Loans - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Credit quality categories
Total	$ 1,854,351		$ 1,838,716
Current period gross write offs
Total	525	$ 262
Commercial, financial, and agricultural
Credit quality categories
2024 & 2023	8,108		31,190
2023 & 2022	30,386		49,798
2022 & 2021	48,668		35,938
2021 & 2020	34,383		32,084
2020 & 2019	31,529		3,123
Prior	32,448		30,382
Revolving Loans	35,242		30,107
Revolving Loans Converted to Term	811		844
Total	221,575		213,466
Current period gross write offs
2024 & 2023	0		0
2023 & 2022	40		41
2022 & 2021	50		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	90	0	41
Commercial, financial, and agricultural | Pass
Credit quality categories
2024 & 2023	8,108		31,190
2023 & 2022	29,936		49,615
2022 & 2021	48,504		35,901
2021 & 2020	34,350		31,980
2020 & 2019	31,511		3,123
Prior	31,719		29,502
Revolving Loans	34,598		29,397
Revolving Loans Converted to Term	82		101
Total	218,808		210,809
Commercial, financial, and agricultural | Special Mention
Credit quality categories
2024 & 2023	0		0
2023 & 2022	450		183
2022 & 2021	164		37
2021 & 2020	33		19
2020 & 2019	18		0
Prior	0		138
Revolving Loans	159		223
Revolving Loans Converted to Term	0		0
Total	824		600
Commercial, financial, and agricultural | Substandard or Lower
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		85
2020 & 2019	0		0
Prior	729		742
Revolving Loans	485		487
Revolving Loans Converted to Term	729		743
Total	1,943		2,057
Real Estate Mortgages | Residential
Credit quality categories
2024 & 2023	23,086		135,939
2023 & 2022	131,413		134,921
2022 & 2021	134,833		89,117
2021 & 2020	86,574		51,378
2020 & 2019	49,751		33,914
Prior	173,293		150,592
Revolving Loans	57,262		56,519
Revolving Loans Converted to Term	148,195		146,121
Total	804,407		798,501
Current period gross write offs
2024 & 2023			0
2023 & 2022			0
2022 & 2021			0
2021 & 2020			0
2020 & 2019			0
Prior			9
Revolving Loans			73
Revolving Loans Converted to Term			0
Total	4	78	82
Real Estate Mortgages | Residential | Pass
Credit quality categories
2024 & 2023	23,086		135,939
2023 & 2022	131,074		134,077
2022 & 2021	133,995		88,844
2021 & 2020	86,303		51,378
2020 & 2019	49,751		33,914
Prior	171,414		148,802
Revolving Loans	57,262		56,519
Revolving Loans Converted to Term	148,132		146,055
Total	801,017		795,528
Real Estate Mortgages | Residential | Special Mention
Credit quality categories
2024 & 2023	0		0
2023 & 2022	339		844
2022 & 2021	524		273
2021 & 2020	0		0
2020 & 2019	0		0
Prior	95		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	958		1,117
Real Estate Mortgages | Residential | Substandard or Lower
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	314		0
2021 & 2020	271		0
2020 & 2019	0		0
Prior	1,784		1,790
Revolving Loans	0		0
Revolving Loans Converted to Term	63		66
Total	2,432		1,856
Current period gross write offs
2024 & 2023	0
2023 & 2022	0
2022 & 2021	0
2021 & 2020	0
2020 & 2019	0
Prior	4
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	4
Real Estate Mortgages | Commercial
Credit quality categories
2024 & 2023	7,471		55,664
2023 & 2022	61,797		107,791
2022 & 2021	106,448		131,084
2021 & 2020	128,180		49,603
2020 & 2019	48,867		24,163
Prior	168,675		150,137
Revolving Loans	11,331		12,338
Revolving Loans Converted to Term	859		821
Total	533,628		531,601
Current period gross write offs
2024 & 2023			59
2023 & 2022			0
2022 & 2021			0
2021 & 2020			0
2020 & 2019			0
Prior			3
Revolving Loans			0
Revolving Loans Converted to Term			0
Total	0	3	62
Real Estate Mortgages | Commercial | Pass
Credit quality categories
2024 & 2023	7,471		55,664
2023 & 2022	61,609		107,638
2022 & 2021	106,296		128,094
2021 & 2020	124,866		49,603
2020 & 2019	48,867		24,104
Prior	162,909		144,377
Revolving Loans	11,331		12,338
Revolving Loans Converted to Term	859		821
Total	524,208		522,639
Real Estate Mortgages | Commercial | Special Mention
Credit quality categories
2024 & 2023	0		0
2023 & 2022	188		153
2022 & 2021	152		2,990
2021 & 2020	2,426		0
2020 & 2019	0		0
Prior	1,861		1,891
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	4,627		5,034
Real Estate Mortgages | Commercial | Substandard or Lower
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	888		0
2020 & 2019	0		59
Prior	3,905		3,869
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	4,793		3,928
Current period gross write offs
2024 & 2023	0
2023 & 2022	0
2022 & 2021	0
2021 & 2020	0
2020 & 2019	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	0
Real Estate Mortgages | Construction
Credit quality categories
2024 & 2023	1,429		25,494
2023 & 2022	22,495		6,837
2022 & 2021	6,435		1,742
2021 & 2020	1,611		1,302
2020 & 2019	1,265		392
Prior	4,609		4,361
Revolving Loans	269		261
Revolving Loans Converted to Term	0		0
Total	38,113		40,389
Current period gross write offs
2024 & 2023			0
2023 & 2022			0
2022 & 2021			0
2021 & 2020			0
2020 & 2019			0
Prior			0
Revolving Loans			0
Revolving Loans Converted to Term			0
Total	0	0	0
Real Estate Mortgages | Construction | Pass
Credit quality categories
2024 & 2023	1,429		25,494
2023 & 2022	22,495		6,837
2022 & 2021	6,435		1,742
2021 & 2020	1,611		1,302
2020 & 2019	1,265		392
Prior	4,523		4,272
Revolving Loans	269		261
Revolving Loans Converted to Term	0		0
Total	38,027		40,300
Real Estate Mortgages | Construction | Special Mention
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	0		0
Real Estate Mortgages | Construction | Substandard or Lower
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	86		89
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	86		89
Current period gross write offs
2024 & 2023	0
2023 & 2022	0
2022 & 2021	0
2021 & 2020	0
2020 & 2019	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	0
Consumer automobile loans
Credit quality categories
2024 & 2023	21,341		119,922
2023 & 2022	114,250		78,443
2022 & 2021	71,858		19,567
2021 & 2020	17,231		15,348
2020 & 2019	13,108		7,305
Prior	8,520		3,813
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	246,308		244,398
Current period gross write offs
2024 & 2023			30
2023 & 2022			320
2022 & 2021			178
2021 & 2020			113
2020 & 2019			8
Prior			17
Revolving Loans			0
Revolving Loans Converted to Term			0
Total	336	93	666
Consumer automobile loans | Pass
Credit quality categories
2024 & 2023	21,341		119,922
2023 & 2022	114,250		78,443
2022 & 2021	71,858		19,567
2021 & 2020	17,231		15,348
2020 & 2019	13,108		7,305
Prior	8,520		3,813
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	246,308		244,398
Consumer automobile loans | Special Mention
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	0		0
Consumer automobile loans | Substandard or Lower
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	0		0
Current period gross write offs
2024 & 2023	0
2023 & 2022	101
2022 & 2021	162
2021 & 2020	35
2020 & 2019	20
Prior	0
Revolving Loans	18
Revolving Loans Converted to Term	0
Total	336
Other consumer installment loans
Credit quality categories
2024 & 2023	1,165		2,952
2023 & 2022	2,595		2,188
2022 & 2021	1,889		1,177
2021 & 2020	1,050		524
2020 & 2019	470		407
Prior	3,113		3,071
Revolving Loans	0		0
Revolving Loans Converted to Term	38		42
Total	10,320		10,361
Current period gross write offs
2024 & 2023			232
2023 & 2022			47
2022 & 2021			23
2021 & 2020			8
2020 & 2019			12
Prior			34
Revolving Loans			13
Revolving Loans Converted to Term			11
Total	95	$ 88	380
Other consumer installment loans | Pass
Credit quality categories
2024 & 2023	1,165		2,952
2023 & 2022	2,595		2,188
2022 & 2021	1,889		1,177
2021 & 2020	1,050		524
2020 & 2019	470		407
Prior	3,113		3,071
Revolving Loans	0		0
Revolving Loans Converted to Term	38		42
Total	10,320		10,361
Current period gross write offs
2024 & 2023	17
2023 & 2022	41
2022 & 2021	23
2021 & 2020	7
2020 & 2019	0
Prior	0
Revolving Loans	7
Revolving Loans Converted to Term	0
Total	95
Other consumer installment loans | Special Mention
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	0		0
Other consumer installment loans | Substandard or Lower
Credit quality categories
2024 & 2023	0		0
2023 & 2022	0		0
2022 & 2021	0		0
2021 & 2020	0		0
2020 & 2019	0		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term	0		0
Total	$ 0		$ 0