Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Service charges on deposits
Revenue from External Customer [Line Items]
Service charges on deposits	$ 3,911	$ 4,147	$ 4,904
ATM and debit card interchange transaction fees
Revenue from External Customer [Line Items]
Service charges on deposits	5,084	4,378	4,036
Escrow fees
Revenue from External Customer [Line Items]
Service charges on deposits	290	273	197
Fee income from non-deposit investment sales
Revenue from External Customer [Line Items]
Service charges on deposits	$ 23	$ 22	$ 46