Goodwill and Other Intangible Assets - Activity for Goodwill and Other Intangible Assets (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)
Goodwill.
Goodwill at beginning of period	$ 19,168	$ 1,901
Acquisition	0	17,457
Measurement period adjustment for previous acquisition		(190)
Goodwill at end of period	19,168	19,168
Other Intangible Assets
Amortization	(81)	(32)
Other intangible assets at end of period	$ 399
Impairment of Intangible Assets
Number of reporting units | segment	1
Impairment charges	$ 0
Core Deposits
Other Intangible Assets
Other intangible assets at beginning of period	480	22
Acquisition	0	490
Amortization	(81)	(32)
Other intangible assets at end of period	$ 399	$ 480