XML 69 R65.htm IDEA: XBRL DOCUMENT v2.4.1.9

Loans - Unallocated Portion of Allowance for Loan Losses (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	$ 105,708us-gaap_LoansAndLeasesReceivableAllowance	$ 99,542us-gaap_LoansAndLeasesReceivableAllowance	$ 95,156us-gaap_LoansAndLeasesReceivableAllowance	$ 92,438us-gaap_LoansAndLeasesReceivableAllowance
Historical Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	63,905us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember	59,604us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember
Specific Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	1,475us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember	1,680us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember
Environmental Risk Adjustment [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	14,347us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember	13,477us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember
Distressed Industries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,996us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember	3,093us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember
Excessive Industry Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	6,433us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_ExcessiveIndustryConcentrationsMember	2,492us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_ExcessiveIndustryConcentrationsMember
Large Relationship Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	4,545us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LargeRelationshipConcentrationsMember	3,807us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LargeRelationshipConcentrationsMember
Highly-Leveraged Credit Relationships [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	7,102us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HighlyLeveragedCreditRelationshipsMember	5,305us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HighlyLeveragedCreditRelationshipsMember
Policy Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	3,002us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_PolicyExceptionsMember	2,782us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_PolicyExceptionsMember
Credit and Collateral Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	3,076us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_CreditAndCollateralExceptionsMember	2,164us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_CreditAndCollateralExceptionsMember
Loans Not Reviewed by Concurrence [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	7,846us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LoansNotReviewedByConcurrenceMember	7,906us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LoansNotReviewedByConcurrenceMember
Adjustment for Recoveries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	(13,684)us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_AdjustmentForRecoveriesMember	(15,837)us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_AdjustmentForRecoveriesMember
General Macroeconomic Risk [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	4,665us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_GeneralMacroeconomicRiskMember	13,069us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_GeneralMacroeconomicRiskMember
Commercial and Industrial [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	64,713us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	59,192us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	57,054us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	52,790us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Historical Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	35,339us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	32,421us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Specific Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	1,404us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	1,613us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Environmental Risk Adjustment [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	7,263us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	6,773us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Distressed Industries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,762us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	3,090us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Excessive Industry Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	5,903us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_ExcessiveIndustryConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	2,114us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_ExcessiveIndustryConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Large Relationship Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,690us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LargeRelationshipConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	2,248us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LargeRelationshipConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Highly-Leveraged Credit Relationships [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	5,395us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HighlyLeveragedCreditRelationshipsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	3,958us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HighlyLeveragedCreditRelationshipsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Policy Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,116us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_PolicyExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	1,907us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_PolicyExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Credit and Collateral Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,168us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_CreditAndCollateralExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	1,483us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_CreditAndCollateralExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Loans Not Reviewed by Concurrence [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,043us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LoansNotReviewedByConcurrenceMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	2,110us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LoansNotReviewedByConcurrenceMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | Adjustment for Recoveries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	(5,199)us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_AdjustmentForRecoveriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	(6,234)us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_AdjustmentForRecoveriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial and Industrial [Member] | General Macroeconomic Risk [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,829us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_GeneralMacroeconomicRiskMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember	7,709us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_GeneralMacroeconomicRiskMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	27,105us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	27,163us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	21,020us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	22,590us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Historical Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	14,620us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	14,684us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Specific Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	71us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	67us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Environmental Risk Adjustment [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	3,546us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	3,547us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Distressed Industries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	234us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	3us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Excessive Industry Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	530us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_ExcessiveIndustryConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	378us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_ExcessiveIndustryConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Large Relationship Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	1,855us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LargeRelationshipConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	1,559us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LargeRelationshipConcentrationsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Highly-Leveraged Credit Relationships [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	1,707us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HighlyLeveragedCreditRelationshipsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	1,347us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HighlyLeveragedCreditRelationshipsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Policy Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	886us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_PolicyExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	875us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_PolicyExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Credit and Collateral Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	908us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_CreditAndCollateralExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	681us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_CreditAndCollateralExceptionsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Loans Not Reviewed by Concurrence [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,261us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LoansNotReviewedByConcurrenceMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	2,284us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_LoansNotReviewedByConcurrenceMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | Adjustment for Recoveries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	(698)us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_AdjustmentForRecoveriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	(1,800)us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_AdjustmentForRecoveriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate Portfolio Segment [Member] | General Macroeconomic Risk [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	1,185us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_GeneralMacroeconomicRiskMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	3,538us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_GeneralMacroeconomicRiskMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Consumer Real Estate [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	4,907us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	5,178us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	4,533us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	5,230us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Consumer Real Estate [Member] | Historical Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	2,046us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	2,017us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_HistoricalValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Consumer Real Estate [Member] | Specific Valuation Allowances [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	0us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	0us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_SpecificValuationAllowancesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Consumer Real Estate [Member] | Environmental Risk Adjustment [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	478us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	474us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_EnvironmentalRiskAdjustmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Consumer Real Estate [Member] | Distressed Industries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
Portion of allowance for loan losses	0us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	0us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_FinancialInstrumentAxis = cfr_DistressedIndustriesMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Consumer Real Estate [Member] | Excessive Industry Concentrations [Member]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer Real Estate [Member] | Policy Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer Real Estate [Member] | Credit and Collateral Exceptions [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer Real Estate [Member] | Loans Not Reviewed by Concurrence [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer Real Estate [Member] | Adjustment for Recoveries [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer Real Estate [Member] | General Macroeconomic Risk [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer and Other [Member] | Large Relationship Concentrations [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Consumer and Other [Member] | Highly-Leveraged Credit Relationships [Member]
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]
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X

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

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-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Paragraph 2

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

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