Allowance for Credit Losses - Loans - Residential and consumer portfolio (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Performing and non-performing outstanding balances of the residential and consumer portfolios
Total loans	$ 1,062,326		$ 1,067,949
Current period gross charge-offs, Total	104	$ 164
Consumer and Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	2,884		24,353
2024/2023	24,180		26,700
2023/2022	25,054		26,843
2022/2021	25,964		65,145
2021/2020	64,326		44,402
Prior	86,699		43,466
Revolving Loans Amortized Cost Basis	53,577		54,148
Revolving Loans Converted to Term	71		664
Total loans	282,755		285,721
Current period gross charge-offs, 2025/2024			5
Current period gross charge-offs, 2024/2023	27		6
Current period gross charge-offs, 2023/2022	25		21
Current period gross charge-offs, 2022/2021	3		19
Current period gross charge-offs, 2021/2020			13
Current period gross charge-offs, Prior	49		143
Current period gross charge-offs, Total	104		207
Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	186		12,877
2024/2023	13,243		15,602
2023/2022	14,861		10,400
2022/2021	10,327		57,540
2021/2020	56,900		41,868
Prior	79,762		38,823
Total loans	175,279		177,110
Consumer
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	2,698		11,476
2024/2023	10,937		11,098
2023/2022	10,193		16,443
2022/2021	15,637		7,605
2021/2020	7,426		2,534
Prior	6,937		4,643
Revolving Loans Amortized Cost Basis	53,577		54,148
Revolving Loans Converted to Term	71		664
Total loans	107,476		108,611
Current period gross charge-offs, 2025/2024			5
Current period gross charge-offs, 2024/2023	27		6
Current period gross charge-offs, 2023/2022	25		21
Current period gross charge-offs, 2022/2021	3		19
Current period gross charge-offs, 2021/2020			13
Current period gross charge-offs, Prior	49		143
Current period gross charge-offs, Total	104	$ 61	207
Performing \| Consumer and Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	2,884		24,353
2024/2023	24,180		26,590
2023/2022	24,970		26,797
2022/2021	25,964		65,145
2021/2020	64,326		44,343
Prior	86,291		42,717
Revolving Loans Amortized Cost Basis	53,316		53,876
Revolving Loans Converted to Term	71		664
Total loans	282,002		284,485
Performing \| Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	186		12,877
2024/2023	13,243		15,602
2023/2022	14,861		10,400
2022/2021	10,327		57,540
2021/2020	56,900		41,868
Prior	79,710		38,418
Total loans	175,227		176,705
Performing \| Consumer
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	2,698		11,476
2024/2023	10,937		10,988
2023/2022	10,109		16,397
2022/2021	15,637		7,605
2021/2020	7,426		2,475
Prior	6,581		4,299
Revolving Loans Amortized Cost Basis	53,316		53,876
Revolving Loans Converted to Term	71		664
Total loans	106,775		107,780
Non-performing \| Consumer and Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2024/2023			110
2023/2022	84		46
2021/2020			59
Prior	408		749
Revolving Loans Amortized Cost Basis	261		272
Total loans	753		1,236
Non-performing \| Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
Prior	52		405
Total loans	52		405
Non-performing \| Consumer
Performing and non-performing outstanding balances of the residential and consumer portfolios
2024/2023			110
2023/2022	84		46
2021/2020			59
Prior	356		344
Revolving Loans Amortized Cost Basis	261		272
Total loans	$ 701		$ 831

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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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