Loans Receivable and the Allowance for Credit Losses - Summary of risk category of loans (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Loans Receivable and the Allowance for Credit Losses
2026/2025	$ 110,284		$ 583,392
2025/2024	631,082		412,339
2024/2023	326,419		313,794
2023/2022	280,455		227,949
2022/2021	185,097		99,329
Prior	166,874		95,208
Revolving Loans Amortized Cost Basis	125,105		127,705
Revolving Loans Converted to Term	2,892		350
Total	1,828,208		1,860,066
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff
2026/2025	27		702
Total	27	$ 117	702
Residential real estate
Loans Receivable and the Allowance for Credit Losses
2026/2025			120,070
2025/2024	119,677		11,994
2024/2023	11,968		75,364
2023/2022	67,765		64,588
2022/2021	64,260		21,735
Prior	56,273		41,068
Total	319,943		334,819
Non-residential real estate
Loans Receivable and the Allowance for Credit Losses
2026/2025			11,013
2025/2024	10,967		13,632
2024/2023	13,567		1,531
2023/2022	1,521		235
2022/2021	233		1,606
Prior	11,917		10,446
Total	38,205		38,463
Construction
Loans Receivable and the Allowance for Credit Losses
2026/2025	110,210		445,820
2025/2024	493,842		380,754
2024/2023	295,163		233,309
2023/2022	207,740		158,283
2022/2021	116,038		75,970
Prior	97,243		42,193
Total	1,320,236		1,336,329
Commercial and industrial
Loans Receivable and the Allowance for Credit Losses
2026/2025	37		6,431
2025/2024	6,596		5,959
2024/2023	5,721		3,590
2023/2022	3,429		4,843
2022/2021	4,566		18
Prior	1,441		1,501
Revolving Loans Amortized Cost Basis	125,105		127,705
Revolving Loans Converted to Term	2,892		350
Total	149,787		150,397
Consumer
Loans Receivable and the Allowance for Credit Losses
2026/2025	37		58
Total	37		58
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff
2026/2025	27		702
Total	27	$ 117	702
Pass
Loans Receivable and the Allowance for Credit Losses
2026/2025	110,284		583,392
2025/2024	631,082		412,113
2024/2023	326,198		313,794
2023/2022	280,455		227,949
2022/2021	185,097		99,329
Prior	166,874		95,208
Revolving Loans Amortized Cost Basis	125,105		127,705
Revolving Loans Converted to Term	2,892		350
Total	1,827,987		1,859,840
Pass \| Residential real estate
Loans Receivable and the Allowance for Credit Losses
2026/2025			120,070
2025/2024	119,677		11,768
2024/2023	11,968		75,364
2023/2022	67,765		64,588
2022/2021	64,260		21,735
Prior	56,273		41,068
Total	319,943		334,593
Pass \| Non-residential real estate
Loans Receivable and the Allowance for Credit Losses
2026/2025			11,013
2025/2024	10,967		13,632
2024/2023	13,567		1,531
2023/2022	1,521		235
2022/2021	233		1,606
Prior	11,917		10,446
Total	38,205		38,463
Pass \| Construction
Loans Receivable and the Allowance for Credit Losses
2026/2025	110,210		445,820
2025/2024	493,842		380,754
2024/2023	295,163		233,309
2023/2022	207,740		158,283
2022/2021	116,038		75,970
Prior	97,243		42,193
Total	1,320,236		1,336,329
Pass \| Commercial and industrial
Loans Receivable and the Allowance for Credit Losses
2026/2025	37		6,431
2025/2024	6,596		5,959
2024/2023	5,500		3,590
2023/2022	3,429		4,843
2022/2021	4,566		18
Prior	1,441		1,501
Revolving Loans Amortized Cost Basis	125,105		127,705
Revolving Loans Converted to Term	2,892		350
Total	149,566		150,397
Pass \| Consumer
Loans Receivable and the Allowance for Credit Losses
2026/2025	37		58
Total	37		58
Special Mention
Loans Receivable and the Allowance for Credit Losses
2025/2024			226
2024/2023	221
Total	221		226
Special Mention \| Residential real estate
Loans Receivable and the Allowance for Credit Losses
2025/2024			226
Total			$ 226
Special Mention \| Commercial and industrial
Loans Receivable and the Allowance for Credit Losses
2024/2023	221
Total	$ 221

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