Loans Receivable And Allowance For Loan Losses: Schedule of loans evaluated individually for impairment and collectively evaluated for impairment in the allowance for loan losses (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	$ 127	$ 127
Allowance for Loan Losses, Collectively Evaluated for Impairment	14,102	13,576
Allowance for Loan Losses, Total	14,229	13,703	$ 13,468	$ 13,469
Recorded Investment in Loans, Individually Evaluated for Impairment	4,499	4,532
Recorded Investment in Loans, Collectively Evaluated for Impairment	1,186,821	1,145,918
Loans receivable	1,191,320	1,150,450
Mortgage loans, one-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,888	1,658
Allowance for Loan Losses, Total	1,888	1,658	1,237	1,154
Recorded Investment in Loans, Individually Evaluated for Impairment	383	388
Recorded Investment in Loans, Collectively Evaluated for Impairment	199,902	175,728
Loans receivable	200,285	176,116
Mortgage loans, multi-family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	871	855
Allowance for Loan Losses, Total	871	855	748	765
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	96,831	95,025
Loans receivable	96,831	95,025
Mortgage loans, commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	6,794	6,682
Allowance for Loan Losses, Total	6,794	6,682	6,807	6,813
Recorded Investment in Loans, Individually Evaluated for Impairment	2,980	2,988
Recorded Investment in Loans, Collectively Evaluated for Impairment	539,591	533,662
Loans receivable	542,571	536,650
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	673	675
Allowance for Loan Losses, Total	673	675	671	644
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	66,840	67,091
Loans receivable	66,840	67,091
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	125	130
Allowance for Loan Losses, Total	125	130	153	188
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	8,032	8,364
Loans receivable	8,032	8,364
Mortgage loans, construction – commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	323	343
Allowance for Loan Losses, Total	323	343	593	784
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	27,432	29,059
Loans receivable	27,432	29,059
Mortgage loans, construction - Multi-family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	577	447
Allowance for Loan Losses, Total	577	447	460	436
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	44,374	34,354
Loans receivable	44,374	34,354
Mortgage loans, construction - Land development
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	222	233
Allowance for Loan Losses, Total	222	233	157	124
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	12,918	13,582
Loans receivable	12,918	13,582
Mortgage loans, land
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	383	397
Allowance for Loan Losses, Total	383	397	435	470
Recorded Investment in Loans, Individually Evaluated for Impairment	425	450
Recorded Investment in Loans, Collectively Evaluated for Impairment	25,447	26,404
Loans receivable	25,872	26,854
Consumer loans, home equity and second mortgage
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	493	440
Allowance for Loan Losses, Total	493	440	532	528
Recorded Investment in Loans, Individually Evaluated for Impairment	405	394
Recorded Investment in Loans, Collectively Evaluated for Impairment	35,562	34,793
Loans receivable	35,967	35,187
Consumer loans, other
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	47	42
Allowance for Loan Losses, Total	47	42	48	50
Recorded Investment in Loans, Individually Evaluated for Impairment	2	3
Recorded Investment in Loans, Collectively Evaluated for Impairment	2,480	2,125
Loans receivable	2,482	2,128
Commercial business loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	127	127
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,706	1,674
Allowance for Loan Losses, Total	1,833	1,801	$ 1,627	$ 1,513
Recorded Investment in Loans, Individually Evaluated for Impairment	304	309
Recorded Investment in Loans, Collectively Evaluated for Impairment	126,781	124,730
Loans receivable	127,085	125,039
SBA PPP Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	0	0
Allowance for Loan Losses, Total	0	0
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	631	1,001
Loans receivable	$ 631	$ 1,001