Loans Receivable And Allowance For Credit Losses (Troubled Debt Restructurings On Financing Receivables That Subsequently Defaulted) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023 USD ($) contract	Jun. 30, 2022 USD ($) contract	Jun. 30, 2023 USD ($) contract	Jun. 30, 2022 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	1	1	2
Amortized Cost | $	$ 0	$ 19	$ 8	$ 703
One- to Four-Family Segment [Member] | Originated [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	0	1	1
Amortized Cost | $	$ 0	$ 0	$ 8	$ 684
One- to Four-Family Segment [Member] | Correspondent Purchased [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	0	0	0
Amortized Cost | $	$ 0	$ 0	$ 0	$ 0
One- to Four-Family Segment [Member] | Bulk Purchased [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	0	0	0
Amortized Cost | $	$ 0	$ 0	$ 0	$ 0
Commercial Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	0	0	0
Amortized Cost | $	$ 0	$ 0	$ 0	$ 0
Commercial Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	0	0	0
Amortized Cost | $	$ 0	$ 0	$ 0	$ 0
Consumer Segment [Member] | Home Equity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	1	0	1
Amortized Cost | $	$ 0	$ 19	$ 0	$ 19
Consumer Segment [Member] | Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	0	0	0	0
Amortized Cost | $	$ 0	$ 0	$ 0	$ 0