$CBSH
COMMERCE BANCSHARES INC /MO/ Stock $cbsh

$cbsh Overview Financials Valuation SEC Filings Company Website

2021 Q3 Form 10-Q Financial Statement

#000002235621000040 Filed on August 05, 2021

Income Statement

Concept	2021 Q3	2021 Q2	2020 Q2
Revenue	$0.00	$0.00	$0.00
YoY Change
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$11.10M	$11.10M	$10.70M
YoY Change	-0.89%	3.74%	3.88%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$2.944M	$3.151M	$10.27M
YoY Change	-58.84%	-69.31%	-61.66%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$160.4M	$211.5M	$48.39M
YoY Change	-4.36%	336.97%	-64.73%
Income Tax	$34.66M	$45.21M	$9.661M
% Of Pretax Income	21.61%	21.38%	19.96%
Net Earnings	$122.6M	$162.3M	$39.86M
YoY Change	-7.46%	307.21%	-63.08%
Net Earnings / Revenue
Basic Earnings Per Share	$1.05	$1.32	$0.32
Diluted Earnings Per Share	$1.05	$1.32	$0.32
COMMON SHARES
Basic Shares Outstanding	116.8M shares	117.0M shares	111.5M shares
Diluted Shares Outstanding

Balance Sheet

Concept	2021 Q3	2021 Q2	2020 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$2.252B	$2.546B	$1.818B
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$377.5M	$372.0M	$368.6M
YoY Change	-0.1%	0.93%	1.38%
Goodwill	$138.9M	$138.9M	$138.9M
YoY Change	0.0%	0.0%	0.0%
Intangibles	$14.46M	$14.15M	$7.179M
YoY Change	101.28%	97.07%	-18.08%
Long-Term Investments	$1.834M	$15.84M
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$34.50B	$33.86B	$30.50B
YoY Change	9.68%	11.02%	18.33%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$2.254B	$2.318B	$1.740B
YoY Change	36.36%	33.22%	-27.32%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$2.254B	$2.318B	$1.740B
YoY Change	36.36%	33.22%	6114.29%
LONG-TERM LIABILITIES
Long-Term Debt	$4.000M	$2.000M	$1.000M
YoY Change	300.0%	100.0%	-80.0%
Other Long-Term Liabilities	$602.0M	$556.0M	$869.0M
YoY Change	-23.99%	-36.02%	151.88%
Total Long-Term Liabilities	$606.0M	$558.0M	$870.0M
YoY Change	-23.58%	-35.86%	148.57%
TOTAL LIABILITIES
Total Short-Term Liabilities	$2.254B	$2.318B	$1.740B
Total Long-Term Liabilities	$606.0M	$558.0M	$870.0M
Total Liabilities	$31.01B	$30.36B	$27.14B
YoY Change	10.16%	11.88%	20.08%
SHAREHOLDERS EQUITY
Retained Earnings	$396.7M	$304.7M	$232.1M
YoY Change	21.34%	31.31%	-39.6%
Common Stock	$589.4M	$589.4M	$564.0M
YoY Change	4.5%	4.5%	0.81%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$92.05M	$53.02M	$69.11M
YoY Change	33.3%	-23.29%	-34.87%
Treasury Stock Shares	1.303M shares	742.8K shares	1.041M shares
Shareholders Equity	$3.481B	$3.486B	$3.358B
YoY Change
Total Liabilities & Shareholders Equity	$34.50B	$33.86B	$30.50B
YoY Change	9.68%	11.02%	18.33%

Cashflow Statement

Concept	2021 Q3	2021 Q2	2020 Q2
OPERATING ACTIVITIES
Net Income	$122.6M	$162.3M	$39.86M
YoY Change	-7.46%	307.21%	-63.08%
Depreciation, Depletion And Amortization	$11.10M	$11.10M	$10.70M
YoY Change	-0.89%	3.74%	3.88%
Cash From Operating Activities	$158.9M	$125.5M	$149.9M
YoY Change	-34.53%	-16.28%	36.89%
INVESTING ACTIVITIES
Capital Expenditures	-$15.50M	-$11.20M	-$6.100M
YoY Change	0.0%	83.61%	-32.22%
Acquisitions
YoY Change
Other Investing Activities	-$917.2M	-$357.2M	-$2.652B
YoY Change	-38.36%	-86.53%	2362.21%
Cash From Investing Activities	-$932.6M	-$368.5M	-$2.658B
YoY Change	-37.97%	-86.14%	2177.55%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	479.0M	408.3M	3.427B
YoY Change	-52.1%	-88.08%	846.05%
NET CHANGE
Cash From Operating Activities	158.9M	125.5M	149.9M
Cash From Investing Activities	-932.6M	-368.5M	-2.658B
Cash From Financing Activities	479.0M	408.3M	3.427B
Net Change In Cash	-294.7M	165.3M	918.6M
YoY Change	13.09%	-82.01%	158.76%
FREE CASH FLOW
Cash From Operating Activities	$158.9M	$125.5M	$149.9M
Capital Expenditures	-$15.50M	-$11.20M	-$6.100M
Free Cash Flow	$174.4M	$136.7M	$156.0M
YoY Change	-32.46%	-12.37%	31.65%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Entity Central Index Key EntityCentralIndexKey	0000022356
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Amendment Flag AmendmentFlag	false
CY2021Q2	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0
	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0
CY2020Q2	cbsh	Purchase Of Risk Participation Agreement PurchaseOfRiskParticipationAgreement	0	USD
CY2020Q2	cbsh	Sales And Repayments Of Private Equity Securities SalesAndRepaymentsOfPrivateEquitySecurities	0	USD
	cbsh	Purchase Of Risk Participation Agreement PurchaseOfRiskParticipationAgreement	0	USD
CY2021Q2	cbsh	Loans Nonrecurring Basis LoansNonrecurringBasis	0	USD
	cbsh	Loans Nonrecurring Basis Gains Losses LoansNonrecurringBasisGainsLosses	0	USD
	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2021-06-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	001-36502
	dei	Entity Registrant Name EntityRegistrantName	COMMERCE BANCSHARES, INC.
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	MO
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	43-0889454
	dei	Entity Address Address Line1 EntityAddressAddressLine1	1000 Walnut
	dei	Entity Address City Or Town EntityAddressCityOrTown	Kansas City,
	dei	Local Phone Number LocalPhoneNumber	234-2000
	dei	Entity Address State Or Province EntityAddressStateOrProvince	MO
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	64106
	dei	City Area Code CityAreaCode	816
	dei	Security12b Title Security12bTitle	$5 Par Value Common Stock
	dei	Trading Symbol TradingSymbol	CBSH
	dei	Security Exchange Name SecurityExchangeName	NASDAQ
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
CY2021Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	116804211	shares
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CY2020Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	80539000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-51887000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	138492000	USD
CY2021Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	253637000	USD
CY2020Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	122518000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	465617000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	265630000	USD
CY2021Q2	cbsh	Bank Card Transaction Fees BankCardTransactionFees	42608000	USD
CY2020Q2	cbsh	Bank Card Transaction Fees BankCardTransactionFees	33745000	USD
	cbsh	Bank Card Transaction Fees BankCardTransactionFees	80303000	USD
	cbsh	Bank Card Transaction Fees BankCardTransactionFees	73945000	USD
CY2021Q2	cbsh	Trustfeerevenue Trustfeerevenue	46257000	USD
CY2020Q2	cbsh	Trustfeerevenue Trustfeerevenue	37942000	USD
	cbsh	Trustfeerevenue Trustfeerevenue	90384000	USD
	cbsh	Trustfeerevenue Trustfeerevenue	77907000	USD
CY2021Q2	cbsh	Depositfeerevenue Depositfeerevenue	23988000	USD
CY2020Q2	cbsh	Depositfeerevenue Depositfeerevenue	22279000	USD
	cbsh	Depositfeerevenue Depositfeerevenue	46563000	USD
	cbsh	Depositfeerevenue Depositfeerevenue	45956000	USD
CY2021Q2	us-gaap	Noninterest Income Other NoninterestIncomeOther	3327000	USD
CY2020Q2	us-gaap	Noninterest Income Other NoninterestIncomeOther	3772000	USD
	us-gaap	Noninterest Income Other NoninterestIncomeOther	8308000	USD
	us-gaap	Noninterest Income Other NoninterestIncomeOther	7562000	USD
CY2021Q2	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	4503000	USD
	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	8584000	USD
CY2020Q2	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	3011000	USD
	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	7088000	USD
CY2021Q2	cbsh	Loan Fees And Sales LoanFeesAndSales	7446000	USD
CY2020Q2	cbsh	Loan Fees And Sales LoanFeesAndSales	4649000	USD
	cbsh	Loan Fees And Sales LoanFeesAndSales	17630000	USD
	cbsh	Loan Fees And Sales LoanFeesAndSales	7884000	USD
CY2021Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	11014000	USD
CY2020Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	12117000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	23416000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	20836000	USD
CY2021Q2	us-gaap	Noninterest Income NoninterestIncome	139143000	USD
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	117515000	USD
	us-gaap	Noninterest Income NoninterestIncome	275188000	USD
	us-gaap	Noninterest Income NoninterestIncome	241178000	USD
CY2021Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	16804000	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-4129000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	26657000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
CY2021Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	130751000	USD
CY2020Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	126759000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	259784000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	255696000	USD
CY2021Q2	us-gaap	Occupancy Net OccupancyNet	11527000	USD
CY2020Q2	us-gaap	Occupancy Net OccupancyNet	11269000	USD
	us-gaap	Occupancy Net OccupancyNet	23548000	USD
	us-gaap	Occupancy Net OccupancyNet	23017000	USD
CY2021Q2	us-gaap	Equipment Expense EquipmentExpense	4605000	USD
CY2020Q2	us-gaap	Equipment Expense EquipmentExpense	4755000	USD
	us-gaap	Equipment Expense EquipmentExpense	8958000	USD
	us-gaap	Equipment Expense EquipmentExpense	9576000	USD
CY2021Q2	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	4033000	USD
CY2020Q2	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	4427000	USD
	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	8158000	USD
	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	9085000	USD
CY2021Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	24954000	USD
CY2020Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	23837000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	50417000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	47392000	USD
CY2021Q2	us-gaap	Marketing Expense MarketingExpense	5680000	USD
CY2020Q2	us-gaap	Marketing Expense MarketingExpense	3801000	USD
	us-gaap	Marketing Expense MarketingExpense	10838000	USD
	us-gaap	Marketing Expense MarketingExpense	9780000	USD
CY2021Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	16576000	USD
CY2020Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	12664000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	28996000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	26664000	USD
CY2021Q2	us-gaap	Noninterest Expense NoninterestExpense	198126000	USD
CY2020Q2	us-gaap	Noninterest Expense NoninterestExpense	187512000	USD
	us-gaap	Noninterest Expense NoninterestExpense	390699000	USD
	us-gaap	Noninterest Expense NoninterestExpense	381210000	USD
CY2021Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	211458000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	48392000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	376763000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	108168000	USD
CY2021Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	45209000	USD
CY2020Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9661000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	77285000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	19834000	USD
CY2021Q2	us-gaap	Profit Loss ProfitLoss	166249000	USD
CY2020Q2	us-gaap	Profit Loss ProfitLoss	38731000	USD
	us-gaap	Profit Loss ProfitLoss	299478000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
CY2021Q2	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	3923000	USD
CY2020Q2	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-1132000	USD
	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	6180000	USD
	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-3386000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	162326000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	39863000	USD
	us-gaap	Net Income Loss NetIncomeLoss	293298000	USD
	us-gaap	Net Income Loss NetIncomeLoss	91720000	USD
CY2021Q2	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	0	USD
CY2020Q2	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	2250000	USD
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	0	USD
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	4500000	USD
CY2021Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	162326000	USD
CY2020Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	37613000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	293298000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	87220000	USD
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.38
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.32
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.50
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.74
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.38
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.32
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.49
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.74
CY2021Q2	us-gaap	Profit Loss ProfitLoss	166249000	USD
CY2020Q2	us-gaap	Profit Loss ProfitLoss	38731000	USD
	us-gaap	Profit Loss ProfitLoss	299478000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	55725000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	86462000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-102951000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	165134000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-438000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-355000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-875000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-711000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	-4525000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	9308000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	-8911000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	72972000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	51638000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	96125000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-110987000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	238817000	USD
CY2021Q2	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	217887000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	134856000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	188491000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	327151000	USD
CY2021Q2	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	3923000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-1132000	USD
	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	6180000	USD
	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-3386000	USD
CY2021Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	213964000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	135988000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	182311000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	330537000	USD
CY2021Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3317385000	USD
CY2021Q2	us-gaap	Profit Loss ProfitLoss	166249000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	51638000	USD
CY2021Q2	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	508000	USD
CY2021Q2	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	13964000	USD
CY2021Q2	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	0	USD
CY2021Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3790000	USD
CY2021Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.263
CY2021Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	30760000	USD
CY2021Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3493830000	USD
CY2020Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3252464000	USD
CY2020Q2	us-gaap	Profit Loss ProfitLoss	38731000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	96125000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-15000	USD
CY2020Q2	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	15000	USD
CY2020Q2	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	448000	USD
CY2020Q2	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-3000	USD
CY2020Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3739000	USD
CY2020Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.257
CY2020Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	30174000	USD
CY2020Q2	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.375
CY2020Q2	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	2250000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3358169000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3399972000	USD
	us-gaap	Profit Loss ProfitLoss	299478000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-110987000	USD
	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	895000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	39887000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	7723000	USD
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.525
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	61559000	USD
CY2021Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3493830000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3138472000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	238817000	USD
	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	100000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	53593000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-27000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	7466000	USD
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.514
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	60466000	USD
	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.750
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	4500000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3358169000	USD
	us-gaap	Profit Loss ProfitLoss	299478000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-51887000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	138492000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	22525000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	21320000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-41270000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-25665000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	26657000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	13677000	USD
	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	1826000	USD
	cbsh	Origination Of Loans Held For Sale OriginationOfLoansHeldForSale	325714000	USD
	cbsh	Origination Of Loans Held For Sale OriginationOfLoansHeldForSale	41167000	USD
	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	356559000	USD
	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	43877000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-1287000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-5249000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	7723000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	7466000	USD
	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	-6688000	USD
	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	3672000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-2809000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-5145000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	19095000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	12842000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	6632000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	79137000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	327249000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	229728000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	10060000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	174597000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1789405000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1224190000	USD
	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	2707024000	USD
	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	2648074000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-678554000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	1676552000	USD
	us-gaap	Payments For Securities Purchased Under Agreements To Resell PaymentsForSecuritiesPurchasedUnderAgreementsToResell	450000000	USD
	us-gaap	Payments For Securities Purchased Under Agreements To Resell PaymentsForSecuritiesPurchasedUnderAgreementsToResell	0	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	21944000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	13677000	USD
	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	4786000	USD
	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	21000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-696163000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2939495000	USD
	cbsh	Net Increase Decrease Non Interest Bearing Savings Interest Checking And Money Market Deposits NetIncreaseDecreaseNonInterestBearingSavingsInterestCheckingAndMoneyMarketDeposits	685582000	USD
	cbsh	Net Increase Decrease Non Interest Bearing Savings Interest Checking And Money Market Deposits NetIncreaseDecreaseNonInterestBearingSavingsInterestCheckingAndMoneyMarketDeposits	3824235000	USD
	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-98436000	USD
	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	25701000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	219845000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-110334000	USD
	cbsh	Net Increase Decrease In Short Term Borrowings NetIncreaseDecreaseInShortTermBorrowings	1392000	USD
	cbsh	Net Increase Decrease In Short Term Borrowings NetIncreaseDecreaseInShortTermBorrowings	-943000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	39887000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	53593000	USD
	cbsh	Paymentsforstockvalueissuedundersharebasedcompensationplans Paymentsforstockvalueissuedundersharebasedcompensationplans	15000	USD
	cbsh	Paymentsforstockvalueissuedundersharebasedcompensationplans Paymentsforstockvalueissuedundersharebasedcompensationplans	27000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	61559000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	60466000	USD
	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	0	USD
	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	4500000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	706922000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	3620073000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	338008000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	910306000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2208328000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	907808000	USD
CY2021Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2546336000	USD
CY2020Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1818114000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	55440000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	4833000	USD
	us-gaap	Interest Paid Net InterestPaidNet	9909000	USD
	us-gaap	Interest Paid Net InterestPaidNet	35832000	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	172000	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	57000	USD
CY2021Q2	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	20600000	USD
CY2020Q2	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	21900000	USD
CY2021Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	15640264000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	16329641000	USD
CY2021Q2	us-gaap	Interest Receivable InterestReceivable	37200000	USD
CY2020Q4	us-gaap	Interest Receivable InterestReceivable	41900000	USD
CY2021Q2	us-gaap	Pledged Financial Instruments Not Separately Reported Loans Receivable Pledged For Federal Home Loan Bank Debt PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedForFederalHomeLoanBankDebt	3500000000	USD
CY2021Q2	us-gaap	Pledged Financial Instruments Not Separately Reported Loans Receivable Pledged As Collateral PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedAsCollateral	1400000000	USD
CY2021Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	200527000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	220834000	USD
CY2021Q2	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	27433000	USD
	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	37788000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	8868000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	21809000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	8169000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	11158000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	699000	USD
	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	10651000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	172395000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	172395000	USD
CY2021Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	42430000	USD
CY2020Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	38307000	USD
CY2021Q2	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	-18222000	USD
	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	-14099000	USD
CY2021Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	24208000	USD
CY2021Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	24208000	USD
CY2021Q2	cbsh	Financing Receivable Allowance For Credit Loss And Unfunded Lending Commitments Total FinancingReceivableAllowanceForCreditLossAndUnfundedLendingCommitmentsTotal	196603000	USD
CY2021Q2	cbsh	Financing Receivable Allowance For Credit Loss And Unfunded Lending Commitments Total FinancingReceivableAllowanceForCreditLossAndUnfundedLendingCommitmentsTotal	196603000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	171653000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	139643000	USD
CY2020Q2	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-77491000	USD
	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-120359000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	11245000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	25637000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2845000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	6379000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	8400000	USD
	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	19258000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	240744000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	240744000	USD
CY2020Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	32250000	USD
CY2019Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	17165000	USD
CY2020Q2	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	3049000	USD
	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	18134000	USD
CY2020Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	35299000	USD
CY2020Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	35299000	USD
CY2020Q2	cbsh	Financing Receivable Allowance For Credit Loss And Unfunded Lending Commitments Total FinancingReceivableAllowanceForCreditLossAndUnfundedLendingCommitmentsTotal	276043000	USD
CY2020Q2	cbsh	Financing Receivable Allowance For Credit Loss And Unfunded Lending Commitments Total FinancingReceivableAllowanceForCreditLossAndUnfundedLendingCommitmentsTotal	276043000	USD
CY2021Q2	cbsh	Financing Receivable Recorded Investment Currentor Lessthan30days Past Due FinancingReceivableRecordedInvestmentCurrentorLessthan30daysPastDue	15564795000	USD
CY2021Q2	cbsh	Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due FinancingReceivableRecordedInvestmentThirtyToEightyNineDaysPastDue	51965000	USD
CY2021Q2	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	12338000	USD
CY2021Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	11166000	USD
CY2021Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	15640264000	USD
CY2020Q4	cbsh	Financing Receivable Recorded Investment Currentor Lessthan30days Past Due FinancingReceivableRecordedInvestmentCurrentorLessthan30daysPastDue	16230056000	USD
CY2020Q4	cbsh	Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due FinancingReceivableRecordedInvestmentThirtyToEightyNineDaysPastDue	50855000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	22190000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	26540000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	16329641000	USD
CY2021Q2	cbsh	Credit Quality Personal Real Estate Loans Excluded CreditQualityPersonalRealEstateLoansExcluded	187400000	USD
CY2020Q4	cbsh	Credit Quality Personal Real Estate Loans Excluded CreditQualityPersonalRealEstateLoansExcluded	191100000	USD
CY2021Q2	cbsh	Consumer Healthcare Loans Excluded ConsumerHealthcareLoansExcluded	187800000	USD
CY2020Q4	cbsh	Consumer Healthcare Loans Excluded ConsumerHealthcareLoansExcluded	188100000	USD
CY2021Q2	cbsh	Credit Quality Personal Banking Loan Table Percentage Loans Excluded CreditQualityPersonalBankingLoanTablePercentageLoansExcluded	0.07	Rate
CY2021Q2	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	118419000	USD
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	140627000	USD
	cbsh	Period After Which Loans Are Deemed In Default PeriodAfterWhichLoansAreDeemedInDefault	P90D
CY2021Q2	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	118419000	USD
CY2021Q2	cbsh	Financing Receivable Troubled Debt Restructurings That Subsequently Defaulted Recorded Investment FinancingReceivableTroubledDebtRestructuringsThatSubsequentlyDefaultedRecordedInvestment	1501000	USD
	cbsh	Effect On Interest Income Resulting From Modification To Credit Card Loans EffectOnInterestIncomeResultingFromModificationToCreditCardLoans	867000	USD
CY2021Q2	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	745000	USD
CY2021Q2	cbsh	Letters Of Credit To Customers With Substandard Risk Rating LettersOfCreditToCustomersWithSubstandardRiskRating	24000000.0	USD
CY2021Q2	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	17400000	USD
CY2021Q2	cbsh	Unpaid Principal Balanceon Personal Real Estate Loans Heldfor Sale UnpaidPrincipalBalanceonPersonalRealEstateLoansHeldforSale	16900000	USD
CY2021Q2	cbsh	Student Loans Heldfor Sale Lowerof Costor Fair Value StudentLoansHeldforSaleLowerofCostorFairValue	6300000	USD
CY2021Q2	cbsh	Hfs Loansonnonaccrualstatus HFSLoansonnonaccrualstatus	0	USD
CY2021Q2	cbsh	Loans Held For Sale90 Days Past Dueand Still Accruing LoansHeldForSale90DaysPastDueandStillAccruing	0	USD
CY2021Q2	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	229000	USD
CY2020Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	93000	USD
CY2021Q2	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	1100000	USD
CY2020Q4	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	1400000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	13291506000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	12449264000	USD
CY2021Q2	us-gaap	Trading Securities TradingSecurities	29002000	USD
CY2020Q4	us-gaap	Trading Securities TradingSecurities	35321000	USD
CY2021Q2	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	6981000	USD
CY2020Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	2966000	USD
CY2021Q2	cbsh	Equtiy Securitieswithout Readily Determinable Fair Values EqutiySecuritieswithoutReadilyDeterminableFairValues	1697000	USD
CY2020Q4	cbsh	Equtiy Securitieswithout Readily Determinable Fair Values EqutiySecuritieswithoutReadilyDeterminableFairValues	1397000	USD
CY2021Q2	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	34222000	USD
CY2020Q4	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	34070000	USD
CY2021Q2	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	10135000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	10307000	USD
CY2021Q2	us-gaap	Equity Method Investments EquityMethodInvestments	15836000	USD
CY2020Q4	us-gaap	Equity Method Investments EquityMethodInvestments	18000000	USD
CY2021Q2	cbsh	Private Equity Investments PrivateEquityInvestments	116246000	USD
CY2020Q4	cbsh	Private Equity Investments PrivateEquityInvestments	94368000	USD
CY2021Q2	cbsh	Total Investment Securities TotalInvestmentSecurities	13505625000	USD
CY2020Q4	cbsh	Total Investment Securities TotalInvestmentSecurities	12645693000	USD
CY2021Q2	us-gaap	Interest Receivable Current InterestReceivableCurrent	39700000	USD
CY2020Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	41500000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	13077042000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	13291506000	USD
	cbsh	Percentage Decrease In Fair Value Below Amortized Cost PercentageDecreaseInFairValueBelowAmortizedCost	0.20
CY2021Q2	cbsh	Fair Value Securities On Impairment Watch List FairValueSecuritiesOnImpairmentWatchList	14000000.0	USD
CY2020Q4	cbsh	Fair Value Securities On Impairment Watch List FairValueSecuritiesOnImpairmentWatchList	31000000.0	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	3974375000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	39716000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	148624000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	1069000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	4122999000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	40785000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	694458000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	3741000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	253734000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	2617000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	948192000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	6358000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	4100000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	948200000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	40800000	USD
	cbsh	Af Ssecuritiesinlosspositionatperiodendchangeinunrealizedloss AFSsecuritiesinlosspositionatperiodendchangeinunrealizedloss	34400000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	13077042000	USD
CY2021Q2	cbsh	Available For Sale Securities Gross Unreailzed Gainat Period End AvailableForSaleSecuritiesGrossUnreailzedGainatPeriodEnd	255249000	USD
CY2021Q2	cbsh	Available For Sale Securities Gross Unrealized Lossat Period End AvailableForSaleSecuritiesGrossUnrealizedLossatPeriodEnd	40785000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	13291506000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	12097533000	USD
CY2020Q4	cbsh	Available For Sale Securities Gross Unreailzed Gainat Period End AvailableForSaleSecuritiesGrossUnreailzedGainatPeriodEnd	358089000	USD
CY2020Q4	cbsh	Available For Sale Securities Gross Unrealized Lossat Period End AvailableForSaleSecuritiesGrossUnrealizedLossatPeriodEnd	6358000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	12449264000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	0	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	174595000	USD
	cbsh	Proceedsfromsaleofequitysecurities Proceedsfromsaleofequitysecurities	0	USD
	cbsh	Proceedsfromsaleofequitysecurities Proceedsfromsaleofequitysecurities	2000	USD
	cbsh	Proceeds From Sale Of Other Securities ProceedsFromSaleOfOtherSecurities	10060000	USD
	cbsh	Proceeds From Sale Of Other Securities ProceedsFromSaleOfOtherSecurities	0	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	10060000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	174597000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	26657000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
CY2021Q2	cbsh	Investment Securities Pledged At Fair Value InvestmentSecuritiesPledgedAtFairValue	5600000000	USD
CY2020Q4	cbsh	Investment Securities Pledged At Fair Value InvestmentSecuritiesPledgedAtFairValue	4800000000	USD
CY2021Q2	us-gaap	Financial Instruments Owned And Pledged As Collateral Amount Eligible To Be Repledged By Counterparty FinancialInstrumentsOwnedAndPledgedAsCollateralAmountEligibleToBeRepledgedByCounterparty	215300000	USD
CY2021Q2	cbsh	Investments Exceeding Ten Percent Of Stockholders Equity InvestmentsExceedingTenPercentOfStockholdersEquity	0
CY2021Q2	cbsh	Percentage Of Stockholders Equity Of Which No Investment From Single Issuer Exceeds PercentageOfStockholdersEquityOfWhichNoInvestmentFromSingleIssuerExceeds	0.10
CY2021Q2	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	49846000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	38494000	USD
CY2021Q2	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	804000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	10548000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	46508000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	36798000	USD
CY2020Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	2103000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	7607000	USD
CY2021Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	745000	USD
CY2020Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	442000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1700000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	710000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	2661000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	1646000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	1377000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	1149000	USD
CY2021Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	952000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	138921000	USD
CY2021Q2	us-gaap	Goodwill Goodwill	138921000	USD
CY2021Q2	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	5795000	USD
CY2020Q2	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	6304000	USD
	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	11916000	USD
	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	12662000	USD
CY2021Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	1930000	USD
CY2020Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	2160000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	4004000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	4221000	USD
CY2021Q2	us-gaap	Lease Income LeaseIncome	7725000	USD
CY2020Q2	us-gaap	Lease Income LeaseIncome	8464000	USD
	us-gaap	Lease Income LeaseIncome	15920000	USD
	us-gaap	Lease Income LeaseIncome	16883000	USD
CY2021Q2	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	94000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	101000	USD
	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	189000	USD
	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	202000	USD
CY2021Q2	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	556000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	823000	USD
	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	1112000	USD
	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	1645000	USD
CY2021Q2	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1124000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1297000	USD
	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	2248000	USD
	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	2594000	USD
CY2021Q2	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	-68000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	-68000	USD
	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	-136000	USD
	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	-136000	USD
CY2021Q2	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-651000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-542000	USD
	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-1302000	USD
	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-1084000	USD
CY2021Q2	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	109000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	101000	USD
	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	219000	USD
	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	201000	USD
	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	0	USD
CY2021Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	72000	shares
CY2020Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	321000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	51000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	276000	shares
CY2020Q3	us-gaap	Preferred Stock Dividend Rate Percentage PreferredStockDividendRatePercentage	0.0600
CY2020Q3	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1.00
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	331377000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Before Tax OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax	-137270000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	10715000	USD
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	117515000	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-4129000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-147985000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-36998000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-110987000	USD
CY2021Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	220390000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	110444000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Before Tax OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax	322653000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	4231000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	318422000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	79605000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	238817000	USD
CY2020Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	349261000	USD
	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	Operating_Segments
CY2021Q2	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	Operating_Segments
CY2021Q2	cbsh	Number Of Locations NumberOfLocations	160	Locations
	us-gaap	Revenues Revenues	0	USD
CY2020Q2	us-gaap	Revenues Revenues	0	USD
CY2021Q2	us-gaap	Revenues Revenues	0	USD
	us-gaap	Revenues Revenues	0	USD
CY2021Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	207982000	USD
CY2021Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-45655000	USD
CY2021Q2	us-gaap	Noninterest Income NoninterestIncome	139143000	USD
CY2021Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	16804000	USD
CY2021Q2	us-gaap	Noninterest Expense NoninterestExpense	198126000	USD
CY2021Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	211458000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	413730000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-51887000	USD
	us-gaap	Noninterest Income NoninterestIncome	275188000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	26657000	USD
	us-gaap	Noninterest Expense NoninterestExpense	390699000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	376763000	USD
CY2020Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	203057000	USD
CY2020Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	80539000	USD
CY2020Q2	us-gaap	Noninterest Expense NoninterestExpense	187512000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	48392000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	404122000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	138492000	USD
	us-gaap	Noninterest Income NoninterestIncome	241178000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
	us-gaap	Noninterest Expense NoninterestExpense	381210000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	108168000	USD
CY2021Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	2977293000	USD
CY2020Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	3015189000	USD
CY2021Q2	us-gaap	Derivative Assets DerivativeAssets	61358000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	89889000	USD
CY2021Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	13349000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	18675000	USD
CY2021Q2	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	61358000	USD
CY2021Q2	cbsh	Derivative Asset Amount Offset By Liabiilty DerivativeAssetAmountOffsetByLiabiilty	0	USD
CY2021Q2	us-gaap	Derivative Assets DerivativeAssets	61358000	USD
CY2021Q2	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	13349000	USD
CY2021Q2	cbsh	Derivative Liability Amount Offset By Asset DerivativeLiabilityAmountOffsetByAsset	0	USD
CY2021Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	13349000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	89889000	USD
CY2020Q4	cbsh	Derivative Asset Amount Offset By Liabiilty DerivativeAssetAmountOffsetByLiabiilty	0	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	89889000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	18675000	USD
CY2020Q4	cbsh	Derivative Liability Amount Offset By Asset DerivativeLiabilityAmountOffsetByAsset	0	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	18675000	USD
CY2021Q2	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3800000	USD
CY2020Q2	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3700000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	7700000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	7500000	USD
CY2020Q4	cbsh	Nonvested Share Awards Balances NonvestedShareAwardsBalances	1099866	shares
CY2020Q4	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Nonvested Share Awards Weighted Average Grant Date Unit Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsNonvestedShareAwardsWeightedAverageGrantDateUnitFairValue	52.11
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	cbsh	Share Based Compensation Granted Nonvested Share Award Weighted Average Grant Date Fair Value ShareBasedCompensationGrantedNonvestedShareAwardWeightedAverageGrantDateFairValue	72.09
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	cbsh	Share Based Compensation Forfeited Nonvested Share Award Weighted Average Grant Date Fair Value ShareBasedCompensationForfeitedNonvestedShareAwardWeightedAverageGrantDateFairValue	56.84
CY2021Q2	cbsh	Nonvested Share Awards Balances NonvestedShareAwardsBalances	1061496	shares
CY2021Q2	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Nonvested Share Awards Weighted Average Grant Date Unit Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsNonvestedShareAwardsWeightedAverageGrantDateUnitFairValue	57.74
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CY2020Q4	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageExercisePrice	44.95
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	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	3906	shares
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	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expired In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpiredInPeriodWeightedAverageExercisePrice	57.95
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Exercised In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedInPeriod	214271	shares
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Exercised In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedInPeriodWeightedAverageExercisePrice	39.59
CY2021Q2	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumber	859855	shares
CY2021Q2	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageExercisePrice	48.57
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Weighted Average Remaining Contractual Terms ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms	P6Y3M18D
CY2021Q2	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Equity Instruments Other Than Options Aggregate Intrinsic Value Outstanding SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding	22356000	USD
	cbsh	Percentof Revenuenotinscopeof Asc606 PercentofRevenuenotinscopeofASC606	0.60	Rate
CY2021Q2	us-gaap	Noninterest Income NoninterestIncome	139143000	USD
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	117515000	USD
	us-gaap	Noninterest Income NoninterestIncome	275188000	USD
	us-gaap	Noninterest Income NoninterestIncome	241178000	USD
CY2021Q2	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	17374000	USD
CY2021Q2	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	780152000	USD
CY2021Q2	cbsh	Us Government Sponsored Enterprises Debt Securities USGovernmentSponsoredEnterprisesDebtSecurities	52978000	USD
CY2021Q2	us-gaap	Financial Instruments Owned State And Municipal Government Obligations At Fair Value FinancialInstrumentsOwnedStateAndMunicipalGovernmentObligationsAtFairValue	2052030000	USD
CY2021Q2	cbsh	Financial Instruments Owned Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedAgencyMortgageBackedSecuritiesAtFairValue	6071295000	USD
CY2021Q2	cbsh	Financial Instruments Owned Non Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedNonAgencyMortgageBackedSecuritiesAtFairValue	825608000	USD
CY2021Q2	cbsh	Other Asset Backed Securities Disclosure OtherAssetBackedSecuritiesDisclosure	2891799000	USD
CY2021Q2	cbsh	Financial Instruments Owned Other Debt Securities At Fair Value FinancialInstrumentsOwnedOtherDebtSecuritiesAtFairValue	617644000	USD
CY2021Q2	us-gaap	Trading Securities TradingSecurities	29002000	USD
CY2021Q2	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	6981000	USD
CY2021Q2	us-gaap	Financial Instruments Owned Principal Investments At Fair Value FinancialInstrumentsOwnedPrincipalInvestmentsAtFairValue	116246000	USD
CY2021Q2	us-gaap	Derivative Assets DerivativeAssets	61358000	USD
CY2021Q2	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	20969000	USD
CY2021Q2	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	13543436000	USD
CY2021Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	13349000	USD
CY2021Q2	us-gaap	Deferred Compensation Liability Current And Noncurrent DeferredCompensationLiabilityCurrentAndNoncurrent	20969000	USD
CY2021Q2	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	34318000	USD
CY2020Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	39396000	USD
CY2020Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	838059000	USD
CY2020Q4	cbsh	Us Government Sponsored Enterprises Debt Securities USGovernmentSponsoredEnterprisesDebtSecurities	54485000	USD
CY2020Q4	us-gaap	Financial Instruments Owned State And Municipal Government Obligations At Fair Value FinancialInstrumentsOwnedStateAndMunicipalGovernmentObligationsAtFairValue	2045099000	USD
CY2020Q4	cbsh	Financial Instruments Owned Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedAgencyMortgageBackedSecuritiesAtFairValue	6712085000	USD
CY2020Q4	cbsh	Financial Instruments Owned Non Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedNonAgencyMortgageBackedSecuritiesAtFairValue	361074000	USD
CY2020Q4	cbsh	Other Asset Backed Securities Disclosure OtherAssetBackedSecuritiesDisclosure	1882243000	USD
CY2020Q4	cbsh	Financial Instruments Owned Other Debt Securities At Fair Value FinancialInstrumentsOwnedOtherDebtSecuritiesAtFairValue	556219000	USD
CY2020Q4	us-gaap	Trading Securities TradingSecurities	35321000	USD
CY2020Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	2966000	USD
CY2020Q4	us-gaap	Financial Instruments Owned Principal Investments At Fair Value FinancialInstrumentsOwnedPrincipalInvestmentsAtFairValue	94368000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	89889000	USD
CY2020Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	19278000	USD
CY2020Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	12730482000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	18675000	USD
CY2020Q4	us-gaap	Deferred Compensation Liability Current And Noncurrent DeferredCompensationLiabilityCurrentAndNoncurrent	19278000	USD
CY2020Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	37953000	USD
CY2021Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	103863000	USD
CY2021Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-16246000	USD
CY2021Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	18000	USD
CY2021Q2	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion	3000	USD
CY2021Q2	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	5656000	USD
CY2021Q2	cbsh	Sales And Repayments Of Private Equity Securities SalesAndRepaymentsOfPrivateEquitySecurities	356000	USD
CY2021Q2	cbsh	Capitalized Interest Or Dividends CapitalizedInterestOrDividends	23000	USD
CY2021Q2	cbsh	Purchase Of Risk Participation Agreement PurchaseOfRiskParticipationAgreement	445000	USD
CY2021Q2	cbsh	Sale Of Risk Participation Agreement SaleOfRiskParticipationAgreement	32000	USD
CY2021Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	125866000	USD
CY2021Q2	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	18100000	USD
CY2021Q2	cbsh	Gains Losses Included In Oci Attributable To Change In Unrealized Gains Losses Relating To Assets Still Held Total GainsLossesIncludedInOCIAttributableToChangeInUnrealizedGainsLossesRelatingToAssetsStillHeldTotal	18000	USD
CY2020Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	105077000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	-23604000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	17000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion	6000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	5656000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	5656000	USD
	cbsh	Sales And Repayments Of Private Equity Securities SalesAndRepaymentsOfPrivateEquitySecurities	8832000	USD
	cbsh	Capitalized Interest Or Dividends CapitalizedInterestOrDividends	23000	USD
	cbsh	Purchase Of Risk Participation Agreement PurchaseOfRiskParticipationAgreement	445000	USD
	cbsh	Sale Of Risk Participation Agreement SaleOfRiskParticipationAgreement	130000	USD
CY2021Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	125866000	USD
	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	26660000	USD
	cbsh	Gains Losses Included In Oci Attributable To Change In Unrealized Gains Losses Relating To Assets Still Held Total GainsLossesIncludedInOCIAttributableToChangeInUnrealizedGainsLossesRelatingToAssetsStillHeldTotal	17000	USD
CY2020Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	88964000	USD
CY2020Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	4683000	USD
CY2020Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	1123000	USD
CY2020Q2	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion	5000	USD
CY2020Q2	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	155000	USD
CY2020Q2	cbsh	Capitalized Interest Or Dividends CapitalizedInterestOrDividends	29000	USD
CY2020Q2	cbsh	Sale Of Risk Participation Agreement SaleOfRiskParticipationAgreement	369000	USD
CY2020Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	85224000	USD
CY2020Q2	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-4682000	USD
CY2020Q2	cbsh	Gains Losses Included In Oci Attributable To Change In Unrealized Gains Losses Relating To Assets Still Held Total GainsLossesIncludedInOCIAttributableToChangeInUnrealizedGainsLossesRelatingToAssetsStillHeldTotal	1123000	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	104344000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	18177000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	-372000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion	9000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	269000	USD
	cbsh	Sales And Repayments Of Private Equity Securities SalesAndRepaymentsOfPrivateEquitySecurities	69000	USD
	cbsh	Capitalized Interest Or Dividends CapitalizedInterestOrDividends	29000	USD
	cbsh	Sale Of Risk Participation Agreement SaleOfRiskParticipationAgreement	809000	USD
CY2020Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	85224000	USD
	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-17746000	USD
	cbsh	Gains Losses Included In Oci Attributable To Change In Unrealized Gains Losses Relating To Assets Still Held Total GainsLossesIncludedInOCIAttributableToChangeInUnrealizedGainsLossesRelatingToAssetsStillHeldTotal	-372000	USD
CY2021Q2	cbsh	Total Gains Or Losses Included In Earnings Level3 Fair Measurements TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements	16246000	USD
CY2021Q2	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	18100000	USD
	cbsh	Total Gains Or Losses Included In Earnings Level3 Fair Measurements TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements	23604000	USD
	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	26660000	USD
CY2020Q2	cbsh	Total Gains Or Losses Included In Earnings Level3 Fair Measurements TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements	-4683000	USD
CY2020Q2	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-4682000	USD
	cbsh	Total Gains Or Losses Included In Earnings Level3 Fair Measurements TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements	-18177000	USD
	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-17746000	USD
CY2021Q2	cbsh	Mortgage Servicing Rights Nonrecurring Basis MortgageServicingRightsNonrecurringBasis	9376000	USD
	cbsh	Mortgage Servicing Rights Nonrecurring Basis Gains Losses MortgageServicingRightsNonrecurringBasisGainsLosses	1299000	USD
CY2021Q2	cbsh	Long Lived Assets Nonrecurring Basis LongLivedAssetsNonrecurringBasis	984000	USD
	cbsh	Long Lived Assets Nonrecurring Basis Gains Losses LongLivedAssetsNonrecurringBasisGainsLosses	-276000	USD
CY2020Q2	cbsh	Loans Nonrecurring Basis LoansNonrecurringBasis	12066000	USD
	cbsh	Loans Nonrecurring Basis Gains Losses LoansNonrecurringBasisGainsLosses	-3079000	USD
CY2020Q2	cbsh	Mortgage Servicing Rights Nonrecurring Basis MortgageServicingRightsNonrecurringBasis	5625000	USD
	cbsh	Mortgage Servicing Rights Nonrecurring Basis Gains Losses MortgageServicingRightsNonrecurringBasisGainsLosses	-1851000	USD
CY2020Q2	cbsh	Long Lived Assets Nonrecurring Basis LongLivedAssetsNonrecurringBasis	348000	USD
	cbsh	Long Lived Assets Nonrecurring Basis Gains Losses LongLivedAssetsNonrecurringBasisGainsLosses	-5000	USD
	cbsh	Fair Value Discounted Cash Flow Valuation Techniques FairValueDiscountedCashFlowValuationTechniques	Discounted cash flow

Files In Submission

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$CBSH
COMMERCE BANCSHARES INC /MO/ Stock $cbsh

2021 Q3 Form 10-Q Financial Statement

#000002235621000040 Filed on August 05, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CBSH COMMERCE BANCSHARES INC /MO/ Stock $cbsh

2021 Q3 Form 10-Q Financial Statement

#000002235621000040 Filed on August 05, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CBSH
COMMERCE BANCSHARES INC /MO/ Stock $cbsh