$CBSH
COMMERCE BANCSHARES INC /MO/ Stock $cbsh

$cbsh Overview Financials Valuation SEC Filings Company Website

2020 Q3 Form 10-Q Financial Statement

#000002235620000046 Filed on August 06, 2020

Income Statement

Concept	2020 Q3	2020 Q2	2019 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	$11.20M	$10.70M	$10.30M
YoY Change	7.69%	3.88%	7.29%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$7.152M	$10.27M	$26.78M
YoY Change	-74.67%	-61.66%	82.61%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$167.7M	$48.39M	$137.2M
YoY Change	20.51%	-64.73%	-2.58%
Income Tax	$34.38M	$9.661M	$28.90M
% Of Pretax Income	20.49%	19.96%	21.06%
Net Earnings	$132.4M	$39.86M	$108.0M
YoY Change	21.24%	-63.08%	-2.14%
Net Earnings / Revenue
Basic Earnings Per Share	$1.06	$0.32	$0.91
Diluted Earnings Per Share	$1.06	$0.32	$0.91
COMMON SHARES
Basic Shares Outstanding	111.5M shares	111.5M shares	110.5M shares
Diluted Shares Outstanding

Balance Sheet

Concept	2020 Q3	2020 Q2	2019 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$1.557B	$1.818B	$961.5M
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	$377.9M	$368.6M	$363.6M
YoY Change	3.25%	1.38%	9.58%
Goodwill	$138.9M	$138.9M	$138.9M
YoY Change	0.0%	0.0%	0.0%
Intangibles	$7.183M	$7.179M	$8.763M
YoY Change	-21.4%	-18.08%	8.41%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$31.45B	$30.50B	$25.77B
YoY Change	21.55%	18.33%	5.09%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses			$28.00M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$1.653B	$1.740B	$2.394B
YoY Change	0.73%	-27.32%	105.14%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$1.653B	$1.740B	$28.00M
YoY Change	6022.22%	6114.29%	-97.6%
LONG-TERM LIABILITIES
Long-Term Debt	$1.000M	$1.000M	$5.000M
YoY Change	-99.61%	-80.0%	-44.44%
Other Long-Term Liabilities	$792.0M	$869.0M	$345.0M
YoY Change	48.04%	151.88%	34.77%
Total Long-Term Liabilities	$793.0M	$870.0M	$350.0M
YoY Change	0.13%	148.57%	32.08%
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.653B	$1.740B	$28.00M
Total Long-Term Liabilities	$793.0M	$870.0M	$350.0M
Total Liabilities	$28.15B	$27.14B	$22.60B
YoY Change	23.61%	20.08%	3.9%
SHAREHOLDERS EQUITY
Retained Earnings	$326.9M	$232.1M	$384.2M
YoY Change	-29.43%	-39.6%	-5.91%
Common Stock	$564.0M	$564.0M	$559.4M
YoY Change	0.81%	0.81%	4.49%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$69.05M	$69.11M	$106.1M
YoY Change	-72.56%	-34.87%	569.27%
Treasury Stock Shares	1.041M shares	1.041M shares	1.753M shares
Shareholders Equity	$3.306B	$3.358B	$3.169B
YoY Change
Total Liabilities & Shareholders Equity	$31.45B	$30.50B	$25.77B
YoY Change	21.55%	18.33%	5.09%

Cashflow Statement

Concept	2020 Q3	2020 Q2	2019 Q2
OPERATING ACTIVITIES
Net Income	$132.4M	$39.86M	$108.0M
YoY Change	21.24%	-63.08%	-2.14%
Depreciation, Depletion And Amortization	$11.20M	$10.70M	$10.30M
YoY Change	7.69%	3.88%	7.29%
Cash From Operating Activities	$242.7M	$149.9M	$109.5M
YoY Change	93.23%	36.89%	-24.01%
INVESTING ACTIVITIES
Capital Expenditures	-$15.50M	-$6.100M	-$9.000M
YoY Change	70.33%	-32.22%	5.88%
Acquisitions
YoY Change
Other Investing Activities	-$1.488B	-$2.652B	-$107.7M
YoY Change	400.84%	2362.21%	391.78%
Cash From Investing Activities	-$1.503B	-$2.658B	-$116.7M
YoY Change	390.83%	2177.55%	282.62%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	1.000B	3.427B	362.2M
YoY Change	865.35%	846.05%	-340.03%
NET CHANGE
Cash From Operating Activities	242.7M	149.9M	109.5M
Cash From Investing Activities	-1.503B	-2.658B	-116.7M
Cash From Financing Activities	1.000B	3.427B	362.2M
Net Change In Cash	-260.6M	918.6M	355.0M
YoY Change	238.0%	158.76%	-1051.74%
FREE CASH FLOW
Cash From Operating Activities	$242.7M	$149.9M	$109.5M
Capital Expenditures	-$15.50M	-$6.100M	-$9.000M
Free Cash Flow	$258.2M	$156.0M	$118.5M
YoY Change	91.69%	31.65%	-22.35%

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	2020
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Amendment Flag AmendmentFlag	false
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	8435531000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2020Q2	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	6854000	USD
CY2020Q2	cbsh	Investment Securities Called InvestmentSecuritiesCalled	0	USD
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
	cbsh	Investment Securities Called InvestmentSecuritiesCalled	0	USD
	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2020-06-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	0-2989
	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	Entity Address State Or Province EntityAddressStateOrProvince	MO
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	64106
	dei	City Area Code CityAreaCode	816
	dei	Local Phone Number LocalPhoneNumber	234-2000
	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
CY2020Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	111533322	shares
CY2020Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	16395054000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	14737817000	USD
CY2020Q2	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	240744000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	160682000	USD
CY2020Q2	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	16154310000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	14577135000	USD
CY2020Q2	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	6854000	USD
CY2019Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	9181000	USD
CY2020Q2	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	12785000	USD
CY2019Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	13809000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	9961155000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	10317427000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	8571626000	USD
CY2020Q2	us-gaap	Trading Securities TradingSecurities	28813000	USD
CY2019Q4	us-gaap	Trading Securities TradingSecurities	28161000	USD
CY2020Q2	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	4128000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni And Without Readily Determinable Fair Value EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue	4209000	USD
CY2020Q2	cbsh	Other Securities OtherSecurities	117761000	USD
CY2019Q4	cbsh	Other Securities OtherSecurities	137892000	USD
CY2020Q2	cbsh	Total Investment Securities TotalInvestmentSecurities	10468129000	USD
CY2019Q4	cbsh	Total Investment Securities TotalInvestmentSecurities	8741888000	USD
CY2020Q2	cbsh	Long Term Securities Purchased Under Agreements To Resell LongTermSecuritiesPurchasedUnderAgreementsToResell	850000000	USD
CY2019Q4	cbsh	Long Term Securities Purchased Under Agreements To Resell LongTermSecuritiesPurchasedUnderAgreementsToResell	850000000	USD
CY2020Q2	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	1404968000	USD
CY2019Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	395850000	USD
CY2020Q2	us-gaap	Cash And Due From Banks CashAndDueFromBanks	391268000	USD
CY2019Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	491615000	USD
CY2020Q2	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	368565000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	370637000	USD
CY2020Q2	us-gaap	Goodwill Goodwill	138921000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	138921000	USD
CY2020Q2	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	7179000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	9534000	USD
CY2020Q2	us-gaap	Other Assets OtherAssets	699996000	USD
CY2019Q4	us-gaap	Other Assets OtherAssets	476400000	USD
CY2020Q2	us-gaap	Assets Assets	30496121000	USD
CY2019Q4	us-gaap	Assets Assets	26065789000	USD
CY2020Q2	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	9700261000	USD
CY2019Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	6890687000	USD
CY2020Q2	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	12792993000	USD
CY2019Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	11621716000	USD
CY2020Q2	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	590635000	USD
CY2019Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	626157000	USD
CY2020Q2	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	1443078000	USD
CY2019Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	1381855000	USD
CY2020Q2	us-gaap	Deposits Deposits	24526967000	USD
CY2019Q4	us-gaap	Deposits Deposits	20520415000	USD
CY2020Q2	us-gaap	Federal Funds Purchased And Securities Sold Under Agreements To Repurchase FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	1740438000	USD
CY2019Q4	us-gaap	Federal Funds Purchased And Securities Sold Under Agreements To Repurchase FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	1850772000	USD
CY2020Q2	us-gaap	Other Borrowings OtherBorrowings	1475000	USD
CY2019Q4	us-gaap	Other Borrowings OtherBorrowings	2418000	USD
CY2020Q2	us-gaap	Other Liabilities OtherLiabilities	869072000	USD
CY2019Q4	us-gaap	Other Liabilities OtherLiabilities	553712000	USD
CY2020Q2	us-gaap	Liabilities Liabilities	27137952000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	22927317000	USD
CY2019Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1
CY2020Q2	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2020Q2	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2020Q2	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	6000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	6000	shares
CY2020Q2	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	144784000	USD
CY2019Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding	144784000	USD
CY2020Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	5
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	5
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	140000000	shares
CY2020Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	140000000	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	112795605	shares
CY2020Q2	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	112795605	shares
CY2020Q2	us-gaap	Common Stock Value CommonStockValue	563978000	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	563978000	USD
CY2020Q2	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	2136874000	USD
CY2019Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	2151464000	USD
CY2020Q2	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	232082000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	201562000	USD
CY2020Q2	us-gaap	Treasury Stock Shares TreasuryStockShares	1040898	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	445952	shares
CY2020Q2	us-gaap	Treasury Stock Value TreasuryStockValue	69112000	USD
CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	37548000	USD
CY2020Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	349261000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	110444000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	3357867000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3134684000	USD
CY2020Q2	us-gaap	Minority Interest MinorityInterest	302000	USD
CY2019Q4	us-gaap	Minority Interest MinorityInterest	3788000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3358169000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3138472000	USD
CY2020Q2	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	30496121000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	26065789000	USD
CY2020Q2	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	151545000	USD
CY2019Q2	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	167709000	USD
	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	310692000	USD
	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	334141000	USD
CY2020Q2	us-gaap	Interest And Fee Income Loans And Leases Held For Sale InterestAndFeeIncomeLoansAndLeasesHeldForSale	127000	USD
CY2019Q2	us-gaap	Interest And Fee Income Loans And Leases Held For Sale InterestAndFeeIncomeLoansAndLeasesHeldForSale	361000	USD
	us-gaap	Interest And Fee Income Loans And Leases Held For Sale InterestAndFeeIncomeLoansAndLeasesHeldForSale	324000	USD
	us-gaap	Interest And Fee Income Loans And Leases Held For Sale InterestAndFeeIncomeLoansAndLeasesHeldForSale	695000	USD
CY2020Q2	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	50472000	USD
CY2019Q2	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	64658000	USD
	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	103857000	USD
	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	120080000	USD
CY2020Q2	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	0	USD
CY2019Q2	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	11000	USD
	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	2000	USD
	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	44000	USD
CY2020Q2	cbsh	Interest On Long Term Securities Purchased Under Agreements To Resell InterestOnLongTermSecuritiesPurchasedUnderAgreementsToResell	10736000	USD
CY2019Q2	cbsh	Interest On Long Term Securities Purchased Under Agreements To Resell InterestOnLongTermSecuritiesPurchasedUnderAgreementsToResell	3687000	USD
	cbsh	Interest On Long Term Securities Purchased Under Agreements To Resell InterestOnLongTermSecuritiesPurchasedUnderAgreementsToResell	18198000	USD
	cbsh	Interest On Long Term Securities Purchased Under Agreements To Resell InterestOnLongTermSecuritiesPurchasedUnderAgreementsToResell	7445000	USD
CY2020Q2	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	443000	USD
CY2019Q2	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	1986000	USD
	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	1735000	USD
	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	3872000	USD
CY2020Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	213323000	USD
CY2019Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	238412000	USD
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	434808000	USD
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	466277000	USD
CY2020Q2	us-gaap	Interest Expense Now Accounts Money Market Accounts And Savings Deposits InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits	3977000	USD
CY2019Q2	us-gaap	Interest Expense Now Accounts Money Market Accounts And Savings Deposits InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits	10254000	USD
	us-gaap	Interest Expense Now Accounts Money Market Accounts And Savings Deposits InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits	12286000	USD
	us-gaap	Interest Expense Now Accounts Money Market Accounts And Savings Deposits InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits	19856000	USD
CY2020Q2	us-gaap	Interest Expense Time Deposits Less Than100000 InterestExpenseTimeDepositsLessThan100000	1393000	USD
CY2019Q2	us-gaap	Interest Expense Time Deposits Less Than100000 InterestExpenseTimeDepositsLessThan100000	1531000	USD
	us-gaap	Interest Expense Time Deposits Less Than100000 InterestExpenseTimeDepositsLessThan100000	3168000	USD
	us-gaap	Interest Expense Time Deposits Less Than100000 InterestExpenseTimeDepositsLessThan100000	2790000	USD
CY2020Q2	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	3610000	USD
CY2019Q2	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	6931000	USD
	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	8845000	USD
	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	12933000	USD
CY2020Q2	us-gaap	Interest Expense Federal Funds Purchased And Securities Sold Under Agreements To Repurchase InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	585000	USD
CY2019Q2	us-gaap	Interest Expense Federal Funds Purchased And Securities Sold Under Agreements To Repurchase InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	8057000	USD
	us-gaap	Interest Expense Federal Funds Purchased And Securities Sold Under Agreements To Repurchase InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	5355000	USD
	us-gaap	Interest Expense Federal Funds Purchased And Securities Sold Under Agreements To Repurchase InterestExpenseFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	15566000	USD
CY2020Q2	cbsh	Interest On Other Borrowings InterestOnOtherBorrowings	701000	USD
CY2019Q2	cbsh	Interest On Other Borrowings InterestOnOtherBorrowings	5000	USD
	cbsh	Interest On Other Borrowings InterestOnOtherBorrowings	1032000	USD
	cbsh	Interest On Other Borrowings InterestOnOtherBorrowings	10000	USD
CY2020Q2	us-gaap	Interest Expense InterestExpense	10266000	USD
CY2019Q2	us-gaap	Interest Expense InterestExpense	26778000	USD
	us-gaap	Interest Expense InterestExpense	30686000	USD
	us-gaap	Interest Expense InterestExpense	51155000	USD
CY2020Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	203057000	USD
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	211634000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	404122000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	415122000	USD
CY2020Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	80539000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	11806000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	138492000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	24269000	USD
CY2020Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	122518000	USD
CY2019Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	199828000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	265630000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	390853000	USD
CY2020Q2	cbsh	Bank Card Transaction Fees BankCardTransactionFees	33745000	USD
CY2019Q2	cbsh	Bank Card Transaction Fees BankCardTransactionFees	42646000	USD
	cbsh	Bank Card Transaction Fees BankCardTransactionFees	73945000	USD
	cbsh	Bank Card Transaction Fees BankCardTransactionFees	82290000	USD
CY2020Q2	cbsh	Trustfeerevenue Trustfeerevenue	37942000	USD
CY2019Q2	cbsh	Trustfeerevenue Trustfeerevenue	38375000	USD
	cbsh	Trustfeerevenue Trustfeerevenue	77907000	USD
	cbsh	Trustfeerevenue Trustfeerevenue	75631000	USD
CY2020Q2	cbsh	Depositfeerevenue Depositfeerevenue	22279000	USD
CY2019Q2	cbsh	Depositfeerevenue Depositfeerevenue	23959000	USD
	cbsh	Depositfeerevenue Depositfeerevenue	45956000	USD
	cbsh	Depositfeerevenue Depositfeerevenue	46977000	USD
CY2020Q2	us-gaap	Noninterest Income Other NoninterestIncomeOther	3772000	USD
CY2019Q2	us-gaap	Noninterest Income Other NoninterestIncomeOther	1944000	USD
	us-gaap	Noninterest Income Other NoninterestIncomeOther	7562000	USD
	us-gaap	Noninterest Income Other NoninterestIncomeOther	3823000	USD
CY2020Q2	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	3011000	USD
CY2019Q2	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	3888000	USD
	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	7088000	USD
	us-gaap	Brokerage Commissions Revenue BrokerageCommissionsRevenue	7635000	USD
CY2020Q2	cbsh	Loan Fees And Sales LoanFeesAndSales	4649000	USD
CY2019Q2	cbsh	Loan Fees And Sales LoanFeesAndSales	4238000	USD
	cbsh	Loan Fees And Sales LoanFeesAndSales	7884000	USD
	cbsh	Loan Fees And Sales LoanFeesAndSales	7547000	USD
CY2020Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	12117000	USD
CY2019Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	12209000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	20836000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	24596000	USD
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	117515000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	127259000	USD
	us-gaap	Noninterest Income NoninterestIncome	241178000	USD
	us-gaap	Noninterest Income NoninterestIncome	248499000	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-4129000	USD
CY2019Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-110000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1035000	USD
CY2020Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	126759000	USD
CY2019Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	120062000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	255696000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	242190000	USD
CY2020Q2	us-gaap	Occupancy Net OccupancyNet	11269000	USD
CY2019Q2	us-gaap	Occupancy Net OccupancyNet	11145000	USD
	us-gaap	Occupancy Net OccupancyNet	23017000	USD
	us-gaap	Occupancy Net OccupancyNet	22646000	USD
CY2020Q2	us-gaap	Equipment Expense EquipmentExpense	4755000	USD
CY2019Q2	us-gaap	Equipment Expense EquipmentExpense	4790000	USD
	us-gaap	Equipment Expense EquipmentExpense	9576000	USD
	us-gaap	Equipment Expense EquipmentExpense	9261000	USD
CY2020Q2	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	4427000	USD
CY2019Q2	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	5275000	USD
	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	9085000	USD
	cbsh	Supplies Postage And Communication SuppliesPostageAndCommunication	10437000	USD
CY2020Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	23837000	USD
CY2019Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	23248000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	47392000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	45508000	USD
CY2020Q2	us-gaap	Marketing Expense MarketingExpense	3801000	USD
CY2019Q2	us-gaap	Marketing Expense MarketingExpense	6015000	USD
	us-gaap	Marketing Expense MarketingExpense	9780000	USD
	us-gaap	Marketing Expense MarketingExpense	11915000	USD
CY2020Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	12664000	USD
CY2019Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	19244000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	26664000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	39247000	USD
CY2020Q2	us-gaap	Noninterest Expense NoninterestExpense	187512000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	189779000	USD
	us-gaap	Noninterest Expense NoninterestExpense	381210000	USD
	us-gaap	Noninterest Expense NoninterestExpense	381204000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	48392000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	137198000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	108168000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	257113000	USD
CY2020Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9661000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28899000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	19834000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	51759000	USD
CY2020Q2	us-gaap	Profit Loss ProfitLoss	38731000	USD
CY2019Q2	us-gaap	Profit Loss ProfitLoss	108299000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
	us-gaap	Profit Loss ProfitLoss	205354000	USD
CY2019Q2	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	328000	USD
	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-3386000	USD
	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	245000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	39863000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	107971000	USD
	us-gaap	Net Income Loss NetIncomeLoss	91720000	USD
	us-gaap	Net Income Loss NetIncomeLoss	205109000	USD
CY2020Q2	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	2250000	USD
CY2019Q2	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	2250000	USD
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	4500000	USD
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	4500000	USD
CY2020Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	37613000	USD
CY2019Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	105721000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	87220000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	200609000	USD
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.34
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.91
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.78
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.72
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.34
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.91
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.78
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.72
CY2020Q2	us-gaap	Profit Loss ProfitLoss	38731000	USD
CY2019Q2	us-gaap	Profit Loss ProfitLoss	108299000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
	us-gaap	Profit Loss ProfitLoss	205354000	USD
CY2020Q2	cbsh	Net Unrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings NetUnrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings	0	USD
CY2019Q2	cbsh	Net Unrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings NetUnrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings	-228000	USD
	cbsh	Net Unrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings NetUnrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings	0	USD
	cbsh	Net Unrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings NetUnrealizedgainslossesonsecuritiesforwhichaportionofanotherthantemporaryimpairmenthasbeenrecordedinearnings	-187000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	86462000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	76950000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	165134000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	150391000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-355000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-388000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-711000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-777000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	9308000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	19807000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	72972000	USD
	us-gaap	Other Comprehensive Income Loss Derivatives Qualifying As Hedges Net Of Tax OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	22586000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	96125000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	96917000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	238817000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	173567000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	134856000	USD
CY2019Q2	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	205216000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	327151000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	378921000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-1132000	USD
CY2019Q2	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	328000	USD
	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-3386000	USD
	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	245000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	135988000	USD
CY2019Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	204888000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	330537000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	378676000	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
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	0.270
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
CY2019Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3043213000	USD
CY2019Q2	us-gaap	Profit Loss ProfitLoss	108299000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	96917000	USD
CY2019Q2	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	3154000	USD
CY2019Q2	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	46380000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	1000	USD
CY2019Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3399000	USD
CY2019Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.248
CY2019Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	28682000	USD
CY2019Q2	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.375
CY2019Q2	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	2250000	USD
CY2019Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3171363000	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	0.540
	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
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	2937149000	USD
	us-gaap	Profit Loss ProfitLoss	205354000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	173567000	USD
	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	3464000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	86079000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-3000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	6879000	USD
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.496
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	57540000	USD
	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.750
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	4500000	USD
CY2019Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3171363000	USD
	us-gaap	Profit Loss ProfitLoss	88334000	USD
	us-gaap	Profit Loss ProfitLoss	205354000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	138492000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	24269000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	21320000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	20297000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-25665000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-12825000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1035000	USD
	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	1826000	USD
	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	4584000	USD
	cbsh	Origination Of Loans Held For Sale OriginationOfLoansHeldForSale	41167000	USD
	cbsh	Origination Of Loans Held For Sale OriginationOfLoansHeldForSale	108306000	USD
	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	43877000	USD
	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	112390000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-5249000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-3587000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	7466000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	6879000	USD
	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	3672000	USD
	us-gaap	Increase Decrease In Interest And Dividends Receivable IncreaseDecreaseInInterestAndDividendsReceivable	-876000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-5145000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	4421000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	12842000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	23590000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	79137000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	50899000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	229728000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	251734000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	174597000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	375462000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1224190000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	611223000	USD
	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	2648074000	USD
	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	972274000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	1676552000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	143629000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	13677000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	20289000	USD
	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	21000	USD
	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	1477000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2939495000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-148030000	USD
	cbsh	Net Increase Decrease Non Interest Bearing Savings Interest Checking And Money Market Deposits NetIncreaseDecreaseNonInterestBearingSavingsInterestCheckingAndMoneyMarketDeposits	3824235000	USD
	cbsh	Net Increase Decrease Non Interest Bearing Savings Interest Checking And Money Market Deposits NetIncreaseDecreaseNonInterestBearingSavingsInterestCheckingAndMoneyMarketDeposits	-1080769000	USD
	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	25701000	USD
	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	443799000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	-110334000	USD
	us-gaap	Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet	437905000	USD
	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	0	USD
	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	108000	USD
	cbsh	Net Increase Decrease In Short Term Borrowings NetIncreaseDecreaseInShortTermBorrowings	-943000	USD
	cbsh	Net Increase Decrease In Short Term Borrowings NetIncreaseDecreaseInShortTermBorrowings	-4194000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	53593000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	86079000	USD
	cbsh	Paymentsforstockvalueissuedundersharebasedcompensationplans Paymentsforstockvalueissuedundersharebasedcompensationplans	27000	USD
	cbsh	Paymentsforstockvalueissuedundersharebasedcompensationplans Paymentsforstockvalueissuedundersharebasedcompensationplans	3000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	60466000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	57540000	USD
	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	4500000	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	3620073000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-351489000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	910306000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-247785000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	907808000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1209240000	USD
CY2020Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1818114000	USD
CY2019Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	961455000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	4833000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	26042000	USD
	us-gaap	Interest Paid Net InterestPaidNet	35832000	USD
	us-gaap	Interest Paid Net InterestPaidNet	46734000	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	57000	USD
	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	558000	USD
CY2020Q2	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	21900000	USD
CY2019Q2	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	12900000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	160682000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	139643000	USD
CY2019Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	1075000	USD
CY2020Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	17165000	USD
CY2019Q4	cbsh	Loans And Leases Receivable And Liability For Unfunded Lending Commitments Allowance LoansAndLeasesReceivableAndLiabilityForUnfundedLendingCommitmentsAllowance	161757000	USD
CY2020Q1	cbsh	Financing Receivable Allowance For Credit Losses And Liability For Unfunded Lending Commitments FinancingReceivableAllowanceForCreditLossesAndLiabilityForUnfundedLendingCommitments	156808000	USD
CY2020Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	16395054000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	14737817000	USD
CY2020Q2	us-gaap	Interest Receivable InterestReceivable	37000000.0	USD
CY2020Q2	us-gaap	Pledged Financial Instruments Not Separately Reported Loans Receivable Pledged For Federal Home Loan Bank Debt PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedForFederalHomeLoanBankDebt	4300000000	USD
CY2020Q2	cbsh	Pledged Financial Instruments Not Separately Reported Loans Pledged For Federal Reserve Bank Debt PledgedFinancialInstrumentsNotSeparatelyReportedLoansPledgedForFederalReserveBankDebt	1500000000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	171653000	USD
CY2020Q1	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
CY2020Q1	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
CY2019Q1	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	160682000	USD
CY2018Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	159932000	USD
CY2019Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	11806000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	24269000	USD
CY2019Q2	us-gaap	Allowance For Loan And Lease Losses Write Offs AllowanceForLoanAndLeaseLossesWriteOffs	14458000	USD
	us-gaap	Allowance For Loan And Lease Losses Write Offs AllowanceForLoanAndLeaseLossesWriteOffs	29189000	USD
CY2019Q2	us-gaap	Allowance For Loan And Lease Loss Recovery Of Bad Debts AllowanceForLoanAndLeaseLossRecoveryOfBadDebts	3152000	USD
	us-gaap	Allowance For Loan And Lease Loss Recovery Of Bad Debts AllowanceForLoanAndLeaseLossRecoveryOfBadDebts	6170000	USD
CY2019Q2	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	11306000	USD
	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	23019000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	161182000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	161182000	USD
CY2020Q2	cbsh	Financing Receivable Recorded Investment Currentor Lessthan30days Past Due FinancingReceivableRecordedInvestmentCurrentorLessthan30daysPastDue	16276066000	USD
CY2020Q2	cbsh	Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due FinancingReceivableRecordedInvestmentThirtyToEightyNineDaysPastDue	71769000	USD
CY2020Q2	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	24584000	USD
CY2020Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	22635000	USD
CY2020Q2	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	16395054000	USD
CY2019Q4	cbsh	Financing Receivable Recorded Investment Currentor Lessthan30days Past Due FinancingReceivableRecordedInvestmentCurrentorLessthan30daysPastDue	14627638000	USD
CY2019Q4	cbsh	Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due FinancingReceivableRecordedInvestmentThirtyToEightyNineDaysPastDue	80100000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	19859000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	10220000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Gross Carrying Amount LoansAndLeasesReceivableGrossCarryingAmount	14737817000	USD
CY2020Q2	cbsh	Credit Quality Personal Real Estate Loans Excluded CreditQualityPersonalRealEstateLoansExcluded	190100000	USD
CY2019Q4	cbsh	Credit Quality Personal Real Estate Loans Excluded CreditQualityPersonalRealEstateLoansExcluded	198200000	USD
CY2020Q2	cbsh	Consumer Healthcare Loans Excluded ConsumerHealthcareLoansExcluded	195000000.0	USD
CY2019Q4	cbsh	Consumer Healthcare Loans Excluded ConsumerHealthcareLoansExcluded	199200000	USD
CY2020Q2	cbsh	Credit Quality Personal Banking Loan Table Percentage Loans Excluded CreditQualityPersonalBankingLoanTablePercentageLoansExcluded	0.07	Rate
CY2020Q2	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	80215000	USD
CY2019Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	79450000	USD
	cbsh	Period After Which Loans Are Deemed In Default PeriodAfterWhichLoansAreDeemedInDefault	P90D
CY2020Q2	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	80215000	USD
CY2020Q2	cbsh	Financing Receivable Troubled Debt Restructurings That Subsequently Defaulted Recorded Investment FinancingReceivableTroubledDebtRestructuringsThatSubsequentlyDefaultedRecordedInvestment	633000	USD
	cbsh	Effect On Interest Income Resulting From Modification To Credit Card Loans EffectOnInterestIncomeResultingFromModificationToCreditCardLoans	881000	USD
CY2020Q2	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	12300000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	10220000	USD
CY2019Q4	cbsh	Accruing Restructured Loans AccruingRestructuredLoans	71512000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	81732000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2746000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	81732000	USD
CY2019Q4	cbsh	Loans And Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance LoansAndLeasesReceivableAllowanceExcludingImpairedFinancingReceivableRelatedAllowance	157936000	USD
CY2019Q4	cbsh	Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment LoansAndLeasesReceivableExcludingImpairedFinancingReceivablesRecordedInvestment	14656085000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	7054000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	13738000	USD
CY2019Q4	cbsh	Impaired Financing Receivablewith No Related Allowance Allowance ImpairedFinancingReceivablewithNoRelatedAllowanceAllowance	0	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	74678000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	76652000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2746000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	81732000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	90390000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2746000	USD
CY2019Q2	cbsh	Financing Receivable Average Recorded Investment Nonaccrual Status FinancingReceivableAverageRecordedInvestmentNonaccrualStatus	11996000	USD
CY2019Q2	cbsh	Financing Receivable Modifications Average Recorded Investment FinancingReceivableModificationsAverageRecordedInvestment	53352000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	65348000	USD
	cbsh	Financing Receivable Average Recorded Investment Nonaccrual Status FinancingReceivableAverageRecordedInvestmentNonaccrualStatus	12157000	USD
	cbsh	Financing Receivable Modifications Average Recorded Investment FinancingReceivableModificationsAverageRecordedInvestment	61155000	USD
	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	73312000	USD
CY2019Q2	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	742000	USD
	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	1480000	USD
CY2020Q2	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	6900000	USD
CY2020Q2	cbsh	Unpaid Principal Balanceon Personal Real Estate Loans Heldfor Sale UnpaidPrincipalBalanceonPersonalRealEstateLoansHeldforSale	6500000	USD
CY2020Q2	cbsh	Student Loans Heldfor Sale Lowerof Costor Fair Value StudentLoansHeldforSaleLowerofCostorFairValue	5900000	USD
CY2020Q2	cbsh	Hfs Loansonnonaccrualstatus HFSLoansonnonaccrualstatus	0	USD
CY2020Q2	cbsh	Loans Held For Sale90 Days Past Dueand Still Accruing LoansHeldForSale90DaysPastDueandStillAccruing	0	USD
CY2020Q2	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	422000	USD
CY2019Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	365000	USD
CY2019Q4	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	5500000	USD
CY2020Q2	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	1400000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	10317427000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	8571626000	USD
CY2020Q2	us-gaap	Trading Securities TradingSecurities	28813000	USD
CY2019Q4	us-gaap	Trading Securities TradingSecurities	28161000	USD
CY2020Q2	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	2711000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	2929000	USD
CY2020Q2	cbsh	Equtiy Securitieswithout Readily Determinable Fair Values EqutiySecuritieswithoutReadilyDeterminableFairValues	1417000	USD
CY2019Q4	cbsh	Equtiy Securitieswithout Readily Determinable Fair Values EqutiySecuritieswithoutReadilyDeterminableFairValues	1280000	USD
CY2020Q2	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	33915000	USD
CY2019Q4	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	33770000	USD
CY2020Q2	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	10000000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	10000000	USD
CY2020Q2	cbsh	Private Equity Investments PrivateEquityInvestments	73846000	USD
CY2019Q4	cbsh	Private Equity Investments PrivateEquityInvestments	94122000	USD
CY2020Q2	cbsh	Total Investment Securities TotalInvestmentSecurities	10468129000	USD
CY2019Q4	cbsh	Total Investment Securities TotalInvestmentSecurities	8741888000	USD
CY2020Q2	us-gaap	Interest Receivable Current InterestReceivableCurrent	36400000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	9961155000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	10317427000	USD
	cbsh	Percentage Decrease In Fair Value Below Amortized Cost PercentageDecreaseInFairValueBelowAmortizedCost	0.20
CY2020Q2	cbsh	Fair Value Securities On Impairment Watch List FairValueSecuritiesOnImpairmentWatchList	52100000	USD
CY2019Q4	cbsh	Fair Value Securities On Impairment Watch List FairValueSecuritiesOnImpairmentWatchList	51600000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	318063000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	4678000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	236270000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	8383000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	554333000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	13061000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	1136297000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	9413000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	517817000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	3451000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	1654114000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	12864000	USD
CY2020Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	554300000	USD
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	1700000000	USD
CY2020Q2	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	13100000	USD
	cbsh	Af Ssecuritiesinlosspositionatperiodendchangeinunrealizedloss AFSsecuritiesinlosspositionatperiodendchangeinunrealizedloss	197000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	9961155000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-17430000	USD
CY2020Q2	cbsh	Available For Sale Securities Gross Unreailzed Gainat Period End AvailableForSaleSecuritiesGrossUnreailzedGainatPeriodEnd	369333000	USD
CY2020Q2	cbsh	Available For Sale Securities Gross Unrealized Lossat Period End AvailableForSaleSecuritiesGrossUnrealizedLossatPeriodEnd	13061000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	10317427000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	8435531000	USD
CY2019Q4	cbsh	Available For Sale Securities Gross Unreailzed Gainat Period End AvailableForSaleSecuritiesGrossUnreailzedGainatPeriodEnd	148959000	USD
CY2019Q4	cbsh	Available For Sale Securities Gross Unrealized Lossat Period End AvailableForSaleSecuritiesGrossUnrealizedLossatPeriodEnd	12864000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	8571626000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	174595000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	368219000	USD
	cbsh	Proceedsfromsaleofequitysecurities Proceedsfromsaleofequitysecurities	2000	USD
	cbsh	Proceedsfromsaleofequitysecurities Proceedsfromsaleofequitysecurities	0	USD
	cbsh	Proceeds From Sale Of Other Securities ProceedsFromSaleOfOtherSecurities	0	USD
	cbsh	Proceeds From Sale Of Other Securities ProceedsFromSaleOfOtherSecurities	7243000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	174597000	USD
	cbsh	Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities Proceedsfromsalesandmaturitiesofavailableforsaledebtequityandothersecurities	375462000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1035000	USD
CY2020Q2	cbsh	Investment Securities Pledged At Fair Value InvestmentSecuritiesPledgedAtFairValue	4600000000	USD
CY2020Q2	us-gaap	Financial Instruments Owned And Pledged As Collateral Amount Eligible To Be Repledged By Counterparty FinancialInstrumentsOwnedAndPledgedAsCollateralAmountEligibleToBeRepledgedByCounterparty	205600000	USD
CY2020Q2	cbsh	Investments Exceeding Ten Percent Of Stockholders Equity InvestmentsExceedingTenPercentOfStockholdersEquity	0
CY2020Q2	cbsh	Percentage Of Stockholders Equity Of Which No Investment From Single Issuer Exceeds PercentageOfStockholdersEquityOfWhichNoInvestmentFromSingleIssuerExceeds	0.10
CY2020Q2	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	44418000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	35061000	USD
CY2020Q2	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	2178000	USD
CY2020Q2	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	7179000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	44212000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	34351000	USD
CY2019Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	327000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	9534000	USD
CY2020Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	442000	USD
CY2019Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	373000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	710000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	715000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	1614000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	1168000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	950000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	784000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	639000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	138921000	USD
CY2020Q2	us-gaap	Goodwill Goodwill	138921000	USD
CY2020Q2	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	6304000	USD
CY2019Q2	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	6034000	USD
	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	12662000	USD
	us-gaap	Sales Type And Direct Financing Leases Profit Loss SalesTypeAndDirectFinancingLeasesProfitLoss	11896000	USD
CY2020Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	2160000	USD
CY2019Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	1926000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	4221000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	3832000	USD
CY2020Q2	us-gaap	Lease Income LeaseIncome	8464000	USD
CY2019Q2	us-gaap	Lease Income LeaseIncome	7960000	USD
	us-gaap	Lease Income LeaseIncome	16883000	USD
	us-gaap	Lease Income LeaseIncome	15728000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	101000	USD
CY2019Q2	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	159000	USD
	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	202000	USD
	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	318000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	823000	USD
CY2019Q2	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	1065000	USD
	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	1645000	USD
	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	2130000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1297000	USD
CY2019Q2	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1197000	USD
	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	2594000	USD
	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	2393000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	-68000	USD
CY2019Q2	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	-67000	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	-135000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-542000	USD
CY2019Q2	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-585000	USD
	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-1084000	USD
	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-1171000	USD
CY2020Q2	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	101000	USD
CY2019Q2	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	545000	USD
	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	201000	USD
	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	1091000	USD
	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	0	USD
CY2020Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	311000	shares
CY2019Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	380000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	271000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	338000	shares
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
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-64669000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Before Tax OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax	229303000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	-2118000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	231421000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	57854000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	173567000	USD
	cbsh	Reclassification Where Impairment Was Not Previously Recognized ReclassificationWhereImpairmentWasNotPreviouslyRecognized	0	USD
CY2019Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	108898000	USD
	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	Operating_Segments
CY2020Q2	cbsh	Number Of Locations NumberOfLocations	160	Locations
CY2019Q2	us-gaap	Revenues Revenues	0	USD
	us-gaap	Revenues Revenues	0	USD
	us-gaap	Revenues Revenues	0	USD
CY2020Q2	us-gaap	Revenues Revenues	0	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 Income NoninterestIncome	117515000	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-4129000	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
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	211634000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	11806000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	127259000	USD
CY2019Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	-110000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	189779000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	137198000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	415122000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	24269000	USD
	us-gaap	Noninterest Income NoninterestIncome	248499000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1035000	USD
	us-gaap	Noninterest Expense NoninterestExpense	381204000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	257113000	USD
CY2020Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	4607919000	USD
CY2019Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	4525856000	USD
CY2020Q2	us-gaap	Derivative Assets DerivativeAssets	269010000	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	105674000	USD
CY2020Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	21373000	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	10219000	USD
CY2020Q2	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	269010000	USD
CY2020Q2	cbsh	Derivative Asset Amount Offset By Liabiilty DerivativeAssetAmountOffsetByLiabiilty	0	USD
CY2020Q2	us-gaap	Derivative Assets DerivativeAssets	269010000	USD
CY2020Q2	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	21373000	USD
CY2020Q2	cbsh	Derivative Liability Amount Offset By Asset DerivativeLiabilityAmountOffsetByAsset	0	USD
CY2020Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	21373000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	105674000	USD
CY2019Q4	cbsh	Derivative Asset Amount Offset By Liabiilty DerivativeAssetAmountOffsetByLiabiilty	0	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	105674000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	10219000	USD
CY2019Q4	cbsh	Derivative Liability Amount Offset By Asset DerivativeLiabilityAmountOffsetByAsset	0	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	10219000	USD
CY2020Q2	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3700000	USD
CY2019Q2	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3400000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	7500000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	6900000	USD
CY2019Q4	cbsh	Nonvested Share Awards Balances NonvestedShareAwardsBalances	1104211	shares
CY2019Q4	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Nonvested Share Awards Weighted Average Grant Date Unit Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsNonvestedShareAwardsWeightedAverageGrantDateUnitFairValue	47.57
	cbsh	Nonvested Share Awards Granted In Period NonvestedShareAwardsGrantedInPeriod	214938	shares
	cbsh	Share Based Compensation Granted Nonvested Share Award Weighted Average Grant Date Fair Value ShareBasedCompensationGrantedNonvestedShareAwardWeightedAverageGrantDateFairValue	64.31
	cbsh	Nonvested Share Awards Vested In Period NonvestedShareAwardsVestedInPeriod	267472	shares
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Nonvested Share Awards Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsNonvestedShareAwardsVestedInPeriodWeightedAverageGrantDateFairValue	33.83
	cbsh	Nonvested Share Awards Forfeited In Period NonvestedShareAwardsForfeitedInPeriod	4886	shares
	cbsh	Share Based Compensation Forfeited Nonvested Share Award Weighted Average Grant Date Fair Value ShareBasedCompensationForfeitedNonvestedShareAwardWeightedAverageGrantDateFairValue	54.77
CY2020Q2	cbsh	Nonvested Share Awards Balances NonvestedShareAwardsBalances	1046791	shares
CY2020Q2	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Nonvested Share Awards Weighted Average Grant Date Unit Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsNonvestedShareAwardsWeightedAverageGrantDateUnitFairValue	54.49
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	10.12
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.017
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.202
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.010
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P5Y9M18D
CY2019Q4	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumber	1049816	shares
CY2019Q4	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageExercisePrice	43.55
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	103210	shares
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageExercisePrice	63.18
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	2780	shares
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodWeightedAverageExercisePrice	58.36
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expired In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpiredInPeriod	131	shares
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expired In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpiredInPeriodWeightedAverageExercisePrice	56.64
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Exercised In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedInPeriod	145549	shares
	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Exercised In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisedInPeriodWeightedAverageExercisePrice	34.49
CY2020Q2	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumber	1004566	shares
CY2020Q2	cbsh	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageExercisePrice	46.84
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Weighted Average Remaining Contractual Terms ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms	P6Y8M12D
CY2020Q2	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Equity Instruments Other Than Options Aggregate Intrinsic Value Outstanding SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding	13116000	USD
	cbsh	Percentof Revenuenotinscopeof Asc606 PercentofRevenuenotinscopeofASC606	0.63	Rate
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	117515000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	127259000	USD
	us-gaap	Noninterest Income NoninterestIncome	241178000	USD
	us-gaap	Noninterest Income NoninterestIncome	248499000	USD
CY2020Q2	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	6854000	USD
CY2020Q2	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	826494000	USD
CY2020Q2	cbsh	Us Government Sponsored Enterprises Debt Securities USGovernmentSponsoredEnterprisesDebtSecurities	109883000	USD
CY2020Q2	us-gaap	Financial Instruments Owned State And Municipal Government Obligations At Fair Value FinancialInstrumentsOwnedStateAndMunicipalGovernmentObligationsAtFairValue	1448952000	USD
CY2020Q2	cbsh	Financial Instruments Owned Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedAgencyMortgageBackedSecuritiesAtFairValue	5382187000	USD
CY2020Q2	cbsh	Financial Instruments Owned Non Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedNonAgencyMortgageBackedSecuritiesAtFairValue	600196000	USD
CY2020Q2	cbsh	Other Asset Backed Securities Disclosure OtherAssetBackedSecuritiesDisclosure	1448225000	USD
CY2020Q2	cbsh	Financial Instruments Owned Other Debt Securities At Fair Value FinancialInstrumentsOwnedOtherDebtSecuritiesAtFairValue	501490000	USD
CY2020Q2	us-gaap	Trading Securities TradingSecurities	28813000	USD
CY2020Q2	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	2711000	USD
CY2020Q2	us-gaap	Financial Instruments Owned Principal Investments At Fair Value FinancialInstrumentsOwnedPrincipalInvestmentsAtFairValue	73846000	USD
CY2020Q2	us-gaap	Derivative Assets DerivativeAssets	269010000	USD
CY2020Q2	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	16310000	USD
CY2020Q2	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	10714971000	USD
CY2020Q2	us-gaap	Derivative Liabilities DerivativeLiabilities	21373000	USD
CY2020Q2	us-gaap	Deferred Compensation Liability Current And Noncurrent DeferredCompensationLiabilityCurrentAndNoncurrent	16310000	USD
CY2020Q2	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	37683000	USD
CY2019Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	9181000	USD
CY2019Q4	us-gaap	Financial Instruments Owned Us Government And Agency Obligations At Fair Value FinancialInstrumentsOwnedUSGovernmentAndAgencyObligationsAtFairValue	851776000	USD
CY2019Q4	cbsh	Us Government Sponsored Enterprises Debt Securities USGovernmentSponsoredEnterprisesDebtSecurities	139277000	USD
CY2019Q4	us-gaap	Financial Instruments Owned State And Municipal Government Obligations At Fair Value FinancialInstrumentsOwnedStateAndMunicipalGovernmentObligationsAtFairValue	1267927000	USD
CY2019Q4	cbsh	Financial Instruments Owned Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedAgencyMortgageBackedSecuritiesAtFairValue	3937964000	USD
CY2019Q4	cbsh	Financial Instruments Owned Non Agency Mortgage Backed Securities At Fair Value FinancialInstrumentsOwnedNonAgencyMortgageBackedSecuritiesAtFairValue	809782000	USD
CY2019Q4	cbsh	Other Asset Backed Securities Disclosure OtherAssetBackedSecuritiesDisclosure	1233489000	USD
CY2019Q4	cbsh	Financial Instruments Owned Other Debt Securities At Fair Value FinancialInstrumentsOwnedOtherDebtSecuritiesAtFairValue	331411000	USD
CY2019Q4	us-gaap	Trading Securities TradingSecurities	28161000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	2929000	USD
CY2019Q4	us-gaap	Financial Instruments Owned Principal Investments At Fair Value FinancialInstrumentsOwnedPrincipalInvestmentsAtFairValue	94122000	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	105674000	USD
CY2019Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	16518000	USD
CY2019Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	8828211000	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	10219000	USD
CY2019Q4	us-gaap	Deferred Compensation Liability Current And Noncurrent DeferredCompensationLiabilityCurrentAndNoncurrent	16518000	USD
CY2019Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	26737000	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	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
CY2019Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	101211000	USD
CY2019Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	1051000	USD
CY2019Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	-5000	USD
CY2019Q2	cbsh	Investment Securities Called InvestmentSecuritiesCalled	-2920000	USD
CY2019Q2	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion	37000	USD
CY2019Q2	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	7829000	USD
CY2019Q2	cbsh	Sales And Repayments Of Private Equity Securities SalesAndRepaymentsOfPrivateEquitySecurities	6150000	USD
CY2019Q2	cbsh	Capitalized Interest Or Dividends CapitalizedInterestOrDividends	31000	USD
CY2019Q2	cbsh	Purchase Of Risk Participation Agreement PurchaseOfRiskParticipationAgreement	26000	USD
CY2019Q2	cbsh	Sale Of Risk Participation Agreement SaleOfRiskParticipationAgreement	73000	USD
CY2019Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	98935000	USD
CY2019Q2	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-214000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	100307000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	2578000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	359000	USD
	cbsh	Investment Securities Called InvestmentSecuritiesCalled	-2920000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Discount Accretion FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDiscountAccretion	44000	USD
	cbsh	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchase Of Private Equity Securities FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchaseOfPrivateEquitySecurities	9889000	USD
	cbsh	Sales And Repayments Of Private Equity Securities SalesAndRepaymentsOfPrivateEquitySecurities	6150000	USD
	cbsh	Capitalized Interest Or Dividends CapitalizedInterestOrDividends	31000	USD
	cbsh	Purchase Of Risk Participation Agreement PurchaseOfRiskParticipationAgreement	26000	USD
	cbsh	Sale Of Risk Participation Agreement SaleOfRiskParticipationAgreement	73000	USD
CY2019Q2	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	98935000	USD
	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-3478000	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
CY2019Q2	cbsh	Total Gains Or Losses Included In Earnings Level3 Fair Measurements TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements	-1051000	USD
CY2019Q2	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-214000	USD
	cbsh	Total Gains Or Losses Included In Earnings Level3 Fair Measurements TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements	-2578000	USD
	cbsh	Change In Unrealized Gains Or Losses Related To Assets Held Level3 Fair Value Measurements ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements	-3478000	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
CY2019Q2	cbsh	Loans Nonrecurring Basis LoansNonrecurringBasis	135000	USD
	cbsh	Loans Nonrecurring Basis Gains Losses LoansNonrecurringBasisGainsLosses	-58000	USD
CY2019Q2	cbsh	Mortgage Servicing Rights Nonrecurring Basis MortgageServicingRightsNonrecurringBasis	6730000	USD
	cbsh	Mortgage Servicing Rights Nonrecurring Basis Gains Losses MortgageServicingRightsNonrecurringBasisGainsLosses	-309000	USD
CY2019Q2	cbsh	Long Lived Assets Nonrecurring Basis LongLivedAssetsNonrecurringBasis	820000	USD
	cbsh	Long Lived Assets Nonrecurring Basis Gains Losses LongLivedAssetsNonrecurringBasisGainsLosses	-318000	USD
CY2020Q2	cbsh	Mortgage Servicing Rights Nonrecurring Basis MortgageServicingRightsNonrecurringBasis	5600000	USD
	cbsh	Fair Value Discounted Cash Flow Valuation Techniques FairValueDiscountedCashFlowValuationTechniques	Discounted cash flow

Files In Submission

Name	View Source	Status
0000022356-20-000046-index-headers.html	Edgar Link	pending
0000022356-20-000046-index.html	Edgar Link	pending
0000022356-20-000046.txt	Edgar Link	pending
0000022356-20-000046-xbrl.zip	Edgar Link	pending
cbsh-20200630.htm	Edgar Link	pending
cbsh-20200630.xsd	Edgar Link	pending
cbsh-20200630_cal.xml	Edgar Link	unprocessable
cbsh-20200630_def.xml	Edgar Link	unprocessable
cbsh-20200630_htm.xml	Edgar Link	completed
cbsh-20200630_lab.xml	Edgar Link	unprocessable
cbsh-20200630_pre.xml	Edgar Link	unprocessable
cbsh06302020ex311.htm	Edgar Link	pending
cbsh06302020ex312.htm	Edgar Link	pending
cbsh06302020ex32.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$CBSH
COMMERCE BANCSHARES INC /MO/ Stock $cbsh

2020 Q3 Form 10-Q Financial Statement

#000002235620000046 Filed on August 06, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CBSH COMMERCE BANCSHARES INC /MO/ Stock $cbsh

2020 Q3 Form 10-Q Financial Statement

#000002235620000046 Filed on August 06, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$CBSH
COMMERCE BANCSHARES INC /MO/ Stock $cbsh