Loans and Asset Quality Information (Schedule of Recorded Investment in Loans by Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 4,337,713	$ 4,247,765	$ 4,149,459
Unamortized net deferred loan costs (fees)	1,784	1,299	(69)
Total loans	4,339,497	4,249,064	4,149,390
Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	471,188	457,037	417,366
Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	69,600	71,392	71,823
Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	470,924	456,806
Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	69,456	71,140
Real estate – construction, land development & other land loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	456,781	518,976	600,031
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	456,609	518,798
Real estate – mortgage – residential (1-4 family) first mortgages | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,090,601	1,054,176	1,000,189
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	1,084,659	1,047,924
Real estate – mortgage – home equity loans / lines of credit | Real estate, mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	349,355	359,162	369,875
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	349,145	358,818
Real estate – mortgage – commercial and other | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,900,188	1,787,022	$ 1,690,175
Real estate – mortgage – commercial and other | Loans, Excluding Purchased Credit Impaired Loans | Real estate, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,892,745	1,776,886
PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	14,175	17,393
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4,222,992	4,144,395
Pass | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	460,804	452,372
Pass | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	68,190	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	447,686	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	1,040,778	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	340,085	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	1,857,389	1,750,810
Pass | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	8,060	8,355
Special Mention Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	53,604	42,579
Special Mention Loans | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,643	3,056
Special Mention Loans | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	223	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	4,680	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	16,274	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	1,361	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	20,539	14,484
Special Mention Loans | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,884	5,214
Classified Accruing Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	43,742	38,216
Classified Accruing Loans | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	987	459
Classified Accruing Loans | Loans, Excluding Purchased Credit Impaired Loans | Installment loans to individuals
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	939	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	2,823	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	18,910	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	6,295	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	10,557	4,140
Classified Accruing Loans | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,231	3,824
Classified Nonaccrual Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	17,375	22,575
Classified Nonaccrual Loans | Loans, Excluding Purchased Credit Impaired Loans | Commercial, financial, and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,490	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	1,420	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	8,697	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	1,404	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	4,260	7,452
Classified Nonaccrual Loans | PCI Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 0	$ 0