Loans and Allowance for Loan Losses - Troubled Debt Restructurings (Details)		3 Months Ended		9 Months Ended
		Sep. 30, 2019 USD ($) contract	Sep. 30, 2018 USD ($) contract	Sep. 30, 2019 USD ($) contract		Sep. 30, 2018 USD ($) contract		Dec. 31, 2018 USD ($)
Troubled Debt Restructurings
Troubled debt restructurings		$ 4,000,000		$ 4,000,000				$ 5,000,000
Amount of specific reserves related to TDRs which were allocated to the allowance for loan losses		$ 471,000		$ 471,000				543,000
Number of contracts called for default and charged off | contract		1	0	1		0
Number of Contracts | contract			3	2	[1]	8	[1]
Pre- Modification			$ 465,000	$ 80,000	[1]	$ 588,000	[1]
Post- Modification			$ 406,000	$ 76,000	[1]	$ 430,000	[1]
Commercial, financial, and agricultural
Troubled Debt Restructurings
Number of Contracts | contract			2	2	[1]	2	[1]
Pre- Modification			$ 353,000	$ 80,000	[1]	$ 353,000	[1]
Post- Modification			$ 353,000	76,000	[1]	$ 353,000	[1]
Residential real estate | Mortgages
Troubled Debt Restructurings
Number of Contracts | contract	[1]					1
Pre- Modification	[1]					$ 75,000
Post- Modification	[1]					$ 74,000
Installment and other consumer
Troubled Debt Restructurings
Number of Contracts | contract			1			5	[1]
Pre- Modification			$ 112,000			$ 160,000	[1]
Post- Modification			$ 53,000			$ 3,000	[1]
Performing TDRs
Troubled Debt Restructurings
Troubled debt restructurings		$ 2,600,000		2,600,000				3,000,000
Non-accrual and non-performing TDRs
Troubled Debt Restructurings
Troubled debt restructurings		$ 1,400,000		$ 1,400,000				$ 2,000,000

[1] The amounts reported post-modification are inclusive of all partial pay-downs and charge-offs, and no portion of the debt was forgiven. Loans modified as a TDR that were fully paid down, charged-off or foreclosed upon during the period ended are not reported.