Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Statement of Financial Position [Abstract]
Mortgage-backed securities and other investments held to maturity-fair value	$ 253,766	$ 249,783
Allowance for loan losses	$ 15,817	$ 13,703
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock shares authorized (in shares)	1,000,000	1,000,000
Preferred stock shares issued (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized (in shares)	50,000,000	50,000,000
Common stock shares issued (in shares)	8,105,338	8,221,952
Common stock shares outstanding (in shares)	8,105,338	8,221,952