Amount of accrued interest on financing receivable.

No definition available.

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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

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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

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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

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables collateralized by various chattel.

+ References

No definition available.

+ Details

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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

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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

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

- Definition

Amount of unearned fee income.

+ References

No definition available.

+ Details

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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 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: 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 4: 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

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

- 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

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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

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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

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

- Details

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- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
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Data Type:	na
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Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ctbi_ConsumerIndirectMember
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- Details

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Data Type:	na
Balance Type:
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Balance Type:
Period Type:

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- Details

Name:	us-gaap_CollateralAxis=ctbi_AccountsReceivableEquipmentAndInventoryMember
Namespace Prefix:
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Loans (Details)	3 Months Ended		6 Months Ended		12 Months Ended
Loans (Details)	Jun. 30, 2026 USD ($) Loan	Jun. 30, 2025 USD ($) Loan	Jun. 30, 2026 USD ($) Segment Loan	Jun. 30, 2025 USD ($) Loan	Dec. 31, 2025 USD ($)
Loans [Abstract]
Unearned fees	$ 419,000		$ 419,000		$ 359,000
Loans held for sale	0		0		200,000
Accrued interest receivable	21,300,000		$ 21,300,000		19,700,000
Number of portfolio segments (in Segment) \| Segment			9
Interest income	137,800		$ 142,200		66,200
Consumer mortgage loans secured by real estate properties for which formal foreclosure proceedings are in process	3,500,000		3,500,000		3,100,000
Commitment to extend additional credit on loans modified in TDRs	$ 3,000	$ 0	$ 3,000	$ 0
Loans to borrowers experiencing financial difficulty (in Loan) \| Loan	7	2	9	5
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	$ 36,900,000		$ 36,900,000		$ 34,500,000
Consumer [Member] \| Commercial Other [Member]
Loans [Abstract]
Loans to borrowers experiencing financial difficulty (in Loan) \| Loan			2
Commercial [Member]
Loans [Abstract]
Expected loss			$ 500,000
Number of financing receivables liquidation of collateral (in Loan) \| Loan			2
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]
Loans [Abstract]
Loans to borrowers experiencing financial difficulty (in Loan) \| Loan	2	1
Commercial [Member] \| Commercial Other [Member] \| Accounts Receivable, Equipment, and Inventory [Member]
Loans [Abstract]
Number of financing receivables collateralized (in Loan) \| Loan			4