XML 105 R94.htm IDEA: XBRL DOCUMENT
v3.25.2

Fair Value Measurements (Summary Of Gains And Losses On Level 3 Assets And Liabilities) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items] |  |  |  |
Change in unrealized gains or losses relating to assets still held at period end | $ 4,414 | $ 5,677 | $ (3,312) | $ 11,002
Investment Securities Gains (Losses), Net |  |  |  |
Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items] |  |  |  |
Total gains or losses included in earnings | 4,414 | 5,677 | (4,111) | 12,777
Change in unrealized gains or losses relating to assets still held at period end | $ 4,414 | $ 5,677 | $ (3,312) | $ 11,002

X
- Definition Change in unrealized gains or losses related to assets held, level 3 fair measurements + References No definition available. + Details
Name: | cbsh_ChangeInUnrealizedGainsOrLossesRelatedToAssetsHeldLevel3FairValueMeasurements
Namespace Prefix: | cbsh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total gains or losses included in earnings, level 3 fair measurements + References No definition available. + Details
Name: | cbsh_TotalGainsOrLossesIncludedInEarningsLevel3FairMeasurements
Namespace Prefix: | cbsh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 184 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-184 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (a)(5) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (a)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4F -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F + Details
Name: | us-gaap_TradingActivityGainsAndLossesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=cbsh_InvestmentSecuritiesGainsLossesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |