Loans and Asset Quality Information - Schedule of Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	$ 35,076	$ 24,866
Commercial, financial, and agricultural
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	9,681	5,518
Real estate, commercial | Real estate – construction, land development & other land loans
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	643	1,067
Real estate, commercial | Real estate – mortgage – commercial and other
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	17,191	8,820
Real estate, mortgage | Real estate – mortgage – residential (1-4 family) first mortgages
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	6,048	7,552
Real estate, mortgage | Real estate – mortgage – home equity loans / lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	1,333	1,797
Installment loans to individuals
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	$ 180	$ 112