Recent Accounting Pronouncements - Impact of adopting ASC 326 (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Oct. 01, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				$ 16,838	$ 16,458	$ 15,360
Liabilities
Allowance for credit losses on off balance sheet credit exposures	$ 1,781		$ 0
Residential real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				4,132	3,537	2,716
Commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				1,783	1,783	1,590
Single tenant net lease
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				3,723	3,726	3,838
SBA commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				2,308	2,607	2,578
Multifamily
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				265	326	251
Residential construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				327	246	305
Commercial construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				206	83	107
Land and land development
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				201	198	212
Commercial Business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				1,493	1,322	1,193
SBA commercial business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				1,922	2,088	2,122
Consumer
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans				$ 478	$ 542	$ 448
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		$ 18,329
Net deferred tax assets		19,718
Liabilities
Allowance for credit losses on off balance sheet credit exposures		1,940
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Residential real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		5,678
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		2,032
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Single tenant net lease
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		4,032
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | SBA commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		2,433
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Multifamily
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		247
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Residential construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		208
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Commercial construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		325
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Land and land development
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		233
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Commercial Business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,219
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | SBA commercial business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,407
Accounting Standards Update 2022-02 (ASC 326) | As Reported under ASC 326 | Consumer
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		515
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		16,900
Net deferred tax assets		18,859
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Residential real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		4,641
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,777
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Single tenant net lease
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		3,810
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | SBA commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,922
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Multifamily
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		268
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Residential construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		434
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Commercial construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		282
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Land and land development
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		307
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Commercial Business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,714
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | SBA commercial business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,247
Accounting Standards Update 2022-02 (ASC 326) | Pre-ASC 326 | Consumer
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		498
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,429
Net deferred tax assets		859
Liabilities
Allowance for credit losses on off balance sheet credit exposures		1,940
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Residential real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		1,037
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		255
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Single tenant net lease
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		222
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | SBA commercial real estate
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		511
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Multifamily
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		(21)
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Residential construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		(226)
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Commercial construction
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		43
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Land and land development
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		(74)
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Commercial Business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		(495)
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | SBA commercial business
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		160
Accounting Standards Update 2022-02 (ASC 326) | Impact of ASC 326 Adoption | Consumer
Allowance for credit losses ("ACL") on loans
Allowance for credit losses on loans		$ 17