FAIR VALUE - Carrying Amount and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Sep. 30, 2021
Carrying Amount [Member]
Financial Assets [Abstract]
Cash and cash equivalents	$ 133,974	$ 166,544
Securities held to maturity	4,509	8,611
Securities available-for-sale	6,740	7,747
Federal Home Loan Bank stock	3,858	3,714
Loans, net	1,404,891	1,238,573
Accrued interest receivable	7,643	9,363
Financial Liabilities [Abstract]
Time deposits	298,272	377,836
Demand and other deposits	1,051,277	786,826
Borrowings	56,963	159,642
Subordinated debentures	24,554	24,513
Accrued interest payable	611	1,290
As Adjusted
Financial Assets [Abstract]
Cash and cash equivalents	133,974	166,544
Securities held to maturity	4,309	8,865
Securities available-for-sale	6,740	7,747
Loans, net	1,379,005	1,278,056
Accrued interest receivable	7,643	9,363
Financial Liabilities [Abstract]
Time deposits	291,890	378,333
Demand and other deposits	1,051,277	786,826
Borrowings	57,192	159,608
Subordinated debentures	24,698	27,092
Accrued interest payable	611	1,290
As Adjusted | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial Assets [Abstract]
Cash and cash equivalents	133,974	166,544
Securities held to maturity	0	0
Securities available-for-sale	0	0
Loans, net	0	0
Accrued interest receivable	0	0
Financial Liabilities [Abstract]
Time deposits	0	0
Demand and other deposits	1,051,277	786,826
Borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	1	1
As Adjusted | Significant Other Observable Inputs (Level 2) [Member]
Financial Assets [Abstract]
Cash and cash equivalents	0	0
Securities held to maturity	4,309	8,865
Securities available-for-sale	6,740	7,747
Loans, net	0	0
Accrued interest receivable	117	211
Financial Liabilities [Abstract]
Time deposits	291,890	378,333
Demand and other deposits	0	0
Borrowings	57,192	159,608
Subordinated debentures	24,698	27,092
Accrued interest payable	610	713
As Adjusted | Significant Unobservable Inputs (Level 3) [Member]
Financial Assets [Abstract]
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Securities available-for-sale	0	0
Loans, net	1,379,005	1,278,056
Accrued interest receivable	7,526	9,152
Financial Liabilities [Abstract]
Time deposits	0	0
Demand and other deposits	0	0
Borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	$ 0	$ 576