Loans - Aging Categories of Loans by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	$ 1,405,966	$ 1,392,147
Past due 90 days or more & still accruing	364	861
Non-accrual	4,917	5,389
Total	1,405,706	1,391,846
Net deferred loan fees and discounts	260	301
Allowance for loan losses	(14,023)	(14,176)	$ (14,202)	$ (13,803)
Current loans, net	1,382,982	1,366,184
Loans, net	1,391,943	1,377,971
Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	1,396,745	1,380,059
Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	3,680	5,537
Commercial, financial, and agricultural
Aging categories of loans by segment
Past due 90 days or more & still accruing	0	0
Non-accrual	509	575
Total	162,273	163,285
Allowance for loan losses	(1,936)	(1,946)	(2,606)	(1,936)
Commercial, financial, and agricultural | Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	161,764	162,571
Commercial, financial, and agricultural | Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	0	139
Real Estate Mortgages | Residential
Aging categories of loans by segment
Past due 90 days or more & still accruing	319	687
Non-accrual	715	837
Total	613,161	595,847
Allowance for loan losses	(4,801)	(4,701)	(4,401)	(4,460)
Real Estate Mortgages | Residential | Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	609,728	590,240
Real Estate Mortgages | Residential | Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	2,399	4,083
Real Estate Mortgages | Commercial
Aging categories of loans by segment
Past due 90 days or more & still accruing	0	0
Non-accrual	3,693	3,937
Total	443,415	446,734
Allowance for loan losses	(5,215)	(5,336)	(4,176)	(3,635)
Real Estate Mortgages | Commercial | Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	439,344	442,573
Real Estate Mortgages | Commercial | Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	378	224
Real Estate Mortgages | Construction
Aging categories of loans by segment
Past due 90 days or more & still accruing	0	0
Non-accrual	0	40
Total	41,923	37,295
Allowance for loan losses	(197)	(179)	(142)	(134)
Real Estate Mortgages | Construction | Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	41,609	36,701
Real Estate Mortgages | Construction | Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	314	554
Consumer automobile loans
Aging categories of loans by segment
Past due 90 days or more & still accruing	8	143
Non-accrual	0	0
Total	135,568	139,408
Allowance for loan losses	(1,376)	(1,411)	(1,735)	(1,906)
Consumer automobile loans | Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	135,015	138,775
Consumer automobile loans | Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	545	490
Other consumer installment loans
Aging categories of loans by segment
Past due 90 days or more & still accruing	37	31
Non-accrual	0	0
Total	9,366	9,277
Allowance for loan losses	(114)	(111)	$ (235)	$ (261)
Other consumer installment loans | Current
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	9,285	9,199
Other consumer installment loans | Past Due 30 to 89 Days
Aging categories of loans by segment
Loans, current and past due 30 to 89 days	$ 44	$ 47