Loans, Reserve Estimates in ACL (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	$ 48,719	$ 48,018	$ 45,981	$ 44,433	$ 42,344	$ 41,756
CTBI Internal ACL Model		47,907
Change in Allocation		111
Commercial [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software		24,071
CTBI Internal ACL Model		25,767
Change in Allocation		(1,696)
Commercial [Member] | Hotel/Motel [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	5,803	5,192	5,171	4,883	4,844	5,080
CTBI Internal ACL Model		6,038
Change in Allocation		(846)
Commercial [Member] | Commercial Real Estate Residential [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	3,824	3,749	4,894	4,876	4,200	3,986
CTBI Internal ACL Model		4,669
Change in Allocation		(920)
Commercial [Member] | Commercial Real Estate Nonresidential [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	8,017	7,797	9,419	9,595	8,968	8,884
CTBI Internal ACL Model		8,794
Change in Allocation		(997)
Commercial [Member] | Dealer Floorplans [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	843	1,157	1,776	1,538	1,477	1,436
CTBI Internal ACL Model		1,719
Change in Allocation		(562)
Commercial [Member] | Commercial Other [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	5,545	6,176	5,285	5,197	4,473	4,422
CTBI Internal ACL Model		4,547
Change in Allocation		1,629
Residential [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software		8,992
CTBI Internal ACL Model		9,508
Change in Allocation		(516)
Residential [Member] | Real Estate Mortgage [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	8,336	7,884	7,932	7,835	8,179	7,637
CTBI Internal ACL Model		8,443
Change in Allocation		(559)
Residential [Member] | Home Equity Lines [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	1,158	1,108	1,106	940	887	866
CTBI Internal ACL Model		1,065
Change in Allocation		43
Consumer [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software		14,955
CTBI Internal ACL Model		12,632
Change in Allocation		2,323
Consumer [Member] | Consumer Direct [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	2,613	2,563	1,694	1,674	1,621	1,951
CTBI Internal ACL Model		1,673
Change in Allocation		890
Consumer [Member] | Consumer Indirect [Member]
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	$ 12,580	12,392	$ 8,704	$ 7,895	$ 7,695	$ 7,494
CTBI Internal ACL Model		10,959
Change in Allocation		$ 1,433