Loans, Troubled Debt Restructurings Segregated by Class Subsequently Defaulted (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2024 USD ($) Loan	Dec. 31, 2023 USD ($) Loan
Troubled Debt Restructurings Segregated by Class [Abstract]
Defaulted restructured loans, number of loans \| Loan	9	0
Defaulted restructured loans, recorded balance	$ 1,031
Off-balance sheet credit exposure	$ 1,500	$ 1,500
Minimum [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Past due period for loan to be considered in default	90 days
Commercial [Member] \| Commercial Other [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Defaulted restructured loans, number of loans \| Loan	4
Defaulted restructured loans, recorded balance	$ 422
Commercial [Member] \| Commercial Real Estate Residential [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Defaulted restructured loans, number of loans \| Loan	2
Defaulted restructured loans, recorded balance	$ 412
Commercial [Member] \| Real Estate Mortgage [Member]
Troubled Debt Restructurings Segregated by Class [Abstract]
Defaulted restructured loans, number of loans \| Loan	3
Defaulted restructured loans, recorded balance	$ 197

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

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amortized cost of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481933/310-10-55-12A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 44
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-44

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-34

+ Details

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

- Definition

Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482454/460-10-45-1

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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

- Details

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Namespace Prefix:
Data Type:	na
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