Loans - Average Recorded Investment - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	$ 15,580	$ 18,060	$ 22,321	$ 18,182
Interest Income Recognized on an Accrual Basis on Impaired Loans	110	112	326	298
Interest Income Recognized on a Cash Basis on Impaired Loans	57	66	165	165
Commercial, financial, and agricultural
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	346	699	586	924
Interest Income Recognized on an Accrual Basis on Impaired Loans	4	5	12	15
Interest Income Recognized on a Cash Basis on Impaired Loans	0	0	1	10
Real estate mortgage \| Residential
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	2,784	2,245	4,539	1,954
Interest Income Recognized on an Accrual Basis on Impaired Loans	23	17	67	45
Interest Income Recognized on a Cash Basis on Impaired Loans	41	14	68	31
Real estate mortgage \| Commercial
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	12,383	14,210	16,988	14,492
Interest Income Recognized on an Accrual Basis on Impaired Loans	83	90	247	238
Interest Income Recognized on a Cash Basis on Impaired Loans	16	35	96	71
Real estate mortgage \| Construction
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	67	906	208	812
Interest Income Recognized on an Accrual Basis on Impaired Loans	0	0	0	0
Interest Income Recognized on a Cash Basis on Impaired Loans		$ 17		$ 53

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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