Investment Securities: Narrative-Realized Gains (Losses) (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($) security	Sep. 30, 2020 USD ($) security
Investments [Abstract]
Loss on sale of securities	$ 1	$ 12	$ 66
Held-to-maturity securities, realized loss, number of securities | security		19	19
Security owned and pledged as collateral	$ 133,824	$ 97,602