Loans and Allowance for Credit Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands			3 Months Ended			9 Months Ended			12 Months Ended
	Jan. 01, 2023		Sep. 30, 2023		Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022	Dec. 31, 2022
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	$ 15,588	[1]	$ 22,236		$ 15,353	$ 15,588	[1]	$ 16,903	$ 16,903
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			300		300	1,115		(1,000)
Deductions:
Loans charged off			95		191	291		546	637
Less recoveries on loans			(21)		(43)	(257)		(148)
Net loan charge-offs (recoveries)			74		148	34		398
Balance at end of period			22,462	[1]	15,505	22,462	[1]	15,505	15,588	[1]
Liability for Unfunded Commitments
Beginning balance	0					0
Ending balance									0
Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	5,793					5,793
Additions:
Provision for (release of) credit losses on loans and unfunded commitments	5,800
Deductions:
Balance at end of period	5,793								5,793
Liability for Unfunded Commitments
Ending balance	1,272
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	21,381					21,381
Deductions:
Balance at end of period	21,381								21,381
Liability for Unfunded Commitments
Ending balance	1,272
Unfunded Loan Commitment
Deductions:
Balance at end of period			900			900
Liability for Unfunded Commitments
Beginning balance	0		1,137			0
Provision for credit losses on unfunded commitments			(190)			(325)
Ending balance			947			947			0
Allowance for credit losses on loans and liability for unfunded commitments			23,409			23,409
Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Deductions:
Balance at end of period	1,300
Liability for Unfunded Commitments
Beginning balance	1,272					1,272
Ending balance									1,272
Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	1,272					1,272
Ending balance									1,272
Commercial, Financial, and Agricultural
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	2,735		1,844		3,005	2,735		2,717	2,717
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			99		(124)	(274)		188
Deductions:
Loans charged off			16		46	59		106	135
Less recoveries on loans			(9)		(13)	(183)		(49)
Net loan charge-offs (recoveries)			7		33	(124)		57
Balance at end of period			1,936		2,848	1,936		2,848	2,735
Commercial, Financial, and Agricultural | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(649)					(649)
Deductions:
Balance at end of period									(649)
Commercial, Financial, and Agricultural | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	2,086					2,086
Deductions:
Balance at end of period									2,086
Commercial, Financial, and Agricultural | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		112			0
Provision for credit losses on unfunded commitments			9			17
Ending balance			121			121			0
Allowance for credit losses on loans and liability for unfunded commitments			2,057			2,057
Commercial, Financial, and Agricultural | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	104					104
Ending balance									104
Commercial, Financial, and Agricultural | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	104					104
Ending balance									104
Real Estate Construction - Residential
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	157		748		66	157		137	137
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			125		5	425		(66)
Deductions:
Loans charged off			0		0	0		0	0
Less recoveries on loans			0		0	0		0
Net loan charge-offs (recoveries)			0		0	0		0
Balance at end of period			873		71	873		71	157
Real Estate Construction - Residential | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	291					291
Deductions:
Balance at end of period									291
Real Estate Construction - Residential | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	448					448
Deductions:
Balance at end of period									448
Real Estate Construction - Residential | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		355			0
Provision for credit losses on unfunded commitments			(68)			(54)
Ending balance			287			287			0
Allowance for credit losses on loans and liability for unfunded commitments			1,160			1,160
Real Estate Construction - Residential | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	341					341
Ending balance									341
Real Estate Construction - Residential | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	341					341
Ending balance									341
Real Estate Construction - Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	875		3,422		762	875		588	588
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			(157)		87	(504)		261
Deductions:
Loans charged off			0		0	0		0	0
Less recoveries on loans			0		0	0		0
Net loan charge-offs (recoveries)			0		0	0		0
Balance at end of period			3,265		849	3,265		849	875
Real Estate Construction - Commercial | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	2,894					2,894
Deductions:
Balance at end of period									2,894
Real Estate Construction - Commercial | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	3,769					3,769
Deductions:
Balance at end of period									3,769
Real Estate Construction - Commercial | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		414			0
Provision for credit losses on unfunded commitments			(110)			(265)
Ending balance			304			304			0
Allowance for credit losses on loans and liability for unfunded commitments			3,569			3,569
Real Estate Construction - Commercial | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	569					569
Ending balance									569
Real Estate Construction - Commercial | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	569					569
Ending balance									569
Real Estate Mortgage - Residential
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	3,329		5,465		2,747	3,329		2,482	2,482
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			(153)		481	89		723
Deductions:
Loans charged off			0		0	0		0	0
Less recoveries on loans			(2)		(4)	(6)		(27)
Net loan charge-offs (recoveries)			(2)		(4)	(6)		(27)
Balance at end of period			5,314		3,232	5,314		3,232	3,329
Real Estate Mortgage - Residential | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	1,890					1,890
Deductions:
Balance at end of period									1,890
Real Estate Mortgage - Residential | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	5,219					5,219
Deductions:
Balance at end of period									5,219
Real Estate Mortgage - Residential | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		108			0
Provision for credit losses on unfunded commitments			(4)			(3)
Ending balance			104			104			0
Allowance for credit losses on loans and liability for unfunded commitments			5,418			5,418
Real Estate Mortgage - Residential | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	107					107
Ending balance									107
Real Estate Mortgage - Residential | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	107					107
Ending balance									107
Real Estate Mortgage - Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	8,000		10,295		8,410	8,000		10,662	10,662
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			440		(414)	1,145		(2,491)
Deductions:
Loans charged off			3		(1)	28		178	181
Less recoveries on loans			(1)		(5)	(3)		(9)
Net loan charge-offs (recoveries)			2		(6)	25		169
Balance at end of period			10,733		8,002	10,733		8,002	8,000
Real Estate Mortgage - Commercial | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	1,613					1,613
Deductions:
Balance at end of period									1,613
Real Estate Mortgage - Commercial | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	9,613					9,613
Deductions:
Balance at end of period									9,613
Real Estate Mortgage - Commercial | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		126			0
Provision for credit losses on unfunded commitments			(1)			(25)
Ending balance			125			125			0
Allowance for credit losses on loans and liability for unfunded commitments			10,858			10,858
Real Estate Mortgage - Commercial | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	150					150
Ending balance									150
Real Estate Mortgage - Commercial | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	150					150
Ending balance									150
Installment and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	326		217		312	326		256	256
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			94		129	137		259
Deductions:
Loans charged off			76		146	204		262	321
Less recoveries on loans			(9)		(21)	(65)		(63)
Net loan charge-offs (recoveries)			67		125	139		199
Balance at end of period			244		316	244		316	326
Installment and Other Consumer | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(80)					(80)
Deductions:
Balance at end of period									(80)
Installment and Other Consumer | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	246					246
Deductions:
Balance at end of period									246
Installment and Other Consumer | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		1			0
Provision for credit losses on unfunded commitments			0			0
Ending balance			1			1			0
Allowance for credit losses on loans and liability for unfunded commitments			245			245
Installment and Other Consumer | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	1					1
Ending balance									1
Installment and Other Consumer | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	1					1
Ending balance									1
Un- allocated
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	166		245		51	166		61	61
Additions:
Provision for (release of) credit losses on loans and unfunded commitments			(148)		136	97		126
Deductions:
Loans charged off			0			0		0
Less recoveries on loans			0			0		0
Net loan charge-offs (recoveries)			0		0	0		0
Balance at end of period			97		$ 187	97		$ 187	166
Un- allocated | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	(166)					(166)
Deductions:
Balance at end of period									(166)
Un- allocated | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period	0					0
Deductions:
Balance at end of period									0
Un- allocated | Unfunded Loan Commitment
Liability for Unfunded Commitments
Beginning balance	0		21			0
Provision for credit losses on unfunded commitments			(16)			5
Ending balance			5			5			0
Allowance for credit losses on loans and liability for unfunded commitments			$ 102			102
Un- allocated | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjustment
Liability for Unfunded Commitments
Beginning balance	0					0
Ending balance									0
Un- allocated | Unfunded Loan Commitment | Cumulative Effect, Period of Adoption, Adjusted Balance
Liability for Unfunded Commitments
Beginning balance	$ 0					$ 0
Ending balance									$ 0

[1] amounts include the impacts of the January 1, 2023 adoption of ASU 2016-13. See Note 2 for details.See accompanying notes to the consolidated financial statements (unaudited)