Amount of accrued interest on financing receivable.

No definition available.

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

- Definition

Amount of allowance for credit loss expected loss during the period on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

+ References

No definition available.

+ Details

Name:	ctbi_FinancingReceivableAllowanceForCreditLossExpectedLoss
Namespace Prefix:	ctbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of loan contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

No definition available.

+ Details

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

- Definition

Refers to the past due period after which a loan is considered in default, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

Number of financing receivables collateralized by various chattel.

+ References

No definition available.

+ Details

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

- Definition

Number of financing receivables liquidation of collateral and after estimated selling costs.

+ References

No definition available.

+ Details

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

- Definition

Amount of unamortized premiums over or discounts from face amounts of acquired loans.

+ References

No definition available.

+ Details

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

- Definition

Amount of unearned fee income.

+ References

No definition available.

+ Details

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

- Definition

Number of portfolio segments through which the Company segregates and evaluates its loan portfolio.

+ References

No definition available.

+ Details

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

- Definition

Refers to the review period considered for loans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

+ Details

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

- Definition

Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableNonaccrualInterestIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of commitment to lend additional funds to debtor experiencing financial difficulty for which creditor has modified terms of financing receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481746/310-40-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 36
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-36

+ Details

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

- Definition

Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

+ Details

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

- Definition

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 35
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-35

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_CollateralAxis=ctbi_AccountsReceivableEquipmentAndInventoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loans (Details)	3 Months Ended		12 Months Ended
Loans (Details)	Mar. 31, 2026 USD ($) Segment Loan	Mar. 31, 2025 USD ($) Loan	Dec. 31, 2025 USD ($)
Loans [Abstract]
Unearned fees	$ 386,000		$ 359,000
Loans held for sale	73,000		211,000
Accrued interest receivable	$ 20,800,000		19,700,000
Number of portfolio segments (in Segment) \| Segment	9
Interest income	$ 4,300		66,200
Consumer mortgage loans secured by real estate properties for which formal foreclosure proceedings are in process	2,800,000		3,100,000
Commitment to extend additional credit on loans modified in TDRs	$ 5,000	$ 2,000
Loans to borrowers experiencing financial difficulty (in Loan) \| Loan	3	8
Minimum [Member]
Loans [Abstract]
Past due period for loan to be considered in default	90 days
Consumer [Member] \| Consumer Indirect [Member]
Loans [Abstract]
Unamortized premiums	$ 35,400,000		$ 34,500,000
Commercial [Member]
Loans [Abstract]
Expected loss	$ 700,000
Number of financing receivables liquidation of collateral (in Loan) \| Loan	3
Commercial [Member] \| Pass [Member] \| Minimum [Member]
Loans [Abstract]
Review period for loans	12 months
Commercial [Member] \| Pass [Member] \| Maximum [Member]
Loans [Abstract]
Review period for loans	18 months
Commercial [Member] \| Commercial Other [Member] \| Accounts Receivable, Equipment, and Inventory [Member]
Loans [Abstract]
Number of financing receivables collateralized (in Loan) \| Loan	6