Interest Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest receivable	$ 87,003	$ 63,872
Loans receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest receivable	77,349	57,070
Mortgage-backed securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest receivable	3,431	3,313
Investment securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest receivable	$ 6,223	$ 3,489