Loans Receivable - Summary of Allowance for Loan Losses On Loans Receivables (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Allowance for loan losses:
Beginning balance	$ 18,492	$ 16,461
CECL adoption		(301)
Provision		344
Charge-offs		0
Recoveries		3
Total	18,618	16,507
Commercial real estate [Member]
Allowance for loan losses:
Beginning balance	16,047	8,654
CECL adoption		1,384
Provision	631	(4)
Charge-offs	(237)	0
Recoveries	5	3
Total	16,446	10,037
Commercial and industrial [Member]
Allowance for loan losses:
Beginning balance	488	271
CECL adoption		(73)
Provision	(31)	16
Charge-offs	(46)	0
Recoveries	102	0
Total	513	214
Construction [Member]
Allowance for loan losses:
Beginning balance	1,145	6,289
CECL adoption		(1,269)
Provision	(124)	329
Charge-offs	0	0
Recoveries	0	0
Total	1,021	5,349
Residential first-lien mortgage [Member]
Allowance for loan losses:
Beginning balance	725	236
CECL adoption		428
Provision	(153)	(10)
Charge-offs	0	0
Recoveries	0	0
Total	572	654
Home equity/consumer [Member]
Allowance for loan losses:
Beginning balance	87	45
CECL adoption		195
Provision	(21)	13
Charge-offs	0	0
Recoveries	0	0
Total	66	253
PPP [Member]
Allowance for loan losses:
Beginning balance		0
CECL adoption		0
Provision		0
Charge-offs		0
Recoveries		0
Total		0
Unallocated [Member]
Allowance for loan losses:
Beginning balance	18,492	966
CECL adoption		(966)
Provision	302	0
Charge-offs	(283)	0
Recoveries	107	0
Total	$ 18,618	$ 0