Loans, Reserve Estimates in ACL (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	$ 49,543		$ 45,981	$ 41,756
Change in Allocation		$ 111
ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		48,018
CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		47,907
Commercial [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Change in Allocation		(1,696)
Commercial [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		24,071
Commercial [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		25,767
Commercial [Member] | Hotel/Motel [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	4,592		5,171	5,080
Change in Allocation		(846)
Commercial [Member] | Hotel/Motel [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		5,192
Commercial [Member] | Hotel/Motel [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		6,038
Commercial [Member] | Commercial Real Estate Residential [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	4,285		4,894	3,986
Change in Allocation		(920)
Commercial [Member] | Commercial Real Estate Residential [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		3,749
Commercial [Member] | Commercial Real Estate Residential [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		4,669
Commercial [Member] | Commercial Real Estate Nonresidential [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	7,560		9,419	8,884
Change in Allocation		(997)
Commercial [Member] | Commercial Real Estate Nonresidential [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		7,797
Commercial [Member] | Commercial Real Estate Nonresidential [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		8,794
Commercial [Member] | Dealer Floorplans [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	659		1,776	1,436
Change in Allocation		(562)
Commercial [Member] | Dealer Floorplans [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		1,157
Commercial [Member] | Dealer Floorplans [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		1,719
Commercial [Member] | Commercial Other [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	3,760		5,285	4,422
Change in Allocation		1,629
Commercial [Member] | Commercial Other [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		6,176
Commercial [Member] | Commercial Other [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		4,547
Residential [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Change in Allocation		(516)
Residential [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		8,992
Residential [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		9,508
Residential [Member] | Real Estate Mortgage [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	10,197		7,932	7,637
Change in Allocation		(559)
Residential [Member] | Real Estate Mortgage [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		7,884
Residential [Member] | Real Estate Mortgage [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		8,443
Residential [Member] | Home Equity Lines [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	1,367		1,106	866
Change in Allocation		43
Residential [Member] | Home Equity Lines [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		1,108
Residential [Member] | Home Equity Lines [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		1,065
Consumer [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Change in Allocation		2,323
Consumer [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		14,955
Consumer [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		12,632
Consumer [Member] | Consumer Direct [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	3,261		1,694	1,951
Change in Allocation		890
Consumer [Member] | Consumer Direct [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		2,563
Consumer [Member] | Consumer Direct [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		1,673
Consumer [Member] | Consumer Indirect [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss	$ 13,862		$ 8,704	$ 7,494
Change in Allocation		1,433
Consumer [Member] | Consumer Indirect [Member] | ACL Software [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		12,392
Consumer [Member] | Consumer Indirect [Member] | CTBI Internal ACL Model [Member]
Shift in Reserve Estimates Due to Change in Modeling [Abstract]
Loans and lease financing allowance for credit loss		$ 10,959