Loans and Leases - Nonperforming Loans and Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	$ 37,368	$ 26,208
Accruing troubled debt restructured loans and lease modifications	54	542
Loans and lease 90 days or more past due and accruing interest	2,488	192
Total nonperforming loans and leases	39,910	26,942
Nonaccrual troubled debt restructured loans and lease modifications	2,300	1,300
Commercial, Financial and Agricultural [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	2,233	3,365
Accruing troubled debt restructured loans and lease modifications	0	382
Loans and lease 90 days or more past due and accruing interest	0	0
Total nonperforming loans and leases	2,233	3,747
Real Estate-Commercial [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	28,024	18,214
Accruing troubled debt restructured loans and lease modifications	0	0
Loans and lease 90 days or more past due and accruing interest	760	0
Total nonperforming loans and leases	28,784	18,214
Real Estate-Construction [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	256	106
Accruing troubled debt restructured loans and lease modifications	0	0
Loans and lease 90 days or more past due and accruing interest	0	0
Total nonperforming loans and leases	256	106
Real Estate-Residential Secured For Business Purpose [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	2,887	1,318
Accruing troubled debt restructured loans and lease modifications	0	160
Loans and lease 90 days or more past due and accruing interest	1,109	0
Total nonperforming loans and leases	3,996	1,478
Real Estate-Residential Secured For Personal Purpose [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	2,087	1,587
Accruing troubled debt restructured loans and lease modifications	0	0
Loans and lease 90 days or more past due and accruing interest	0	0
Total nonperforming loans and leases	2,087	1,587
Real Estate-Home Equity Secured For Personal Purpose [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	1,379	1,448
Accruing troubled debt restructured loans and lease modifications	54	0
Loans and lease 90 days or more past due and accruing interest	0	0
Total nonperforming loans and leases	1,433	1,448
Loans to Individuals [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	2	0
Accruing troubled debt restructured loans and lease modifications	0	0
Loans and lease 90 days or more past due and accruing interest	129	55
Total nonperforming loans and leases	131	55
Lease Financings [Member]
Nonperforming Loans And Leases [Line Items]
Nonaccrual loans and leases	500	170
Accruing troubled debt restructured loans and lease modifications	0	0
Loans and lease 90 days or more past due and accruing interest	490	137
Total nonperforming loans and leases	$ 990	$ 307