Loans and Asset Quality Information (Summary of Major Categories of Total Loans Outstanding) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 4,337,713	$ 4,149,459	$ 4,247,765
Unamortized net deferred loan costs (fees)	1,784	(69)	1,299
Total loans	$ 4,339,497	$ 4,149,390	$ 4,249,064
Percentage	100.00%	100.00%	100.00%
SBA Loans
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 149,311	$ 118,479	$ 150,777
SBA Loans, Guaranteed Portion
Loans and Leases Receivable Disclosure [Line Items]
Total loans	43,157	20,466	53,205
SBA Loans, Unguaranteed Portion
Loans and Leases Receivable Disclosure [Line Items]
Total loans	106,154	98,013	97,572
SBA Loans, Sold Portion
Loans and Leases Receivable Disclosure [Line Items]
Total loans	288,914	171,462	230,424
Commercial, financial, and agricultural
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 471,188	$ 417,366	$ 457,037
Percentage	11.00%	10.00%	11.00%
Real estate, commercial \| Real estate – construction, land development & other land loans
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 456,781	$ 600,031	$ 518,976
Percentage	10.00%	14.00%	12.00%
Real estate, commercial \| Real estate – mortgage – commercial and other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 1,900,188	$ 1,690,175	$ 1,787,022
Percentage	44.00%	41.00%	42.00%
Real estate, mortgage \| Real estate – mortgage – residential (1-4 family) first mortgages
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 1,090,601	$ 1,000,189	$ 1,054,176
Percentage	25.00%	24.00%	25.00%
Real estate, mortgage \| Real estate – mortgage – home equity loans / lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 349,355	$ 369,875	$ 359,162
Percentage	8.00%	9.00%	8.00%
Installment loans to individuals
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 69,600	$ 71,823	$ 71,392
Percentage	2.00%	2.00%	2.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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