Loans Receivable And Allowance For Credit Losses (Allowance For Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		$ 31,527
Beginning Balance	$ 19,823
Charge-offs	(15)	(532)
Recoveries	46	68
Provision for credit losses	(2,319)	(177)
Ending Balance	17,535	26,125
Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		(4,761)
Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		26,766
One- to Four-Family Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		9,243
Beginning Balance	3,978
Charge-offs	(4)	(14)
Recoveries	9	34
Provision for credit losses	6	(732)
Ending Balance	3,989	4,148
One- to Four-Family Segment [Member] | Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		(4,383)
One- to Four-Family Segment [Member] | Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		4,860
One- to Four-Family Segment [Member] | Originated [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		6,085
Beginning Balance	1,612
Charge-offs	(4)	(14)
Recoveries	9	34
Provision for credit losses	22	(115)
Ending Balance	1,639	1,538
One- to Four-Family Segment [Member] | Originated [Member] | Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		(4,452)
One- to Four-Family Segment [Member] | Originated [Member] | Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		1,633
One- to Four-Family Segment [Member] | Correspondent Purchased [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		2,691
Beginning Balance	2,062
Charge-offs	0	0
Recoveries	0	0
Provision for credit losses	20	(566)
Ending Balance	2,082	1,758
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		(367)
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		2,324
One- to Four-Family Segment [Member] | Bulk Purchased [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		467
Beginning Balance	304
Charge-offs	0	0
Recoveries	0	0
Provision for credit losses	(36)	(51)
Ending Balance	268	852
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		436
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		903
Commercial Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		21,800
Beginning Balance	15,652
Charge-offs	(10)	(515)
Recoveries	36	12
Provision for credit losses	(2,325)	603
Ending Balance	13,353	21,707
Commercial Segment [Member] | Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		(193)
Commercial Segment [Member] | Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		21,607
Consumer Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		484
Beginning Balance	193
Charge-offs	(1)	(3)
Recoveries	1	22
Provision for credit losses	0	(48)
Ending Balance	$ 193	270
Consumer Segment [Member] | Adoption of CECL [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		(185)
Consumer Segment [Member] | Balance at October 1, 2020 [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Balance		$ 299