Loans Receivable - Summary of components of allowance for credit losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ (17,970)	$ (16,507)	$ (16,461)	$ (16,666)	$ (16,654)	$ (16,620)
Allowance for credit losses - off balance sheet	(699)		(332)
Allowance for credit losses	$ (18,669)		$ (16,793)

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

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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant