Loans and Leases - Allowance for Credit Losses, Loans and Leases, Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 79,004	$ 71,924
Provision (reversal of provision) for credit losses	3,872	(3,562)
Charge-offs	(3,230)	(348)
Recoveries	388	272
Ending balance	80,034	68,286
Commercial Financial And Agricultural [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	16,920	13,538
Provision (reversal of provision) for credit losses	547	(1,672)
Charge-offs	(2,848)	(214)
Recoveries	106	189
Ending balance	14,725	11,841
Real-Estate Commercial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	41,673	41,095
Provision (reversal of provision) for credit losses	1,524	(669)
Charge-offs	(50)	0
Recoveries	3	0
Ending balance	43,150	40,426
Real-Estate Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,952	4,575
Provision (reversal of provision) for credit losses	(64)	(941)
Charge-offs	(207)	0
Recoveries	0	0
Ending balance	4,681	3,634
Real Estate Residential Secured For Business Purpose [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	7,054	6,482
Provision (reversal of provision) for credit losses	1,125	(328)
Charge-offs	0	0
Recoveries	181	48
Ending balance	8,360	6,202
Real Estate Residential Secured For Personal Purpose [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,685	2,403
Provision (reversal of provision) for credit losses	1,327	189
Charge-offs	0	0
Recoveries	0	0
Ending balance	5,012	2,592
Real Estate Home Equity Secured For Personal Purpose [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,287	1,028
Provision (reversal of provision) for credit losses	(66)	(53)
Charge-offs	0	0
Recoveries	50	1
Ending balance	1,271	976
Loans to Individuals [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	351	363
Provision (reversal of provision) for credit losses	113	57
Charge-offs	(105)	(75)
Recoveries	16	24
Ending balance	375	369
Lease Financings [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,082	2,290
Provision (reversal of provision) for credit losses	(634)	5
Charge-offs	(20)	(59)
Recoveries	32	10
Ending balance	2,460	2,246
Unallocated [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0	150
Provision (reversal of provision) for credit losses	0	(150)
Ending balance	$ 0	$ 0