Loans and Asset Quality Information (Schedule of Recorded Investment in Loans by Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 4,394,984	$ 4,247,765	$ 4,190,139
Unamortized net deferred loan costs	1,560	1,299	489
Total loans	4,396,544	4,249,064	4,190,628
Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	486,768	457,037	435,730
Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	70,962	71,392	70,096
Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	486,526	456,806
Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	70,844	71,140
Real estate – construction, land development & other land loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	471,326	518,976	559,450
Real estate – construction, land development & other land loans | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	471,157	518,798
Real estate – mortgage – residential (1-4 family) first mortgages | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,093,619	1,054,176	1,038,436
Real estate – mortgage – residential (1-4 family) first mortgages | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,087,946	1,047,924
Real estate – mortgage – home equity loans / lines of credit | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	343,378	359,162	362,829
Real estate – mortgage – home equity loans / lines of credit | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	343,169	358,818
Real estate – mortgage – commercial and other | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,928,931	1,787,022	$ 1,723,598
Real estate – mortgage – commercial and other | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,921,544	1,776,886
PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	13,798	17,393
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4,282,443	4,144,395
Pass | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	471,225	452,372
Pass | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	70,122	70,357
Pass | Real estate – construction, land development & other land loans | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	463,122	509,251
Pass | Real estate – mortgage – residential (1-4 family) first mortgages | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,047,592	1,004,458
Pass | Real estate – mortgage – home equity loans / lines of credit | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	334,054	348,792
Pass | Real estate – mortgage – commercial and other | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,888,049	1,750,810
Pass | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	8,279	8,355
Special Mention Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	51,931	42,579
Special Mention Loans | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,735	3,056
Special Mention Loans | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	218	231
Special Mention Loans | Real estate – construction, land development & other land loans | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4,640	5,668
Special Mention Loans | Real estate – mortgage – residential (1-4 family) first mortgages | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	15,193	12,238
Special Mention Loans | Real estate – mortgage – home equity loans / lines of credit | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,267	1,688
Special Mention Loans | Real estate – mortgage – commercial and other | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	20,081	14,484
Special Mention Loans | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,797	5,214
Classified Accruing Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	40,890	38,216
Classified Accruing Loans | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	5,094	459
Classified Accruing Loans | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	400	413
Classified Accruing Loans | Real estate – construction, land development & other land loans | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,160	1,614
Classified Accruing Loans | Real estate – mortgage – residential (1-4 family) first mortgages | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	17,500	21,113
Classified Accruing Loans | Real estate – mortgage – home equity loans / lines of credit | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	5,970	6,653
Classified Accruing Loans | Real estate – mortgage – commercial and other | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,044	4,140
Classified Accruing Loans | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,722	3,824
Classified Nonaccrual Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	19,720	22,575
Classified Nonaccrual Loans | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,472	919
Classified Nonaccrual Loans | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	104	139
Classified Nonaccrual Loans | Real estate – construction, land development & other land loans | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,235	2,265
Classified Nonaccrual Loans | Real estate – mortgage – residential (1-4 family) first mortgages | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,661	10,115
Classified Nonaccrual Loans | Real estate – mortgage – home equity loans / lines of credit | Loans, Excluding Purchased Credit Impaired Loans | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,878	1,685
Classified Nonaccrual Loans | Real estate – mortgage – commercial and other | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,370	7,452
Classified Nonaccrual Loans | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 0	$ 0