Loans Receivable And Allowance For Credit Losses (Troubled Debt Restructurings On Financing Receivables) (Details) $ in Thousands	12 Months Ended
Sep. 30, 2020 USD ($) contract	Sep. 30, 2019 USD ($) contract	Sep. 30, 2018 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	11	5	7
Pre-Restructured Outstanding	$ 3,073	$ 762	$ 670
Post-Restructured Outstanding	$ 3,157	$ 763	$ 687
One- to Four-Family Segment [Member] \| Originated [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	5	3	5
Pre-Restructured Outstanding	$ 241	$ 385	$ 264
Post-Restructured Outstanding	$ 242	$ 386	$ 281
One- to Four-Family Segment [Member] \| Correspondent Purchased [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	1	0	2
Pre-Restructured Outstanding	$ 192	$ 0	$ 406
Post-Restructured Outstanding	$ 191	$ 0	$ 406
One- to Four-Family Segment [Member] \| Bulk Purchased [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	1	2	0
Pre-Restructured Outstanding	$ 75	$ 377	$ 0
Post-Restructured Outstanding	$ 134	$ 377	$ 0
Commercial Segment [Member] \| Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	1	0	0
Pre-Restructured Outstanding	$ 837	$ 0	$ 0
Post-Restructured Outstanding	$ 837	$ 0	$ 0
Commercial Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	1	0	0
Pre-Restructured Outstanding	$ 1,683	$ 0	$ 0
Post-Restructured Outstanding	$ 1,709	$ 0	$ 0
Consumer Segment [Member] \| Home Equity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	2	0	0
Pre-Restructured Outstanding	$ 45	$ 0	$ 0
Post-Restructured Outstanding	$ 44	$ 0	$ 0
Consumer Segment [Member] \| Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	0	0	0
Pre-Restructured Outstanding	$ 0	$ 0	$ 0
Post-Restructured Outstanding	$ 0	$ 0	$ 0

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No definition available.

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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