Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Other Intangible Assets, Net
Total	$ 399
Core Deposits
Other Intangible Assets, Net
Gross carrying amount	517	$ 517
Accumulated amortization	(118)	(37)
Total	$ 399	$ 480	$ 22
Weighted-average remaining life of other intangible assets	4 years 22 days