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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Amount, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Loans, Allowance for Credit Losses, and Asset Quality Information (Summary of Major Categories of Total Loans Outstanding) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 4,873,230	$ 4,735,013	$ 4,819,175
Unamortized net deferred loan fees	(3,389)	(3,698)	(5,439)
Loans	$ 4,869,841	$ 4,731,315	4,813,736
Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	100.00%	100.00%
SBA Loans
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 151,060	$ 169,662
SBA Loans, Guaranteed Portion
Loans and Leases Receivable Disclosure [Line Items]
Loans	27,542	33,959
SBA Loans, Unguaranteed Portion
Loans and Leases Receivable Disclosure [Line Items]
Loans	123,518	135,703
SBA Loans, Sold Portion
Loans and Leases Receivable Disclosure [Line Items]
Loans	424,662	395,398
Commercial, financial, and agricultural
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 612,554	$ 782,549	804,831
Commercial, financial, and agricultural \| Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	12.00%	17.00%
Real estate, commercial \| Real estate – construction, land development & other land loans
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 588,103	$ 570,672	653,120
Real estate, commercial \| Real estate – construction, land development & other land loans \| Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	12.00%	12.00%
Real estate, commercial \| Real estate – mortgage – commercial and other
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 2,423,341	$ 2,049,203	1,983,622
Real estate, commercial \| Real estate – mortgage – commercial and other \| Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	50.00%	43.00%
Real estate, mortgage \| Real estate – mortgage – residential (1-4 family) first mortgages
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 914,266	$ 972,378	1,017,087
Real estate, mortgage \| Real estate – mortgage – residential (1-4 family) first mortgages \| Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	19.00%	21.00%
Real estate, mortgage \| Real estate – mortgage – home equity loans / lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 281,219	$ 306,256	310,326
Real estate, mortgage \| Real estate – mortgage – home equity loans / lines of credit \| Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	6.00%	6.00%
Consumer loans
Loans and Leases Receivable Disclosure [Line Items]
Loans, gross	$ 53,747	$ 53,955	$ 50,189
Consumer loans \| Loan Category Concentration Risk \| Financing Receivable
Loans and Leases Receivable Disclosure [Line Items]
Percentage	1.00%	1.00%