Loans - Recorded investment in loans based on impairment method (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2023	Dec. 31, 2023
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	$ 2,841	$ 2,841
Impact of adopting 326	246	246
Charge offs	(11)	(11)
Recoveries	0	29
Provisions	6	166
Ending balance	3,082	3,271
Commercial Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	204	204
Impact of adopting 326	(75)	(75)
Charge offs	(11)	(11)
Recoveries	0	0
Provisions	(26)	338
Ending balance	92	456
Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	111	111
Impact of adopting 326	94	94
Charge offs	0	0
Recoveries	0	0
Provisions	40	(10)
Ending balance	245	195
One To Four Family [Member] \| Real estate loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	1,710	1,710
Impact of adopting 326	117	117
Charge offs	0	0
Recoveries	0	16
Provisions	(5)	(241)
Ending balance	1,822	1,602
Multi-Family [Member] \| Real estate loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	17	17
Impact of adopting 326	1	1
Charge offs	0	0
Recoveries	0	0
Provisions	(1)	7
Ending balance	17	25
Commercial [Member] \| Real estate loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	654	654
Impact of adopting 326	130	130
Charge offs	0	0
Recoveries	0	0
Provisions	(39)	71
Ending balance	745	855
Construction [Member] \| Real estate loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance	145	145
Impact of adopting 326	(21)	(21)
Charge offs	0	0
Recoveries	0	13
Provisions	37	1
Ending balance	$ 161	$ 138

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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