XML 36 R76.htm IDEA: XBRL DOCUMENT v2.4.1.9
Investment Securities - Additional Information (Detail) (USD $)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Investment Securities [Line Items]      
Investment securities sold $ 0us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities $ 0us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities  
Investment securities carrying value 153,121,000us-gaap_AssetBackedSecuritiesAtCarryingValue   143,992,000us-gaap_AssetBackedSecuritiesAtCarryingValue
Mortgage-backed securities $ 993,365,000us-gaap_USGovernmentAgenciesSecuritiesAtCarryingValue    
Life of mortgage-backed securities 5 years 2 months 12 days    
Obligations of U.S. government corporations and agencies [Member]      
Investment Securities [Line Items]      
Debt securities 14us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
   
Percentage of aggregate depreciation in unrealized losses (0.21%)tcbk_PercentageOfAggregateDepreciationInUnrealizedLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
   
Obligations of states and political subdivisions [Member]      
Investment Securities [Line Items]      
Debt securities 13us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
   
Percentage of aggregate depreciation in unrealized losses (2.48%)tcbk_PercentageOfAggregateDepreciationInUnrealizedLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
   
Corporate debt securities [Member]      
Investment Securities [Line Items]      
Debt securities 0us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
   
Marketable equity securities [Member]      
Investment Securities [Line Items]      
Debt securities 0us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= tcbk_MarketableEquitySecuritiesMember