Loans, Allowance for Credit Losses, and Asset Quality Information - Accrued Interest Receivable Written Off (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	$ 156	$ 132	$ 324
Commercial, financial, and agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	123	8	102
Real estate, commercial | Real estate – construction, land development & other land loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	0	12	16
Real estate, commercial | Real estate mortgage – commercial and other
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	16	100	139
Real estate, mortgage | Real estate mortgage – residential (1-4 family) first mortgages
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	8	10	45
Real estate, mortgage | Real estate mortgage – home equity loans / lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	9	2	20
Consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	$ 0	$ 0	$ 2