Credit Quality of Loans and Allowance for Loan Losses - Age Analysis of Past Due Loans by Class of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	$ 71,520	$ 37,396
Current	986,443	1,146,030
Total Loans	1,057,963	1,183,426
Recorded Investment, 90 days past due and Accruing	3	728
Commercial, financial and agricultural
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	37,613	17,935
Current	317,331	417,272
Total Loans	354,944	435,207
Recorded Investment, 90 days past due and Accruing	3	545
Real estate - construction
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	1,395	806
Current	96,713	89,481
Total Loans	98,108	90,287
Recorded Investment, 90 days past due and Accruing	0	125
Real estate – commercial
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	29,280	16,454
Current	385,246	431,952
Total Loans	414,526	448,406
Recorded Investment, 90 days past due and Accruing	0	58
Real estate - residential
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	2,868	1,859
Current	138,236	144,892
Total Loans	141,104	146,751
Recorded Investment, 90 days past due and Accruing	0	0
Installment loans to individuals
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	303	342
Current	47,103	56,056
Total Loans	47,406	56,398
Recorded Investment, 90 days past due and Accruing	0	0
Lease financing receivable
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	0	0
Current	632	732
Total Loans	632	732
Recorded Investment, 90 days past due and Accruing	0	0
Other loans
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	61	0
Current	1,182	5,645
Total Loans	1,243	5,645
Recorded Investment, 90 days past due and Accruing	0	0
30-59 Days Past Due
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	12,677	9,041
30-59 Days Past Due | Commercial, financial and agricultural
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	8,504	1,195
30-59 Days Past Due | Real estate - construction
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	1,175	616
30-59 Days Past Due | Real estate – commercial
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	1,655	5,889
30-59 Days Past Due | Real estate - residential
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	1,077	1,065
30-59 Days Past Due | Installment loans to individuals
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	215	276
30-59 Days Past Due | Lease financing receivable
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	0	0
30-59 Days Past Due | Other loans
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	51	0
Financing Receivables, 60 to 89 Days Past Due [Member]
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	14,006	8,562
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial, financial and agricultural
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	4,347	1,893
Financing Receivables, 60 to 89 Days Past Due [Member] | Real estate - construction
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Real estate – commercial
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	9,523	6,402
Financing Receivables, 60 to 89 Days Past Due [Member] | Real estate - residential
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	99	235
Financing Receivables, 60 to 89 Days Past Due [Member] | Installment loans to individuals
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	27	32
Financing Receivables, 60 to 89 Days Past Due [Member] | Lease financing receivable
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Other loans
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	10	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	44,837	19,793
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial, financial and agricultural
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	24,762	14,847
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real estate - construction
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	220	190
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real estate – commercial
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	18,102	4,163
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real estate - residential
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	1,692	559
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Installment loans to individuals
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	61	34
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Lease financing receivable
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Other loans
Age Analysis of Past Due Loans by Class of Loans [Abstract]
Total Past Due	$ 0	$ 0