Loans, Allowance for Credit Losses, and Asset Quality Information - Accrued Interest Receivable Written Off (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	$ 293
Commercial, financial, and agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	64
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
Real estate, commercial | Real estate – mortgage – commercial and other
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	220
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	5
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	4
Consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable written off	$ 0