Revenue from Contract with Customer (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Deposit Account
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 970	$ 1,052	$ 2,810	$ 2,979
Credit and Debit Card
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,335	1,345	3,861	3,868
Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	27	41	85	164
Investment Advice
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 1	$ 4	$ 35	$ 14