Loans, Reserve Estimates in ACL (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Loans and Lease Financing Allowance for Credit Loss [Abstract]
ACL Software	$ 48,018	$ 46,683	$ 45,981	$ 42,344	$ 42,309	$ 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	5,192	5,287	5,171	4,844	4,711	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	3,749	5,157	4,894	4,200	4,070	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	7,797	9,010	9,419	8,968	9,169	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	1,157	1,694	1,776	1,477	1,519	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	6,176	4,782	5,285	4,473	4,844	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	7,884	7,917	7,932	8,179	7,662	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	1,108	1,044	1,106	887	819	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	2,563	1,746	1,694	1,621	1,787	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	12,392	$ 10,046	$ 8,704	$ 7,695	$ 7,728	$ 7,494
CTBI Internal ACL Model	10,959
Change in Allocation	$ 1,433