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, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	$ 14,229	$ 13,468	$ 13,703	$ 13,469
Provision for (Recapture of) Loan Losses	475	0	1,000	0
Charge- offs	(6)	(50)	(6)	(51)
Recoveries	0	15	1	15
Allowance for loan losses, Ending Allowance	14,698	13,433	14,698	13,433
Mortgage loans, one-to-four family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	1,888	1,237	1,658	1,154
Provision for (Recapture of) Loan Losses	164	10	394	93
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	2,052	1,247	2,052	1,247
Mortgage loans, multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	871	748	855	765
Provision for (Recapture of) Loan Losses	67	(13)	83	(30)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	938	735	938	735
Mortgage loans, commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	6,794	6,807	6,682	6,813
Provision for (Recapture of) Loan Losses	110	124	222	118
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	6,904	6,931	6,904	6,931
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	673	671	675	644
Provision for (Recapture of) Loan Losses	53	15	51	42
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	726	686	726	686
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	125	153	130	188
Provision for (Recapture of) Loan Losses	(4)	(27)	(9)	(62)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	121	126	121	126
Mortgage loans, construction – commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	323	593	343	784
Provision for (Recapture of) Loan Losses	(56)	(130)	(76)	(321)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	267	463	267	463
Mortgage loans, construction - Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	577	460	447	436
Provision for (Recapture of) Loan Losses	85	(24)	215	0
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	662	436	662	436
Mortgage loans, construction - Land development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	222	157	233	124
Provision for (Recapture of) Loan Losses	23	(31)	12	2
Charge- offs	0		0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	245	126	245	126
Mortgage loans, land
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	383	435	397	470
Provision for (Recapture of) Loan Losses	(20)	(58)	(34)	(93)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	363	377	363	377
Consumer loans, home equity and second mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	493	532	440	528
Provision for (Recapture of) Loan Losses	14	(63)	67	(59)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	507	469	507	469
Consumer loans, other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	47	48	42	50
Provision for (Recapture of) Loan Losses	1	(4)	6	(5)
Charge- offs	(1)	(1)	(1)	(2)
Recoveries	0	1	0	1
Allowance for loan losses, Ending Allowance	47	44	47	44
Commercial business loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for loan losses, Beginning Allowance	1,833	1,627	1,801	1,513
Provision for (Recapture of) Loan Losses	38	201	69	315
Charge- offs	(5)	(49)	(5)	(49)
Recoveries	0	14	1	14
Allowance for loan losses, Ending Allowance	1,866	$ 1,793	1,866	$ 1,793
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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