Loans Receivable And Allowance For Loan Losses: Schedule of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	$ 13,468	$ 13,432	$ 13,469	$ 13,414
Provision for (Recapture of) Loan Losses	0	0	0	0
Charge- offs	(50)	(3)	(51)	(3)
Recoveries	15	5	15	23
Allowance for loan losses, Ending Allowance	13,433	13,434	13,433	13,434
Mortgage loans, one-to-four family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	1,237	1,135	1,154	1,163
Provision for (Recapture of) Loan Losses	10	16	93	(12)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	1,247	1,151	1,247	1,151
Mortgage loans, multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	748	757	765	718
Provision for (Recapture of) Loan Losses	(13)	27	(30)	66
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	735	784	735	784
Mortgage loans, commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	6,807	7,136	6,813	7,144
Provision for (Recapture of) Loan Losses	124	102	118	94
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	6,931	7,238	6,931	7,238
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	671	770	644	832
Provision for (Recapture of) Loan Losses	15	(75)	42	(137)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	686	695	686	695
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	153	182	188	158
Provision for (Recapture of) Loan Losses	(27)	(34)	(62)	(10)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	126	148	126	148
Mortgage loans, construction – commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	593	558	784	420
Provision for (Recapture of) Loan Losses	(130)	156	(321)	294
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	463	714	463	714
Mortgage loans, construction - Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	460	186	436	238
Provision for (Recapture of) Loan Losses	(24)	137	0	85
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	436	323	436	323
Mortgage loans, construction - Land development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	157	123	124	133
Provision for (Recapture of) Loan Losses	(31)	(104)	2	(114)
Charge- offs	0		0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	126	19	126	19
Mortgage loans, land
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	435	474	470	572
Provision for (Recapture of) Loan Losses	(58)	(72)	(93)	(175)
Charge- offs	0	0	0	0
Recoveries	0	5	0	10
Allowance for loan losses, Ending Allowance	377	407	377	407
Consumer loans, home equity and second mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	532	605	528	593
Provision for (Recapture of) Loan Losses	(63)	(53)	(59)	(41)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	469	552	469	552
Consumer loans, other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	48	57	50	71
Provision for (Recapture of) Loan Losses	(4)	0	(5)	(18)
Charge- offs	(1)	(1)	(2)	(1)
Recoveries	1	0	1	4
Allowance for loan losses, Ending Allowance	44	56	44	56
Commercial business loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	1,627	1,449	1,513	1,372
Provision for (Recapture of) Loan Losses	201	(100)	315	(32)
Charge- offs	(49)	(2)	(49)	(2)
Recoveries	14	0	14	9
Allowance for loan losses, Ending Allowance	1,793	$ 1,347	1,793	$ 1,347
SBA PPP Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance			0
Allowance for loan losses, Ending Allowance	$ 0		$ 0

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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