing Receivable, Held-for-Sale Equity Securities Equity Securities, FV-NI and without Readily Determinable Fair Value Nature of Revenue [Axis] Nature of Revenue [Axis] Nature of Revenue [Axis]. In scope of ASC 606 versus not within the scope of ASC 606. Treasury Stock, Common, Shares Treasury Stock, Common, Shares August 3, 2023 Floor 2 August 3, 2023 Floor 2 [Member] August 3, 2023 Floor 2 Consolidation Items [Domain] Consolidation Items [Domain] Investments, Debt and Equity Securities [Abstract] Core Deposit Premium Core Deposits [Member] Fair value of securities on impairment watch list Fair Value Securities On Impairment Watch List Fair value of securities on impairment watch list. Originations Servicing Asset at Fair Value, Additions Extended Maturity Extended Maturity [Member] Sales And Repayments Of Private Equity Securities Sales And Repayments Of Private Equity Securities Sales And Repayments Of Private Equity Securities Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process Number Of Locations Number Of Locations Number Of Locations Term, in years Credit Derivative, Term Proceeds from Sale of Equity Securities, FV-NI Proceeds from Sale of Equity Securities, FV-NI Easement Unclassified Indefinite-Lived Intangible Assets [Member] Variation Margin Impact to Positive Fair Values of Cleared Swaps Variation Margin Impact to Positive Fair Values of Cleared Swaps Variation Margin Impact to Positive Fair Values of Cleared Swaps Income tax payments, net Income Taxes Paid, Net 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Two Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Net unrealized gains (losses) on available for sale debt securities OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 5 through 10 Years, Fair Value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 5 through 10 Years, Fair Value Loans Total Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Distributions to non-controlling interest Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Securities Sold under Agreements to Repurchase Securities Sold under Agreements to Repurchase Trade Names Trade Names [Member] Amount of Gain or (Loss) Recognized in Income on Derivatives Gain (Loss) on Derivative Instruments, Net, Pretax Over 90 days past due Over 90 days past due [Member] Over 90 days past due Securities With Unrealized Losses and Length of Impairment Period Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Expiration Date Trading Arrangement Expiration Date 2030 Finite-Lived Intangible Asset, Expected Amortization, Year Five Equity Securities, FV-NI, Unrealized Gain (Loss) Equity Securities, FV-NI, Unrealized Gain (Loss) Premises and equipment, net Property, Plant and Equipment, Net Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Entity Current Reporting Status Entity Current Reporting Status Receivables [Abstract] Derivative [Line Items] Derivative [Line Items] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Collateral [Axis] Collateral Held [Axis] Loans Loans [Member] Derivative Liability, Gross Liability Including Not Subject to Master Netting Arrangement Derivative Liability, Gross Liability Including Not Subject to Master Netting Arrangement Financial Instrument [Axis] Financial Instrument [Axis] Trust fee revenue Trust fee revenue Trust fee revenue Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Executive Category: Executive Category [Axis] Unrealized Loss, Greater than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Amortized Cost Basis of Collateral-Dependent Loans Amortized Cost Basis of Collateral-Dependent Loans [Table Text Block] Amortized Cost Basis of Collateral-Dependent Loans Other comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Document Fiscal Year Focus Current Fiscal Year End Date Commercial segment Commercial Segment [Member] Commercial segment member Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Unrealized Loss, Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Total deposits Deposits Debt Securities, Available-for-Sale, Planned Sale, Reinvestment Debt Securities, Available-for-Sale, Planned Sale, Reinvestment The available for sale debt securities acquired as part of the Company's plan to reposition a portion of its available for sale debt securities portfolio. Federal Home Loan Bank Stock Federal Home Loan Bank Stock Professional and other services Professional Fees Derivative Liabilities Derivative Liabilities Derivative Liabilities Derivative Liability Equity Securities without Readily Determinable Fair Value [Table] Equity Securities without Readily Determinable Fair Value [Table] Other Other Noninterest Expense Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Pass [Member] Pass [Member] Business Combination, Recognized Liability Assumed, Non-Interest bearing deposits Business Combination, Recognized Liability Assumed, Non-Interest bearing deposits Business Combination, Recognized Liability Assumed, Non-Interest bearing deposits Deposit account charges and other fees Deposit Account Charges and Other Fees [Member] Fees earned from providing corporate cash management services to the Company's business and non-profit customers and other deposit account charges including overdraft fees and other service charges. Derivative Asset, Not Subject to Master Netting Arrangement Derivative Asset, Not Subject to Master Netting Arrangement Equity Securities without Readily Determinable Fair Value [Line Items] Equity Securities without Readily Determinable Fair Value [Line Items] Lessor, Lease, Description [Line Items] Lessor, Lease, Description [Line Items] Unrealized Loss on AFS Debt Securities Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Summary Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Equity securities with a readily determinable fair value Equity securities Equity Securities, FV-NI, Current Derivative, Effective Date Derivative, Effective Date Derivative, Effective Date Stock Issued During Period, Value, Acquisitions Stock Issued During Period, Value, Acquisitions Gross Unrealized Losses Available For Sale Securities, Gross Unrealized Loss at Period End This item represents the gross unrealized losses for securities which are categorized neither as held-to-maturity nor trading securities. Such gross unrealized losses are the excess of the carrying value of the Available-for-sale Securities over their fair value as of the reporting date. Such gross unrealized losses are included in other comprehensive income in the statement of shareholders' equity. This concept represents the balance in unrealized loss at period end. Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) Real estate - construction and land Construction And Land Loans [Member] Construction and land loans [Member]. Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Aging Information On Past Due And Nonaccrual Loans Financing Receivable, Past Due [Table Text Block] Savings, interest checking and money market Savings, interest checking and money market deposits Interest-Bearing Deposit Liabilities Net cash provided by (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Measure: Measure [Axis] Provision for credit losses on loans Financing Receivable, Credit Loss, Expense (Reversal) Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Resale and Repurchase Agreements [Abstract] Resale and Repurchase Agreements [Abstract] Resale and Repurchase Agreements [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Fair Value Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Entity Tax Identification Number Entity Tax Identification Number August 3, 2023 Floor 1 August 3, 2023 Floor 1 [Member] August 3, 2023 Floor 1 Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Fair Value, Concentration of Risk, Financial Statement Captions [Line Items] Fair Value, Concentration of Risk, Financial Statement Captions [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Resale and Repurchase Agreements [Text Block] Resale and Repurchase Agreements [Text Block] Resale and Repurchase Agreements [Text Block] Common stock, shares issued Common Stock, Shares, Issued Revolving home equity Revolving Home Equity [Member] Revolving Home Equity [Member] Goodwill And Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Schedule Of Goodwill Allocated By Operating Segments Schedule of Goodwill [Table Text Block] Trading Arrangement: Trading Arrangement [Axis] Increase (decrease) in income taxes payable Increase (Decrease) in Income Taxes Payable Total Shareholder Return Amount Total Shareholder Return Amount Operating leases Operating Lease, Lease Income Savings, interest checking and money market Interest Expense, NOW Accounts, Money Market Accounts, and Savings Deposits Corporate, Non-Segment Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Security Exchange Name Security Exchange Name Mortgage loan commitments Mortgage Loan Commitments [Member] Mortgage Loan Commitments Member Total lease income Lease Income OCI Derivative Instruments GainLossBeforeReclassificationAndTaxEffectivePortion OCIDerivativeInstrumentsGainLossBeforeReclassificationAndTaxEffectivePortion The effective portion of net gain (loss) included in other comprehensive income before tax and before reclassification into income on derivative instruments designated and qualifying as hedging instruments. Securities purchased under agreements to resell Securities Purchased under Agreements to Resell Interest and fees on loans held for sale Interest and Fee Income, Loan and Lease, Held-for-Sale Financing Receivables Financing Receivables [Text Block] Unrealized Gains (Losses) on Securities (1) Unrealized Gain Loss on Securities Other [Member] The unrealized holding gains included in accumulated other comprehensive income that arose from available for sale securities that have not suffered other than temporary impairment. [Member] Business Combination, Consideration Transferred, Equity Interest, Type [Domain] Business Combination, Consideration Transferred, Equity Interest, Type [Domain] Investment Securities Investment Holdings [Text Block] Business Combination, Date of Acquisition Agreement Business Combination, Date of Acquisition Agreement Asset Class [Domain] Asset Class [Domain] Certificates of deposit of less than $100,000 Interest Expense, Time Deposits, Less than $100,000 Total gains (losses) (realized/unrealized), included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Financing Receivable, Modified, Subsequent Default [Table] Financing Receivable, Modified, Subsequent Default [Table] Business Combination, Achieved in Stages, Preacquisition Equity Interest in Acquiree, Fair Value Business Combination, Achieved in Stages, Preacquisition Equity Interest in Acquiree, Fair Value Statement [Line Items] Statement [Line Items] Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities Security Sold under Agreement to Repurchase, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Security Not Offset Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Performance Restricted Stock Units Performance Restricted Stock Units [Member] Common Stock [Member] Common Stock [Member] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Securities Purchased under Agreements to Resell, Liability Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, Liability Offset Personal property acquired in repossession Other Repossessed Assets Common Stock, Dividends, Per Share, Cash Paid Common Stock, Dividends, Per Share, Cash Paid Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Statistical Measurement [Domain] Statistical Measurement [Domain] Overdrafts Overdrafts [Member] Overdrafts member. Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Schedule Of Notional Amounts Of Derivative Instruments Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Nonvested Performance-Based Units Activity Schedule of Nonvested Performance-Based Units Activity [Table Text Block] Fair Value by Asset Class [Axis] Asset Class [Axis] Interest Rate Floor Summary Interest Rate Floor Summary [Table Text Block] Interest Rate Floor Summary Derivative, Floor Interest Rate Derivative, Floor Interest Rate Interest rate swaps Interest Rate Swap [Member] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Total gains (losses) (realized/unrealized), included in other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Leases [Abstract] Leases [Abstract] Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares Other non-interest income Other Non Interest Income [Member] Other Non-Interest Income [Member] Mortgage Servicing Rights Mortgage Servicing Rights [Member] Mortgage Servicing Rights [Member] Share-based Payment Arrangement, Noncash Expense [Abstract] Share-Based Payment Arrangement, Noncash Expense [Abstract] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Direct financing and sales-type leases Sales-type and Direct Financing Leases, Profit (Loss) Net income per common share — basic Basic income per common share Earnings Per Share, Basic Debt Securities, Available-for-Sale, Planned Sale, Yield of Reinvestment Debt Securities, Available-for-Sale, Planned Sale, Yield of Reinvestment Yield of the available for sale debt securities acquired as part of the Company's plan to reposition a portion of its available for sale debt securities portfolio. Balance Sheet Offsetting [Table] Balance Sheet Offsetting [Table] Balance Sheet Offsetting Securities Purchased under Agreements to Resell, Gross Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, before Offset Current period other comprehensive income (loss), net of tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Schedule Of Financial Information By Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Business Combination, Recognized Liability Assumed, Repurchase Agreements Business Combination, Recognized Liability Assumed, Repurchase Agreements Business Combination, Recognized Liability Assumed, Repurchase Agreements Measurement Input Type [Domain] Measurement Input Type [Domain] Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Securities Purchased under Agreements to Resell, Amount Offset Against Collateral Security Purchased under Agreement to Resell, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Trading debt securities Debt Securities, Trading, and Equity Securities, FV-NI Federal funds purchased Federal Funds Purchased, Fair Value Disclosure Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Share-based Payment Arrangement, Expense Share-Based Payment Arrangement, Expense Hedging Designation [Domain] Hedging Designation [Domain] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Total liabilities and equity Liabilities and Equity Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] HFS loans 90 days past due and still accruing Loans Held For Sale 90 Days Past Due and Still Accruing Loans Held For Sale 90 Days Past Due and Still Accruing Available-for-sale Securities [Member] Available-for-Sale Securities [Member] Interest on federal funds sold and short-term securities purchased under agreements to resell Interest Income, Federal Funds Sold Up to 90 days Maturity up to 90 days [Member] Period of maturity for a group of securities or other assets sold under repurchase agreements which mature up to 90 days from the reporting date. Guarantees [Abstract] Guarantees [Abstract] Securities Sold under Agreements to Repurchase, Asset Security Sold under Agreement to Repurchase, Subject to Master Netting Arrangement, Asset Offset Forward TBA contracts Forward Contracts [Member] Business Combinations, Recognized Asset Acquired, Trading Securities Business Combinations, Recognized Asset Acquired, Trading Securities Business Combinations, Recognized Asset Acquired, Trading Securities Treasury Stock, Common Treasury Stock, Common [Member] Current Fiscal Year Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Interest rate floor trade date [Axis] Interest rate floor trade date [Axis] Interest rate floor trade date Pay vs Performance Disclosure [Line Items] Interest Rate Floor [Table] Interest Rate Floor [Table] Interest Rate Floor [Table] Visa Class C Shares Visa Class C Shares [Member] Visa Class C Shares Equity Securities without Readily Determinable Fair Value, Downward Price Adjustment, Annual Amount Equity Securities without Readily Determinable Fair Value, Downward Price Adjustment, Annual Amount Purchase of private equity securities Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase of Private Equity Securities Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase of Private Equity Securities Visa Class A Shares Visa Class A Shares [Member] Visa Class A Shares Business Combination [Text Block] Business Combination [Text Block] Financial Liabilities Fair Value Disclosure Financial Liabilities Fair Value Disclosure Visa Class B-2 Shares Visa Class B-2 Shares [Member] Visa Class B-2 Shares Fair Value Assets Measured on Recurring Basis [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] (Increase) decrease in interest receivable Increase (Decrease) in Interest and Dividends Receivable Two Years before Current Fiscal Year Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Plan Assets, Contributions by Employer Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Comprehensive income (loss) attributable to Commerce Bancshares, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Measurement Input Type [Axis] Measurement Input Type [Axis] Name Measure Name Equity Securities without Readily Determinable Fair Value, Carrying Value Equity Securities without Readily Determinable Fair Value, Carrying Value Equity Securities without Readily Determinable Fair Value, Carrying Value Income per common share [Axis] Antidilutive securities excluded from EPS [Axis] Antidilutive securities excluded from EPS Proceeds from maturities/pay downs of investment securities (A) Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Interest Rate Below Market Reduction Interest Rate Below Market Reduction [Member] Available For Sale Securities Unrealized Gains And Losses By Security Type Unrealized Gain (Loss) on Investments [Table Text Block] Financing Receivable, Modified, Subsequent Default Financing Receivable, Modified, Subsequent Default [Table Text Block] Total assets Assets Financial Impacts of Loan Modifications and Deferrals [Table] Financial Impacts of Loan Modifications and Deferrals [Table] Financial Impacts of Loan Modifications and Deferrals [Table] Stock Issued During Period RSAs and SARs Stock Issued During Period RSAs and SARs Aggregate value of stock issued during the period related to grants of Restricted Stock Awards and exercises of Stock Appreciation Rights during the period Schedule of Nonvested Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year One Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Allowance for Credit Loss [Roll Forward] Financing Receivable, Allowance for Credit Loss [Roll Forward] OPERATING ACTIVITIES: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Business Combination, Pro Forma Information [Line Items] Business Combination, Pro Forma Information [Line Items] Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] Private Equity Investments [Member] Private Equity Funds [Member] Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Four Derivative Asset, Not Offset, Policy Election Deduction Derivative Asset, Subject to Master Netting Arrangement, Deduction of Financial Instrument Not Offset Marketing Marketing Expense Other Other Investments Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Total Mortgage And Asset-Backed Securities [Member] Total Mortgage And Asset Backed Securities [Member] Total mortgage and asset-backed securities [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Business Combination, Recognized Asset Acquired, Asset Business Combination, Recognized Asset Acquired, Asset Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments and Tax Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments and Tax Significant Other Observable Inputs (Level 2) Level 2 Fair Value, Inputs, Level 2 [Member] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Business Combination [Domain] Business Combination [Domain] PEO PEO [Member] Summary Of Available For Sale Investment Securities By Maturity Groupings Investments Classified by Contractual Maturity Date [Table Text Block] Debt Securities, Trading Trading debt securities Debt Securities, Trading Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Other Securities, Gains realized on sales Other Securities Gain On Sale Other Securities Gain On Sale Financial Asset Acquired with Credit Deterioration Financial Asset Acquired with Credit Deterioration [Member] Certificates of deposits Time Deposits Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Retained Earnings [Member] Retained Earnings [Member] Share-Based Payment Arrangement [Abstract] Cash, cash equivalents and restricted cash at beginning of year Cash, cash equivalents and restricted cash at June 30 Cash, cash equivalents and restricted cash at June 30 Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Derivative Asset Derivative Assets Derivative Asset Derivative Asset Revenue, Major Customer [Line Items] Revenue, Major Customer [Line Items] Fair Value, Greater than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Balance Sheet Offsetting, Derivatives [Table Text Block] Balance Sheet Offsetting, Derivatives [Table Text Block] [Table Text Block] for Balance Sheet Offsetting, Derivatives [Table] Income per common share [Axis] Income per common share [Axis] Income per common share [Axis] Derivative Liability, Net Amount Presented in the Balance Sheet Derivative Liability, Noncurrent Investment securities Investments, Fair Value Disclosure Increase (decrease) in interest payable Increase (Decrease) in Interest Payable, Net Other intangible assets, net Intangible Assets, Net (Excluding Goodwill) Financing Receivable, Modified [Table] Financing Receivable, Modified [Table] Capital market fees Noninterest Income, Other Federal Reserve Bank Stock Federal Reserve Bank Stock Provision for credit losses on unfunded lending commitments Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Product and Service [Domain] Product and Service [Domain] Business Combination, Transaction Cost, Excluding Separately Recognized Transaction Business Combination, Transaction Cost, Excluding Separately Recognized Transaction Net income Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Total Liabilities Liabilities, Fair Value Disclosure Business Combination [Table] Business Combination [Table] Notional amount of underlying interest rate swaps associated with risk participation agreements Derivative, Notional Amount Derivative, Notional Amount Business Combination, Consideration Transferred, Equity Interest, Type [Axis] Business Combination, Consideration Transferred, Equity Interest, Type [Axis] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Revolving Loans Amortized Cost Basis Financing Receivable, Excluding Accrued Interest, Revolving City Area Code City Area Code Summary Of Activity In The Allowance For Credit Losses Financing Receivable, Allowance for Credit Loss [Table Text Block] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Financing Receivable, Interest Rate Decrease from Modification Financing Receivable, Interest Rate Decrease from Modification Decrease in interest rate from Weighted Average initial rate to a set lower rate as terms of modification. Bank card transaction fees Bank Card Transaction Fees Fees earned from the issuance of debt and credit cards to the Company's retail and commercial banking customers who use the cards to purchase goods and services from merchants through an electronic payment system. Exchange Offer, Conversion Rate of Common Stock Exchange Offer, Conversion Rate of Common Stock Exchange Offer, Conversion Rate of Common Stock. Conversion rate to Visa Class A shares from each share of Visa Class B-2 shares. Contract with Customer, Asset and Liability [Table Text Block] Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] INVESTING ACTIVITIES: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Long-lived assets Long Lived Assets Nonrecurring Basis Represents the fair value of long-lived assets measured on a nonrecurring basis during the period(s) presented and which are still held as of the period end. Accrued Interest Receivable Interest Receivable Fair Value Hedging Fair Value Hedging [Member] Defined Benefit Plan, Amortization of (Gain) Loss Defined Benefit Plan, Amortization of Gain (Loss) Other liabilities Other Liabilities Goodwill Goodwill INVESTMENT SECURITIES GAINS (LOSSES), NET Investment securities (gains) losses, net (A) INVESTMENT SECURITIES GAINS (LOSSES), NET Gain (Loss) on Investments Exchange Offer, Common Shares Received Exchange Offer, Common Shares Received Exchange Offer, Common Shares Received Financing Receivable, Modified in Period, Amount Financing Receivable, Modified in Period, Amount Business Combination, Recognized Liability Assumed, Other Liabilities Business Combination, Recognized Liability Assumed, Other Liabilities Business Combination, Recognized Liability Assumed, Other Liabilities Operating Lease Income [Line Items] Operating Lease Income [Line Items] [Line Items] for Operating Lease Income [Table] Supplemental Cash Flow Information: Supplemental Cash Flow Information [Abstract] Debt Securities, Available-for-sale, Amortized Cost Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost Other Performance Measure, Amount Other Performance Measure, Amount U.S. government and federal agency obligations US Treasury and Government [Member] Real Estate Real Estate [Member] Increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation Equity Securities, FV-NI, Gain (Loss) Equity Securities, FV-NI, Gain (Loss) Derivative Instrument [Axis] Derivative Instrument [Axis] ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LIABILITY FOR UNFUNDED LENDING COMMITMENTS Financing Receivable, Allowance for Credit Loss and Unfunded Lending Commitments, Total Financing Receivable, Allowance for Credit Loss and Unfunded Lending Commitments, Total Gross Unrealized Gains Available For Sale Securities, Gross Unrealized Gain at Period End This item represents the gross unrealized gains for securities which are categorized as neither held-to-maturity nor trading securities. Such gross unrealized gains are the excess of the fair value of the Available-for-sale Securities over their carrying value as of the reporting date. Such gross unrealized gains are included in other comprehensive income in the statement of shareholders' equity. This concept represents the balance in unrealized gains at period-end. Supplies and communication Supplies Postage And Communication Supplies, postage and communication expense. Proceeds from sales of debt securities, available for sale, including pending trades Proceeds from sales of available for sale debt securities including pending trades Amount of proceeds from sale of investment in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Includes pending transactions for which cash has not yet been received. Credit Loss Status [Axis] Credit Loss Status [Axis] Net cash provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation 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] Derivative Asset, Net Amount Presented in the Balance Sheet Derivative Asset, Noncurrent Interest paid on deposits and borrowings Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Financing Receivable, Unamortized Purchase Premium (Discount) Financing Receivable, Unamortized Purchase Premium (Discount) Assets held in trust for deferred compensation plan Assets held in trust for deferred compensation plan Deferred Compensation Plan Assets Carrying Amount Reported Value Measurement [Member] Legal Matters and Contingencies [Text Block] Legal Matters and Contingencies [Text Block] Other Securities, Loss realized on sales Other Securities Loss On Sale Other Securities Loss On Sale Investment Securities Gains (Losses), Net Investment Securities Gains Losses [Member] Investment Securities Gains Losses [Member] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Visa Class B-3 Shares Visa Class B-3 Shares [Member] Visa Class B-3 Shares Interest on Long-Term Securities Purchased Under Agreements To Resell Interest Income, Securities Purchased under Agreements to Resell Non-accrual loans Financing Receivable, Nonaccrual Financing receivable, financial impacts of loan modifications and payment deferrals Financing receivable, financial impacts of loan modifications and payment deferrals [Table Text Block] Financing receivable, financial impacts of loan modifications and payment deferrals Segments Segment Reporting Disclosure [Text Block] Schedule of Goodwill [Table] Goodwill [Table] Fair Value Measurements [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Data processing and software Information Technology and Data Processing Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Schedule of Net Benefit Costs [Table Text Block] Schedule of Net Benefit Costs [Table Text Block] Other debt securities Other Debt Obligations [Member] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Weighted Average [Member] Weighted Average [Member] Fair Value Measurements Fair Value, Recurring and Nonrecurring [Table] Amortization of Intangible Assets Amortization Amortization of Intangible Assets Loans Receivable Loans Receivable [Member] Mortgages Held-for-sale, Fair Value Disclosure Residential mortgage loans held for sale Loan, Mortgage, Held-for-Sale, Fair Value Disclosure Current Year Per Share Average Fair Value and Valuation Model Assumptions [Abstract] Current Year Per Share Average Fair Value and Valuation Model Assumptions [Abstract] Current Year Per Share Average Fair Value and Valuation Model Assumptions [Abstract] Components of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] No investment in a single issuer exceeds this percentage of stockholder's equity Percentage Of Stockholders Equity Of Which No Investment From A Single Issuer Exceeds No investment in a single issuer exceeds this percentage of stockholder's equity, other than obligations of various government-sponsored enterprises such as FNMA, FHLB, and FHLMC. Derivatives not subject to master netting agreements Derivative Not Subject to Master Netting Agreement [Member] Derivative Not Subject to Master Netting Agreement [Member] Business Combinations, Recognized Asset Acquired, Other Investments Business Combinations, Recognized Asset Acquired, Other Investments Business Combinations, Recognized Asset Acquired, Other Investments Revolving home equity Revolving Credit Facility [Member] Arrangement Duration Trading Arrangement Duration Segments [Axis] Segments [Axis] Retail banking segment Retail Banking Segment [Member] Retail Banking segment member Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Financing Receivable, Accrued Interest, Writeoff Financing Receivable, Accrued Interest, Writeoff Interest on other borrowings Interest on other borrowings Interest expense on Federal Home Loan Bank advances and other borrowings Share-Based Payment Arrangement Share-Based Payment Arrangement [Text Block] Summary Of Quantitative Information About Level 3 Fair Value Measurements Schedule Of Quantitative Information About Level Three Fair Value Measurements - Recurring Basis [Table Text Block] Schedule Of Quantitative Information About Level Three Fair Value Measurements, Measured at Fair Value on a Recurring Basis [Table Text Block]. Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Liability for Unfunded Lending Commitments, Beginning Balance Liability for Unfunded Lending Commitments, Ending Balance Off-Balance-Sheet, Credit Loss, Liability Federal funds purchased and securities sold under agreements to repurchase Federal Funds Purchased and Securities Sold under Agreements to Repurchase ASSETS Assets [Abstract] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Business Combination, Name of Acquiree Business Combination, Name of Acquiree Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Pension Retirement Benefits [Text Block] Business Combination [Line Items] Business Combination [Line Items] Commerce Bancshares, Inc. stockholders' equity: Equity, Attributable to Parent [Abstract] Business Combination, Pro Forma Information, Nonrecurring Adjustment [Axis] Business Combination, Pro Forma Information, Nonrecurring Adjustment [Axis] Outstanding Balance Of Modified Loans to Borrowers Experiencing Financial Difficulty Financing Receivable, Modified [Table Text Block] Purchase of treasury stock Treasury Stock, Value, Acquired, Cost Method Total gains (losses) for the annual period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end Change in unrealized gains or losses relating to assets still held at period end Change In Unrealized Gains or Losses Related to Assets Held Level 3 Fair Value Measurements Change in unrealized gains or losses related to assets held, level 3 fair measurements Contract with Customer, Receivable Contract with Customer, Receivable, after Allowance for Credit Loss Derivative Liability, Not Subject to Master Netting Arrangement Derivative Liability, Not Subject to Master Netting Arrangement Derivative Asset, Fair Value, Gross Asset Derivative Asset, Subject to Master Netting Arrangement, before Offset Commitments to lend additional funds to customers with restructured loans Financing Receivable, Modified, Commitment to Lend Business Combinations, Recognized Asset Acquired, Loans, Net of Allowance for Credit Losses on Loans Business Combinations, Recognized Asset Acquired, Loans, Net of Allowance for Credit Losses on Loans Business Combinations, Recognized Asset Acquired, Loans, Net of Allowance for Credit Losses on Loans Provision for depreciation and amortization Depreciation, Amortization and Accretion, Net Entity Registrant Name Entity Registrant Name Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Cash Flow Hedge Gain (Loss) to be Reclassified within 12 Months Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Net periodic pension cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Location, Statement of Financial Position, Balance [Domain] Location, Statement of Financial Position, Balance [Domain] Location, Statement of Financial Position, Balance [Domain] Total assets Assets, Fair Value Disclosure Fair value of financial instruments [Table Text Block] Fair value of financial instruments [Table Text Block] [Table Text Block] for Fair value of financial instruments [Table] Provision for credit losses Provision for credit losses Provision for Loan, Lease, and Other Losses Federal Funds Sold Federal Funds Sold Revision of Prior Period [Domain] Revision of Prior Period [Domain] Deposits: Deposits [Abstract] Equity Securities without Readily Determinable Fair Value, Amount Equity Securities without Readily Determinable Fair Value, Amount Number of Operating Segments Number of Operating Segments Amortization (accretion) of investment security premiums (discounts), net Accretion (Amortization) of Discounts and Premiums, Investments Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Interest cost on projected benefit obligation Defined Benefit Plan, Interest Cost Schedule Of Intangible Assets With Estimable Useful Lives Schedule of Finite-Lived Intangible Assets [Table Text Block] Restatement Determination Date: Restatement Determination Date [Axis] Loans And Allowance For Credit Losses [Table] Loans And Allowance For Credit Losses [Table] Loans And Allowance For Credit Losses [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 5 through 10 Years, Amortized Cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 5 through 10 Years, Amortized Cost Proceeds from (Payment for) Other Financing Activity Proceeds from (Payment for) Other Financing Activity Derivative, Description of Terms Derivative, Description of Terms Name Trading Arrangement, Individual Name Mortgage loan forward sale contracts Mortgage Loan Forward Sale Contracts [Member] MortgageLoanForwardSaleContractsMember Financing Receivable, Modified, Subsequent Default Financing Receivable, Modified, Subsequent Default Loans held for sale Loan, Held-for-Sale, Fair Value Disclosure Equity Securities without Readily Determinable Fair Value, Shares Equity Securities without Readily Determinable Fair Value, Shares Equity Securities without Readily Determinable Fair Value, Shares Personal Banking Portfolio Segment [Member] Personal Banking Portfolio Segment [Member] Personal Banking Portfolio Segment [Member] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Goodwill Goodwill [Member] Business Combination, Consideration Transferred, Equity Interest Business Combination, Consideration Transferred, Equity Interest Name Awards Close in Time to MNPI Disclosures, Individual Name Non-agency mortgage-backed securities Financial Instruments Owned Non Agency Mortgage Backed Securities At Fair Value The fair value as of the balance sheet date of firm holdings in non-agency mortgage-backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the non-agency mortgage-backed security). Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Originations of loans held for sale Origination Of Loans Held For Sale The amount of cash paid for the origination of loans that are held for sale. This represents origination of mortgage and student loans held for sale. Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral Security Sold under Agreement to Repurchase, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items] Trading Activity, Gains and Losses, Net [Line Items] Balance Sheet Offsetting [Line Items] Balance Sheet Offsetting [Line Items] [Line Items] for Balance Sheet Offsetting [Table] Total gains or losses included in earnings Total gains or losses included in earnings, level 3 fair measurements Total gains or losses included in earnings, level 3 fair measurements Derivative Asset, Amount Offset by Liabiilty Derivative Asset, Amount Offset by Liabiilty Amount of the liability offset against the fair value of gross derivative assets on the balance sheet. Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Treasury stock, at cost Treasury Stock, Value Equity Securities without Readily Determinable Fair Value, Impairment Loss, Annual Amount Equity Securities without Readily Determinable Fair Value, Impairment Loss, Annual Amount Derivative Liability, Fair Value of Collateral Derivative Liability, Fair Value of Collateral Total repurchase agreements, gross amount recognized Repurchase Agreements [Member] Lessor, Lease, Description [Table] Lessor, Lease, Description [Table] Segments [Domain] Segments [Domain] Credit Loss Status [Domain] Credit Loss Status [Domain] Business Combination, Effective Date of Acquisition Business Combination, Effective Date of Acquisition Contractual terms of stock options granted (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period, Contractual Terms Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period, Contractual Terms Income Statement Location [Axis] Statement of Income Location, Balance [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Assets Sold under Agreements to Repurchase, Maturity Period [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] INTEREST EXPENSE Interest Expense, Operating and Nonoperating [Abstract] Total non-interest income from contracts with customers Revenue from Contracts with Customers In Scope of ASC 606 [Member] Revenue from Contracts with Customers In Scope of ASC 606 [Member] Share-Based Compensation Arrangement by Share Based Payment Award, Equity Instruments other than Options, Net Adjustment Due To Performance Share-Based Compensation Arrangement by Share Based Payment Award, Equity Instruments other than Options, Net Adjustment Due To Performance Share-Based Compensation Arrangement by Share Based Payment Award, Equity Instruments other than Options, Net Adjustment Due To Performance Private equity investments Private Equity Investments Private equity investment securities held. State and municipal obligations [Member] State and municipal obligations [Member] US States and Political Subdivisions Debt Securities [Member] Loss on Available for Sale debt securities portfolio repositioning Loss on Available for Sale debt securities portfolio repositioning Loss on Available for Sale debt securities sold as part of the Company's planned AFS portfolio repositioning. Summary Of Gains And Losses On Level 3 Assets And Liabilities Fair Value Level Three Gains And Losses Disclosure [Table Text Block] Fair Value Level Three Gains And Losses Disclosure [Table Text Block] Monetized Interest Rate Floor [Member] Monetized Interest Rate Floor [Member] Monetized Interest Rate Floor Fiscal Year before Current Fiscal Year Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Off-Balance-Sheet, Credit Loss at Acquisition, Liability Off-Balance-Sheet, Credit Loss at Acquisition, Liability Off-Balance-Sheet, Credit Loss at Acquisition, Liability Business Combination, Recognized Liability Assumed, Liability Business Combination, Recognized Liability Assumed, Liability Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] All Executive Categories All Executive Categories [Member] Common stock Common Stock, Value, Issued Remaining Contractual Maturities of Repurchase Agreements [Abstract] Remaining Contractual Maturities of Repurchase Agreements [Abstract] Remaining Contractual Maturities of Repurchase Agreements [Abstract] Securities purchased under agreements to resell Payments for Securities Purchased under Agreements to Resell Net (gains) losses on sales of loans held for sale Gain (Loss) on Sale of Loans and Leases Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year, Writeoff Asset-backed securities Other Asset Backed Securities Disclosure Other Asset Backed Securities Disclosure Financing Receivable at acquisition on purchased credit deteriorated loans, Excluding Accrued Interest, after Allowance for Credit Loss Financing Receivable at acquisition on purchased credit deteriorated loans, Allowance for Credit Loss, Excluding Accrued Interest Financing Receivable at acquisition on purchased credit deteriorated loans, Allowance for Credit Loss, Excluding Accrued Interest Business Combination [Axis] Business Combination [Axis] Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Non-Accrual [Member] Non Accrual [Member] Non Accrual [Member] Schedule of Nonvested Share Activity Schedule of Nonvested Share Activity [Table Text Block] Common Stock [Abstract] Common Stock [Abstract] Common Stock [Abstract] Non-Controlling Interest [Member] Noncontrolling Interest [Member] Investment securities: Marketable Securities [Abstract] Leases Leases [Text Block] Leases [Text Block] Risk Category of Loans in Personal Banking Portfolio Risk Category of Loans in Personal Banking Portfolio [Table Text Block] Risk Category of Loans in Personal Banking Portfolio Net loan charge-offs (recoveries) Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Financing Receivable, Modified in Period, Amount Financing Receivable, Modified in Previous 12 months, Amount Financing Receivable, Modified in Previous 12 months, Amount Period after which loans are deemed in default (in days) Period After Which Loans are Deemed in Default Period After Which Loans are Deemed in Default Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Hedging Designation [Axis] Hedging Designation [Axis] Change in pension loss Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Derivative Liability, Fair Value, Amount Offset Against Collateral Derivative Liability, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Derivative Contract Type [Domain] Derivative Contract [Domain] Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Lessor, Operating Lease, Term of Contract Lessor, Operating Lease, Term of Contract Available-for-sale Securities, Losses realized on sales Debt Securities, Available-for-Sale, Realized Loss Carrying Value of Hedged Items Derivative, Amount of Hedged Item All Individuals All Individuals [Member] Purchases of premises and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sales of investment securities (A) Cash proceeds from sales of investment securities Cash proceeds from sales of investment securities. Excludes pending sales for which cash is not yet received. Name Forgone Recovery, Individual Name 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] Government-sponsored enterprise obligations U S Government Sponsored Enterprises Debt Securities U S Government Sponsored Enterprises Debt Securities Wealth segment Wealth Segment [Member] Wealth segment member. Securities pledged as collateral Investment Securities Pledged At Fair Value The fair value of investment securities pledged for public funds, repurchase agreements, and borrowings Remaining Contractual Maturities of Repurchase Agreements [Table] Remaining Contractual Maturities of Repurchase Agreements [Table] Schedule, as of the most recent balance sheet date, of securities or other assets sold under repurchase agreements. Disclosure may include the following: the type of securities or assets sold under agreements to repurchase, the carrying amount, market value (including accrued interest plus any cash or other assets on deposit. The information is segregated into securities maturing (1) overnight; (2) term up to 90 days; (3) term over 90 days. Financing Receivable, Nonaccrual, No Allowance Financing Receivable, Nonaccrual, No Allowance Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Schedule of Finite-Lived Intangible Assets by Major Class [Table] Intangible Asset, Finite-Lived [Table] Indefinite-Lived Intangible Assets Acquired Indefinite-Lived Intangible Assets Acquired Accretion of discount related to acquired loans Accretion of discount related to acquired loans Accretion of discount related to acquired loans Other borrowings Other Borrowings Commercial Portfolio Segment [Member] Commercial Portfolio Segment [Member] Financing Receivable, Modified, Past Due [Line Items] Financing Receivable, Modified, Past Due [Line Items] Other changes, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Summary of Cash Flow Hedge Activity [Line Items] Summary of Cash Flow Hedge Activity [Line Items] [Line Items] for Summary of Cash Flow Hedge Activity [Table] Business Combination, Pro Forma Information, Pro Forma Revenue Business Combination, Pro Forma Information, Pro Forma Revenue Credit Card Receivable [Member] Credit Card Receivable [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Financing Receivable, Modified, Past Due [Table] Financing Receivable, Modified, Past Due [Table] Equipment Equipment Expense Certificates of deposit of $100,000 and over Interest Expense, Time Deposits, $100,000 or More Loan fees and sales Loans Fees And Sales [Member] Loans Fees And Sales [Member] Operating Lease Income [Table] Operating Lease Income [Table] Operating Lease Income [Table] Interest Expense, Securities Sold under Agreements to Repurchase Interest Expense, Securities Sold under Agreements to Repurchase Number of investments in a single issuer that exceed 10% of stockholder's equity Investments Exceeding Ten Percent Of Stockholders Equity The number of investments in a single issuer that exceed 10% of stockholder's equity, excluding obligations of various government-sponsored enterprises such as FNMA, FHLB, and FHLMC. Contract with Customer, Asset and Liability [Line Items] Contract with Customer, Asset and Liability [Line Items] [Line Items] for Disclosure of information about accounts receivable due from contracts with customers. Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff Components of Other Comprehensive Income [Domain] Components of Other Comprehensive Income [Domain] Components of Other Comprehensive Income [Domain] Fair Value Assets Measured on Recurring Basis [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Consumer brokerage services Consumer Brokerage Services [Member] Revenue earned from the commissions received upon the execution of purchases and sales of mutual fund shares, equity securities, annuities, and insurance products, and fees earned on professionally managed advisory programs through sub-advisors. Award Timing Disclosures [Line Items] Other debt securities Financial Instruments Owned Other Debt Securities At Fair Value The fair value as of balance sheet date of firm holdings in debt securities which are not otherwise provided for in the existing taxonomy in the form of individual elements. Securities sold under agreements to repurchase Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure Collateral Dependent Loans Loans Nonrecurring Basis Represents the fair value of loans measured on a nonrecurring basis during the period(s) presented and which are still held as of the period end. Service cost - benefits earned during the period Defined Benefit Plan, Service Cost Securities Sold under Agreements to Repurchase, Gross Security Sold under Agreement to Repurchase, Subject to Master Netting Arrangement, before Offset Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Net loans Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss March 24, 2026 Floor March 24, 2026 Floor [Member] March 24, 2026 Floor Net income attributable to Commerce Bancshares, Inc. Net Income (Loss) Attributable to Parent Schedule of Underlying Assets of Repurchase Agreements [Table Text Block] Schedule of Underlying Assets of Repurchase Agreements [Table Text Block] Tabular disclosure, as of the most recent balance sheet date, of securities or other assets sold under repurchase agreements. Disclosure may include the following: the type of securities or assets sold under agreements to repurchase, the carrying amount, market value (including accrued interest plus any cash or other assets on deposit. The information is segregated into securities maturing (1) overnight; (2) term up to 90 days; (3) term over 90 days. Business Combinations, Recognized Asset Acquired, Interest Earning Deposits with Banks Business Combinations, Recognized Asset Acquired, Interest Earning Deposits with Banks Business Combinations, Recognized Asset Acquired, Interest Earning Deposits with Banks Summary Of The Effects Of Derivative Instruments On Consolidated Statements Of Income Effects Of Derivative Instruments On Consolidated Statements Of Income [Table Text Block] Effects of derivative instruments on consolidated statements of income. Vesting period (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Real Estate - construction and land [Member] Real Estate - construction and land [Member] Real Estate - construction and land Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Purchases of treasury stock Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date August 7, 2023 August 7, 2023 [Member] August 7, 2023 30 - 89 Days Past Due Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due Financing Receivable, Recorded Investment, 30 to 89 Days Past Due Customer Relationships Customer Relationships [Member] Retained earnings Retained Earnings (Accumulated Deficit) Pension [Abstract] Pension [Abstract] Pension [Abstract] FineMark Holdings, Inc. FineMark Holdings, Inc. [Member] FineMark Holdings, Inc. 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] Class of Stock [Axis] Class of Stock [Axis] Unrealized Gains (Losses) on Cash Flow Hedge Derivatives (2) Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Consumer brokerage services Brokerage Commissions Revenue 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] Statement [Table] Statement [Table] Business Combination Business Combination [Table Text Block] Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits Net Increase Decrease Non-Interest Bearing Savings Interest Checking And Money Market Deposits Net Increase (Decrease) In Non-Interest Bearing, Savings, Interest, Checking, And Money Market Deposits 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] FINANCING ACTIVITIES: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Resale and Repurchase Agreements [Table Text Block] Offsetting, Resale and Repurchase Agreements [Table Text Block] [Table Text Block] for Offsetting, Resale and Repurchase Agreements [Table] Share Based Compensation Arrangement By Share Based Payment Award, Equity Instrument Other Than Options, Net Adjustment Weighted Average Fair Value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instrument Other Than Options, Net Adjustment Weighted Average Fair Value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instrument Other Than Options, Net Adjustment Weighted Average Fair Value Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt Principles Of Consolidation And Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Net (increase) decrease in trading debt securities, excluding unsettled transactions Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag Fair Value of Assets Acquired Fair Value of Assets Acquired Schedule Of Fair Value Disclosures Measured On Nonrecurring Basis [Table Text Block] Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge Termination Date Trading Arrangement Termination Date Interest earning deposits with banks Interest-Bearing Deposits in Banks and Other Financial Institutions Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Allowance for credit losses on loans Allowance for Credit Loss, Beginning Balance Allowance for Credit Loss, Ending Balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Proceeds from Sale of Equity Securities Proceeds from Sale of Equity Securities Proceeds from Sale of Equity Securities Current to 90 Days Past Due Current to 90 Days Past Due [Member] Current to 90 Days Past Due Weighted average common shares outstanding Weighted Average Number of Shares Outstanding, Basic INVESTMENT SECURITIES GAINS (LOSSES), NET Investment Income, Net [Abstract] Summary Of Components Used To Calculate Basic And Diluted Income Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Derivative Asset, Gross Asset Including Not Subject to Master Netting Arrangement Derivative Asset, Gross Asset Including Not Subject to Master Netting Arrangement Segment Reporting [Abstract] Segment Reporting [Abstract] U.S. government and federal agency obligations Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value Fair Value Measurements [Abstract] Fair Value Measurements [Abstract] Fair Value Measurements [Abstract] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common stock, par value Common Stock, Par or Stated Value Per Share Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross AFS securities in loss position at period-end, change in unrealized loss AFS securities in loss position at period-end, change in unrealized loss AFS securities in loss position at period-end, change in unrealized loss. Guarantor Obligations by Nature [Axis] Guarantor Obligations, Nature [Axis] EBITDA multiple Fair Value inputs, Earnings before interest, taxes, depreciation, amortization (EBITDA) multiple Fair Value, Earnings before interest, taxes, depreciation, amortization (EBITDA) multiple. Payments of Dividends Payments of Dividends Net occupancy Occupancy, Net Operating Lease Income [Domain] Operating Lease Income [Domain] [Domain] for Operating Lease Income [Axis] Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount Insider Trading Arrangements [Line Items] Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Equity Securities [Member] Equity Securities [Member] Total liabilities Liabilities Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Indirect Guarantee Of Indebtedness [Member] Indirect Guarantee of Indebtedness [Member] Resale and Repurchase Agreements [Table] Offsetting, Resale and Repurchase Agreements [Table] Offsetting, Resale and Repurchase Agreements [Table] Net (increase) decrease in loans Payments for (Proceeds from) Loans and Leases Unrealized gain (loss) on interest rate cash flow hedges, pretax, amount recorded in accumulated other comprehensive income Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss) Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses Recognized In Earnings [Table Text Block] Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses Recognized In Earnings [Table Text Block] Other Security Investments Other Security Investments [Member] Interest Expense, Federal Funds Purchased Interest Expense, Federal Funds Purchased Asset-backed securities Asset-Backed Securities [Member] Consolidation Items [Axis] Consolidation Items [Axis] Schedule Of Changes In Carrying Amount Of Goodwill And Net Other Intangible Assets Summary Of Changes In Goodwill And Other Intangible Assets [Table Text Block] Disclosure of major changes in the carrying amount of goodwill and other intangible assets during the period Business Combination, Recognized Liability Assumed, Interest bearing deposits Business Combination, Recognized Liability Assumed, Interest bearing deposits Business Combination, Recognized Liability Assumed, Interest bearing deposits Available for sale debt securities Fair Value Debt Securities, Available-for-Sale Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Exchange Offer, Original Shares Held Exchange Offer, Original Shares Held Shares held at time of exchange offer.