Loans Receivable and the Allowance for Credit Losses - Summary of risk category of loans (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Loans Receivable and the Allowance for Credit Losses
2025/2024	$ 275,715		$ 275,715		$ 443,177
2024/2023	510,710		510,710		544,997
2023/2022	412,501		412,501		380,540
2022/2021	269,038		269,038		191,190
2021/2020	112,504		112,504		55,822
Prior	117,597		117,597		90,896
Revolving Loans Amortized Cost Basis	99,203		99,203		100,050
Revolving Loans Converted to Term	350		350		5,975
Total	1,797,618		1,797,618		1,812,647
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff
2025/2024			602		347
Prior					1,000
Total	485	$ 12	602	$ 33	1,347
Residential real estate
Loans Receivable and the Allowance for Credit Losses
2025/2024	96,098		96,098		18,326
2024/2023	12,941		12,941		78,603
2023/2022	78,085		78,085		70,892
2022/2021	69,758		69,758		22,292
2021/2020	22,028		22,028		11,361
Prior	43,129		43,129		35,175
Total	322,039		322,039		236,649
Non-residential real estate
Loans Receivable and the Allowance for Credit Losses
2025/2024					13,881
2024/2023	13,759		13,759		1,569
2023/2022	1,550		1,550		243
2022/2021	239		239		1,669
2021/2020	1,637		1,637		974
Prior	11,786		11,786		11,110
Total	28,971		28,971		29,446
Construction
Loans Receivable and the Allowance for Credit Losses
2025/2024	174,077		174,077		408,072
2024/2023	477,202		477,202		460,460
2023/2022	328,866		328,866		303,417
2022/2021	193,573		193,573		166,997
2021/2020	88,712		88,712		43,405
Prior	61,047		61,047		43,816
Total	1,323,477		1,323,477		1,426,167
Commercial and industrial
Loans Receivable and the Allowance for Credit Losses
2025/2024	5,493		5,493		1,250
2024/2023	6,808		6,808		4,365
2023/2022	4,000		4,000		5,988
2022/2021	5,468		5,468		232
2021/2020	127		127		82
Prior	1,635		1,635		795
Revolving Loans Amortized Cost Basis	99,203		99,203		100,049
Revolving Loans Converted to Term	350		350		5,975
Total	123,084		123,084		118,736
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff
Prior					1,000
Total					1,000
Consumer
Loans Receivable and the Allowance for Credit Losses
2025/2024	47		47		1,648
Revolving Loans Amortized Cost Basis					1
Total	47		47		1,649
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff
2025/2024			602		347
Total	485	$ 12	602	$ 33	347
Pass
Loans Receivable and the Allowance for Credit Losses
2025/2024	275,715		275,715		443,177
2024/2023	510,476		510,476		544,997
2023/2022	412,501		412,501		380,540
2022/2021	269,038		269,038		191,190
2021/2020	112,504		112,504		55,822
Prior	117,597		117,597		90,896
Revolving Loans Amortized Cost Basis	99,203		99,203		100,050
Revolving Loans Converted to Term	350		350		5,734
Total	1,797,384		1,797,384		1,812,406
Pass \| Residential real estate
Loans Receivable and the Allowance for Credit Losses
2025/2024	96,098		96,098		18,326
2024/2023	12,941		12,941		78,603
2023/2022	78,085		78,085		70,892
2022/2021	69,758		69,758		22,292
2021/2020	22,028		22,028		11,361
Prior	43,129		43,129		35,175
Total	322,039		322,039		236,649
Pass \| Non-residential real estate
Loans Receivable and the Allowance for Credit Losses
2025/2024					13,881
2024/2023	13,759		13,759		1,569
2023/2022	1,550		1,550		243
2022/2021	239		239		1,669
2021/2020	1,637		1,637		974
Prior	11,786		11,786		11,110
Total	28,971		28,971		29,446
Pass \| Construction
Loans Receivable and the Allowance for Credit Losses
2025/2024	174,077		174,077		408,072
2024/2023	477,202		477,202		460,460
2023/2022	328,866		328,866		303,417
2022/2021	193,573		193,573		166,997
2021/2020	88,712		88,712		43,405
Prior	61,047		61,047		43,816
Total	1,323,477		1,323,477		1,426,167
Pass \| Commercial and industrial
Loans Receivable and the Allowance for Credit Losses
2025/2024	5,493		5,493		1,250
2024/2023	6,574		6,574		4,365
2023/2022	4,000		4,000		5,988
2022/2021	5,468		5,468		232
2021/2020	127		127		82
Prior	1,635		1,635		795
Revolving Loans Amortized Cost Basis	99,203		99,203		100,049
Revolving Loans Converted to Term	350		350		5,734
Total	122,850		122,850		118,495
Pass \| Consumer
Loans Receivable and the Allowance for Credit Losses
2025/2024	47		47		1,648
Revolving Loans Amortized Cost Basis					1
Total	47		47		1,649
Substandard
Loans Receivable and the Allowance for Credit Losses
2024/2023	234		234
Revolving Loans Converted to Term					241
Total	234		234		241
Substandard \| Commercial and industrial
Loans Receivable and the Allowance for Credit Losses
2024/2023	234		234
Revolving Loans Converted to Term					241
Total	$ 234		$ 234		$ 241

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