Loans Receivable and Allowance for Credit Losses (Financial Effect of Modifications) (Details) - Combination Extended Maturity and Payment Deferral [Member]	3 Months Ended	9 Months Ended
	Jun. 30, 2024	Jun. 30, 2024
One- to Four-Family Segment [Member] | Originated [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Weighted Average Term Increase from Modification	20 months	31 months
Financing Receivable, Modified, Payment Deferral, Period	8 months	4 months
One- to Four-Family Segment [Member] | Correspondent Purchased [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Weighted Average Term Increase from Modification		17 months
Financing Receivable, Modified, Payment Deferral, Period		4 months
Commercial Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Weighted Average Term Increase from Modification		24 months
Financing Receivable, Modified, Payment Deferral, Period		24 months
Commercial Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, Modified [Line Items]
Financing Receivable, Modified, Weighted Average Term Increase from Modification	9 months	6 months
Financing Receivable, Modified, Payment Deferral, Period	6 months	6 months