XML 111 R125.htm IDEA: XBRL DOCUMENT v2.4.1.9
Derivative Instruments (Schedule Of Notional Amounts Of Derivative Instruments) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Derivative [Line Items]    
Notional Amount of Derivatives $ 797,030invest_DerivativeNotionalAmount $ 740,332invest_DerivativeNotionalAmount
Interest Rate Swaps [Member]    
Derivative [Line Items]    
Notional Amount of Derivatives 647,709invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateSwapMember		 596,933invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateSwapMember
Interest Rate Caps [Member]    
Derivative [Line Items]    
Notional Amount of Derivatives 53,587invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateCapMember		 9,736invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateCapMember
Credit Risk Participation Agreements [Member]    
Derivative [Line Items]    
Notional Amount of Derivatives 75,943invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= cbsh_CreditRiskParticipationAgreementsMember		 52,456invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= cbsh_CreditRiskParticipationAgreementsMember
Foreign Exchange Contracts [Member]    
Derivative [Line Items]    
Notional Amount of Derivatives $ 19,791invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember		 $ 81,207invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember