Loans Receivable, Net - Performance of Loans Modified in Last Twelve Months (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Modified
Total	$ 53,638	$ 53,744
Non-Accrual	1,901	2,169
Current
Financing Receivable, Modified
Total	50,269	50,624
30-89 Days Past Due
Financing Receivable, Modified
Total	907	926
90 Days or More Past Due
Financing Receivable, Modified
Total	561	25
Residential real estate
Financing Receivable, Modified
Total	204	679
Non-Accrual	0	0
Residential real estate | Current
Financing Receivable, Modified
Total	204	679
Residential real estate | 30-89 Days Past Due
Financing Receivable, Modified
Total	0	0
Residential real estate | 90 Days or More Past Due
Financing Receivable, Modified
Total	0	0
Commercial real estate
Financing Receivable, Modified
Total	39,706	40,749
Non-Accrual	1,901	1,553
Commercial real estate | Current
Financing Receivable, Modified
Total	37,143	39,196
Commercial real estate | 30-89 Days Past Due
Financing Receivable, Modified
Total	101	0
Commercial real estate | 90 Days or More Past Due
Financing Receivable, Modified
Total	561	0
Other commercial
Financing Receivable, Modified
Total	13,728	11,597
Non-Accrual	0	565
Other commercial | Current
Financing Receivable, Modified
Total	12,922	10,081
Other commercial | 30-89 Days Past Due
Financing Receivable, Modified
Total	806	926
Other commercial | 90 Days or More Past Due
Financing Receivable, Modified
Total	$ 0	25
Home equity
Financing Receivable, Modified
Total		51
Non-Accrual		51
Home equity | Current
Financing Receivable, Modified
Total		0
Home equity | 30-89 Days Past Due
Financing Receivable, Modified
Total		0
Home equity | 90 Days or More Past Due
Financing Receivable, Modified
Total		0
Other consumer
Financing Receivable, Modified
Total		668
Non-Accrual		0
Other consumer | Current
Financing Receivable, Modified
Total		668
Other consumer | 30-89 Days Past Due
Financing Receivable, Modified
Total		0
Other consumer | 90 Days or More Past Due
Financing Receivable, Modified
Total		$ 0