Loans and Asset Quality Information (Summary of Major Categories of Total Loans Outstanding) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 4,819,175	$ 4,451,525	$ 4,394,984
Unamortized net deferred loan costs (fees)	(5,439)	1,941	1,560
Total loans	$ 4,813,736	$ 4,453,466	4,396,544
Percentage	100.00%	100.00%
SBA Loans
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 181,038	$ 165,182
SBA Loans, Guaranteed Portion
Loans and Leases Receivable Disclosure [Line Items]
Total loans	46,085	54,400
SBA Loans, Unguaranteed Portion
Loans and Leases Receivable Disclosure [Line Items]
Total loans	134,953	110,782
SBA Loans, Sold Portion
Loans and Leases Receivable Disclosure [Line Items]
Total loans	379,123	316,730
Commercial, financial, and agricultural
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 804,831	$ 504,271	486,768
Percentage	17.00%	11.00%
Real estate, commercial \| Real estate – construction, land development & other land loans
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 653,120	$ 530,866	471,326
Percentage	14.00%	12.00%
Real estate, commercial \| Real estate – mortgage – commercial and other
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 1,983,622	$ 1,917,280	1,928,931
Percentage	41.00%	43.00%
Real estate, mortgage \| Real estate – mortgage – residential (1-4 family) first mortgages
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 1,017,087	$ 1,105,014	1,093,619
Percentage	21.00%	25.00%
Real estate, mortgage \| Real estate – mortgage – home equity loans / lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 310,326	$ 337,922	343,378
Percentage	6.00%	8.00%
Consumer loans
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 50,189	$ 56,172	$ 70,962
Percentage	1.00%	1.00%

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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