Loans Receivable And Allowance for Credit Losses (Financial Effect of Modifications) (Details)	3 Months Ended		9 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
One- to Four-Family Segment [Member] \| Originated [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Payment Deferral, Period	8 months	8 months	8 months	8 months
Financing Receivable, Modified, Weighted-Average Term Increase from Modification	43 months	26 months	41 months	23 months
One- to Four-Family Segment [Member] \| Correspondent Purchased [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Payment Deferral, Period		8 months	8 months	8 months
Financing Receivable, Modified, Weighted-Average Term Increase from Modification	39 months	27 months	30 months	44 months
Commercial Segment [Member] \| Commercial Real Estate [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Payment Deferral, Period	13 months	8 months	13 months	8 months
Commercial Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Payment Deferral, Period	5 months		9 months
Financing Receivable, Modified, Weighted-Average Term Increase from Modification	18 months	6 months	21 months	5 months
Consumer Segment [Member] \| Home Equity [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Payment Deferral, Period			8 months	7 months
Financing Receivable, Modified, Weighted-Average Term Increase from Modification				14 months