Commitments and Contingencies (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Reserve for unfunded loan commitments	$ 365	$ 384
Employee severance compensation plan, employee minimum service requirement (in years)	2 years
Employee severance compensation plan, period following effective date of a change in company control (in months)	12 months
Employee severance compensation plan, eligible payment, maximum compensation term (in months)	18 months
Employee severance compensation plan, annual compensation multiplier	2.99
Employee severance compensation plan, period following effective date of change in control for eligible severance benefits (in years)	5 years