Fair Value Measurements - Carrying Amount and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Carrying Amount
Financial Assets
Cash and cash equivalents	$ 149,947	$ 166,544
Securities held to maturity	4,414	8,611
Loans, net	1,610,687	1,238,573
Accrued interest receivable	8,546	9,363
Financial Liabilities
Time deposits	339,073	377,836
Demand and other deposits	1,189,033	786,826
Borrowings	101,752	159,642
Subordinated debentures	24,568	24,513
Accrued interest payable	915	1,290
Total Fair Value
Financial Assets
Cash and cash equivalents	149,947	166,544
Securities held to maturity	4,095	8,865
Loans, net	1,564,991	1,278,056
Accrued interest receivable	8,546	9,363
Financial Liabilities
Time deposits	328,964	378,333
Demand and other deposits	1,189,033	786,826
Borrowings	99,597	159,608
Subordinated debentures	24,199	27,092
Accrued interest payable	915	1,290
Total Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets
Cash and cash equivalents	149,947	166,544
Securities held to maturity	0	0
Loans, net	0
Accrued interest receivable	0	0
Financial Liabilities
Time deposits	0	0
Demand and other deposits	1,189,033	786,826
Borrowings	0	0
Subordinated debentures	0
Accrued interest payable	1	1
Total Fair Value | Significant Other Observable Inputs (Level 2)
Financial Assets
Cash and cash equivalents	0	0
Securities held to maturity	4,095	8,865
Loans, net	0
Accrued interest receivable	219	211
Financial Liabilities
Time deposits	328,964	378,333
Demand and other deposits	0	0
Borrowings	99,597	159,608
Subordinated debentures	24,199	27,092
Accrued interest payable	914	713
Total Fair Value | Significant Unobservable Inputs (Level 3)
Financial Assets
Cash and cash equivalents	0	0
Securities held to maturity	0	0
Loans, net	1,564,991	1,278,056
Accrued interest receivable	8,327	9,152
Financial Liabilities
Time deposits	0	0
Demand and other deposits	0	0
Borrowings	0	0
Subordinated debentures	0
Accrued interest payable	$ 0	$ 576