Loans - Average Recorded Investment - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	$ 16,825	$ 20,677
Interest Income Recognized on an Accrual Basis on Impaired Loans	84	60
Interest Income Recognized on a Cash Basis on Impaired Loans	0	93
Commercial, financial, and agricultural
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	2,155	5,302
Interest Income Recognized on an Accrual Basis on Impaired Loans	1	1
Interest Income Recognized on a Cash Basis on Impaired Loans	0	38
Real Estate Mortgages \| Residential
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	5,953	4,163
Interest Income Recognized on an Accrual Basis on Impaired Loans	57	28
Interest Income Recognized on a Cash Basis on Impaired Loans	0	17
Real Estate Mortgages \| Commercial
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	8,568	11,069
Interest Income Recognized on an Accrual Basis on Impaired Loans	26	31
Interest Income Recognized on a Cash Basis on Impaired Loans	0	36
Real Estate Mortgages \| Construction
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	65	73
Interest Income Recognized on an Accrual Basis on Impaired Loans	0	0
Interest Income Recognized on a Cash Basis on Impaired Loans	0	1
Consumer automobile loans
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	76	52
Interest Income Recognized on an Accrual Basis on Impaired Loans	0	0
Interest Income Recognized on a Cash Basis on Impaired Loans	0	1
Other consumer installment loans
Credit Quality and Related Allowance for Loan Losses
Average Investment in Impaired Loans	8	18
Interest Income Recognized on an Accrual Basis on Impaired Loans	0	0
Interest Income Recognized on a Cash Basis on Impaired Loans	$ 0	$ 0

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118936363&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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