Fair Market Value of Financial Assets and Liabilities, Fair Value Measurements of Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	$ 1,455,429	$ 997,261
Equity securities at fair value	2,253	2,471
Liabilities measured - recurring basis [Abstract]
Liabilities	0	0
U.S. Treasury and Government Agencies [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	295,770	148,793
State and Political Subdivisions [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	334,203	140,416
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	730,809	651,807
Asset-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	94,647	56,245
Recurring [Member]
Assets measured - recurring basis [Abstract]
Equity securities at fair value	2,253	2,471
Mortgage servicing rights	6,774	4,068
Recurring [Member] \| U.S. Treasury and Government Agencies [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	295,770	148,793
Recurring [Member] \| State and Political Subdivisions [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	334,203	140,416
Recurring [Member] \| U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	730,809	651,807
Recurring [Member] \| Asset-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	94,647	56,245
Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets measured - recurring basis [Abstract]
Equity securities at fair value	0	0
Mortgage servicing rights	0	0
Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| U.S. Treasury and Government Agencies [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	242,214	74,991
Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| State and Political Subdivisions [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	0	0
Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	0	0
Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Asset-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	0	0
Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets measured - recurring basis [Abstract]
Equity securities at fair value	0	0
Mortgage servicing rights	0	0
Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| U.S. Treasury and Government Agencies [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	53,556	73,802
Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| State and Political Subdivisions [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	334,203	140,416
Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	730,809	651,807
Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Asset-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	94,647	56,245
Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Assets measured - recurring basis [Abstract]
Equity securities at fair value	2,253	2,471
Mortgage servicing rights	6,774	4,068
Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| U.S. Treasury and Government Agencies [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	0	0
Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| State and Political Subdivisions [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	0	0
Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	0	0
Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Asset-backed Securities [Member]
Assets measured - recurring basis [Abstract]
Debt securities available-for-sale	$ 0	$ 0

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents mortgage servicing right at fair value.

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: 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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 3: 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=124260329&loc=d3e26610-111562

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

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

- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

+ Details

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

- Definition

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: