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Threshold amount of outstanding loan balance for a specific reserve equal to the difference between book value of the loan and the fair value assigned to the collateral to be created until such time as the loan is foreclosed.

No definition available.

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Percentage of the impact of the difference in amortized cost basis versus consideration of loan balances on the allowance for credit losses.

No definition available.

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The maximum number of delinquent payments that a closed-end loan (excluding conventional 1-4 family residential loans and installment and revolving loans secured by real estate) may be delinquent before being charged-off. If a loan is considered uncollectable, it is charged off earlier.

No definition available.

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Refers to the past due period after which loans must be well secured and in the process of collection to continue accruing interest, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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Period for which principal and interest payments must remain current for reclassifying nonaccrual loans as accruing loans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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Threshold amount outstanding loan balance for individual evaluations of a loan under internal risk grading system.

No definition available.

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Threshold period past due for individual evaluation, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	ctbi_ThresholdPeriodPastDueForIndividualEvaluations
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Threshold period past due for the initiation of foreclosure proceedings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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No definition available.

Name:	us-gaap_AllowanceForCreditLossAbstract
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Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Threshold period for when financing receivable is considered past due to write off as uncollectible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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No definition available.

Name:	us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract
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No definition available.

Name:	us-gaap_LoansAndLeasesReceivableDisclosureAbstract
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No definition available.

Name:	us-gaap_MarketableSecuritiesAbstract
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
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Name:	srt_RangeAxis=srt_MinimumMember
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