Fair Value Measurements Fair Value Measurement, Measured On Non-Recurring Basis, Signfiicant Unobservable Inputs, Quantitative Information (Details) - Fair Value, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	Sep. 30, 2021		Sep. 30, 2020
Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 12,538		$ 13,001
Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	0		2,993
Discounted Cash Flow [Member] | Nonaccruing Loans [Member] | Management knowledge of Industry [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 12,538		13,001
Discounted Cash Flow [Member] | Real estate and other repossessed assets [Member] | Management knowledge of Industry [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure			$ 2,993
Minimum [Member] | Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	1.00%	[1]	0.00%	[2]
Maximum [Member] | Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	97.00%	[1]	73.00%	[2]
Weighted Average [Member] | Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	23.00%	[1]	18.00%	[2]

[1] Represents fair value as a percentage of the unpaid principal balance.

[2] Represents fair value as a percentage of the unpaid principal balance.