Allowance for Credit Losses - Loans - Residential and consumer portfolio (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Performing and non-performing outstanding balances of the residential and consumer portfolios
Total loans	$ 1,069,060	$ 1,069,060		$ 1,069,060		$ 1,067,949
Current period gross charge-offs, Total	2,800	2,977	$ 252	3,081	$ 416
Consumer and Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	6,966	6,966		6,966		24,353
2024/2023	23,736	23,736		23,736		26,700
2023/2022	24,756	24,756		24,756		26,843
2022/2021	25,061	25,061		25,061		65,145
2021/2020	62,423	62,423		62,423		44,402
Prior	85,784	85,784		85,784		43,466
Revolving Loans Amortized Cost Basis	55,777	55,777		55,777		54,148
Revolving Loans Converted to Term	31	31		31		664
Total loans	284,534	284,534		284,534		285,721
Current period gross charge-offs, 2025/2024				1		5
Current period gross charge-offs, 2024/2023				28		6
Current period gross charge-offs, 2023/2022				29		21
Current period gross charge-offs, 2022/2021				4		19
Current period gross charge-offs, 2021/2020						13
Current period gross charge-offs, Prior				57		143
Current period gross charge-offs, Total				119		207
Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	852	852		852		12,877
2024/2023	13,844	13,844		13,844		15,602
2023/2022	15,451	15,451		15,451		10,400
2022/2021	10,258	10,258		10,258		57,540
2021/2020	55,573	55,573		55,573		41,868
Prior	79,052	79,052		79,052		38,823
Total loans	175,030	175,030		175,030		177,110
Consumer
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	6,114	6,114		6,114		11,476
2024/2023	9,892	9,892		9,892		11,098
2023/2022	9,305	9,305		9,305		16,443
2022/2021	14,803	14,803		14,803		7,605
2021/2020	6,850	6,850		6,850		2,534
Prior	6,732	6,732		6,732		4,643
Revolving Loans Amortized Cost Basis	55,777	55,777		55,777		54,148
Revolving Loans Converted to Term	31	31		31		664
Total loans	109,504	109,504		109,504		108,611
Current period gross charge-offs, 2025/2024				1		5
Current period gross charge-offs, 2024/2023				28		6
Current period gross charge-offs, 2023/2022				29		21
Current period gross charge-offs, 2022/2021				4		19
Current period gross charge-offs, 2021/2020						13
Current period gross charge-offs, Prior				57		143
Current period gross charge-offs, Total		15	$ 63	119	$ 124	207
Performing \| Consumer and Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	6,966	6,966		6,966		24,353
2024/2023	23,729	23,729		23,729		26,590
2023/2022	24,678	24,678		24,678		26,797
2022/2021	25,061	25,061		25,061		65,145
2021/2020	62,423	62,423		62,423		44,343
Prior	85,274	85,274		85,274		42,717
Revolving Loans Amortized Cost Basis	55,520	55,520		55,520		53,876
Revolving Loans Converted to Term	31	31		31		664
Total loans	283,682	283,682		283,682		284,485
Performing \| Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	852	852		852		12,877
2024/2023	13,844	13,844		13,844		15,602
2023/2022	15,451	15,451		15,451		10,400
2022/2021	10,258	10,258		10,258		57,540
2021/2020	55,573	55,573		55,573		41,868
Prior	78,916	78,916		78,916		38,418
Total loans	174,894	174,894		174,894		176,705
Performing \| Consumer
Performing and non-performing outstanding balances of the residential and consumer portfolios
2025/2024	6,114	6,114		6,114		11,476
2024/2023	9,885	9,885		9,885		10,988
2023/2022	9,227	9,227		9,227		16,397
2022/2021	14,803	14,803		14,803		7,605
2021/2020	6,850	6,850		6,850		2,475
Prior	6,358	6,358		6,358		4,299
Revolving Loans Amortized Cost Basis	55,520	55,520		55,520		53,876
Revolving Loans Converted to Term	31	31		31		664
Total loans	108,788	108,788		108,788		107,780
Non-performing \| Consumer and Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
2024/2023	7	7		7		110
2023/2022	78	78		78		46
2021/2020						59
Prior	510	510		510		749
Revolving Loans Amortized Cost Basis	257	257		257		272
Total loans	852	852		852		1,236
Non-performing \| Residential mortgages
Performing and non-performing outstanding balances of the residential and consumer portfolios
Prior	136	136		136		405
Total loans	136	136		136		405
Non-performing \| Consumer
Performing and non-performing outstanding balances of the residential and consumer portfolios
2024/2023	7	7		7		110
2023/2022	78	78		78		46
2021/2020						59
Prior	374	374		374		344
Revolving Loans Amortized Cost Basis	257	257		257		272
Total loans	$ 716	$ 716		$ 716		$ 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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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease.

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