Business Combinations - Summary of purchase price calculation and bargain purchase gain (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
	May 19, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Business Acquisition [Line Items]
Cash consideration				$ 25,414	$ 0
Liabilities Assumed:
Bargain purchase gain		$ 0	$ 0	$ (9,696)	$ 0
Noah Bank [Member]
Business Acquisition [Line Items]
Noah Bank number of common shares outstanding				4,235,666
Purchase price per share assigned to cash consideration	$ 6	$ 6		$ 6
Cash consideration				$ 25,414
Assets Acquired:
Cash and cash equivalents		$ 23,181		23,181
Securities available-for-sale		6,454		6,454
Loans receivable, net of allowance		185,891		185,891
Core deposit intangible		99		99
Premises and equipment		2,495		2,495
Operating leases right-of-use		10,523		10,523
Deferred tax assets		4,308		4,308
Other assets		6,500		6,500
Fair value of assets acquired		239,451		239,451
Liabilities Assumed:
Deposits		191,700		191,700
Operating lease liability		10,523		10,523
Other liabilities assumed		2,118		2,118
Fair value of liabilities assumed		204,341		204,341
Total identifiable net assets		$ 35,110		35,110
Bargain purchase gain	$ (9,700)			$ (9,696)