Loans Receivable And Allowance For Credit Losses (Loans, Nonaccrual) (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Sep. 30, 2024
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	$ 48,194	$ 10,166
Nonaccrual loans with no ACL	44,502	3,010
One- to Four-Family Segment [Member] \| Originated [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	2,165	2,271
Nonaccrual loans with no ACL	889	764
One- to Four-Family Segment [Member] \| Correspondent Purchased [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	1,764	4,090
Nonaccrual loans with no ACL	0	182
One- to Four-Family Segment [Member] \| Bulk Purchased [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	137	1,539
Nonaccrual loans with no ACL	0	812
Commercial Segment [Member] \| Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	43,440	1,495
Nonaccrual loans with no ACL	43,088	901
Commercial Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	511	335
Nonaccrual loans with no ACL	511	335
Consumer Segment [Member] \| Home Equity [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	109	338
Nonaccrual loans with no ACL	0	0
Consumer Segment [Member] \| Other [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual loans	68	98
Nonaccrual loans with no ACL	$ 14	$ 16

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

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