Loans Receivable And Allowance For Credit Losses (Loans, Nonaccrual) (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Sep. 30, 2024
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	$ 10,861	$ 10,166
Nonaccrual loans with no ACL	6,059	3,010
One- to Four-Family Segment [Member] \| Originated [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	2,806	2,271
Nonaccrual loans with no ACL	982	764
One- to Four-Family Segment [Member] \| Correspondent Purchased [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	1,994	4,090
Nonaccrual loans with no ACL	507	182
One- to Four-Family Segment [Member] \| Bulk Purchased [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	623	1,539
Nonaccrual loans with no ACL	172	812
Commercial Segment [Member] \| Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	4,443	1,495
Nonaccrual loans with no ACL	3,849	901
Commercial Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	521	335
Nonaccrual loans with no ACL	521	335
Consumer Segment [Member] \| Home Equity [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	401	338
Nonaccrual loans with no ACL	14	0
Consumer Segment [Member] \| Other [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	73	98
Nonaccrual loans with no ACL	$ 14	$ 16

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-14

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
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-Name Accounting Standards Codification
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-Paragraph 80
-Publisher FASB
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