Allowance for Credit Losses - Credit risk profile of loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Nonperforming loans past due			90 days
Current period gross charge offs, Total	$ 3,601	$ 5,653	$ 11,520	$ 11,318
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	284,730		284,730		$ 424,209
Prior year	344,246		344,246		217,824
Two years before current year	163,564		163,564		145,349
Three years before current year	104,841		104,841		54,134
Four years before current year	37,689		37,689		35,258
Prior	136,933		136,933		129,134
Revolving Loans	70,875		70,875		69,873
Total loans	1,142,878		1,142,878		1,075,781
Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	66		66		937
Prior year	1,409		1,409		990
Two years before current year	1,042		1,042		681
Three years before current year	958		958		932
Four years before current year	694		694		366
Prior	1,852		1,852		2,040
Revolving Loans	3		3		178
Total loans	6,024		6,024		6,124
Total other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	284,796		284,796		425,146
Prior year	345,655		345,655		218,814
Two years before current year	164,606		164,606		146,030
Three years before current year	105,799		105,799		55,066
Four years before current year	38,383		38,383		35,624
Prior	138,785		138,785		131,174
Revolving Loans	70,878		70,878		70,051
Total loans	1,148,902		1,148,902		1,081,905
Residential | First Liens
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	35,883		35,883		71,713
Prior year	73,022		73,022		70,197
Two years before current year	66,344		66,344		45,080
Three years before current year	40,973		40,973		17,109
Four years before current year	16,197		16,197		20,358
Prior	122,845		122,845		119,270
Revolving Loans	1,970		1,970		3,245
Total loans	357,234		357,234		346,972
Current period gross charge offs, Prior			156
Current period gross charge offs, Total			156
Residential | First Liens | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	35,883		35,883		71,607
Prior year	72,998		72,998		70,197
Two years before current year	65,931		65,931		45,080
Three years before current year	40,751		40,751		16,968
Four years before current year	16,167		16,167		20,258
Prior	121,304		121,304		117,488
Revolving Loans	1,970		1,970		3,245
Total loans	355,004		355,004		344,843
Residential | First Liens | Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year					106
Prior year	24		24
Two years before current year	413		413
Three years before current year	222		222		141
Four years before current year	30		30		100
Prior	1,541		1,541		1,782
Total loans	2,230		2,230		2,129
Residential | Home Equity
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	141		141		1,995
Prior year	322		322		943
Two years before current year					86
Three years before current year	26		26		115
Four years before current year	94		94		69
Prior	946		946		860
Revolving Loans	61,829		61,829		60,051
Total loans	63,358		63,358		64,119
Residential | Home Equity | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	141		141		1,995
Prior year	271		271		943
Two years before current year					8
Three years before current year	7		7		115
Four years before current year	94		94		55
Prior	875		875		820
Revolving Loans	61,829		61,829		59,875
Total loans	63,217		63,217		63,811
Residential | Home Equity | Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Prior year	51		51
Two years before current year					78
Three years before current year	19		19
Four years before current year					14
Prior	71		71		40
Revolving Loans					176
Total loans	141		141		308
Residential | Junior Liens
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	10,899		10,899		19,074
Prior year	16,419		16,419		10,489
Two years before current year	8,789		8,789		7,584
Three years before current year	6,030		6,030		5,920
Four years before current year	4,674		4,674		5,505
Prior	9,197		9,197		6,336
Revolving Loans	1,625		1,625		1,928
Total loans	57,633		57,633		56,836
Current period gross charge offs, 2019			24
Current period gross charge offs, Prior			12
Current period gross charge offs, Total			36
Residential | Junior Liens | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	10,899		10,899		19,074
Prior year	16,419		16,419		10,485
Two years before current year	8,781		8,781		7,507
Three years before current year	5,926		5,926		5,830
Four years before current year	4,609		4,609		5,366
Prior	9,037		9,037		6,195
Revolving Loans	1,625		1,625		1,928
Total loans	57,296		57,296		56,385
Residential | Junior Liens | Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Prior year					4
Two years before current year	8		8		77
Three years before current year	104		104		90
Four years before current year	65		65		139
Prior	160		160		141
Total loans	337		337		451
Residential | All Other Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	6,090		6,090		11,542
Prior year	10,078		10,078		9,923
Two years before current year	3,471		3,471		501
Three years before current year	431		431		1,340
Four years before current year	1,047		1,047		533
Prior	1,600		1,600		1,600
Revolving Loans	302		302
Total loans	23,019		23,019		25,439
Residential | All Other Residential | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	6,090		6,090		11,542
Prior year	10,078		10,078		9,923
Two years before current year	3,471		3,471		501
Three years before current year	431		431		915
Four years before current year	653		653		498
Prior	1,557		1,557		1,582
Revolving Loans	302		302
Total loans	22,582		22,582		24,961
Residential | All Other Residential | Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Three years before current year					425
Four years before current year	394		394		35
Prior	43		43		18
Total loans	437		437		478
Consumer | Motor Vehicle
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	221,219		221,219		307,378
Prior year	237,450		237,450		119,101
Two years before current year	81,380		81,380		88,581
Three years before current year	55,805		55,805		29,241
Four years before current year	15,501		15,501		8,718
Prior	3,443		3,443		2,277
Revolving Loans					6
Total loans	614,798		614,798		555,302
Current period gross charge offs, 2023			284
Current period gross charge offs, 2022			5,802
Current period gross charge offs, 2021			2,590
Current period gross charge offs, 2020			1,159
Current period gross charge offs, 2019			359
Current period gross charge offs, Prior			161
Current period gross charge offs, Total			10,355
Consumer | Motor Vehicle | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	221,153		221,153		306,565
Prior year	236,144		236,144		118,362
Two years before current year	80,919		80,919		88,144
Three years before current year	55,243		55,243		29,004
Four years before current year	15,316		15,316		8,652
Prior	3,412		3,412		2,230
Revolving Loans					6
Total loans	612,187		612,187		552,963
Consumer | Motor Vehicle | Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	66		66		813
Prior year	1,306		1,306		739
Two years before current year	461		461		437
Three years before current year	562		562		237
Four years before current year	185		185		66
Prior	31		31		47
Total loans	2,611		2,611		2,339
Consumer | All Other Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	10,564		10,564		13,444
Prior year	8,364		8,364		8,161
Two years before current year	4,622		4,622		4,198
Three years before current year	2,534		2,534		1,341
Four years before current year	870		870		441
Prior	754		754		831
Revolving Loans	5,152		5,152		4,821
Total loans	32,860		32,860		33,237
Current period gross charge offs, 2023			6
Current period gross charge offs, 2022			83
Current period gross charge offs, 2021			49
Current period gross charge offs, 2020			30
Current period gross charge offs, 2019			3
Current period gross charge offs, Prior			5
Current period gross charge offs, Revolving Loans			95
Current period gross charge offs, Total			271
Consumer | All Other Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	10,564		10,564		13,426
Prior year	8,336		8,336		7,914
Two years before current year	4,462		4,462		4,109
Three years before current year	2,483		2,483		1,302
Four years before current year	850		850		429
Prior	748		748		819
Revolving Loans	5,149		5,149		4,819
Total loans	32,592		32,592		32,818
Consumer | All Other Consumer | Nonperforming Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current year					18
Prior year	28		28		247
Two years before current year	160		160		89
Three years before current year	51		51		39
Four years before current year	20		20		12
Prior	6		6		12
Revolving Loans	3		3		2
Total loans	$ 268		$ 268		$ 419