Commitments and Contingencies - Summary of Balance and Activity in Allowance for Credit Losses for Unfunded Loan Commitments (Detail) - Unfunded Loan Commitment [Member]	3 Months Ended
Mar. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Balance, December 31, 2022	$ 141,000
Provision for (recovery of) credit losses	(7,000)
Balance, March 31, 2023	143,000
Cumulative Effect, Period of Adoption [Member]
Loss Contingencies [Line Items]
Balance, December 31, 2022	$ 9,000

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