XML 57 R48.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Loans And Allowance For Credit Losses (Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding by FICO Score ) (Details) - USD ($) $ in Millions | Sep. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Loans And Allowance For Loan Losses [Line Items] |  |
Credit Quality Personal Real Estate Loans Excluded | $ 186.8 | $ 185.6
Consumer Healthcare Loans Excluded | $ 197.7 | $ 186.6
Credit quality personal banking loan table percentage loans excluded | 7.00% |
Real estate - personal |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 100.00% | 100.00%
Real estate - personal | Under 600 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 1.30% | 1.00%
Real estate - personal | 600 - 659 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 2.50% | 2.40%
Real estate - personal | 660 - 719 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 8.10% | 7.40%
Real estate - personal | 720 - 779 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 23.50% | 25.20%
Real estate - personal | 780 and over |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 64.60% | 64.00%
Consumer |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 100.00% | 100.00%
Consumer | Under 600 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 1.80% | 1.90%
Consumer | 600 - 659 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 3.90% | 3.90%
Consumer | 660 - 719 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 13.20% | 13.80%
Consumer | 720 - 779 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 23.80% | 25.30%
Consumer | 780 and over |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 57.30% | 55.10%
Revolving Home Equity [Member] |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 100.00% | 100.00%
Revolving Home Equity [Member] | Under 600 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 1.50% | 0.90%
Revolving Home Equity [Member] | 600 - 659 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 3.40% | 2.60%
Revolving Home Equity [Member] | 660 - 719 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 9.10% | 9.40%
Revolving Home Equity [Member] | 720 - 779 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 22.40% | 20.40%
Revolving Home Equity [Member] | 780 and over |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 63.60% | 66.70%
Consumer credit card |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 100.00% | 100.00%
Consumer credit card | Under 600 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 3.60% | 3.40%
Consumer credit card | 600 - 659 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 11.80% | 11.30%
Consumer credit card | 660 - 719 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 30.20% | 29.90%
Consumer credit card | 720 - 779 |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 27.90% | 28.20%
Consumer credit card | 780 and over |  |
Loans And Allowance For Loan Losses [Line Items] |  |
Percentage of Loan Category | 26.50% | 27.20%

X
- Definition Recorded investment of consumer loans related to the Company's patient healthcare loan program. As the healthcare loans are guaranteed by the hospital, FICO scores are not obtained. These loans are excluded from the Credit Quality of Personal Banking Loans Portfolio Table. + References No definition available. + Details
Name: | cbsh_ConsumerHealthcareLoansExcluded
Namespace Prefix: | cbsh_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Consumer and personal real estate loans, as a percentage of the personal banking portfolio, for which FICO scores are not obtained. These loans are excluded from the Schedule of Credit Quality Personal Banking Loan Table. + References No definition available. + Details
Name: | cbsh_CreditQualityPersonalBankingLoanTablePercentageLoansExcluded
Namespace Prefix: | cbsh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Recorded investment of personal real estate loans for which FICO scores are not obtained. These loans are excluded from the Credit Quality of Personal Banking Loans Portfolio Table. + References No definition available. + Details
Name: | cbsh_CreditQualityPersonalRealEstateLoansExcluded
Namespace Prefix: | cbsh_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans And Allowance For Loan Losses [Line Items] + References No definition available. + Details
Name: | cbsh_LoansAndAllowanceForLoanLossesLineItems
Namespace Prefix: | cbsh_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Recorded investment of loans in designated class currently in specified FICO range. + References No definition available. + Details
Name: | cbsh_RecordedInvestmentFicoRange
Namespace Prefix: | cbsh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cbsh_PersonalRealEstateLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cbsh_FicoUnderSixHundredMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cbsh_FicoSixHundredToSixHundredFiftyNineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cbsh_FicoSixHundredSixtyToSevenHundredNineteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cbsh_FicoSevenHundredTwentyToSevenHundredSeventyNineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cbsh_FicoSevenHundredEightyAndOverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CreditCardReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |