Loans Receivable, Net and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended
	Dec. 31, 2022 USD ($) Contract	Dec. 31, 2021 Contract
Receivables [Abstract]
Criteria in internal rating system	Ten-point
Categories considered as not criticized	six
Days past due over which loans are considered as substandard	90 days
Minimum internal review amount	$ 750,000
Minimum external review amount	1,000,000
Loans greater than 90 days past due and still accruing interest	$ 0
Number of Contracts | Contract	0
Number of troubled debt restructurings, loan modified, defaulted within one year of modification | Contract	0	0