Loans Receivable And Allowance For Credit Losses (Loans, Nonaccrual) (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Sep. 30, 2025
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	$ 54,638	$ 47,796
Nonaccrual loans with no ACL	30,159	45,254
One- to Four-Family Segment [Member] \| Originated [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	4,122	2,751
Nonaccrual loans with no ACL	1,693	1,833
One- to Four-Family Segment [Member] \| Correspondent Purchased [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	5,332	1,409
Nonaccrual loans with no ACL	266	0
One- to Four-Family Segment [Member] \| Bulk Purchased [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	339	135
Nonaccrual loans with no ACL	0	0
Commercial Segment [Member] \| Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	43,359	43,087
Nonaccrual loans with no ACL	27,528	43,087
Commercial Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	1,415	320
Nonaccrual loans with no ACL	640	320
Consumer Segment [Member] \| Home Equity [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	53	46
Nonaccrual loans with no ACL	32	0
Consumer Segment [Member] \| Other [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	18	48
Nonaccrual loans with no ACL	$ 0	$ 14

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

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