Name:	ctbi_CommitmentToExtendCreditWithFixedInterestRate
Namespace Prefix:	ctbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

This line item represents the term of fixed rate loan commitments agreed by the entity for the period, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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

This line item represents the percentage of interest rate on loan commitments agreed by the entity for the period.

No definition available.

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

This line item represents the percentage of secured standby letters of credit out of total standby letters of credit.

No definition available.

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

This line item represents the period of commitment to sell the loans at specified prices by the entity, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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

The amount of off-balance sheet standby letters of credit that is secured by cash of the borrower.

No definition available.

Name:	ctbi_StandbyLettersOfCreditSecuredByCash
Namespace Prefix:	ctbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The face amount of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

No definition available.

Name:	us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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

The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65670824&loc=d3e14764-158437

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (cc)
-URI http://asc.fasb.org/extlink&oid=65670824&loc=d3e14764-158437

Name:	us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of undisbursed portion of the loan receivable balance (loans in process). Excludes loans and leases covered under loss sharing agreements.

No definition available.

Name:	us-gaap_LoansAndLeasesReceivableLoansInProcess
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

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

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: