Allowance for Credit Losses - Loans - Commercial and commercial real estate loan portfolios (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 1,062,326		$ 1,067,949
Current period gross charge-offs, Total	104	$ 164
Other commercial real estate (non-owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	232,579		233,882
Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	15,273		110,142
2024/2023	107,092		137,086
2023/2022	138,796		101,631
2022/2021	96,038		113,330
2021/2020	111,918		65,020
Prior	246,864		192,032
Revolving Loans Amortized Cost Basis	63,555		60,995
Revolving Loans Converted to Term	35		1,992
Total loans	779,571		782,228
Current period gross charge-offs, 2023/2022			427
Current period gross charge-offs, Prior			1,571
Current period gross charge-offs, Total			1,998
Commercial Portfolio Segment \| Commercial real estate (owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	2,421		10,294
2024/2023	10,407		17,016
2023/2022	16,892		6,648
2022/2021	7,280		14,355
2021/2020	14,197		10,476
Prior	36,473		26,984
Revolving Loans Amortized Cost Basis	528		324
Revolving Loans Converted to Term			856
Total loans	88,198		86,953
Commercial Portfolio Segment \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	4,174		16,714
2024/2023	13,561		19,837
2023/2022	19,029		21,386
2022/2021	17,558		9,150
2021/2020	8,656		4,568
Prior	23,323		19,969
Revolving Loans Amortized Cost Basis	57,384		55,627
Revolving Loans Converted to Term	35
Total loans	143,720		147,251
Current period gross charge-offs, 2023/2022			427
Current period gross charge-offs, Total		$ 103	427
Commercial Portfolio Segment \| Commercial real estate (non-owner occupied) - retail
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	7,579		29,349
2024/2023	28,398		38,912
2023/2022	38,376		21,240
2022/2021	19,596		31,934
2021/2020	31,625		21,322
Prior	58,042		38,047
Revolving Loans Amortized Cost Basis	31		32
Revolving Loans Converted to Term			942
Total loans	183,647		181,778
Commercial Portfolio Segment \| Commercial real estate (non-owner occupied) - multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	137		25,984
2024/2023	26,624		28,807
2023/2022	30,485		16,423
2022/2021	16,045		16,816
2021/2020	16,676		12,428
Prior	40,985		31,431
Revolving Loans Amortized Cost Basis	475		475
Total loans	131,427		132,364
Commercial Portfolio Segment \| Other commercial real estate (non-owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	962		27,801
2024/2023	28,102		32,514
2023/2022	34,014		35,934
2022/2021	35,559		41,075
2021/2020	40,764		16,226
Prior	88,041		75,601
Revolving Loans Amortized Cost Basis	5,137		4,537
Revolving Loans Converted to Term			194
Total loans	232,579		233,882
Current period gross charge-offs, Prior			1,571
Current period gross charge-offs, Total			1,571
Pass \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	15,273		110,142
2024/2023	107,092		136,606
2023/2022	138,316		100,348
2022/2021	94,755		107,698
2021/2020	106,282		64,105
Prior	224,742		175,405
Revolving Loans Amortized Cost Basis	61,115		59,823
Revolving Loans Converted to Term	10		1,992
Total loans	747,585		756,119
Pass \| Commercial Portfolio Segment \| Commercial real estate (owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	2,421		10,294
2024/2023	10,407		17,016
2023/2022	16,892		6,648
2022/2021	7,280		10,675
2021/2020	10,519		10,476
Prior	35,361		26,393
Revolving Loans Amortized Cost Basis	378		324
Revolving Loans Converted to Term			856
Total loans	83,258		82,682
Pass \| Commercial Portfolio Segment \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	4,174		16,714
2024/2023	13,561		19,357
2023/2022	18,549		20,977
2022/2021	17,135		7,397
2021/2020	6,897		4,568
Prior	22,408		19,280
Revolving Loans Amortized Cost Basis	55,094		54,455
Revolving Loans Converted to Term	10
Total loans	137,828		142,748
Pass \| Commercial Portfolio Segment \| Commercial real estate (non-owner occupied) - retail
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	7,579		29,349
2024/2023	28,398		38,912
2023/2022	38,376		20,935
2022/2021	19,293		31,934
2021/2020	31,625		21,322
Prior	58,042		38,047
Revolving Loans Amortized Cost Basis	31		32
Revolving Loans Converted to Term			942
Total loans	183,344		181,473
Pass \| Commercial Portfolio Segment \| Commercial real estate (non-owner occupied) - multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	137		25,984
2024/2023	26,624		28,807
2023/2022	30,485		16,423
2022/2021	16,045		16,816
2021/2020	16,676		11,513
Prior	38,727		30,066
Revolving Loans Amortized Cost Basis	475		475
Total loans	129,169		130,084
Pass \| Commercial Portfolio Segment \| Other commercial real estate (non-owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
2025/2024	962		27,801
2024/2023	28,102		32,514
2023/2022	34,014		35,365
2022/2021	35,002		40,876
2021/2020	40,565		16,226
Prior	70,204		61,619
Revolving Loans Amortized Cost Basis	5,137		4,537
Revolving Loans Converted to Term			194
Total loans	213,986		219,132
Special Mention \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2023/2022			305
2022/2021	303
Prior	7,949		3,488
Revolving Loans Amortized Cost Basis	1,333
Total loans	9,585		3,793
Special Mention \| Commercial Portfolio Segment \| Commercial real estate (owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
Prior	561
Revolving Loans Amortized Cost Basis	150
Total loans	711
Special Mention \| Commercial Portfolio Segment \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans Amortized Cost Basis	1,183
Total loans	1,183
Special Mention \| Commercial Portfolio Segment \| Commercial real estate (non-owner occupied) - retail
Financing Receivable, Credit Quality Indicator [Line Items]
2023/2022			305
2022/2021	303
Total loans	303		305
Special Mention \| Commercial Portfolio Segment \| Other commercial real estate (non-owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
Prior	7,388		3,488
Total loans	7,388		3,488
Substandard \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024/2023			480
2023/2022	480		978
2022/2021	980		5,632
2021/2020	5,636		915
Prior	13,775		13,139
Revolving Loans Amortized Cost Basis	1,107		1,172
Revolving Loans Converted to Term	25
Total loans	22,003		22,316
Substandard \| Commercial Portfolio Segment \| Commercial real estate (owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
2022/2021			3,680
2021/2020	3,678
Prior	551		591
Total loans	4,229		4,271
Substandard \| Commercial Portfolio Segment \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2024/2023			480
2023/2022	480		409
2022/2021	423		1,753
2021/2020	1,759
Prior	517		689
Revolving Loans Amortized Cost Basis	1,107		1,172
Revolving Loans Converted to Term	25
Total loans	4,311		4,503
Substandard \| Commercial Portfolio Segment \| Commercial real estate (non-owner occupied) - multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
2021/2020			915
Prior	2,258		1,365
Total loans	2,258		2,280
Substandard \| Commercial Portfolio Segment \| Other commercial real estate (non-owner occupied)
Financing Receivable, Credit Quality Indicator [Line Items]
2023/2022			569
2022/2021	557		199
2021/2020	199
Prior	10,449		10,494
Total loans	11,205		$ 11,262
Doubtful \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
Prior	398
Total loans	398
Doubtful \| Commercial Portfolio Segment \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Prior	398
Total loans	$ 398

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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