Name:	ctbi_CurrentValueAssessmentPeriodForPastDueLoansSecuredAgainstRealEstate
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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.

Name:	ctbi_FinancingReceivablesThresholdOutstandingLoanBalanceForSpecificReserveToBeCreated
Namespace Prefix:	ctbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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.

Name:	ctbi_LoansAndLeasesReceivableAllowanceForCreditLossesDifferenceInAmortizedCostBasisVersusConsiderationOfLoanBalancesPercentage
Namespace Prefix:	ctbi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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.

Name:	ctbi_NumberOfDelinquentMonthlyPaymentsBeforeLoanChargeOff
Namespace Prefix:	ctbi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The frequency of periodic reviews for appraisals on foreclosed properties and other real estate owned generally, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	ctbi_OtherRealEstateOwnedFrequencyOfPeriodicReviews
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The typical frequency of periodic reviews for appraisals on foreclosed properties and other real estate owned, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	ctbi_OtherRealEstateOwnedTypicalFrequencyOfPeriodReviews
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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.

Name:	ctbi_PastDuePeriodAfterWhichLoansMustBeWellSecuredAndInProcessOfCollectionToContinueAccruingInterest
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The required percentage exposure of capital included as factors in the allowance for credit losses (ACL) model.

No definition available.

Name:	ctbi_PercentageExposureOfCapitalIncludedAsFactorsInAllowanceForCreditLossesModel
Namespace Prefix:	ctbi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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.

Name:	ctbi_PeriodOfCurrentPrincipalAndInterestPaymentsForReclassifyingNonaccrualLoansAsAccruingLoans
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

No definition available.

Name:	ctbi_ThresholdOutstandingLoanBalanceForIndividualEvaluations
Namespace Prefix:	ctbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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.

Name:	ctbi_ThresholdPeriodPastDueForInitiationOfForeclosureProceedings
Namespace Prefix:	ctbi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

No definition available.

Name:	us-gaap_AllowanceForCreditLossAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919253-210447

Name:	us-gaap_FinancingReceivableThresholdPeriodPastDueWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

Amount of investment in debt security measured at amortized cost (held-to-maturity).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Name:	us-gaap_HeldToMaturitySecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.

Name:	us-gaap_LoansAndLeasesReceivableDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

No definition available.

Name:	us-gaap_MarketableSecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

No definition available.

Name:	us-gaap_OtherRealEstateAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
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Balance Type:
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Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=ctbi_NonaccrualStatusMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=ctbi_TroubledDebtRestructuringMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_CriticizedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ctbi_UnsecuredCommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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