Loans Receivable And Allowance For Credit Losses (Allowance For Credit Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 23,759	$ 16,371	$ 19,823
Charge-offs	160	115	70
Recoveries	49	9	256
Provision for credit losses	(633)	7,494	(3,638)
Ending Balance	23,035	23,759	16,371
Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	20
Ending Balance		20
Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	23,779
Ending Balance		23,779
One- to Four-Family Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	5,328	5,006	3,978
Charge-offs	0	0	9
Recoveries	28	6	138
Provision for credit losses	(1,701)	316	899
Ending Balance	3,673	5,328	5,006
One- to Four-Family Segment [Member] | Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	18
Ending Balance		18
One- to Four-Family Segment [Member] | Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	5,346
Ending Balance		5,346
One- to Four-Family Segment [Member] | Originated [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2,149	2,066	1,612
Charge-offs	0	0	9
Recoveries	28	6	138
Provision for credit losses	(514)	77	325
Ending Balance	1,666	2,149	2,066
One- to Four-Family Segment [Member] | Originated [Member] | Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	3
Ending Balance		3
One- to Four-Family Segment [Member] | Originated [Member] | Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2,152
Ending Balance		2,152
One- to Four-Family Segment [Member] | Correspondent Purchased [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2,972	2,734	2,062
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for credit losses	(1,112)	238	672
Ending Balance	1,861	2,972	2,734
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	1
Ending Balance		1
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2,973
Ending Balance		2,973
One- to Four-Family Segment [Member] | Bulk Purchased [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	207	206	304
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for credit losses	(75)	1	(98)
Ending Balance	146	207	206
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	14
Ending Balance		14
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	221
Ending Balance		221
Commercial Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	18,180	11,120	15,652
Charge-offs	80	75	40
Recoveries	5	1	101
Provision for credit losses	1,047	7,134	(4,593)
Ending Balance	19,154	18,180	11,120
Commercial Segment [Member] | Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	2
Ending Balance		2
Commercial Segment [Member] | Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	18,182
Ending Balance		18,182
Consumer Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	251	245	193
Charge-offs	80	40	21
Recoveries	16	2	17
Provision for credit losses	21	44	56
Ending Balance	208	251	$ 245
Consumer Segment [Member] | Accounting Standards Update 2022-02 Cumulative Effect, Period of Adoption [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	0
Ending Balance		0
Consumer Segment [Member] | Balance at October 1, 2023 [Member] | Accounting Standards Update 2022-02 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 251
Ending Balance		$ 251